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Chandrabhatla AS, Pomeraniec IJ, Ksendzovsky A. Co-evolution of machine learning and digital technologies to improve monitoring of Parkinson's disease motor symptoms. NPJ Digit Med 2022; 5:32. [PMID: 35304579 PMCID: PMC8933519 DOI: 10.1038/s41746-022-00568-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/21/2022] [Indexed: 11/09/2022] Open
Abstract
Parkinson’s disease (PD) is a neurodegenerative disorder characterized by motor impairments such as tremor, bradykinesia, dyskinesia, and gait abnormalities. Current protocols assess PD symptoms during clinic visits and can be subjective. Patient diaries can help clinicians evaluate at-home symptoms, but can be incomplete or inaccurate. Therefore, researchers have developed in-home automated methods to monitor PD symptoms to enable data-driven PD diagnosis and management. We queried the US National Library of Medicine PubMed database to analyze the progression of the technologies and computational/machine learning methods used to monitor common motor PD symptoms. A sub-set of roughly 12,000 papers was reviewed that best characterized the machine learning and technology timelines that manifested from reviewing the literature. The technology used to monitor PD motor symptoms has advanced significantly in the past five decades. Early monitoring began with in-lab devices such as needle-based EMG, transitioned to in-lab accelerometers/gyroscopes, then to wearable accelerometers/gyroscopes, and finally to phone and mobile & web application-based in-home monitoring. Significant progress has also been made with respect to the use of machine learning algorithms to classify PD patients. Using data from different devices (e.g., video cameras, phone-based accelerometers), researchers have designed neural network and non-neural network-based machine learning algorithms to categorize PD patients across tremor, gait, bradykinesia, and dyskinesia. The five-decade co-evolution of technology and computational techniques used to monitor PD motor symptoms has driven significant progress that is enabling the shift from in-lab/clinic to in-home monitoring of PD symptoms.
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Affiliation(s)
- Anirudha S Chandrabhatla
- School of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA, 22903, USA
| | - I Jonathan Pomeraniec
- Surgical Neurology Branch, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA. .,Department of Neurosurgery, University of Virginia Health Sciences Center, Charlottesville, VA, 22903, USA.
| | - Alexander Ksendzovsky
- Department of Neurosurgery, University of Maryland Medical System, Baltimore, MD, 21201, USA
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Chan PY, Ripin ZM, Halim SA, Tharakan J, Muzaimi M, Ng KS, Kamarudin MI, Eow GB, Hor JY, Tan K, Cheah CF, Soong N, Then L, Yahya AS. An In-Laboratory Validity and Reliability Tested System for Quantifying Hand-Arm Tremor in Motions. IEEE Trans Neural Syst Rehabil Eng 2018; 26:460-467. [PMID: 29432113 DOI: 10.1109/tnsre.2017.2782361] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Despite the advancement of the tremor assessment systems, the current technology still lacks a method that can objectively characterize tremors in relative segmental movements. This paper presents a measurement system, which quantifies multi-degrees-of-freedom coupled relative motions of hand-arm tremor, in terms of joint angular displacement. In-laboratory validity and reliability tests of the system algorithm to provide joint angular displacement was carried out by using the two-degrees-of-freedom tremor simulator with incremental rotary encoder systems installed. The statistical analyses show that the developed system has high validity results and comparable reliability performances using the rotary encoder system as the reference. In the clinical trials, the system was tested on 38 Parkinson's disease patients. The system readings were correlated with the observational tremor ratings of six trained medical doctors. The moderate to very high clinical correlations of the system readings in measuring rest, postural and task-specific tremors add merits to the degree of readiness of the developed tremor measurement system in a routine clinical setting and/or intervention trial for tremor amelioration.
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Rigas G, Gatsios D, Fotiadis DI, Chondrogiorgi M, Tsironis C, Konitsiotis S, Gentile G, Marcante A, Antonini A. Tremor UPDRS estimation in home environment. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:3642-3645. [PMID: 28269083 DOI: 10.1109/embc.2016.7591517] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this paper, a method for the assessment of the Unified Parkinson Disease Rating scale (UPDRS) related to tremor is presented. The method described consists of hand resting and posture state detection, tremor detection and tremor quantification based on accelerometer and gyroscope readings from a wrist worn sensor. The initial results on PD patient recordings on home environment indicate the feasibility of the proposed method in monitoring UPDRS tremor in patient home environment.
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Lalvay L, Lara M, Mora A, Alarcón F, Fraga M, Pancorbo J, Marina JL, Mena MÁ, Lopez Sendón JL, García de Yébenes J. Quantitative Measurement of Akinesia in Parkinson's Disease. Mov Disord Clin Pract 2017; 4:316-322. [PMID: 30363442 PMCID: PMC6174408 DOI: 10.1002/mdc3.12410] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/09/2016] [Accepted: 06/10/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND There is great interest in developing simple, user-friendly, and inexpensive tools for the quantification and elucidation of motor deficits in patients with Parkinson's disease (PD). These systems could help to monitor the clinical status of patients with PD, to develop better treatments, and to identify individuals who have subtle motor signs that might pass unnoticed in the conventional neurological examination. METHODS Mememtum, a smartphone application that allows for the quantification of several parameters of movement, such as regularity, rhythm, and changes in the number of taps while taping with a single finger and with alternating fingers, was developed and then tested in a pilot study in Madrid and in an extensive study in Quito, Ecuador. RESULTS Almost all patients could successfully perform single-finger tapping, but approximately 10% of patients with severe parkinsonism had problems taping with alternating fingers. The results revealed changes in the regularity of the pressure applied while tapping and a reduction in the number of taps on the device screen when alternating tapping among patients who had idiopathic PD and vascular parkinsonism compared with controls and individuals who had prediagnostic motor abnormalities of PD. CONCLUSION Applications available in smartphones could be used for investigation and treatment of patients with PD, but much research is needed to optimize the ideal parameters to be investigated and the potential usefulness of this technique for patients with PD in different stages of the disease.
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Affiliation(s)
| | - Miguel Lara
- Servicio de NeurologíaHospital Eugenio EspejoQuitoEcuador
| | - Andrea Mora
- Servicio de NeurologíaHospital Eugenio EspejoQuitoEcuador
| | | | | | | | | | - María Ángeles Mena
- Fundación para Investigaciones NeurológicasMadridSpain
- Centro de Investigación Biomedica en Red de Enfermedades Neurodegenerativas (CIBERNED)Instituto de Salud Carlos IIIMadridSpain
| | | | - Justo García de Yébenes
- Servicio de NeurologíaHospital Eugenio EspejoQuitoEcuador
- Fundación para Investigaciones NeurológicasMadridSpain
- Centro de Investigación Biomedica en Red de Enfermedades Neurodegenerativas (CIBERNED)Instituto de Salud Carlos IIIMadridSpain
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An IoT approach for integration of computational intelligence and wearable sensors for Parkinson’s disease diagnosis and monitoring. HEALTH AND TECHNOLOGY 2016. [DOI: 10.1007/s12553-016-0148-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Elble RJ, McNames J. Using Portable Transducers to Measure Tremor Severity. Tremor Other Hyperkinet Mov (N Y) 2016; 6:375. [PMID: 27257514 PMCID: PMC4872171 DOI: 10.7916/d8dr2vcc] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 03/23/2016] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Portable motion transducers, suitable for measuring tremor, are now available at a reasonable cost. The use of these transducers requires knowledge of their limitations and data analysis. The purpose of this review is to provide a practical overview and example software for using portable motion transducers in the quantification of tremor. METHODS Medline was searched via PubMed.gov in December 2015 using the Boolean expression "tremor AND (accelerometer OR accelerometry OR gyroscope OR inertial measurement unit OR digitizing tablet OR transducer)." Abstracts of 419 papers dating back to 1964 were reviewed for relevant portable transducers and methods of tremor analysis, and 105 papers written in English were reviewed in detail. RESULTS Accelerometers, gyroscopes, and digitizing tablets are used most commonly, but few are sold for the purpose of measuring tremor. Consequently, most software for tremor analysis is developed by the user. Wearable transducers are capable of recording tremor continuously, in the absence of a clinician. Tremor amplitude, frequency, and occurrence (percentage of time with tremor) can be computed. Tremor amplitude and occurrence correlate strongly with clinical ratings of tremor severity. DISCUSSION Transducers provide measurements of tremor amplitude that are objective, precise, and valid, but the precision and accuracy of transducers are mitigated by natural variability in tremor amplitude. This variability is so great that the minimum detectable change in amplitude, exceeding random variability, is comparable for scales and transducers. Research is needed to determine the feasibility of detecting smaller change using averaged data from continuous long-term recordings with wearable transducers.
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Affiliation(s)
- Rodger J. Elble
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - James McNames
- Department of Electrical and Computer Engineering, Maseeh College of Engineering and Computer Science, Portland State University, Portland, OR, USA
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Lee HJ, Kim SK, Park H, Kim HB, Jeon HS, Jung YJ, Oh E, Kim HJ, Yun JY, Jeon BS, Park KS. Clinicians' Tendencies to Under-Rate Parkinsonian Tremors in the Less Affected Hand. PLoS One 2015; 10:e0131703. [PMID: 26110768 PMCID: PMC4482425 DOI: 10.1371/journal.pone.0131703] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 06/04/2015] [Indexed: 11/18/2022] Open
Abstract
The standard assessment method for tremor severity in Parkinson’s disease is visual observation by neurologists using clinical rating scales. This is, therefore, a subjective rating that is dependent on clinical expertise. The objective of this study was to report clinicians’ tendencies to under-rate Parkinsonian tremors in the less affected hand. This was observed through objective tremor measurement with accelerometers. Tremor amplitudes were measured objectively using tri-axis-accelerometers for both hands simultaneously in 53 patients with Parkinson’s disease during resting and postural tremors. The videotaped tremor was rated by neurologists using clinical rating scales. The tremor measured by accelerometer was compared with clinical ratings. Neurologists tended to under-rate the less affected hand in resting tremor when the contralateral hand had severe tremor in Session I. The participating neurologists corrected this tendency in Session II after being informed of it. The under-rating tendency was then repeated by other uninformed neurologists in Session III. Kappa statistics showed high inter-rater agreements and high agreements between estimated scores derived from the accelerometer signals and the mean Clinical Tremor Rating Scale evaluated in every session. Therefore, clinicians need to be aware of this under-rating tendency in visual inspection of the less affected hand in order to make accurate tremor severity assessments.
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Affiliation(s)
- Hong Ji Lee
- The Interdisciplinary Program for Bioengineering, Seoul National University, Seoul, Republic of Korea
| | - Sang Kyong Kim
- The Interdisciplinary Program for Bioengineering, Seoul National University, Seoul, Republic of Korea
| | - Hyeyoung Park
- The Department of Neurology and Movement Disorder Center, Seoul National University Hospital, Seoul, Republic of Korea
| | - Han Byul Kim
- The Interdisciplinary Program for Bioengineering, Seoul National University, Seoul, Republic of Korea
| | - Hyo Seon Jeon
- The Interdisciplinary Program for Bioengineering, Seoul National University, Seoul, Republic of Korea
| | - Yu Jin Jung
- The Department of Neurology, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea
| | - Eungseok Oh
- The Department of Neurology, Chungnam National University Hospital, Daejeon, Republic of Korea
| | - Hee Jin Kim
- The Department of Neurology, Konkuk University Hospital, Seoul, Republic of Korea
| | - Ji Young Yun
- The Department of Neurology, Ewha Womans University Mokdong Hospital, Seoul, Republic of Korea
| | - Beom S. Jeon
- The Department of Neurology and Movement Disorder Center, Seoul National University Hospital, Seoul, Republic of Korea
| | - Kwang Suk Park
- The Department of Biomedical Engineering, Seoul National University, Seoul, Republic of Korea
- * E-mail:
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PERFORM: a system for monitoring, assessment and management of patients with Parkinson's disease. SENSORS 2014; 14:21329-57. [PMID: 25393786 PMCID: PMC4279536 DOI: 10.3390/s141121329] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/25/2014] [Accepted: 10/20/2014] [Indexed: 01/20/2023]
Abstract
In this paper, we describe the PERFORM system for the continuous remote monitoring and management of Parkinson's disease (PD) patients. The PERFORM system is an intelligent closed-loop system that seamlessly integrates a wide range of wearable sensors constantly monitoring several motor signals of the PD patients. Data acquired are pre-processed by advanced knowledge processing methods, integrated by fusion algorithms to allow health professionals to remotely monitor the overall status of the patients, adjust medication schedules and personalize treatment. The information collected by the sensors (accelerometers and gyroscopes) is processed by several classifiers. As a result, it is possible to evaluate and quantify the PD motor symptoms related to end of dose deterioration (tremor, bradykinesia, freezing of gait (FoG)) as well as those related to over-dose concentration (Levodopa-induced dyskinesia (LID)). Based on this information, together with information derived from tests performed with a virtual reality glove and information about the medication and food intake, a patient specific profile can be built. In addition, the patient specific profile with his evaluation during the last week and last month, is compared to understand whether his status is stable, improving or worsening. Based on that, the system analyses whether a medication change is needed—always under medical supervision—and in this case, information about the medication change proposal is sent to the patient. The performance of the system has been evaluated in real life conditions, the accuracy and acceptability of the system by the PD patients and healthcare professionals has been tested, and a comparison with the standard routine clinical evaluation done by the PD patients' physician has been carried out. The PERFORM system is used by the PD patients and in a simple and safe non-invasive way for long-term record of their motor status, thus offering to the clinician a precise, long-term and objective view of patient's motor status and drug/food intake. Thus, with the PERFORM system the clinician can remotely receive precise information for the PD patient's status on previous days and define the optimal therapeutical treatment.
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Rigas G, Tzallas AT, Tsipouras MG, Bougia P, Tripoliti EE, Baga D, Fotiadis DI, Tsouli SG, Konitsiotis S. Assessment of tremor activity in the Parkinson's disease using a set of wearable sensors. ACTA ACUST UNITED AC 2012; 16:478-87. [PMID: 22231198 DOI: 10.1109/titb.2011.2182616] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Tremor is the most common motor disorder of Parkinson's disease (PD) and consequently its detection plays a crucial role in the management and treatment of PD patients. The current diagnosis procedure is based on subject-dependent clinical assessment, which has a difficulty in capturing subtle tremor features. In this paper, an automated method for both resting and action/postural tremor assessment is proposed using a set of accelerometers mounted on different patient's body segments. The estimation of tremor type (resting/action postural) and severity is based on features extracted from the acquired signals and hidden Markov models. The method is evaluated using data collected from 23 subjects (18 PD patients and 5 control subjects). The obtained results verified that the proposed method successfully: 1) quantifies tremor severity with 87 % accuracy, 2) discriminates resting from postural tremor, and 3) discriminates tremor from other Parkinsonian motor symptoms during daily activities.
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Affiliation(s)
- George Rigas
- Department of Material Sciences and Engineering, University of Ioannina, Ioannina, Greece.
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Giuffrida JP, Riley DE, Maddux BN, Heldman DA. Clinically deployable Kinesia technology for automated tremor assessment. Mov Disord 2009; 24:723-30. [PMID: 19133661 DOI: 10.1002/mds.22445] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The objective was to design, build, and assess Kinesia, a wireless system for automated assessment of Parkinson's disease (PD) tremor. The current standard in evaluating PD is the Unified Parkinson's Disease Rating Scale (UPDRS), a qualitative ranking system typically completed during an office visit. Kinesia integrates accelerometers and gyroscopes in a compact patient-worn unit to capture kinematic movement disorder features. Objectively quantifying PD manifestations with increased time resolution should aid in evaluating efficacy of treatment protocols and improve patient management. In this study, PD subjects performed the tremor subset of the UPDRS motor section while wearing Kinesia. Quantitative kinematic features were processed and highly correlated to clinician scores for rest tremor (r(2) = 0.89), postural tremor (r(2) = 0.90), and kinetic tremor (r(2) = 0.69). The quantitative features were used to develop a mathematical model that predicted tremor severity scores for new data with low errors. Finally, PD subjects indicated high clinical acceptance.
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Affiliation(s)
- Joseph P Giuffrida
- Division of Movement Disorders, Cleveland Medical Devices Inc., Cleveland, Ohio 44103, USA.
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Abstract
Dexterity is a crucial aspect of surgical competence and is considered to be of high priority in the selection of trainees to specialities such as laparoscopic surgery. A motion analysis system, Imperial College Surgical Assessment Device (ICSAD) has undergone validation studies and is sensitive in discriminating surgeons according to their experience. It consists of a signal generator that creates an electromagnetic field in which sensors placed on the surgeon's hands can be detected using a special software. These positional data can be converted to data reflecting the surgeon's dexterity. It is a useful adjunct to training as trainees can be expected to achieve a certain level of proficiency prior to progress. They can also be provided with an objective feedback of their performance. As an assessment method it can be used for credentialing in laparoscopic surgery.
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Vinjamuri R, Crammond DJ, Kondziolka D, Lee HN, Mao ZH. Extraction of sources of tremor in hand movements of patients with movement disorders. ACTA ACUST UNITED AC 2009; 13:49-56. [PMID: 19129023 DOI: 10.1109/titb.2008.2006403] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This paper proposes an efficient method to acquire sources of tremor in patients with movement disorders based on blind source separation of convolutive mixtures. The extracted sources indicated neural activities that might be generated in the central nervous system. Four patients with essential tremor were tested in a set of movement tasks. Subjects wore a data glove that measured finger movements of the hand. The experimental data were then fed to a convolutive-mixture model, which revealed sources that imbibed in them the tremor frequency components of 2--8 Hz. Time--frequency analysis of these sources might be of potential help to clinicians to devise tasks that can manifest visible tremor from patients.
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Affiliation(s)
- Ramana Vinjamuri
- Department of Electrical and Computer Engineering, University of Pittsburgh, PA 15261, USA
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Giuffrida JP, Lerner A, Steiner R, Daly J. Upper-Extremity Stroke Therapy Task Discrimination Using Motion Sensors and Electromyography. IEEE Trans Neural Syst Rehabil Eng 2008; 16:82-90. [DOI: 10.1109/tnsre.2007.914454] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Shih YH, Young MS. Integrated digital image and accelerometer measurements of rat locomotor and vibratory behaviour. J Neurosci Methods 2007; 166:81-8. [PMID: 17765321 DOI: 10.1016/j.jneumeth.2007.07.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2007] [Revised: 07/01/2007] [Accepted: 07/01/2007] [Indexed: 11/29/2022]
Abstract
This study developed a combined IC-type accelerometer and video camera system to simultaneously measure vibration and locomotion activities in rats. A personal computer, adopted as an image frame grabber, was combined with a digital image processing algorithm to measure the precise location of an animal in an experimental cage. An accelerometer-based vibration subsystem, based on an 89C51 single-chip microprocessor, was designed. The acceleration sensor module was attached directly to the shaved back of the rat's body to directly measure the animal's vibration. This module can detect a wide range of vibrations from movements of the entire body to micro-tremors. Along with hardware, this study also proposes novel software for video enhancement and data analysis to calculate the behaviour parameters from recorded movements. In normal mode, three vibration activities (locomotor activity, tremor and twitch) are auto-analyzed every 10 min. The results are saved, and various display, statistical and data organization options are available. The primary merits of this system are the ability to simultaneously record locomotion and vibrational data, the rapid set-up and operation, the low cost, the reduced illumination requirements, the reduction of environmental noise and the high precision. The proposed method will be of interest to researchers in various behavioural, biological and medical fields.
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Affiliation(s)
- Yuan-Hsing Shih
- Department of Electrical Engineering, National Cheng Kung University, Suite 92689, No.1, Dashiue Rd., Tainan 701, Taiwan, ROC
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Elble RJ. Gravitational artifact in accelerometric measurements of tremor. Clin Neurophysiol 2005; 116:1638-43. [PMID: 15905122 DOI: 10.1016/j.clinph.2005.03.014] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Revised: 03/20/2005] [Accepted: 03/25/2005] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To illustrate the problem of gravitational artifact in accelerometric recordings of tremor. METHODS Gravitational and inertial accelerations were computed for a triaxial accelerometer that was attached to a hand, oscillating vertically about the wrist. Mathematical equations for hand motion were solved with commercial software. RESULTS Accelerometer output contains proportionately larger gravitational artifact at lower frequencies of oscillation and when the accelerometer is mounted closer to the wrist. A vertical accelerometer axis contains nearly constant gravitational artifact when the amplitude of wrist oscillation is less than +/-20 degrees. Proportionately large gravitational artifact can occur in accelerometer axes that are perpendicular to the path of motion. Gravitational and inertial oscillations at twice the frequency of wrist oscillation emerge from the equations of motion. CONCLUSIONS When the hand is horizontal, the vertical accelerometer axis contains nearly constant gravitational artifact during the recording of most tremors, and high-pass filtering effectively removes this artifact. Gravitational artifact is more problematic when the hand is vertical, as during the measurement of Parkinson rest tremor, particularly if the accelerometer is mounted close to the wrist. SIGNIFICANCE Two accelerometers, mounted in parallel, are needed to capture hand rotation in a single plane of motion, free of gravitational artifact.
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Affiliation(s)
- Rodger J Elble
- Department of Neurology, Southern Illinois University School of Medicine, P.O. Box 19643, Springfield, IL 62794-9643, USA.
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Pellegrini B, Faes L, Nollo G, Schena F. Quantifying the contribution of arm postural tremor to the outcome of goal-directed pointing task by displacement measures. J Neurosci Methods 2005; 139:185-93. [PMID: 15488231 DOI: 10.1016/j.jneumeth.2004.04.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2003] [Revised: 04/27/2004] [Accepted: 04/28/2004] [Indexed: 11/26/2022]
Abstract
A method for quantifying the outcome of goal-directed postural pointing was presented and used for relating the tremor output to the oscillations of single arm landmarks. The displacement of reflective markers placed on shoulder, upper arm, forearm, and hand were measured by an optoelectronic motion capture system in nine subjects holding a laser penlight pointed at a target. The high signal-to-noise ratio of the measured displacement series (from 7:1 for shoulder marker to 30:1 for hand marker) demonstrated the feasibility of the proposed system to carry out tremor analysis. The track of the laser emission on the target, reconstructed from penlight displacements, was studied as the outcome of the pointing task. By measuring the length and the dispersion of the path covered by the target track in 30 s, a significant and comparable tremor amplitude was found in vertical and lateral directions. The correlation between target track and arm tremor was stronger for distal than for proximal markers. Spectral and cross-spectral analyses evidenced the presence of a dominant low frequency oscillation (1.5 Hz), along with a high frequency one (5-7 Hz), in the displacement of the target track. These two components were significantly linked to the oscillations of the hand, the forearm and the upper arm but not to those of the shoulder, suggesting that the oscillations in the overall tremor output during the pointing task are mainly generated by the arm segments.
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Affiliation(s)
- Barbara Pellegrini
- CeBiSM-Centre of Bioengineering and Motor Science, University of Trento, Via Matteo del Ben 5/B, 38068 Rovereto (TN), Italy.
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Keijsers NL, Horstink MW, Gielen SC. Online monitoring of dyskinesia in patients with Parkinson's disease. IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE : THE QUARTERLY MAGAZINE OF THE ENGINEERING IN MEDICINE & BIOLOGY SOCIETY 2003; 22:96-103. [PMID: 12845825 DOI: 10.1109/memb.2003.1213632] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Noël L Keijsers
- Dept. of Biophysics UMC, BEG 231, University of Nijmegen, 6525 Ez Nijmegen, The Netherlands.
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Chuang TY, Huang WS, Chiang SC, Tsai YA, Doong JL, Cheng H. A virtual reality-based system for hand function analysis. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2002; 69:189-196. [PMID: 12204447 DOI: 10.1016/s0169-2607(01)00190-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The goal of this study was to demonstrate the usability and usefulness of virtual reality technology in assessing hand functions. Ten healthy, non-disabled right-handed adult volunteers were recruited. Each volunteer used a dataglove to insert three-dimensional virtual representations of a cylinder and a prism into the target holes. To verify the reliability of the tests, each subject was retested twice. The performance testing assessed the visual-motor coordination a person needs to achieve a task accurately and within a set time. For each trial, the root mean square (RMS) value of the hand movement trajectory was projected onto the X, Y, and Z axes. This projection enabled us to measure the extent of the genuine, summative displacement of the manipulating hand. The reproducibility of the virtual reality assessment was analyzed using the intraclass correlation (ICC) approach. The total ICC values of 10 subjects demonstrated a high task completion time and RMS on the X and Z axes for the transferring of the prism. However, the values were low for the transferring of the cylinder. Because the individual coefficients of variations (CVs) varied widely in the moving of both the cylinder and the prism, the total (CVs) showed a high reading for the task completion time. Although rehabilitation clinics routinely carry out peg-moving exercises for disabled patients, our model provides a valuable quantitative real time and off-line measure of whole hand functions.
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Affiliation(s)
- Tien-Yow Chuang
- Department of Physical Medicine and Rehabilitation, Veterans General Hospital Taipei and National Yang-Ming University, No 201 Shih-Pai Rd., Sec 2, 11217, Taipei, Taiwan.
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Teodorescu HL, Chelaru M, Kandel A, Tofan I, Irimia M. Fuzzy methods in tremor assessment, prediction, and rehabilitation. Artif Intell Med 2001; 21:107-30. [PMID: 11154876 DOI: 10.1016/s0933-3657(00)00076-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Tremor is a disabling condition for a large segment of population, mainly elderly. To the present date, there are no adequate tools to diagnose and help rehabilitation of subjects with tremor, but recently there is a tremendous surge of interest in the research in the field. We report on the use of fuzzy methods in applications for rehabilitation, namely in tremor diagnosing and control. We synthesize our results regarding the characterization of the tremor by means of nonlinear dynamics techniques and fuzzy logic, and the prediction of tremor movements in view of rehabilitation purposes. Based on linear and nonlinear analysis of tremor, and using fuzzy aggregation, the fusing of tremor parameters in global functional disabling factors is proposed. Nonlinear dynamic parameters, namely correlation dimension and Lyapunov exponent is used in order to improve the assessment of tremor. The benefits of the fuzzy fused tremor parameters rely on more complete and accurate assessment of the functional impairment and on improved feedback for rehabilitation, based on the fused parameters of the tremor. Further steps in rehabilitation may require external muscular control. In turn, the control of tremor by electrical stimulation requires movement prediction. Several neural and neuro-fuzzy predictors are compared and a neuro-fuzzy predictor is presented, allowing us five-step ahead prediction, with an RMS error of the order of 10%. The benefits of the neuro-fuzzy predictor are good prediction capability, versatility, and apparently a high robustness to individual variations of the tremor. The reported research, which extended over several years and included development of sensors, equipment, and software, has been aimed to development of products. The results may also open new ways in tremor rehabilitation.
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Affiliation(s)
- H L Teodorescu
- Computer Science and Engineering (CSEE), University of South Florida, Tampa 33620, USA.
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