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Bhatia A, Hanna J, Stuart T, Kasper KA, Clausen DM, Gutruf P. Wireless Battery-free and Fully Implantable Organ Interfaces. Chem Rev 2024; 124:2205-2280. [PMID: 38382030 DOI: 10.1021/acs.chemrev.3c00425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Advances in soft materials, miniaturized electronics, sensors, stimulators, radios, and battery-free power supplies are resulting in a new generation of fully implantable organ interfaces that leverage volumetric reduction and soft mechanics by eliminating electrochemical power storage. This device class offers the ability to provide high-fidelity readouts of physiological processes, enables stimulation, and allows control over organs to realize new therapeutic and diagnostic paradigms. Driven by seamless integration with connected infrastructure, these devices enable personalized digital medicine. Key to advances are carefully designed material, electrophysical, electrochemical, and electromagnetic systems that form implantables with mechanical properties closely matched to the target organ to deliver functionality that supports high-fidelity sensors and stimulators. The elimination of electrochemical power supplies enables control over device operation, anywhere from acute, to lifetimes matching the target subject with physical dimensions that supports imperceptible operation. This review provides a comprehensive overview of the basic building blocks of battery-free organ interfaces and related topics such as implantation, delivery, sterilization, and user acceptance. State of the art examples categorized by organ system and an outlook of interconnection and advanced strategies for computation leveraging the consistent power influx to elevate functionality of this device class over current battery-powered strategies is highlighted.
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Affiliation(s)
- Aman Bhatia
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Jessica Hanna
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Tucker Stuart
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Kevin Albert Kasper
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - David Marshall Clausen
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Philipp Gutruf
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
- Department of Electrical and Computer Engineering, The University of Arizona, Tucson, Arizona 85721, United States
- Bio5 Institute, The University of Arizona, Tucson, Arizona 85721, United States
- Neuroscience Graduate Interdisciplinary Program (GIDP), The University of Arizona, Tucson, Arizona 85721, United States
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2
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Thompson N, Ravagli E, Mastitskaya S, Challita R, Hadaya J, Iacoviello F, Shah Idil A, Shearing PR, Ajijola OA, Ardell JL, Shivkumar K, Holder D, Aristovich K. Anatomical and functional organization of cardiac fibers in the porcine cervical vagus nerve allows spatially selective efferent neuromodulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.09.574861. [PMID: 38260584 PMCID: PMC10802425 DOI: 10.1101/2024.01.09.574861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Cardiac disease progression reflects the dynamic interaction between adversely remodeled neurohumoral control systems and an abnormal cardiac substrate. Vagal nerve stimulation (VNS) is an attractive neuromodulatory option to dampen this dynamic interaction; however, it is limited by off-target effects. Spatially-selective VNS (sVNS) offers a promising solution to induce cardioprotection while mitigating off-target effects by specifically targeting pre-ganglionic parasympathetic efferent cardiac fibers. This approach also has the potential to enhance therapeutic outcomes by eliminating time-consuming titration required for optimal VNS. Recent studies have demonstrated the independent modulation of breathing rate, heart rate, and laryngeal contraction through sVNS. However, the spatial organization of afferent and efferent cardiac-related fibers within the vagus nerve remains unexplored. By using trial-and-error sVNS in vivo in combination with ex vivo micro-computed tomography fascicle tracing, we show the significant spatial separation of cardiac afferent and efferent fibers (179±55° SD microCT, p<0.05 and 200±137° SD, p<0.05 sVNS - degrees of separation across a cross-section of nerve) at the mid-cervical level. We also show that cardiac afferent fibers are located in proximity to pulmonary fibers consistent with recent findings of cardiopulmonary convergent neurons and circuits. We demonstrate the ability of sVNS to selectively elicit desired scalable heart rate decrease without stimulating afferent-related reflexes. By elucidating the spatial organization of cardiac-related fibers within the vagus nerve, our findings pave the way for more targeted neuromodulation, thereby reducing off-target effects and eliminating the need for titration. This, in turn, will enhance the precision and efficacy of VNS therapy in treating cardiac pathology, allowing for improved therapeutic efficacy.
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Affiliation(s)
- Nicole Thompson
- EIT and Neurophysiology Research Group, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Enrico Ravagli
- EIT and Neurophysiology Research Group, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Svetlana Mastitskaya
- EIT and Neurophysiology Research Group, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Ronald Challita
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Joseph Hadaya
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Francesco Iacoviello
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, United Kingdom
| | - Ahmad Shah Idil
- EIT and Neurophysiology Research Group, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Paul R. Shearing
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, United Kingdom
| | - Olujimi A. Ajijola
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Jeffrey L. Ardell
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - David Holder
- EIT and Neurophysiology Research Group, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Kirill Aristovich
- EIT and Neurophysiology Research Group, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
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3
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Acciarino A, Diwakarla S, Handreck J, Bergola C, Sahakian L, McQuade RM. The role of the gastrointestinal barrier in obesity-associated systemic inflammation. Obes Rev 2024; 25:e13673. [PMID: 38111141 DOI: 10.1111/obr.13673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 10/05/2023] [Accepted: 10/27/2023] [Indexed: 12/20/2023]
Abstract
Systemic inflammation is a key contributor to the onset and progression of several obesity-associated diseases and is thought to predominantly arise from the hyperplasia and hypertrophy of white adipose tissue. However, a growing body of works suggests that early changes in the gastrointestinal (GI) barrier may contribute to both local, within the GI lining, and systemic inflammation in obesity. Intestinal barrier dysfunction is well-characterized in inflammatory GI disorders such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) and is known to contribute to systemic inflammation. Thus, drawing parallels between GI disorders, where intestinal permeability and systemic inflammation are prominent features, and obesity-induced GI manifestations may provide insights into the potential role of the intestinal barrier in systemic inflammation in obesity. This review summarizes the current literature surrounding intestinal barrier dysfunction in obesity and explores the potential role of intestinal hyperpermeability and intestinal barrier dysfunction in the development of systemic inflammation and GI dysfunction in obesity.
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Affiliation(s)
- Adriana Acciarino
- Gut Barrier and Disease Laboratory, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Medicine, Western Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Shanti Diwakarla
- Gut Barrier and Disease Laboratory, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Medicine, Western Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jessica Handreck
- Gut Barrier and Disease Laboratory, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Medicine, Western Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Cedrick Bergola
- Gut Barrier and Disease Laboratory, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Lauren Sahakian
- Gut Barrier and Disease Laboratory, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Rachel M McQuade
- Gut Barrier and Disease Laboratory, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Medicine, Western Health, The University of Melbourne, Melbourne, Victoria, Australia
- Australian Institute for Musculoskeletal Science (AIMSS), Melbourne University, Melbourne, Victoria, Australia
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4
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Thota AK, Jung R. Accelerating neurotechnology development using an Agile methodology. Front Neurosci 2024; 18:1328540. [PMID: 38435056 PMCID: PMC10904481 DOI: 10.3389/fnins.2024.1328540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/18/2024] [Indexed: 03/05/2024] Open
Abstract
Novel bioelectronic medical devices that target neural control of visceral organs (e.g., liver, gut, spleen) or inflammatory reflex pathways are innovative class III medical devices like implantable cardiac pacemakers that are lifesaving and life-sustaining medical devices. Bringing innovative neurotechnologies early into the market and the hands of treatment providers would benefit a large population of patients inflicted with autonomic and chronic immune disorders. Medical device manufacturers and software developers widely use the Waterfall methodology to implement design controls through verification and validation. In the Waterfall methodology, after identifying user needs, a functional unit is fabricated following the verification loop (design, build, and verify) and then validated against user needs. Considerable time can lapse in building, verifying, and validating the product because this methodology has limitations for adjusting to unanticipated changes. The time lost in device development can cause significant delays in final production, increase costs, and may even result in the abandonment of the device development. Software developers have successfully implemented an Agile methodology that overcomes these limitations in developing medical software. However, Agile methodology is not routinely used to develop medical devices with implantable hardware because of the increased regulatory burden of the need to conduct animal and human studies. Here, we provide the pros and cons of the Waterfall methodology and make a case for adopting the Agile methodology in developing medical devices with physical components. We utilize a peripheral nerve interface as an example device to illustrate the use of the Agile approach to develop neurotechnologies.
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Affiliation(s)
- Anil Kumar Thota
- Adaptive Neural Systems Group, The Institute for Integrative and Innovative Research, University of Arkansas, Fayetteville, AR, United States
| | - Ranu Jung
- Adaptive Neural Systems Group, The Institute for Integrative and Innovative Research, University of Arkansas, Fayetteville, AR, United States
- Biomedical Engineering Department, University of Arkansas, Fayetteville, AR, United States
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5
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Miranda JA, Rapeaux A, Samper IC, Silveira C, Willé DR, Hunsberger GE, Dopson WJ, Yao H, Karicherla A, Chew DJ. Functional Electrochemistry: On-Nerve Assessment of Electrode Materials for Electrochemistry and Functional Neurostimulation. IEEE OPEN JOURNAL OF ENGINEERING IN MEDICINE AND BIOLOGY 2024; 5:59-65. [PMID: 38445242 PMCID: PMC10914184 DOI: 10.1109/ojemb.2024.3356818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 12/26/2023] [Accepted: 01/15/2024] [Indexed: 03/07/2024] Open
Abstract
Emerging therapies in bioelectronic medicine highlight the need for deeper understanding of electrode material performance in the context of tissue stimulation. Electrochemical properties are characterized on the benchtop, facilitating standardization across experiments. On-nerve electrochemistry differs from benchtop characterization and the relationship between electrochemical performance and nerve activation thresholds are not commonly established. This relationship is important in understanding differences between electrical stimulation requirements and electrode performance. We report functional electrochemistry as a follow-up to benchtop testing, describing a novel experimental approach for evaluating on-nerve electrochemical performance in the context of nerve activation. An ex-vivo rat sciatic nerve preparation was developed to quantify activation thresholds of fiber subtypes and electrode material charge injection limits for platinum iridium, iridium oxide, titanium nitride and PEDOT. Finally, we address experimental complexities arising in these studies, and demonstrate statistical solutions that support rigorous material performance comparisons for decision making in neural interface development.
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Affiliation(s)
| | - Adrien Rapeaux
- Galvani Bioelectonics Ltd., StevenageSG1 2NYHertfordshireU.K.
- Imperial College LondonSW7 2BXLondonU.K.
| | - Isabelle C. Samper
- Galvani Bioelectonics Ltd., StevenageSG1 2NYHertfordshireU.K.
- Global Health LabsBellevueWA98007USA
| | - Carolina Silveira
- Galvani Bioelectonics Ltd., StevenageSG1 2NYHertfordshireU.K.
- Medicines and Healthcare Products Regulatory AgencyE14 4PULondonU.K.
| | | | | | | | - Huanfen Yao
- Verily Life Sciences LLCSan FranciscoCA94080-4804USA
- Google LLCMountain ViewCA94043USA
| | - Annapurna Karicherla
- Verily Life Sciences LLCSan FranciscoCA94080-4804USA
- Microsoft Corp.Mountain ViewCA94043USA
| | - Daniel J. Chew
- Galvani Bioelectonics Ltd., StevenageSG1 2NYHertfordshireU.K.
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6
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Andrews PLR, Golding JF, Sanger GJ. An assessment of the effects of neurokinin 1 receptor antagonism against nausea and vomiting: Relative efficacy, sites of action and lessons for future drug development. Br J Clin Pharmacol 2023; 89:3468-3490. [PMID: 37452618 DOI: 10.1111/bcp.15852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023] Open
Abstract
A broad-spectrum anti-vomiting effect of neurokinin1 receptor antagonists (NK1 RA), shown in pre-clinical animal studies, has been supported by a more limited range of clinical studies in different indications. However, this review suggests that compared with vomiting, the self-reported sensation of nausea is less affected or possibly unaffected (depending on the stimulus) by NK1 receptor antagonism, a common finding for anti-emetics. The stimulus-independent effects of NK1 RAs against vomiting are explicable by actions within the central pattern generator (ventral brainstem) and the nucleus tractus solitarius (NTS; dorsal brainstem), with additional effects on vagal afferent activity for certain stimuli (e.g., highly emetogenic chemotherapy). The central pattern generator and NTS neurones are multifunctional so the notable lack of obvious effects of NK1 RAs on other reflexes mediated by the same neurones suggests that their anti-vomiting action is dependent on the activation state of the pathway leading to vomiting. Nausea requires activation of cerebral pathways by projection of information from the NTS. Although NK1 receptors are present in cerebral nuclei implicated in nausea, and imaging studies show very high receptor occupancy at clinically used doses, the variable or limited ability of NK1 RAs to inhibit nausea emphasizes: (i) our inadequate understanding of the mechanisms of nausea; and (ii) that classification of a drug as an anti-emetic may give a false impression of efficacy against nausea vs. vomiting. We discuss the potential mechanisms for the differential efficacy of NK1 RA and the implications for future development of drugs that can effectively treat nausea, an area of unmet clinical need.
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Affiliation(s)
- Paul L R Andrews
- Division of Biomedical Sciences, St George's University of London, London, UK
| | | | - Gareth J Sanger
- Blizard Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
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Athavale ON, Cheng LK, Avci R, Clark AR, Du P. Cervical Vagus Nerve Stimulation Disrupts Gastric Slow Wave Activity in Rats. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38082764 DOI: 10.1109/embc40787.2023.10340367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Cervical vagus nerve stimulation (cVNS) is a promising neuromodulation therapy for treating symptoms of disease in peripheral organs. The rat is a common animal model for studying and trialing new applications of cVNS therapy, but the stomach and its activity in rats is less well characterized than other animals, such as pigs. We sought to investigate the effects of acute, in vivo cVNS on gastric bioelectrical activity as an intermediate step to computational modeling of the effects of cVNS on gastric smooth muscle electromechanical coupling. Here we show a method of detecting bioelectrical gastric slow wave events using a non-linear energy operator. The marked events are compared to the underlying bioelectrical slow wave activity.The mean propagation velocity before stimulation was 0.79 ± 0.31 mm s-1, and the mean interval was 17.4 ± 1.4 s. During cVNS, there was a significant increase in velocity (1.02 ± 0.69 mm s-1; p < 0.001), and decrease in interval (15.4 ± 2.9 s; p = 0.0196). At stimulation onset, premature slow waves were induced at an ectopic pacemaker location and waves originating at the ectopic and initial pacemaker sites continued to collide following the cessation of cVNS.This work forms the basis for more thorough investigation of the effects of cVNS on gastric bioelectrical slow wave activity and consequential smooth muscle contractions in rats. A better understanding of the effects of cVNS on gastric function will allow the refinement of cVNS therapy to target the stomach, and avoid off-target effects on the stomach.Clinical relevance- This work presents a signal processing and analysis approach for the investigation of cervical vagus nerve stimulation on gastric bioelectrical activity in rats. Vagus nerve stimulation may enable the control and amelioration of hunger, gastric emptying, or functional gastric disorders.
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8
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Eickhoff S, Garcia-Agundez A, Haidar D, Zaidat B, Adjei-Mosi M, Li P, Eickhoff C. A feasibility study on AI-controlled closed-loop electrical stimulation implants. Sci Rep 2023; 13:10163. [PMID: 37349359 PMCID: PMC10287710 DOI: 10.1038/s41598-023-36384-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 06/02/2023] [Indexed: 06/24/2023] Open
Abstract
Miniaturized electrical stimulation (ES) implants show great promise in practice, but their real-time control by means of biophysical mechanistic algorithms is not feasible due to computational complexity. Here, we study the feasibility of more computationally efficient machine learning methods to control ES implants. For this, we estimate the normalized twitch force of the stimulated extensor digitorum longus muscle on n = 11 Wistar rats with intra- and cross-subject calibration. After 2000 training stimulations, we reach a mean absolute error of 0.03 in an intra-subject setting and 0.2 in a cross-subject setting with a random forest regressor. To the best of our knowledge, this work is the first experiment showing the feasibility of AI to simulate complex ES mechanistic models. However, the results of cross-subject training motivate more research on error reduction methods for this setting.
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Affiliation(s)
- Steffen Eickhoff
- School of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | | | - Daniela Haidar
- Brown Center for Biomedical Informatics, Brown University, Providence, RI, USA
| | - Bashar Zaidat
- Brown Center for Biomedical Informatics, Brown University, Providence, RI, USA
| | - Michael Adjei-Mosi
- Brown Center for Biomedical Informatics, Brown University, Providence, RI, USA
| | - Peter Li
- Brown Center for Biomedical Informatics, Brown University, Providence, RI, USA
| | - Carsten Eickhoff
- Brown Center for Biomedical Informatics, Brown University, Providence, RI, USA.
- Institute for Applied Medical Informatics, University of Tübingen, Tübingen, Germany.
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Occhinegro A, McAllen RM, McKinley MJ, Martelli D. Acute Inhibition of Inflammation Mediated by Sympathetic Nerves: The Inflammatory Reflex. Neuroimmunomodulation 2023; 30:135-142. [PMID: 37302390 PMCID: PMC10428141 DOI: 10.1159/000531469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 06/02/2023] [Indexed: 06/13/2023] Open
Abstract
In this review, we will try to convince the readers that the immune system is controlled by an endogenous neural reflex, termed inflammatory reflex, that inhibits the acute immune response during the course of a systemic immune challenge. We will analyse here the contribution of different sympathetic nerves as possible efferent arms of the inflammatory reflex. We will discuss the evidence that demonstrates that neither the splenic sympathetic nerves nor the hepatic sympathetic nerves are necessary for the endogenous neural reflex inhibition of inflammation. We will discuss the contribution of the adrenal glands to the reflex control of inflammation, noting that the neurally mediated release of catecholamines in the systemic circulation is responsible for the enhancement of the anti-inflammatory cytokine interleukin 10 (IL-10) but not of the inhibition of the pro-inflammatory cytokine tumour necrosis factor α (TNF). We will conclude by reviewing the evidence that demonstrates that the splanchnic anti-inflammatory pathway, composed by preganglionic and postganglionic sympathetic splanchnic fibres with different target organs, including the spleen and the adrenal glands, is the efferent arm of the inflammatory reflex. During the course of a systemic immune challenge, the splanchnic anti-inflammatory pathway is endogenously activated to inhibit the TNF and enhance the IL-10 response, independently, presumably acting on separate populations of leukocytes.
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Affiliation(s)
- Alessandra Occhinegro
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Robin M. McAllen
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Michael J. McKinley
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC, Australia
| | - Davide Martelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
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10
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Peña E, Pelot NA, Grill WM. Spatiotemporal parameters for energy efficient kilohertz-frequency nerve block with low onset response. J Neuroeng Rehabil 2023; 20:72. [PMID: 37271812 PMCID: PMC10240787 DOI: 10.1186/s12984-023-01195-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/23/2023] [Indexed: 06/06/2023] Open
Abstract
BACKGROUND Electrical nerve conduction block has great potential for treatment of disease through reversible and local inactivation of somatic and autonomic nerves. However, the relatively high energy requirements and the presence of undesired excitation at the onset of the kilohertz-frequency (KHF) signals used for block pose obstacles to effective translation. Frequency, electrode geometry, and waveform shape are known to influence block threshold and onset response, but available data provide a limited understanding of how to select these parameters to optimize nerve block. METHODS We evaluated KHF nerve block in rat tibial nerve across frequencies (5-60 kHz), electrode geometries (monopolar, bipolar, and tripolar), and waveform shapes. We present a novel Fourier-based method for constructing composite signals that systematically sample the KHF waveform design space. RESULTS The lowest frequencies capable of blocking (5-16 kHz) were not the most energy-efficient among the tested frequencies. Further, bipolar cuffs required the largest current and power to block, monopolar cuffs required the lowest current, and both tripolar and monopolar cuffs required the lowest power. Tripolar cuffs produced the smallest onset response across frequencies. Composite signals comprised of a first harmonic sinusoid at fundamental frequency (f0) superposed on a second harmonic sinusoid at 2f0 could block at lower threshold and lower onset response compared to the constituent sinusoids alone. This effect was strongly dependent on the phase of the second harmonic and on the relative amplitudes of the first and second harmonics. This effect was also dependent on electrode geometry: monopolar and tripolar cuffs showed clear composite signal effects in most experiments; bipolar cuffs showed no clear effects in most experiments. CONCLUSIONS Our data provide novel information about block threshold and onset response at the boundary of frequencies that can block. Our results also show an interaction between spatial (cuff geometry) and temporal (frequency and waveform shape) parameters. Finally, while previous studies suggested that temporal parameters could reduce onset response only in exchange for increased block threshold (or vice versa), our results show that waveform shape influences KHF response in ways that can be exploited to reduce both energy and onset responses.
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Affiliation(s)
- Edgar Peña
- Department of Biomedical Engineering, Duke University, Room 1427, Fitzpatrick CIEMAS, 101 Science Drive Campus Box 90281, Durham, NC, 27708, USA
| | - Nicole A Pelot
- Department of Biomedical Engineering, Duke University, Room 1427, Fitzpatrick CIEMAS, 101 Science Drive Campus Box 90281, Durham, NC, 27708, USA
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Room 1427, Fitzpatrick CIEMAS, 101 Science Drive Campus Box 90281, Durham, NC, 27708, USA.
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA.
- Department of Neurosurgery, Duke University School of Medicine, Durham, NC, USA.
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11
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Ciotti F, Cimolato A, Valle G, Raspopovic S. Design of an adaptable intrafascicular electrode (AIR) for selective nerve stimulation by model-based optimization. PLoS Comput Biol 2023; 19:e1011184. [PMID: 37228174 DOI: 10.1371/journal.pcbi.1011184] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 05/15/2023] [Indexed: 05/27/2023] Open
Abstract
Peripheral nerve stimulation is being investigated as a therapeutic tool in several clinical scenarios. However, the adopted devices have restricted ability to obtain desired outcomes with tolerable off-target effects. Recent promising solutions are not yet employed in clinical practice due to complex required surgeries, lack of long-term stability, and implant invasiveness. Here, we aimed to design a neural interface to address these issues, specifically dimensioned for pudendal and sacral nerves to potentially target sexual, bladder, or bowel dysfunctions. We designed the adaptable intrafascicular radial electrode (AIR) through realistic computational models. They account for detailed human anatomy, inhomogeneous anisotropic conductance, following the trajectories of axons along curving and branching fascicles, and detailed biophysics of axons. The model was validated against available experimental data. Thanks to computationally efficient geometry-based selectivity estimations we informed the electrode design, optimizing its dimensions to obtain the highest selectivity while maintaining low invasiveness. We then compared the AIR with state-of-the-art electrodes, namely InterStim leads, multipolar cuffs and transversal intrafascicular multichannel electrodes (TIME). AIR, comprising a flexible substrate, surface active sites, and radially inserted intrafascicular needles, is designed to be implanted in a few standard steps, potentially enabling fast implants. It holds potential for repeatable stimulation outcomes thanks to its radial structural symmetry. When compared in-silico, AIR consistently outperformed cuff electrodes and InterStim leads in terms of recruitment threshold and stimulation selectivity. AIR performed similarly or better than a TIME, with quantified less invasiveness. Finally, we showed how AIR can adapt to different nerve sizes and varying shapes while maintaining high selectivity. The AIR electrode shows the potential to fill a clinical need for an effective peripheral nerve interface. Its high predicted performance in all the identified requirements was enabled by a model-based approach, readily applicable for the optimization of electrode parameters in any peripheral nerve stimulation scenario.
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Affiliation(s)
- Federico Ciotti
- Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zürich, Zürich, Switzerland
| | - Andrea Cimolato
- Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zürich, Zürich, Switzerland
| | - Giacomo Valle
- Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zürich, Zürich, Switzerland
| | - Stanisa Raspopovic
- Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zürich, Zürich, Switzerland
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12
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Shemonti AS, Plebani E, Biscola NP, Jaffey DM, Havton LA, Keast JR, Pothen A, Dundar MM, Powley TL, Rajwa B. A novel statistical methodology for quantifying the spatial arrangements of axons in peripheral nerves. Front Neurosci 2023; 17:1072779. [PMID: 36968498 PMCID: PMC10034020 DOI: 10.3389/fnins.2023.1072779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 02/09/2023] [Indexed: 03/11/2023] Open
Abstract
A thorough understanding of the neuroanatomy of peripheral nerves is required for a better insight into their function and the development of neuromodulation tools and strategies. In biophysical modeling, it is commonly assumed that the complex spatial arrangement of myelinated and unmyelinated axons in peripheral nerves is random, however, in reality the axonal organization is inhomogeneous and anisotropic. Present quantitative neuroanatomy methods analyze peripheral nerves in terms of the number of axons and the morphometric characteristics of the axons, such as area and diameter. In this study, we employed spatial statistics and point process models to describe the spatial arrangement of axons and Sinkhorn distances to compute the similarities between these arrangements (in terms of first- and second-order statistics) in various vagus and pelvic nerve cross-sections. We utilized high-resolution transmission electron microscopy (TEM) images that have been segmented using a custom-built high-throughput deep learning system based on a highly modified U-Net architecture. Our findings show a novel and innovative approach to quantifying similarities between spatial point patterns using metrics derived from the solution to the optimal transport problem. We also present a generalizable pipeline for quantitative analysis of peripheral nerve architecture. Our data demonstrate differences between male- and female-originating samples and similarities between the pelvic and abdominal vagus nerves.
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Affiliation(s)
| | - Emanuele Plebani
- Department of Computer & Information Sciences, Indiana University - Purdue University Indianapolis, Indianapolis, IN, United States
| | - Natalia P. Biscola
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Deborah M. Jaffey
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, United States
| | - Leif A. Havton
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY, United States
| | - Janet R. Keast
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC, Australia
| | - Alex Pothen
- Department of Computer Science, Purdue University, West Lafayette, IN, United States
| | - M. Murat Dundar
- Department of Computer & Information Sciences, Indiana University - Purdue University Indianapolis, Indianapolis, IN, United States
| | - Terry L. Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, United States
| | - Bartek Rajwa
- Bindley Bioscience Center, Purdue University, West Lafayette, IN, United States
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13
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Yang M, Chen P, Qu X, Zhang F, Ning S, Ma L, Yang K, Su Y, Zang J, Jiang W, Yu T, Dong X, Luo Z. Robust Neural Interfaces with Photopatternable, Bioadhesive, and Highly Conductive Hydrogels for Stable Chronic Neuromodulation. ACS NANO 2023; 17:885-895. [PMID: 36629747 DOI: 10.1021/acsnano.2c04606] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
A robust neural interface with intimate electrical coupling between neural electrodes and neural tissues is critical for stable chronic neuromodulation. The development of bioadhesive hydrogel neural electrodes is a potential approach for tightly fixing the neural electrodes on the epineurium surface to construct a robust neural interface. Herein, we construct a photopatternable, antifouling, conductive (∼6 S cm-1), bioadhesive (interfacial toughness ∼100 J m-2), soft, and elastic (∼290% strain, Young's modulus of 7.25 kPa) hydrogel to establish a robust neural interface for bioelectronics. The UV-sensitive zwitterionic monomer can facilitate the formation of an electrostatic-assembled conductive polymer PEDOT:PSS network, and it can be further photo-cross-linked into elastic polymer network. Such a semi-interpenetrating network endows the hydrogel electrodes with good conductivity. Especially, the photopatternable feature enables the facile microfabrication processes of multifunctional hydrogel (MH) interface with a characteristic size of 50 μm. The MH neural electrodes, which show improved performance of impedance, charge storage capacity, and charge injection capability, can produce effective electrical stimulation with high current density (1 mA cm-2) at ultralow voltages (±25 mV). The MH interface could realize high-efficient electrical communication at the chronic neural interface for stable recording and stimulation of a sciatic nerve in the rat model.
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Affiliation(s)
- Ming Yang
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan430074, China
| | - Ping Chen
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan430074, China
| | - Xinyu Qu
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing211816, China
| | - Fuchi Zhang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan430030, China
| | - Shan Ning
- School of Optical and Electronic Information and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan430074, China
| | - Li Ma
- School of Physics and Technology, Wuhan University, Wuhan430072, China
| | - Kun Yang
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan430074, China
| | - Yuming Su
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan430074, China
| | - Jianfeng Zang
- School of Optical and Electronic Information and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan430074, China
| | - Wei Jiang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan430030, China
| | - Ting Yu
- School of Physics and Technology, Wuhan University, Wuhan430072, China
| | - Xiaochen Dong
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing211816, China
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou221116, China
| | - Zhiqiang Luo
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan430074, China
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14
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Yan D, Jiman AA, Bottorff EC, Patel PR, Meli D, Welle EJ, Ratze DC, Havton LA, Chestek CA, Kemp SWP, Bruns TM, Yoon E, Seymour JP. Ultraflexible and Stretchable Intrafascicular Peripheral Nerve Recording Device with Axon-Dimension, Cuff-Less Microneedle Electrode Array. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2200311. [PMID: 35491522 PMCID: PMC9167574 DOI: 10.1002/smll.202200311] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/08/2022] [Indexed: 05/03/2023]
Abstract
Peripheral nerve mapping tools with higher spatial resolution are needed to advance systems neuroscience, and potentially provide a closed-loop biomarker in neuromodulation applications. Two critical challenges of microscale neural interfaces are 1) how to apply them to small peripheral nerves, and 2) how to minimize chronic reactivity. A flexible microneedle nerve array (MINA) is developed, which is the first high-density penetrating electrode array made with axon-sized silicon microneedles embedded in low-modulus thin silicone. The design, fabrication, acute recording, and chronic reactivity to an implanted MINA, are presented. Distinctive units are identified in the rat peroneal nerve. The authors also demonstrate a long-term, cuff-free, and suture-free fixation manner using rose bengal as a light-activated adhesive for two time-points. The tissue response is investigated at 1-week and 6-week time-points, including two sham groups and two MINA-implanted groups. These conditions are quantified in the left vagus nerve of rats using histomorphometry. Micro computed tomography (micro-CT) is added to visualize and quantify tissue encapsulation around the implant. MINA demonstrates a reduction in encapsulation thickness over previously quantified interfascicular methods. Future challenges include techniques for precise insertion of the microneedle electrodes and demonstrating long-term recording.
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Affiliation(s)
- Dongxiao Yan
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ahmad A Jiman
- Department of Electrical and Computer Engineering, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Elizabeth C Bottorff
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Paras R Patel
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Dilara Meli
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Elissa J Welle
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - David C Ratze
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Leif A Havton
- Departments of Neurology and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- James J Peters Veterans Affairs Medical Center, Bronx, NY, 10468, USA
| | - Cynthia A Chestek
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Stephen W P Kemp
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
- Section of Plastic Surgery, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Tim M Bruns
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Euisik Yoon
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
- Center for Nanomedicine, Institute for Basic Science (IBS) and Graduate Program of Nano Biomedical Engineering (Nano BME), Advanced Science Institute, Yonsei University, Seoul, South Korea
| | - John P Seymour
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Neurosurgery, UTHealth, Houston, TX, 77030, USA
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, 77030, USA
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15
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Ottaviani MM, Vallone F, Micera S, Recchia FA. Closed-Loop Vagus Nerve Stimulation for the Treatment of Cardiovascular Diseases: State of the Art and Future Directions. Front Cardiovasc Med 2022; 9:866957. [PMID: 35463766 PMCID: PMC9021417 DOI: 10.3389/fcvm.2022.866957] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/14/2022] [Indexed: 01/07/2023] Open
Abstract
The autonomic nervous system exerts a fine beat-to-beat regulation of cardiovascular functions and is consequently involved in the onset and progression of many cardiovascular diseases (CVDs). Selective neuromodulation of the brain-heart axis with advanced neurotechnologies is an emerging approach to corroborate CVDs treatment when classical pharmacological agents show limited effectiveness. The vagus nerve is a major component of the cardiac neuroaxis, and vagus nerve stimulation (VNS) is a promising application to restore autonomic function under various pathological conditions. VNS has led to encouraging results in animal models of CVDs, but its translation to clinical practice has not been equally successful, calling for more investigation to optimize this technique. Herein we reviewed the state of the art of VNS for CVDs and discuss avenues for therapeutic optimization. Firstly, we provided a succinct description of cardiac vagal innervation anatomy and physiology and principles of VNS. Then, we examined the main clinical applications of VNS in CVDs and the related open challenges. Finally, we presented preclinical studies that aim at overcoming VNS limitations through optimization of anatomical targets, development of novel neural interface technologies, and design of efficient VNS closed-loop protocols.
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Affiliation(s)
- Matteo Maria Ottaviani
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
- Department of Excellence in Robotics and Artificial Intelligence, The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy
| | - Fabio Vallone
- Department of Excellence in Robotics and Artificial Intelligence, The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy
| | - Silvestro Micera
- Department of Excellence in Robotics and Artificial Intelligence, The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy
- Bertarelli Foundation Chair in Translational Neural Engineering, Center for Neuroprosthetics, Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Fabio A. Recchia
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
- Fondazione Toscana Gabriele Monasterio, Pisa, Italy
- Department of Physiology, Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
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16
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Abstract
![]()
Electronically interfacing with the
nervous system for the purposes
of health diagnostics and therapy, sports performance monitoring,
or device control has been a subject of intense academic and industrial
research for decades. This trend has only increased in recent years,
with numerous high-profile research initiatives and commercial endeavors.
An important research theme has emerged as a result, which is the
incorporation of semiconducting polymers in various devices that communicate
with the nervous system—from wearable brain-monitoring caps
to penetrating implantable microelectrodes. This has been driven by
the potential of this broad class of materials to improve the electrical
and mechanical properties of the tissue–device interface, along
with possibilities for increased biocompatibility. In this review
we first begin with a tutorial on neural interfacing, by reviewing
the basics of nervous system function, device physics, and neuroelectrophysiological
techniques and their demands, and finally we give a brief perspective
on how material improvements can address current deficiencies in this
system. The second part is a detailed review of past work on semiconducting
polymers, covering electrical properties, structure, synthesis, and
processing.
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Affiliation(s)
- Ivan B Dimov
- Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, U.K
| | - Maximilian Moser
- University of Oxford, Department of Chemistry, Oxford OX1 3TA, United Kingdom
| | - George G Malliaras
- Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, U.K
| | - Iain McCulloch
- University of Oxford, Department of Chemistry, Oxford OX1 3TA, United Kingdom.,King Abdullah University of Science and Technology (KAUST), KAUST Solar Center, Thuwal 23955-6900, Saudi Arabia
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17
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Eiber CD, Payne SC, Biscola NP, Havton LA, Keast JR, Osborne PB, Fallon JB. Computational modelling of nerve stimulation and recording with peripheral visceral neural interfaces. J Neural Eng 2021; 18. [PMID: 34740201 DOI: 10.1088/1741-2552/ac36e2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 11/05/2021] [Indexed: 12/30/2022]
Abstract
Objective.Neuromodulation of visceral nerves is being intensively studied for treating a wide range of conditions, but effective translation requires increasing the efficacy and predictability of neural interface performance. Here we use computational models of rat visceral nerve to predict how neuroanatomical variability could affect both electrical stimulation and recording with an experimental planar neural interface.Approach.We developed a hybrid computational pipeline,VisceralNerveEnsembleRecording andStimulation (ViNERS), to couple finite-element modelling of extracellular electrical fields with biophysical simulations of individual axons. Anatomical properties of fascicles and axons in rat pelvic and vagus nerves were measured or obtained from public datasets. To validate ViNERS, we simulated pelvic nerve stimulation and recording with an experimental four-electrode planar array.Main results.Axon diameters measured from pelvic nerve were used to model a population of myelinated and unmyelinated axons and simulate recordings of electrically evoked single-unit field potentials (SUFPs). Across visceral nerve fascicles of increasing size, our simulations predicted an increase in stimulation threshold and a decrease in SUFP amplitude. Simulated threshold changes were dominated by changes in perineurium thickness, which correlates with fascicle diameter. We also demonstrated that ViNERS could simulate recordings of electrically-evoked compound action potentials (ECAPs) that were qualitatively similar to pelvic nerve recording made with the array used for simulation.Significance.We introduce ViNERS as a new open-source computational tool for modelling large-scale stimulation and recording from visceral nerves. ViNERS predicts how neuroanatomical variation in rat pelvic nerve affects stimulation and recording with an experimental planar electrode array. We show ViNERS can simulate ECAPS that capture features of our recordings, but our results suggest the underlying NEURON models need to be further refined and specifically adapted to accurately simulate visceral nerve axons.
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Affiliation(s)
- Calvin D Eiber
- Department of Anatomy and Physiology, The University of Melbourne, Victoria, Australia
| | - Sophie C Payne
- Bionics Institute, East Melbourne, Victoria, Australia.,Medical Bionics Department, The University of Melbourne, Victoria, Australia
| | - Natalia P Biscola
- Icahn School of Medicine at Mount Sinai, New York, United States of America
| | - Leif A Havton
- Icahn School of Medicine at Mount Sinai, New York, United States of America
| | - Janet R Keast
- Department of Anatomy and Physiology, The University of Melbourne, Victoria, Australia
| | - Peregrine B Osborne
- Department of Anatomy and Physiology, The University of Melbourne, Victoria, Australia
| | - James B Fallon
- Bionics Institute, East Melbourne, Victoria, Australia.,Medical Bionics Department, The University of Melbourne, Victoria, Australia
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18
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Davies K, Ng WF. Autonomic Nervous System Dysfunction in Primary Sjögren's Syndrome. Front Immunol 2021; 12:702505. [PMID: 34381453 PMCID: PMC8350514 DOI: 10.3389/fimmu.2021.702505] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/13/2021] [Indexed: 11/13/2022] Open
Abstract
Primary Sjögren's syndrome (pSS) is an autoimmune disease which primarily affects the exocrine glands, but can also affect other organs, including the nervous system. Many studies have reported evidence of autonomic nervous system (ANS) dysfunction in pSS which may contribute to a wide range of symptoms and functional burden. Symptoms of ANS dysfunction are common and widespread among patients with pSS and are associated with other features of the disease, particularly fatigue. Accumulating data on the inter-relationship between the ANS and the immune system via the vagus nerve have been reported. Vagus nerve stimulation (VNS) has also been associated with improvement in fatigue in patients with pSS. Taken together, these data suggest that the ANS may be a potential treatment target for pSS, in particularly those with fatigue being a predominant symptom. Future research to dissect the link between the ANS, immune dysregulation and clinical manifestations in pSS and to evaluate the potential of VNS as a therapy for pSS is warranted.
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Affiliation(s)
- Kristen Davies
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Wan-Fai Ng
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- National Institute for Health Research (NIHR) Newcastle Biomedical Research Centre, Newcastle University and Newcastle upon Tyne Hospitals National Health Service (NHS) Foundation Trust, Newcastle upon Tyne, United Kingdom
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19
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Cavalcante GL, Brognara F, Oliveira LVDC, Lataro RM, Durand MDT, Oliveira AP, Nóbrega ACL, Salgado HC, Sabino JPJ. Benefits of pharmacological and electrical cholinergic stimulation in hypertension and heart failure. Acta Physiol (Oxf) 2021; 232:e13663. [PMID: 33884761 DOI: 10.1111/apha.13663] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/12/2021] [Accepted: 04/06/2021] [Indexed: 12/11/2022]
Abstract
Systemic arterial hypertension and heart failure are cardiovascular diseases that affect millions of individuals worldwide. They are characterized by a change in the autonomic nervous system balance, highlighted by an increase in sympathetic activity associated with a decrease in parasympathetic activity. Most therapeutic approaches seek to treat these diseases by medications that attenuate sympathetic activity. However, there is a growing number of studies demonstrating that the improvement of parasympathetic function, by means of pharmacological or electrical stimulation, can be an effective tool for the treatment of these cardiovascular diseases. Therefore, this review aims to describe the advances reported by experimental and clinical studies that addressed the potential of cholinergic stimulation to prevent autonomic and cardiovascular imbalance in hypertension and heart failure. Overall, the published data reviewed demonstrate that the use of central or peripheral acetylcholinesterase inhibitors is efficient to improve the autonomic imbalance and hemodynamic changes observed in heart failure and hypertension. Of note, the baroreflex and the vagus nerve activation have been shown to be safe and effective approaches to be used as an alternative treatment for these cardiovascular diseases. In conclusion, pharmacological and electrical stimulation of the parasympathetic nervous system has the potential to be used as a therapeutic tool for the treatment of hypertension and heart failure, deserving to be more explored in the clinical setting.
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Affiliation(s)
- Gisele L. Cavalcante
- Graduate Program in Pharmaceutical Sciences Department of Biophysics and Physiology Federal University of Piaui Teresina PI Brazil
- Department of Pharmacology Ribeirão Preto Medical School University of São Paulo Ribeirão Preto SP Brazil
| | - Fernanda Brognara
- Department of Physiology Ribeirão Preto Medical School University of São Paulo Ribeirão Preto SP Brazil
| | - Lucas Vaz de C. Oliveira
- Graduate Program in Pharmaceutical Sciences Department of Biophysics and Physiology Federal University of Piaui Teresina PI Brazil
| | - Renata M. Lataro
- Department of Physiological Sciences Center of Biological Sciences Federal University of Santa Catarina Florianópolis SP Brazil
| | | | - Aldeidia P. Oliveira
- Graduate Program in Pharmacology Department of Biophysics and Physiology Federal University of Piaui Teresina PI Brazil
| | | | - Helio C. Salgado
- Department of Physiology Ribeirão Preto Medical School University of São Paulo Ribeirão Preto SP Brazil
| | - João Paulo J. Sabino
- Graduate Program in Pharmaceutical Sciences Department of Biophysics and Physiology Federal University of Piaui Teresina PI Brazil
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20
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Shulgach JA, Beam DW, Nanivadekar AC, Miller DM, Fulton S, Sciullo M, Ogren J, Wong L, McLaughlin BL, Yates BJ, Horn CC, Fisher LE. Selective stimulation of the ferret abdominal vagus nerve with multi-contact nerve cuff electrodes. Sci Rep 2021; 11:12925. [PMID: 34155231 PMCID: PMC8217223 DOI: 10.1038/s41598-021-91900-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 06/01/2021] [Indexed: 12/14/2022] Open
Abstract
Dysfunction and diseases of the gastrointestinal (GI) tract are a major driver of medical care. The vagus nerve innervates and controls multiple organs of the GI tract and vagus nerve stimulation (VNS) could provide a means for affecting GI function and treating disease. However, the vagus nerve also innervates many other organs throughout the body, and off-target effects of VNS could cause major side effects such as changes in blood pressure. In this study, we aimed to achieve selective stimulation of populations of vagal afferents using a multi-contact cuff electrode wrapped around the abdominal trunks of the vagus nerve. Four-contact nerve cuff electrodes were implanted around the dorsal (N = 3) or ventral (N = 3) abdominal vagus nerve in six ferrets, and the response to stimulation was measured via a 32-channel microelectrode array (MEA) inserted into the left or right nodose ganglion. Selectivity was characterized by the ability to evoke responses in MEA channels through one bipolar pair of cuff contacts but not through the other bipolar pair. We demonstrated that it was possible to selectively activate subpopulations of vagal neurons using abdominal VNS. Additionally, we quantified the conduction velocity of evoked responses to determine what types of nerve fibers (i.e., Aδ vs. C) responded to stimulation. We also quantified the spatial organization of evoked responses in the nodose MEA to determine if there is somatotopic organization of the neurons in that ganglion. Finally, we demonstrated in a separate set of three ferrets that stimulation of the abdominal vagus via a four-contact cuff could selectively alter gastric myoelectric activity, suggesting that abdominal VNS can potentially be used to control GI function.
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Affiliation(s)
- Jonathan A Shulgach
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.,Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Dylan W Beam
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Center for Neural Basis of Cognition, Pittsburgh, PA, 15213, USA
| | - Ameya C Nanivadekar
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Center for Neural Basis of Cognition, Pittsburgh, PA, 15213, USA
| | - Derek M Miller
- Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Stephanie Fulton
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Michael Sciullo
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - John Ogren
- Micro-Leads Inc., Somerville, MA, 02144, USA
| | - Liane Wong
- Micro-Leads Inc., Somerville, MA, 02144, USA
| | | | - Bill J Yates
- Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Charles C Horn
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Department of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA.,Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Lee E Fisher
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA. .,Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15213, USA. .,Center for Neural Basis of Cognition, Pittsburgh, PA, 15213, USA. .,Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
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21
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Welle EJ, Woods JE, Jiman AA, Richie JM, Bottorff EC, Ouyang Z, Seymour JP, Patel PR, Bruns TM, Chestek CA. Sharpened and Mechanically Durable Carbon Fiber Electrode Arrays for Neural Recording. IEEE Trans Neural Syst Rehabil Eng 2021; 29:993-1003. [PMID: 34014825 PMCID: PMC8459724 DOI: 10.1109/tnsre.2021.3082056] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Bioelectric medicine treatments target disorders of the nervous system unresponsive to pharmacological methods. While current stimulation paradigms effectively treat many disorders, the underlying mechanisms are relatively unknown, and current neuroscience recording electrodes are often limited in their specificity to gross averages across many neurons or axons. Here, we develop a novel, durable carbon fiber electrode array adaptable to many neural structures for precise neural recording. Carbon fibers ( [Formula: see text] diameter) were sharpened using a reproducible blowtorchmethod that uses the reflection of fibers against the surface of a water bath. The arrays were developed by partially embedding carbon fibers in medical-grade silicone to improve durability. We recorded acute spontaneous electrophysiology from the rat cervical vagus nerve (CVN), feline dorsal root ganglia (DRG), and rat brain. Blowtorching resulted in fibers of 72.3 ± 33.5-degree tip angle with [Formula: see text] exposed carbon. Observable neural clusters were recorded using sharpened carbon fiber electrodes fromrat CVN ( [Formula: see text]), feline DRG ( [Formula: see text]), and rat brain ( [Formula: see text]). Recordings from the feline DRG included physiologically relevant signals from increased bladder pressure and cutaneous brushing. These results suggest that this carbon fiber array is a uniquely durable and adaptable neural recordingdevice. In the future, this device may be useful as a bioelectric medicine tool for diagnosis and closed-loop neural control of therapeutic treatments and monitoring systems.
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22
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Horn CC, Forssell M, Sciullo M, Harms JE, Fulton S, Mou C, Sun F, Simpson TW, Xiao G, Fisher LE, Bettinger C, Fedder GK. Hydrogel-based electrodes for selective cervical vagus nerve stimulation. J Neural Eng 2021; 18. [PMID: 33784636 DOI: 10.1088/1741-2552/abf398] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 03/30/2021] [Indexed: 11/11/2022]
Abstract
Objective.Electrical vagus nerve stimulation (VNS) has the potential to treat a wide variety of diseases by modulating afferent and efferent communication to the heart, lungs, esophagus, stomach, and intestines. Although distal vagal nerve branches, close to end organs, could provide a selective therapeutic approach, these locations are often surgically inaccessible. In contrast, the cervical vagus nerve has been targeted for decades using surgically implantable helix electrodes to treat epileptic seizures and depression; however, to date, clinical implementation of VNS has relied on an electrode with contacts that fully wrap around the nerve, producing non-selective activation of the entire nerve. Here we demonstrate selective cervical VNS using cuff electrodes with multiple contacts around the nerve circumference to target different functional pathways.Approach.These flexible probes were adjusted to the diameter of the nerve using an adhesive hydrogel wrap to create a robust electrode interface. Our approach was verified in a rat model by demonstrating that cervical VNS produces neural activity in the abdominal vagus nerve while limiting effects on the cardiovascular system (i.e. changes in heart rate or blood pressure).Main results.This study demonstrates the potential for selective cervical VNS as a therapeutic approach for modulating distal nerve branches while reducing off target effects.Significance.This methodology could potentially be refined to treat gastrointestinal, metabolic, inflammatory, cardiovascular, and respiratory diseases amenable to vagal neuromodulatory control.
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Affiliation(s)
- Charles C Horn
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.,UPMC Hillman Cancer Center, Pittsburgh, PA, United States of America.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Mats Forssell
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | - Michael Sciullo
- UPMC Hillman Cancer Center, Pittsburgh, PA, United States of America
| | - Jonathan E Harms
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America.,UPMC Hillman Cancer Center, Pittsburgh, PA, United States of America
| | - Stephanie Fulton
- UPMC Hillman Cancer Center, Pittsburgh, PA, United States of America
| | - Chenchen Mou
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | - Fan Sun
- UPMC Hillman Cancer Center, Pittsburgh, PA, United States of America.,Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Tyler W Simpson
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Gutian Xiao
- UPMC Hillman Cancer Center, Pittsburgh, PA, United States of America.,Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Lee E Fisher
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States of America.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Christopher Bettinger
- Department of Material Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | - Gary K Fedder
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, United States of America
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23
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Cuttaz EA, Chapman CAR, Syed O, Goding JA, Green RA. Stretchable, Fully Polymeric Electrode Arrays for Peripheral Nerve Stimulation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2004033. [PMID: 33898185 PMCID: PMC8061359 DOI: 10.1002/advs.202004033] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/19/2021] [Indexed: 05/08/2023]
Abstract
There is a critical need to transition research level flexible polymer bioelectronics toward the clinic by demonstrating both reliability in fabrication and stable device performance. Conductive elastomers (CEs) are composites of conductive polymers in elastomeric matrices that provide both flexibility and enhanced electrochemical properties compared to conventional metallic electrodes. This work focuses on the development of nerve cuff devices and the assessment of the device functionality at each development stage, from CE material to fully polymeric electrode arrays. Two device types are fabricated by laser machining of a thick and thin CE sheet variant on an insulative polydimethylsiloxane substrate and lamination into tubing to produce pre-curled cuffs. Device performance and stability following sterilization and mechanical loading are compared to a state-of-the-art stretchable metallic nerve cuff. The CE cuffs are found to be electrically and mechanically stable with improved charge transfer properties compared to the commercial cuff. All devices are applied to an ex vivo whole sciatic nerve and shown to be functional, with the CE cuffs demonstrating superior charge transfer and electrochemical safety in the biological environment.
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Affiliation(s)
- Estelle A. Cuttaz
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
| | | | - Omaer Syed
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
| | - Josef A. Goding
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
| | - Rylie A. Green
- Department of BioengineeringImperial CollegeSouth KensingtonLondonSW7 2AZUK
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24
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Guidance for Acupuncture Robot with Potentially Utilizing Medical Robotic Technologies. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2021; 2021:8883598. [PMID: 33859714 PMCID: PMC8026281 DOI: 10.1155/2021/8883598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 03/20/2021] [Accepted: 03/23/2021] [Indexed: 11/18/2022]
Abstract
Acupuncture is gaining increasing attention and recognition all over the world. However, a lot of physical labor is paid by acupuncturists. It is natural to resort to a robot which can improve the accuracy as well as the efficacy of therapy. Several teams have separately developed real acupuncture robots or related technologies and even went to the stage of clinical trial and then achieved success commercially. A completed clinical practical acupuncture robot is not far from reach with the combination of existing mature medical robotic technologies. A hand-eye-brain coordination framework is proposed in this review to integrate the potential utilizing technologies including force feedback, binocular vision, and automatic prescription. We should take acupuncture prescription with artificial intelligence and future development trends into account and make a feasible choice in development of modern acupuncture.
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25
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Cracchiolo M, Ottaviani MM, Panarese A, Strauss I, Vallone F, Mazzoni A, Micera S. Bioelectronic medicine for the autonomic nervous system: clinical applications and perspectives. J Neural Eng 2021; 18. [PMID: 33592597 DOI: 10.1088/1741-2552/abe6b9] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 02/16/2021] [Indexed: 12/11/2022]
Abstract
Bioelectronic medicine (BM) is an emerging new approach for developing novel neuromodulation therapies for pathologies that have been previously treated with pharmacological approaches. In this review, we will focus on the neuromodulation of autonomic nervous system (ANS) activity with implantable devices, a field of BM that has already demonstrated the ability to treat a variety of conditions, from inflammation to metabolic and cognitive disorders. Recent discoveries about immune responses to ANS stimulation are the laying foundation for a new field holding great potential for medical advancement and therapies and involving an increasing number of research groups around the world, with funding from international public agencies and private investors. Here, we summarize the current achievements and future perspectives for clinical applications of neural decoding and stimulation of the ANS. First, we present the main clinical results achieved so far by different BM approaches and discuss the challenges encountered in fully exploiting the potential of neuromodulatory strategies. Then, we present current preclinical studies aimed at overcoming the present limitations by looking for optimal anatomical targets, developing novel neural interface technology, and conceiving more efficient signal processing strategies. Finally, we explore the prospects for translating these advancements into clinical practice.
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Affiliation(s)
- Marina Cracchiolo
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Matteo Maria Ottaviani
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Alessandro Panarese
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Ivo Strauss
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Fabio Vallone
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Alberto Mazzoni
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Silvestro Micera
- The BioRobotics Institute and Department of Excellence in Robotics & AI, The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy.,Bertarelli Foundation Chair in Translational NeuroEngineering, Centre for Neuroprosthetics and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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26
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Phillips JA, Hutchings C, Djamgoz MBA. Clinical Potential of Nerve Input to Tumors: A Bioelectricity Perspective. Bioelectricity 2021; 3:14-26. [PMID: 34476375 DOI: 10.1089/bioe.2020.0051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
We support the notion that the neural connections of the tumor microenvironment (TME) and the associated 'bioelectricity' play significant role in the pathophysiology of cancer. In several cancers, the nerve input promotes the cancer process. While straightforward surgical denervation of tumors, therefore, could improve prognosis, resulting side effects of such a procedure would be unpredictable and irreversible. On the other hand, tumor innervation can be manipulated effectively for therapeutic purposes by alternative novel approaches broadly termed "electroceuticals." In this perspective, we evaluate the clinical potential of targeting the TME first through manipulation of the nerve input itself and second by application of electric fields directly to the tumor. The former encompasses several different biophysical and biochemical approaches. These include implantable devices, nanoparticles, and electroactive polymers, as well as optogenetics and chemogenetics. As regard bioelectrical manipulation of the tumor itself, the "tumor-treating field" technique, applied to gliomas commonly in combination with chemotherapy, is evaluated. Also, as electroceuticals, drugs acting on ion channels and neurotransmitter receptors are highlighted for completeness. It is concluded, first, that electroceuticals comprise a broad range of biomedical tools. Second, such electroceuticals present significant clinical potential for exploiting the neural component of the TME as a strategy against cancer. Finally, the inherent bioelectric characteristics of tumors themselves are also amenable to complementary approaches. Collectively, these represent an evolving, dynamic field and further progress and applications can be expected to follow both conceptually and technically.
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Affiliation(s)
- Jade A Phillips
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Charlotte Hutchings
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Mustafa B A Djamgoz
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Biotechnology Research Center, Cyprus International University, Nicosia, North Cyprus
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27
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Harris AR, Carter P, Cowan R, Wallace GG. Impact of Protein Fouling on the Charge Injection Capacity, Impedance, and Effective Electrode Area of Platinum Electrodes for Bionic Devices. ChemElectroChem 2021. [DOI: 10.1002/celc.202001574] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Alexander R. Harris
- Aikenhead Centre for Medical Discovery ARC Centre of Excellence for Electromaterials Science Faculty of Medicine, Dentistry and Health Sciences University of Melbourne Melbourne Vic 3010 Australia
- The HEARing CRC University of Melbourne 550 Swanston St Melbourne 3010 Australia
| | - Paul Carter
- Cochlear Ltd Macquarie University 1 University Ave Sydney NSW 2109 Australia
| | - Robert Cowan
- The HEARing CRC University of Melbourne 550 Swanston St Melbourne 3010 Australia
- Department of Audiology & Speech Pathology University of Melbourne 550 Swanston St Melbourne 3010 Australia
| | - Gordon G. Wallace
- ARC Centre of Excellence for Electromaterials Science Intelligent Polymer Research Institute University of Wollongong Wollongong, NSW 2522 Australia
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28
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Fontaine AK, Futia GL, Rajendran PS, Littich SF, Mizoguchi N, Shivkumar K, Ardell JL, Restrepo D, Caldwell JH, Gibson EA, Weir RFF. Optical vagus nerve modulation of heart and respiration via heart-injected retrograde AAV. Sci Rep 2021; 11:3664. [PMID: 33574459 PMCID: PMC7878800 DOI: 10.1038/s41598-021-83280-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 01/18/2021] [Indexed: 12/16/2022] Open
Abstract
Vagus nerve stimulation has shown many benefits for disease therapies but current approaches involve imprecise electrical stimulation that gives rise to off-target effects, while the functionally relevant pathways remain poorly understood. One method to overcome these limitations is the use of optogenetic techniques, which facilitate targeted neural communication with light-sensitive actuators (opsins) and can be targeted to organs of interest based on the location of viral delivery. Here, we tested whether retrograde adeno-associated virus (rAAV2-retro) injected in the heart can be used to selectively express opsins in vagus nerve fibers controlling cardiac function. Furthermore, we investigated whether perturbations in cardiac function could be achieved with photostimulation at the cervical vagus nerve. Viral injection in the heart resulted in robust, primarily afferent, opsin reporter expression in the vagus nerve, nodose ganglion, and brainstem. Photostimulation using both one-photon stimulation and two-photon holography with a GRIN-lens incorporated nerve cuff, was tested on the pilot-cohort of injected mice. Changes in heart rate, surface electrocardiogram, and respiratory responses were observed in response to both one- and two-photon photostimulation. The results demonstrate feasibility of retrograde labeling for organ targeted optical neuromodulation.
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Affiliation(s)
- Arjun K Fontaine
- Departments of Bioengineering, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA.
- Biomechatronics Development Laboratory, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA.
| | - Gregory L Futia
- Departments of Bioengineering, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA
| | - Pradeep S Rajendran
- UCLA Cardiac Arrhythmia Center, University of California Los Angeles, Los Angeles, CA, USA
- UCLA Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA, USA
| | - Samuel F Littich
- Departments of Bioengineering, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA
- Biomechatronics Development Laboratory, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA
| | - Naoko Mizoguchi
- Departments of Cell and Developmental Biology, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA
- Division of Pharmacology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center, University of California Los Angeles, Los Angeles, CA, USA
- UCLA Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA, USA
| | - Jeffrey L Ardell
- UCLA Cardiac Arrhythmia Center, University of California Los Angeles, Los Angeles, CA, USA
- UCLA Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA, USA
| | - Diego Restrepo
- Departments of Cell and Developmental Biology, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA
| | - John H Caldwell
- Departments of Cell and Developmental Biology, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA
| | - Emily A Gibson
- Departments of Bioengineering, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA
| | - Richard F Ff Weir
- Departments of Bioengineering, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA
- Biomechatronics Development Laboratory, University of Colorado - Anschutz Medical Campus, Aurora, CO, USA
- Rocky Mountain Veterans Affairs Medical Center (VAMC), Aurora, CO, USA
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29
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Lee S, Cho EJ, Kwak HB. Personalized Healthcare for Dementia. Healthcare (Basel) 2021; 9:healthcare9020128. [PMID: 33525656 PMCID: PMC7910906 DOI: 10.3390/healthcare9020128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 01/07/2023] Open
Abstract
Dementia is one of the most common health problems affecting older adults, and the population with dementia is growing. Dementia refers to a comprehensive syndrome rather than a specific disease and is characterized by the loss of cognitive abilities. Many factors are related to dementia, such as aging, genetic profile, systemic vascular disease, unhealthy diet, and physical inactivity. As the causes and types of dementia are diverse, personalized healthcare is required. In this review, we first summarize various diagnostic approaches associated with dementia. Particularly, clinical diagnosis methods, biomarkers, neuroimaging, and digital biomarkers based on advances in data science and wearable devices are comprehensively reviewed. We then discuss three effective approaches to treating dementia, including engineering design, exercise, and diet. In the engineering design section, recent advances in monitoring and drug delivery systems for dementia are introduced. Additionally, we describe the effects of exercise on the treatment of dementia, especially focusing on the effects of aerobic and resistance training on cognitive function, and the effects of diets such as the Mediterranean diet and ketogenic diet on dementia.
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Affiliation(s)
- Seunghyeon Lee
- Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Korea; (S.L.); (E.-J.C.)
- Department of Chemical Engineering, Inha University, Incheon 22212, Korea
| | - Eun-Jeong Cho
- Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Korea; (S.L.); (E.-J.C.)
| | - Hyo-Bum Kwak
- Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Korea; (S.L.); (E.-J.C.)
- Correspondence: ; Tel.: +82-32-860-8183
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30
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Payne SC, Wiedmann NM, Eiber CD, Wong AW, Senn P, Osborne PB, Keast JR, Fallon JB. Recording of Electrically Evoked Neural Activity and Bladder Pressure Responses in Awake Rats Chronically Implanted With a Pelvic Nerve Array. Front Neurosci 2020; 14:619275. [PMID: 33390899 PMCID: PMC7773906 DOI: 10.3389/fnins.2020.619275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 11/25/2020] [Indexed: 01/16/2023] Open
Abstract
Bioelectronic medical devices are well established and widely used in the treatment of urological dysfunction. Approved targets include the sacral S3 spinal root and posterior tibial nerve, but an alternate target is the group of pelvic splanchnic nerves, as these contain sacral visceral sensory and autonomic motor pathways that coordinate storage and voiding functions of the bladder. Here, we developed a device suitable for long-term use in an awake rat model to study electrical neuromodulation of the pelvic nerve (homolog of the human pelvic splanchnic nerves). In male Sprague-Dawley rats, custom planar four-electrode arrays were implanted over the distal end of the pelvic nerve, close to the major pelvic ganglion. Electrically evoked compound action potentials (ECAPs) were reliably detected under anesthesia and in chronically implanted, awake rats up to 8 weeks post-surgery. ECAP waveforms showed three peaks, with latencies that suggested electrical stimulation activated several subpopulations of myelinated A-fiber and unmyelinated C-fiber axons. Chronic implantation of the array did not impact on voiding evoked in awake rats by continuous cystometry, where void parameters were comparable to those published in naïve rats. Electrical stimulation with chronically implanted arrays also induced two classes of bladder pressure responses detected by continuous flow cystometry in awake rats: voiding contractions and non-voiding contractions. No evidence of tissue pathology produced by chronically implanted arrays was detected by immunohistochemical visualization of markers for neuronal injury or noxious spinal cord activation. These results demonstrate a rat pelvic nerve electrode array that can be used for preclinical development of closed loop neuromodulation devices targeting the pelvic nerve as a therapy for neuro-urological dysfunction.
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Affiliation(s)
- Sophie C Payne
- Bionics Institute, Fitzroy, VIC, Australia.,Medical Bionics Department, University of Melbourne, Melbourne, VIC, Australia
| | - Nicole M Wiedmann
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC, Australia
| | - Calvin D Eiber
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC, Australia
| | - Agnes W Wong
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC, Australia
| | - Philipp Senn
- Bionics Institute, Fitzroy, VIC, Australia.,Medical Bionics Department, University of Melbourne, Melbourne, VIC, Australia
| | - Peregrine B Osborne
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC, Australia
| | - Janet R Keast
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC, Australia
| | - James B Fallon
- Bionics Institute, Fitzroy, VIC, Australia.,Medical Bionics Department, University of Melbourne, Melbourne, VIC, Australia.,Department of Otolaryngology, University of Melbourne, Melbourne, VIC, Australia
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31
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Ghazavi A, González-González MA, Romero-Ortega MI, Cogan SF. Intraneural ultramicroelectrode arrays for function-specific interfacing to the vagus nerve. Biosens Bioelectron 2020; 170:112608. [PMID: 33035896 PMCID: PMC7654841 DOI: 10.1016/j.bios.2020.112608] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 09/01/2020] [Accepted: 09/09/2020] [Indexed: 11/22/2022]
Abstract
Selective interfacing to small multifunctional nerves such as the vagus nerve (VN) which is the main multimodal autonomic nerve that provides a major communication pathway from vital peripheral organs to the brain, can have significant potential in treating and diagnosing diseases as well as enhancing our understanding of peripheral nerve circuits. Here we describe the fabrication of a 16-channel intraneural electrode array with ultramicro-dimensioned electrodes to achieve improved functionally selective recording. We demonstrate that the amorphous silicon carbide ultramicroelectrode arrays (a-SiC UMEAs) provide selectivity in the detection of neural activity in the cVN related to changes in systemic oxygenation and blood pressure. We will also demonstrate spatially selective recording of micro-compound action potentials (μCAPs) by electrical stimulation of the subdiaphragmatic branches of the VN. Distinct neural activity was recorded on electrodes separated by less than about 100 μm. This is the first time that this level of spatially selectivity recording has been demonstrated in the cVN with an intraneural multielectrode array.
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Affiliation(s)
- Atefeh Ghazavi
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, 75080, USA
| | | | - Mario I Romero-Ortega
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Stuart F Cogan
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, 75080, USA.
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32
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Larauche M, Wang Y, Wang PM, Dubrovsky G, Lo YK, Hsiang EL, Dunn JC, Taché Y, Liu W, Million M. The effect of colonic tissue electrical stimulation and celiac branch of the abdominal vagus nerve neuromodulation on colonic motility in anesthetized pigs. Neurogastroenterol Motil 2020; 32:e13925. [PMID: 32578346 PMCID: PMC7606494 DOI: 10.1111/nmo.13925] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 04/20/2020] [Accepted: 05/27/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Knowledge on optimal electrical stimulation (ES) modalities and region-specific functional effects of colonic neuromodulation is lacking. We aimed to map the regional colonic motility in response to ES of (a) the colonic tissue and (b) celiac branch of the abdominal vagus nerve (CBVN) in an anesthetized porcine model. METHODS In male Yucatan pigs, direct ES (10 Hz, 2 ms, 15 mA) of proximal (pC), transverse (tC), or distal (dC) colon was done using planar flexible multi-electrode array panels and CBVN ES (2 Hz, 0.3-4 ms, 5 mA) using pulse train (PT), continuous (10 min), or square-wave (SW) modalities, with or without afferent nerve block (200 Hz, 0.1 ms, 2 mA). The regional luminal manometric changes were quantified as area under the curve of contractions (AUC) and luminal pressure maps generated. Contractions frequency power spectral analysis was performed. Contraction propagation was assessed using video animation of motility changes. KEY RESULTS Direct colon ES caused visible local circular (pC, tC) or longitudinal (dC) muscle contractions and increased luminal pressure AUC in pC, tC, and dC (143.0 ± 40.7%, 135.8 ± 59.7%, and 142.0 ± 62%, respectively). The colon displayed prominent phasic pressure frequencies ranging from 1 to 12 cpm. Direct pC and tC ES increased the dominant contraction frequency band (1-6 cpm) power locally. Pulse train CBVN ES (2 Hz, 4 ms, 5 mA) triggered pancolonic contractions, reduced by concurrent afferent block. Colon contractions propagated both orally and aborally in short distances. CONCLUSION AND INFERENCES In anesthetized pigs, the dominant contraction frequency band is 1-6 cpm. Direct colonic ES causes primarily local contractions. The CBVN ES-induced pancolonic contractions involve central neural network.
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Affiliation(s)
- Muriel Larauche
- CURE: Digestive Diseases Research Center (DDRCC), Center for Neurobiology of Stress and Resilience (CNSR), Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Yushan Wang
- Department of Bioengineering, California NanoSystems Institute, UCLA, Los Angeles, CA, USA
| | - Po-Min Wang
- Department of Bioengineering, California NanoSystems Institute, UCLA, Los Angeles, CA, USA
| | | | - Yi-Kai Lo
- Department of Bioengineering, California NanoSystems Institute, UCLA, Los Angeles, CA, USA
| | - En-Lin Hsiang
- Department of Bioengineering, California NanoSystems Institute, UCLA, Los Angeles, CA, USA
| | - James C.Y. Dunn
- Departments of Surgery and Bioengineering, Stanford University, Stanford, CA, USA
| | - Yvette Taché
- CURE: Digestive Diseases Research Center (DDRCC), Center for Neurobiology of Stress and Resilience (CNSR), Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Wentai Liu
- Department of Bioengineering, California NanoSystems Institute, UCLA, Los Angeles, CA, USA
| | - Mulugeta Million
- CURE: Digestive Diseases Research Center (DDRCC), Center for Neurobiology of Stress and Resilience (CNSR), Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
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33
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A Review of Different Stimulation Methods for Functional Reconstruction and Comparison of Respiratory Function after Cervical Spinal Cord Injury. Appl Bionics Biomech 2020; 2020:8882430. [PMID: 33014127 PMCID: PMC7519444 DOI: 10.1155/2020/8882430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/30/2020] [Accepted: 09/07/2020] [Indexed: 11/27/2022] Open
Abstract
Background Spinal cord injury (SCI) is a common severe trauma in clinic, hundreds of thousands of people suffer from which every year in the world. In terms of injury location, cervical spinal cord injury (CSCI) has the greatest impact. After cervical spinal cord injury, the lack of innervated muscles is not enough to provide ventilation and other activities to complete the respiratory function. In addition to the decline of respiratory capacity, respiratory complications also have a serious impact on the life of patients. The most commonly used assisted breathing and cough equipment is the ventilator, but in recent years, the functional electrical stimulation method is being used gradually and widely. Methods About hundred related academic papers are cited for data analysis. They all have the following characteristics: (1) basic conditions of patients were reported, (2) patients had received nerve or muscle stimulation and the basic parameters, and (3) the results were evaluated based on some indicators. Results The papers mentioned above are classified as four kinds of stimulation methods: muscle electric/magnetic stimulation, spinal dural electric stimulation, intraspinal microstimulation, and infrared light stimulation. This paper describes the stimulation principle and application experiment. Finally, this paper will compare the indexes and effects of typical stimulation methods, as well as the two auxiliary methods: training and operation. Conclusions Although there is limited evidence for the treatment of respiratory failure by nerve or muscle stimulation after cervical spinal cord injury, the two techniques seem to be safe and effective. At the same time, light stimulation is gradually applied to clinical medicine with its strong advantages and becomes the development trend of nerve stimulation in the future.
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Affiliation(s)
- Jeffrey L. Ardell
- Address for correspondence: Dr. Jeffrey Ardell, University of California-Los Angeles Cardiac Arrhythmia Center, David Geffen School of Medicine, 100 Medical Plaza, Suite 660, Los Angeles, California 90095.
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Peña E, Pelot NA, Grill WM. Quantitative comparisons of block thresholds and onset responses for charge-balanced kilohertz frequency waveforms. J Neural Eng 2020; 17:046048. [PMID: 32777778 DOI: 10.1088/1741-2552/abadb5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE There is growing interest in delivering kilohertz frequency (KHF) electrical signals to block conduction in peripheral nerves for treatment of various diseases. Previous studies used different KHF waveforms to achieve block, and it remains unclear how waveform affects nerve block parameters. APPROACH We quantified the effects of waveform on KHF block of the rat tibial nerve in vivo and in computational models. We compared block thresholds and onset responses across current-controlled sinusoids and charge-balanced rectangular waveforms with different asymmetries and duty cycles. MAIN RESULTS Sine waves had higher block thresholds than square waves, but used less power at block threshold. Block threshold had an inverse relationship with duty cycle of rectangular waveforms irrespective of waveform asymmetry. Computational model results were consistent with relationships measured in vivo, although the models underestimated the effect of duty cycle on increasing thresholds. The axonal membrane substantially filtered waveforms, the filter transfer function was strikingly similar across waveforms, and filtering resulted in post-filtered rms block thresholds that were approximately constant across waveforms in silico and in vivo. Onset response was not consistently affected by waveform shape, but onset response was smaller at amplitudes well above block threshold. Therefore, waveforms with lower block thresholds (e.g. sine waves or square waves) could be more readily increased to higher amplitudes relative to block threshold to reduce onset response. We also observed a reduction in onset responses across consecutive trials after initial application of supra-block threshold amplitudes. SIGNIFICANCE Waveform had substantial effects on block thresholds, and the amplitude relative to block threshold had substantial effects on onset response. These data inform choice of waveform in subsequent studies and clinical applications, enhance effective use of block in therapeutic applications, and facilitate the design of parameters that achieve block with minimal onset responses.
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Affiliation(s)
- Edgar Peña
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States of America
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Harris AR. Current perspectives on the safe electrical stimulation of peripheral nerves with platinum electrodes. ACTA ACUST UNITED AC 2020. [DOI: 10.2217/bem-2020-0007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This review details some peripheral nervous system (PNS) targets and electrode designs used for electrical stimulation. It investigates limitations in current knowledge of safe electrical stimulation and possible future electrode developments. Current PNS targets are large, leading to poor resolution and off-target side-effects. Most clinical devices are platinum or platinum/iridium embedded in an insulation material. Their safety is usually guided by the Shannon plot, which is not valid for the PNS. New electrode designs are needed to target smaller nerve fibers, enabling higher resolution electrical therapies with fewer off-target side-effects. Damage can occur through biological and electrochemical mechanisms. Greater mechanistic understanding is required to ensure safe and efficacious, long-term electrical stimulation with new electrode materials, geometries and stimulation waveforms.
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Affiliation(s)
- Alexander R Harris
- ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, NSW 2522, Australia
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Lu KH, Cao J, Phillips R, Powley TL, Liu Z. Acute effects of vagus nerve stimulation parameters on gastric motility assessed with magnetic resonance imaging. Neurogastroenterol Motil 2020; 32:e13853. [PMID: 32297404 PMCID: PMC7872206 DOI: 10.1111/nmo.13853] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 02/24/2020] [Accepted: 03/19/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Vagus nerve stimulation (VNS) is an emerging bioelectronic therapy for regulating food intake and controlling gastric motility. However, the effects of different VNS parameters and polarity on postprandial gastric motility remain incompletely characterized. METHODS In anesthetized rats (N = 3), we applied monophasic electrical stimuli to the left cervical vagus and recorded compound nerve action potential (CNAP) as a measure of nerve response. We evaluated to what extent afferent or efferent pathway could be selectively activated by monophasic VNS. In a different group of rats (N = 13), we fed each rat a gadolinium-labeled meal and scanned the rat stomach with oral contrast-enhanced magnetic resonance imaging (MRI) while the rat was anesthetized. We evaluated the antral and pyloric motility as a function of pulse amplitude (0.13, 0.25, 0.5, 1 mA), width (0.13, 0.25, 0.5 ms), frequency (5, 10 Hz), and polarity of VNS. KEY RESULTS Monophasic VNS activated efferent and afferent pathways with about 67% and 82% selectivity, respectively. Primarily afferent VNS increased antral motility across a wide range of parameters. Primarily efferent VNS induced a significant decrease in antral motility as the stimulus intensity increased (R = -.93, P < .05 for 5 Hz, R = -.85, P < .05 for 10 Hz). The VNS with either polarity tended to promote pyloric motility to a greater extent given increasing stimulus intensity. CONCLUSIONS AND INFERENCES Monophasic VNS biased toward the afferent pathway is potentially more effective for facilitating occlusive contractions than that biased toward the efferent pathway.
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Affiliation(s)
- Kun-Han Lu
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA,Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA,Correspondence: Kun-Han Lu, PhD, Postdoctoral Research Associate, Weldon School of Biomedical Engineering, College of Engineering, Purdue University, 206 S. Martin Jischke Dr., West Lafayette, IN 47907, USA, Phone: +1 765 714 8776,
| | - Jiayue Cao
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Robert Phillips
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA
| | - Terry L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA,Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA
| | - Zhongming Liu
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
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Bertrand MM, Korajkic N, Osborne PB, Keast JR. Functional segregation within the pelvic nerve of male rats: a meso- and microscopic analysis. J Anat 2020; 237:757-773. [PMID: 32598494 PMCID: PMC7495281 DOI: 10.1111/joa.13221] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/22/2020] [Accepted: 04/27/2020] [Indexed: 01/16/2023] Open
Abstract
The pelvic splanchnic nerves are essential for pelvic organ function and have been proposed as targets for neuromodulation. We have focused on the rodent homologue of these nerves, the pelvic nerves. Our goal was to define within the pelvic nerve the projections of organ-specific sensory axons labelled by microinjection of neural tracer (cholera toxin, subunit B) into the bladder, urethra or rectum. We also examined the location of peptidergic sensory axons within the pelvic nerves to determine whether they aggregated separately from sacral preganglionic and paravertebral sympathetic postganglionic axons travelling in the same nerve. To address these aims, microscopy was performed on the major pelvic ganglion (MPG) with attached pelvic nerves, microdissected from young adult male Sprague-Dawley rats (6-8 weeks old) and processed as whole mounts for fluorescence immunohistochemistry. The pelvic nerves were typically composed of five discrete fascicles. Each fascicle contained peptidergic sensory, cholinergic preganglionic and noradrenergic postganglionic axons. Sensory axons innervating the lower urinary tract (LUT) consistently projected in specific fascicles within the pelvic nerves, whereas sensory axons innervating the rectum projected in a complementary group of fascicles. These discrete aggregations of organ-specific sensory projections could be followed along the full length of the pelvic nerves. From the junction of the pelvic nerve with the MPG, sensory axons immunoreactive for calcitonin gene-related peptide (CGRP) showed several distinct patterns of projection: some projected directly to the cavernous nerve, others projected directly across the surface of the MPG to the accessory nerves and a third class entered the MPG, encircling specific cholinergic neurons projecting to the LUT. A subpopulation of preganglionic inputs to noradrenergic MPG neurons also showed CGRP immunoreactivity. Together, these studies reveal new molecular and structural features of the pelvic nerves and suggest functional targets of sensory nerves in the MPG. These anatomical data will facilitate the design of experimental bioengineering strategies to specifically modulate each axon class.
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Affiliation(s)
- Martin M Bertrand
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Vic., Australia.,Department of Visceral Surgery, CHU de Nîmes, Nîmes, France.,Montpellier Laboratory of Informatics, Robotics and Microelectronics (LIRMM), ICAR Team, French National Centre for Scientific Research (CNRS), Montpellier University, Montpellier, France
| | - Nadja Korajkic
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Vic., Australia
| | - Peregrine B Osborne
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Vic., Australia
| | - Janet R Keast
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Vic., Australia
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Pelot NA, Grill WM. In vivo quantification of excitation and kilohertz frequency block of the rat vagus nerve. J Neural Eng 2020; 17:026005. [PMID: 31945746 DOI: 10.1088/1741-2552/ab6cb6] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE There is growing interest in treating diseases by electrical stimulation and block of peripheral autonomic nerves, but a paucity of studies on the excitation and block of small-diameter autonomic axons. We conducted in vivo quantification of the strength-duration properties, activity-dependent slowing (ADS), and responses to kilohertz frequency (KHF) signals for the rat vagus nerve (VN). APPROACH We conducted acute in vivo experiments in urethane-anaesthetized rats. We placed two cuff electrodes on the left cervical VN and one cuff electrode on the anterior subdiaphragmatic VN. The rostral cervical cuff was used to deliver pulses to quantify recruitment and ADS. The caudal cervical cuff was used to deliver KHF signals. The subdiaphragmatic cuff was used to record compound action potentials (CAPs). MAIN RESULTS We quantified the input-output recruitment and strength-duration curves. Fits to the data using standard strength-duration equations were qualitatively similar, but the resulting chronaxie and rheobase estimates varied substantially. We measured larger thresholds for the slowest fibres (0.5-1 m s-1), especially at shorter pulse widths. Using a novel cross-correlation CAP-based analysis, we measured ADS of ~2.3% after 3 min of 2 Hz stimulation, which is comparable to the ADS reported for sympathetic efferents in somatic nerves, but much smaller than the ADS in cutaneous nociceptors. We found greater ADS with higher stimulation frequency and non-monotonic changes in CV in select cases. We found monotonically increasing block thresholds across frequencies from 10 to 80 kHz for both fast and slow fibres. Further, following 25 s of KHF signal, neural conduction could require tens of seconds to recover. SIGNIFICANCE The quantification of mammalian autonomic nerve responses to conventional and KHF signals provides essential information for the development of peripheral nerve stimulation therapies and for understanding their mechanisms of action.
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Affiliation(s)
- N A Pelot
- Department of Biomedical Engineering, Duke University, Room 1427, Fitzpatrick CIEMAS, 101 Science Drive, Campus Box 90281, Durham, NC 27708, United States of America
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Southwell BR. Electro‐Neuromodulation for Colonic Disorders—Review of Meta‐Analyses, Systematic Reviews, and RCTs. Neuromodulation 2020; 23:1061-1081. [DOI: 10.1111/ner.13099] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/30/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Bridget R. Southwell
- Surgical Research Group Murdoch Children's Research Institute Melbourne Australia
- Department of Urology Royal Children's Hospital Melbourne Australia
- Department of Paediatrics University of Melbourne Melbourne Australia
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Eickhoff S, Jarvis JC. The Effect of Sub-Threshold Pre-Pulses on Neural Activation Depends on Electrode Configuration. IEEE Trans Biomed Eng 2020; 67:2552-2559. [PMID: 31905132 DOI: 10.1109/tbme.2020.2964071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Published research on nerve stimulation with sub-threshold conditioning pre-pulses is contradictory. Like most early research on electrical stimulation (ES), the pioneer work on the use of pre-pulses was modelled and measured only for monopolar electrodes. However, many contemporary ES applications, including miniaturized neuromodulation implants, known as electroceuticals, operate in bipolar mode. METHODS We compared depolarizing (DPPs) and hyperpolarizing (HPPs) pre-pulses on neural excitability in rat nerve with monopolar and bipolar electrodes. The rat common peroneal nerve was stimulated with biphasic stimuli with and without ramp and square DPPs or HPPs of 1, 5 and 10 ms duration and 10%-20% of the amplitude of the following pulse. RESULTS The effects were opposite for the monopolar and bipolar configurations. With monopolar electrodes DPPs increased the amplitude required to activate 50% of the motoneuron pool (between 0.7% and 10.3%) and HPPs decreased the threshold (between 1.7% and 4.7%). With bipolar electrodes both pre-pulse types had the opposite effect: DPPs decreased thresholds (between 1.8% and 5.5%) whereas HPPs increased thresholds (between 0.5% and 4.1%). Electroneurograms from the stimulated nerve revealed spatial and temporal differences in action potential generation for monopolar and bipolar electrodes. In bipolar biphasic stimulation, excitation first occurred at the return electrode as a response to the transition between the cathodic and anodic phase. CONCLUSION These data help to resolve the contradictions in the published data over two decades. SIGNIFICANCE They also show that fundamental research carried out in monopolar configuration is not directly applicable to contemporary bipolar ES applications.
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Ntiloudi D, Qanud K, Tomaio JN, Giannakoulas G, Al-Abed Y, Zanos S. Pulmonary arterial hypertension: the case for a bioelectronic treatment. Bioelectron Med 2019; 5:20. [PMID: 32232109 PMCID: PMC7098229 DOI: 10.1186/s42234-019-0036-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/08/2019] [Indexed: 12/16/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a rare disease of unknown etiology that progresses to right ventricular failure. It has a complex pathophysiology, which involves an imbalance between vasoconstrictive and vasodilative processes in the pulmonary circulation, pulmonary vasoconstriction, vascular and right ventricular remodeling, systemic inflammation, and autonomic imbalance, with a reduced parasympathetic and increased sympathetic tone. Current pharmacological treatments for PAH include several classes of drugs that target signaling pathways in vascular biology and cardiovascular physiology, but they can have severe unwanted effects and they do not typically stop the progression of the disease. Pulmonary artery denervation has been tested clinically as a method to suppress sympathetic overactivation, however it is a nonspecific and irreversible intervention. Bioelectronic medicine, in particular vagus nerve stimulation (VNS), has been used in cardiovascular disorders like arrhythmias, heart failure and arterial hypertension and could, in principle, be tested as a treatment in PAH. VNS can produce pulmonary vasodilation and renormalize right ventricular function, via activation of pulmonary and cardiac vagal fibers. It can suppress systemic inflammation, via activation of fibers that innervate the spleen. Finally, VNS can gradually restore the balance between parasympathetic and sympathetic tone by regulating autonomic reflexes. Preclinical studies support the feasibility of using VNS in PAH. However, there are challenges with such an approach, arising from the need to affect a relatively small number of relevant vagal fibers, and the potential for unwanted cardiac and noncardiac effects of VNS in this sensitive patient population.
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Affiliation(s)
- Despοina Ntiloudi
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY 11030 USA.,2Department of Cardiology, AHEPA University Hospital, Thessaloniki, Greece
| | - Khaled Qanud
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY 11030 USA
| | - Jacquelyn-Nicole Tomaio
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY 11030 USA
| | | | - Yousef Al-Abed
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY 11030 USA
| | - Stavros Zanos
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY 11030 USA
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Auricular Electroacupuncture for Late Posttraumatic Epilepsy after Severe Brain Injury: A Retrospective Study. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2019; 2019:5798912. [PMID: 31737082 PMCID: PMC6815526 DOI: 10.1155/2019/5798912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 08/10/2019] [Accepted: 08/30/2019] [Indexed: 01/20/2023]
Abstract
Background Posttraumatic epilepsy (PTE) is a common complication of traumatic brain injury (TBI), which seriously affects patients' survival and recovery. Vagus nerve stimulation (VNS) is a nonpharmacological therapy for epilepsy. The auricular branch of the vagus nerve (ABVN) is the only peripheral branch and has antiepileptic effects, but the efficacy of ABVN stimulation as treatment of late PTE is uncertain. We retrospectively analyzed the clinical efficacy of ABVN stimulation by auricular electroacupuncture for the treatment of late PTE, and investigated the influence of sodium valproate and edaravone on the anti-PTE effects of auricular electroacupuncture. Method Univariate and multivariate logistic regression analyses were used to investigate the relationship of age, cause of PTE, use of auricular electroacupuncture, sodium valproate, and edaravone with the incidence of late PTE. To compare the curative effects of auricular electroacupuncture, 89 cases of late PTE were divided into an auricular electroacupuncture and a control group according to whether they were treated with auricular electroacupuncture. We further analyzed the influence of sodium valproate and edaravone on the effects of the treatment of PTE with auricular electroacupuncture. Results Among age, cause, use of auricular electroacupuncture, sodium valproate, and edaravone, the use of auricular electroacupuncture was associated with significantly reduced incidence of late PTE (P < 0.05). Compared with the control group, there were more seizure-free cases in the auricular electroacupuncture group (P < 0.01). The total effective rate of the auricular electroacupuncture group was 90%. The seizure-free rate among patients treated with auricular electroacupuncture was significantly reduced, regardless of the use of sodium valproate or edaravone (P < 0.05). Conclusion Auricular electroacupuncture can reduce the incidence of late PTE and is a safe and economical therapy for late PTE.
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Eickhoff S, Jarvis JC. An Investigation of Neural Stimulation Efficiency With Gaussian Waveforms. IEEE Trans Neural Syst Rehabil Eng 2019; 28:104-112. [PMID: 31751280 DOI: 10.1109/tnsre.2019.2954004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Previous computational studies predict that Gaussian shaped waveforms use the least energy to activate nerves. The primary goal of this study was to examine the claimed potential of up to 60% energy savings with these waveforms over a range of phase widths (50- [Formula: see text]) in an animal model. METHODS The common peroneal nerve of anaesthetized rats was stimulated via monopolar and bipolar electrodes with single stimuli. The isometric peak twitch force of the extensor digitorum longus muscle was recorded to indicate the extent of neural activation. The energy consumption, charge injection and maximum instantaneous power values required to reach 50% neural activation were compared between Gaussian pulses and standard rectangular stimuli. RESULTS Energy savings in the 50- [Formula: see text] range of phase widths did not exceed 17% and were accompanied by significant increases in maximum instantaneous power of 110-200%. Charge efficiency was found to be increased over the whole range of tested phase widths with Gaussian compared to rectangular pulses and reached up to 55% at 1ms phase width. CONCLUSION These findings challenge the claims of up to 60% energy savings with Gaussian like stimulation waveforms. The moderate energy savings achieved with the novel waveform are accompanied with considerable increases in maximal instantaneous power. Larger power sources would therefore be required, and this opposes the trend for implant miniaturization. SIGNIFICANCE This is the first study to comprehensively investigate stimulation efficiency of Gaussian waveforms. It sheds new light on the practical potential of such stimulation waveforms.
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Nanivadekar AC, Miller DM, Fulton S, Wong L, Ogren J, Chitnis G, McLaughlin B, Zhai S, Fisher LE, Yates BJ, Horn CC. Machine learning prediction of emesis and gastrointestinal state in ferrets. PLoS One 2019; 14:e0223279. [PMID: 31626659 PMCID: PMC6799899 DOI: 10.1371/journal.pone.0223279] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 09/17/2019] [Indexed: 12/30/2022] Open
Abstract
Although electrogastrography (EGG) could be a critical tool in the diagnosis of patients with gastrointestinal (GI) disease, it remains under-utilized. The lack of spatial and temporal resolution using current EGG methods presents a significant roadblock to more widespread usage. Human and preclinical studies have shown that GI myoelectric electrodes can record signals containing significantly more information than can be derived from abdominal surface electrodes. The current study sought to assess the efficacy of multi-electrode arrays, surgically implanted on the serosal surface of the GI tract, from gastric fundus-to-duodenum, in recording myoelectric signals. It also examines the potential for machine learning algorithms to predict functional states, such as retching and emesis, from GI signal features. Studies were performed using ferrets, a gold standard model for emesis testing. Our results include simultaneous recordings from up to six GI recording sites in both anesthetized and chronically implanted free-moving ferrets. Testing conditions to produce different gastric states included gastric distension, intragastric infusion of emetine (a prototypical emetic agent), and feeding. Despite the observed variability in GI signals, machine learning algorithms, including k-nearest neighbors and support vector machines, were able to detect the state of the stomach with high overall accuracy (>75%). The present study is the first demonstration of machine learning algorithms to detect the physiological state of the stomach and onset of retching, which could provide a methodology to diagnose GI diseases and symptoms such as nausea and vomiting.
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Affiliation(s)
- Ameya C. Nanivadekar
- Dept. Bioengineering, Swanson School of Engineering, Univ. Pittsburgh, Pittsburgh, PA, United States of America
| | - Derek M. Miller
- Dept. Otolaryngology, Univ. Pittsburgh School of Medicine, Pittsburgh, PA, United States of America
| | - Stephanie Fulton
- UPMC Hillman Cancer Center, Univ. Pittsburgh School of Medicine, Pittsburgh, PA, United States of America
| | - Liane Wong
- Micro-Leads Inc., Somerville, MA, United States of America
| | - John Ogren
- Micro-Leads Inc., Somerville, MA, United States of America
| | - Girish Chitnis
- Micro-Leads Inc., Somerville, MA, United States of America
| | | | - Shuyan Zhai
- UPMC Hillman Cancer Center, Univ. Pittsburgh School of Medicine, Pittsburgh, PA, United States of America
| | - Lee E. Fisher
- Dept. Bioengineering, Swanson School of Engineering, Univ. Pittsburgh, Pittsburgh, PA, United States of America
- Dept. Physical Medicine and Rehabilitation, Univ. Pittsburgh School of Medicine, Pittsburgh, PA, United States of America
| | - Bill J. Yates
- Dept. Otolaryngology, Univ. Pittsburgh School of Medicine, Pittsburgh, PA, United States of America
- Dept. Neuroscience, Univ. Pittsburgh, PA, United States of America
- Center for Neuroscience, Univ. Pittsburgh, Pittsburgh, PA, United States of America
| | - Charles C. Horn
- UPMC Hillman Cancer Center, Univ. Pittsburgh School of Medicine, Pittsburgh, PA, United States of America
- Center for Neuroscience, Univ. Pittsburgh, Pittsburgh, PA, United States of America
- Dept. Medicine, Univ. Pittsburgh School of Medicine, Pittsburgh, PA, United States of America
- Dept. Anesthesiology, Univ. Pittsburgh School of Medicine, Pittsburgh, PA, United States of America
- * E-mail:
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Salavatian S, Ardell SM, Hammer M, Gibbons D, Armour JA, Ardell JL. Thoracic spinal cord neuromodulation obtunds dorsal root ganglion afferent neuronal transduction of the ischemic ventricle. Am J Physiol Heart Circ Physiol 2019; 317:H1134-H1141. [PMID: 31538809 DOI: 10.1152/ajpheart.00257.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Aberrant afferent signaling drives adverse remodeling of the cardiac nervous system in ischemic heart disease. The study objective was to determine whether thoracic spinal dorsal column stimulation (SCS) modulates cardiac afferent sensory transduction of the ischemic ventricle. In anesthetized canines (n = 16), extracellular activity generated by 62 dorsal root ganglia (DRG) soma (T1-T3), with verified myocardial ischemic (MI) sensitivity, were evaluated with and without 20-min preemptive SCS (T1-T3 spinal level; 50 Hz, 90% motor threshold). Transient MI was induced by 1-min coronary artery occlusion (CAO) of the left anterior descending (LAD) or circumflex (LCX) artery, randomized as to sequence. LAD and LCX CAO activated cardiac-related DRG neurons (LAD: 0.15 ± 0.04-1.05 ± 0.20 Hz, P < 0.00002; LCX: 0.08 ± 0.02-1.90 ± 0.45 Hz, P < 0.0003). SCS decreased basal neuronal activity of neurons that responded to LAD (0.15 ± 0.04 to 0.02 ± 0.01 Hz, P < 0.006) and LCX (0.08 ± 0.02 to 0.02 ± 0.01 Hz, P < 0.003). SCS suppressed responsiveness to transient MI (LAD: 1.05 ± 0.20-0.03 ± 0.01 Hz; P < 0.0001; LCX: 1.90 ± 0.45-0.03 ± 0.01 Hz; P < 0.001). Suprathreshold SCS (1 Hz) did not activate DRG neurons antidromically (n = 10 animals). Ventricular fibrillation (VF) was associated with a rapid increase in DRG activity to a maximum of 4.39 ± 1.07 Hz at 20 s after VF induction and a return to 90% of baseline within 10 s thereafter. SCS obtunds the capacity of DRG ventricular neurites to transduce the ischemic myocardium to second-order spinal neurons, a mechanism that would blunt reflex sympathoexcitation to myocardial ischemic stress, thereby contributing to its capacity to cardioprotect.NEW & NOTEWORTHY Aberrant afferent signaling drives adverse remodeling of the cardiac nervous system in ischemic heart disease. This study determined that thoracic spinal column stimulation (SCS) obtunds the capacity of dorsal root ganglia ventricular afferent neurons to transduce the ischemic myocardium to second-order spinal neurons, a mechanism that would blunt reflex sympathoexcitation to myocardial ischemic stress. This modulation does not reflect antidromic actions of SCS but likely reflects efferent-mediated changes at the myocyte-sensory neurite interface.
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Affiliation(s)
- Siamak Salavatian
- Neurocardiology Research Program of Excellence, University of California, Los Angeles, California.,Cardiac Arrhythmia Center, University of California, Los Angeles, California
| | - Sarah M Ardell
- Neurocardiology Research Program of Excellence, University of California, Los Angeles, California.,Cardiac Arrhythmia Center, University of California, Los Angeles, California
| | - Mathew Hammer
- Neurocardiology Research Program of Excellence, University of California, Los Angeles, California.,Cardiac Arrhythmia Center, University of California, Los Angeles, California
| | - David Gibbons
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, Tennessee
| | - J Andrew Armour
- Neurocardiology Research Program of Excellence, University of California, Los Angeles, California.,Cardiac Arrhythmia Center, University of California, Los Angeles, California
| | - Jeffrey L Ardell
- Neurocardiology Research Program of Excellence, University of California, Los Angeles, California.,Cardiac Arrhythmia Center, University of California, Los Angeles, California
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Sieck GC. Physiology in Perspective: Responding to a Changing Environment. Physiology (Bethesda) 2019; 34:84-85. [PMID: 30724131 DOI: 10.1152/physiol.00001.2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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