A multifunctional soft robotic shape display with high-speed actuation, sensing, and control

Shape displays which actively manipulate surface geometry are an expanding robotics domain with applications to haptics, manufacturing, aerodynamics, and more. However, existing displays often lack high-fidelity shape morphing, high-speed deformation, and embedded state sensing, limiting their potential uses. Here, we demonstrate a multifunctional soft shape display driven by a 10 × 10 array of scalable cellular units which combine high-speed electrohydraulic soft actuation, magnetic-based sensing, and control circuitry. We report high-performance reversible shape morphing up to 50 Hz, sensing of surface deformations with 0.1 mm sensitivity and external forces with 50 mN sensitivity in each cell, which we demonstrate across a multitude of applications including user interaction, image display, sensing of object mass, and dynamic manipulation of solids and liquids. This work showcases the rich multifunctionality and high-performance capabilities that arise from tightly-integrating large numbers of electrohydraulic actuators, soft sensors, and controllers at a previously undemonstrated scale in soft robotics.

Spider-Inspired Electrohydraulic Actuators for Fast, Soft-Actuated Joints

The impressive locomotion and manipulation capabilities of spiders have led to a host of bioinspired robotic designs aiming to reproduce their functionalities; however, current actuation mechanisms are deficient in either speed, force output, displacement, or efficiency. Here-using inspiration from the hydraulic mechanism used in spider legs-soft-actuated joints are developed that use electrostatic forces to locally pressurize a hydraulic fluid, and cause flexion of a segmented structure. The result is a lightweight, low-profile articulating mechanism capable of fast operation, high forces, and large displacement; these devices are termed spider-inspired electrohydraulic soft-actuated (SES) joints. SES joints with rotation angles up to 70°, blocked torques up to 70 mN m, and specific torques up to 21 N m kg-1 are demonstrated. SES joints demonstrate high speed operation, with measured roll-off frequencies up to 24 Hz and specific power as high as 230 W kg-1 -similar to human muscle. The versatility of these devices is illustrated by combining SES joints to create a bidirectional joint, an artificial limb with independently addressable joints, and a compliant gripper. The lightweight, low-profile design, and high performance of these devices, makes them well-suited toward the development of articulating robotic systems that can rapidly maneuver.

HASEL Artificial Muscles for a New Generation of Lifelike Robots-Recent Progress and Future Opportunities

Future robots and intelligent systems will autonomously navigate in unstructured environments and closely collaborate with humans; integrated with our bodies and minds, they will allow us to surpass our physical limitations. Traditional robots are mostly built from rigid, metallic components and electromagnetic motors, which make them heavy, expensive, unsafe near people, and ill-suited for unpredictable environments. By contrast, biological organisms make extensive use of soft materials and radically outperform robots in terms of dexterity, agility, and adaptability. Particularly, natural muscle-a masterpiece of evolution-has long inspired researchers to create "artificial muscles" in an attempt to replicate its versatility, seamless integration with sensing, and ability to self-heal. To date, natural muscle remains unmatched in all-round performance, but rapid advancements in soft robotics have brought viable alternatives closer than ever. Herein, the recent development of hydraulically amplified self-healing electrostatic (HASEL) actuators, a new class of high-performance, self-sensing artificial muscles that couple electrostatic and hydraulic forces to achieve diverse modes of actuation, is discussed; current designs match or exceed natural muscle in many metrics. Research on materials, designs, fabrication, modeling, and control systems for HASEL actuators is detailed. In each area, research opportunities are identified, which together lays out a roadmap for actuators with drastically improved performance. With their unique versatility and wide potential for further improvement, HASEL actuators are poised to play an important role in a paradigm shift that fundamentally challenges the current limitations of robotic hardware toward future intelligent systems that replicate the vast capabilities of biological organisms.

Design of a High-Speed Prosthetic Finger Driven by Peano-HASEL Actuators

Current designs of powered prosthetic limbs are limited by the nearly exclusive use of DC motor technology. Soft actuators promise new design freedom to create prosthetic limbs which more closely mimic intact neuromuscular systems and improve the capabilities of prosthetic users. This work evaluates the performance of a hydraulically amplified self-healing electrostatic (HASEL) soft actuator for use in a prosthetic hand. We compare a linearly-contracting HASEL actuator, termed a Peano-HASEL, to an existing actuator (DC motor) when driving a prosthetic finger like those utilized in multi-functional prosthetic hands. A kinematic model of the prosthetic finger is developed and validated, and is used to customize a prosthetic finger that is tuned to complement the force-strain characteristics of the Peano-HASEL actuators. An analytical model is used to inform the design of an improved Peano-HASEL actuator with the goal of increasing the fingertip pinch force of the prosthetic finger. When compared to a weight-matched DC motor actuator, the Peano-HASEL and custom finger is 10.6 times faster, has 11.1 times higher bandwidth, and consumes 8.7 times less electrical energy to grasp. It reaches 91% of the maximum range of motion of the original finger. However, the DC motor actuator produces 10 times the fingertip force at a relevant grip position. In this body of work, we present ways to further increase the force output of the Peano-HASEL driven prosthetic finger system, and discuss the significance of the unique properties of Peano-HASELs when applied to the field of upper-limb prosthetic design. This approach toward clinically-relevant actuator performance paired with a substantially different form-factor compared to DC motors presents new opportunities to advance the field of prosthetic limb design.

An Easy-to-Implement Toolkit to Create Versatile and High-Performance HASEL Actuators for Untethered Soft Robots

For soft robots to have ubiquitous adoption in practical applications they require soft actuators that provide well-rounded actuation performance that parallels natural muscle while being inexpensive and easily fabricated. This manuscript introduces a toolkit to rapidly prototype, manufacture, test, and power various designs of hydraulically amplified self-healing electrostatic (HASEL) actuators with muscle-like performance that achieve all three basic modes of actuation (expansion, contraction, and rotation). This toolkit utilizes easy-to-implement methods, inexpensive fabrication tools, commodity materials, and off-the-shelf high-voltage electronics thereby enabling a wide audience to explore HASEL technology. Remarkably, the actuators created from this easy-to-implement toolkit achieve linear strains exceeding 100%, a specific power greater than 150 W kg-1, and ≈20% strain at frequencies above 100 Hz. This combination of large strain, extreme speed, and high specific power yields soft actuators that jump without power-amplifying mechanisms. Additionally, an efficient fabrication technique is introduced for modular designs of HASEL actuators, which is used to develop soft robotic devices driven by portable electronics. Inspired by the versatility of elephant trunks, the above capabilities are combined to create an untethered continuum robot for grasping and manipulating delicate objects, highlighting the wide potential of the introduced methods for soft robots with increasing sophistication.

Hydraulically amplified self-healing electrostatic actuators with muscle-like performance

Existing soft actuators have persistent challenges that restrain the potential of soft robotics, highlighting a need for soft transducers that are powerful, high-speed, efficient, and robust. We describe a class of soft actuators, termed hydraulically amplified self-healing electrostatic (HASEL) actuators, which harness a mechanism that couples electrostatic and hydraulic forces to achieve a variety of actuation modes. We introduce prototypical designs of HASEL actuators and demonstrate their robust, muscle-like performance as well as their ability to repeatedly self-heal after dielectric breakdown-all using widely available materials and common fabrication techniques. A soft gripper handling delicate objects and a self-sensing artificial muscle powering a robotic arm illustrate the wide potential of HASEL actuators for next-generation soft robotic devices.

Efficacy and tolerability of lower-dose topotecan in recurrent ovarian cancer: a retrospective case review

Topotecan (1.5 mg/m(2)/day for 5 consecutive days of a 21-day cycle) is an established recurrent ovarian cancer treatment, but myelosuppression can be dose limiting. This study evaluates the activity and tolerability of low-dose topotecan in our clinical experience. Case records were reviewed for patients with recurrent ovarian cancer in first through third relapse. Eligible patients had received > or =2 cycles of < or =1.25 mg/m(2) topotecan. Adverse events were evaluated using laboratory and clinical evaluation data. Twenty-seven eligible patients, most with advanced disease, received a total of 209 cycles (median, six cycles). Grade 3 or 4 hematologic toxicities during 184 cycles in 24 assessed patients were neutropenia, leukopenia, thrombocytopenia, and anemia in 35%, 28%, 36%, and 11% of cycles, and 21, 19, 16, and 10 patients, respectively. Only four grade 4 toxicities occurred: anemia (one) and thrombocytopenia (three). Myelosuppression was reversible, noncumulative, and manageable. Moreover, nonhematologic toxicity was generally mild to moderate, and the only two grade 3 events were constipation and deep vein thrombosis. Low-dose topotecan was active in this setting. Lower-dose topotecan is generally well tolerated and active in patients with pretreated ovarian cancer. Prospective clinical trials of low-dose topotecan in recurrent ovarian cancer are warranted.

Renal nuclear medicine: a review

Renal nuclear medicine is used to evaluate renal function and morphology. Renal scintigraphy is the best imaging modality for evaluation of functional parameters such as glomerular filtration rate and effective renal plasma flow. The commonly used renal radiopharmaceuticals are reviewed. Both imaging and non-imaging techniques are presented. Specific applications of renal nuclear medicine are discussed.

The eye and orbit

Computed tomography (CT) and magnetic resonance imaging (MRI) provide excellent morphological detail of the eye and its associated structures. In veterinary medicine, these imaging modalities are most often used to diagnose and determine the extent of ocular or periocular tumors. They may also be used to diagnose inflammatory conditions of the orbital region and to determine the severity and extent of ocular trauma. This article reviews the applications of CT and MRI for ocular and orbital diseases, discusses normal findings, and presents representative case examples.

Unusual metastatic behavior and clinicopathologic findings in eight cats with cutaneous or visceral hemangiosarcoma

Eight cats with visceral or cutaneous hemangiosarcoma were evaluated, and unusual metastatic and clinicopathologic behavior was evident in each. Cutaneous hemangiosarcoma is generally believed to be locally aggressive and slow to metastasize. These 8 cats with cutaneous hemangiosarcoma, however, developed metastatic disease after initial surgical resection; only 1 had local regrowth of the tumor. All cats with visceral hemangiosarcoma had metastasis at the time of diagnosis, which is consistent with cats of other reports. Three of 8 cats had evidence of disseminated intravascular coagulation, including increased prothrombin time and partial thromboplastin time, decreased number of platelets, and anemia. These potential complications need to be considered when planning diagnostic and treatment protocols.

Evaluation of renal hemodynamics in awake and isoflurane-anesthetized cats with pulsed-wave Doppler and quantitative renal scintigraphy

The feasibility and reproducibility of obtaining the pulsed-wave Doppler measurements of resistive index (RI) and pulsatility index (PI) were investigated in intrarenal arteries of normal, nonsedated cats, and cats anesthetized with isoflurane. In addition, relative renal function and relative renal blood flow were evaluated using quantitative renal scintigraphy. The percentage of injected dose uptake, time to peak activity, and two indices of renal blood flow (K/A ratio and flow index) obtained during the first pass of 99mTc-MAG3, were determined for both awake and anesthetized cats. Results indicate that measuring RI and PI in nonsedated cats is readily accomplished and that the results are reproducible within an animal. Mean RI and PI values in the awake cats were 0.55 and 0.8, respectively. Significant differences between the awake and anesthetized cats were found for all pulsed-wave Doppler and quantitative renal scintigraphic measurements evaluated.

Chemoprophylaxis with ciprofloxacin in ovarian cancer patients receiving paclitaxel: a randomized trial

The objective of this study was to evaluate the efficacy of oral ciprofloxacin in preventing febrile morbidity superimposed on the neutropenia induced from a paclitaxel regimen in ovarian cancer patients. Eligible patients received paclitaxel at doses of 135 to 175 mg/m2 alone or in combination with a platinum agent. They were randomized to either an observation (control) group or a ciprofloxacin prophylaxis group. Patients in the ciprofloxacin group received 500 mg ciprofloxacin orally twice a day once the absolute neutrophil count (ANC) was less than 500/mm3 and continued until the ANC was greater than 1000/mm3. Ninety patients were enrolled between the control (n = 45) and ciprofloxacin (n = 45) groups. They received 371 cycles of a paclitaxel-based regimen with 177 and 194 cycles in the control and ciprofloxacin groups, respectively. Ciprofloxacin prophylaxis was prescribed for 138 (71%) of the cycles in the ciprofloxacin group and was given for a mean duration of 7.7 days per cycle. The groups were similar in disease status and risk factors for neutropenia. Fifteen patients in the control group developed febrile neutropenia versus 12 of those in the ciprofloxacin group (P = 0.69). The mean ANC and mean length of hospital stay for neutropenic fever were also similar between groups. There was a greater frequency of an ANC < 100 associated with those prophylaxed with ciprofloxacin (P = 0.01). Only 44% of the febrile episodes were associated with a positive culture. Staphylococcus aureus was the most frequently reported organism isolated. Considering these results, it does not appear that febrile neutropenia is reduced by ciprofloxacin during grade IV neutropenia.

Cerebellar cortical degeneration in a Labrador retriever

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Chemoprophylaxis with oral ciprofloxacin in ovarian cancer patients receiving taxol

The purpose of this study was to review the clinical outcomes and cost of administration of a prophylactic antibiotic compared to G-CSF for the prevention of neutropenic morbidity associated with taxol. The study group was composed of 62 patients with ovarian cancer who received a 24-h infusion of a taxol-based regimen at doses less than or equal to 175 mg/m2 between June 1992 and April 1994. The records were retrospectively reviewed and the patients were grouped and analyzed according to the management of their myelosuppression. Group I patients (n = 29) were observed until their absolute neutrophil count (ANC) was less than 500/microliters and then were placed on ciprofloxacin 500 mg orally twice a day until their ANC was 1,000/microliters. Group II patients (n = 15) received G-CSF from Day 2 until the ANC was greater than 10,000/microliters beginning with their first cycle. Group III patients (n = 18) received their taxol regimen without either ciprofloxacin or G-CSF. Two hundred eighty-two taxol-based chemotherapy cycles were administered to these 62 patients. There was no statistically significant difference between the groups concerning disease status as measured by age, stage, performance status, dose intensity, or number of previous regimens. There were two episodes of febrile neutropenia in Group I and three episodes in Group II. Group III had 15 episodes of febrile neutropenia. The estimated cost of the different prophylactic regimens was $5,215.00 for Group I versus $104,000.00 for G-CSF in Group II. Within the three groups, there were 27 patients with an episode of febrile neutropenia (n = 20) or prolonged myelosuppression (n = 7) that were followed for an additional 104 taxol cycles. Twenty-four of these patients received G-CSF prophylaxis with intermittent ciprofloxacin and three received only ciprofloxacin. There were eight more episodes of febrile neutropenia in the patients receiving G-CSF. There were no additional febrile episodes on cycles prophylaxed with ciprofloxacin. There was no septic mortality. For patients receiving a 24 h infusion of taxol at doses less than 175 mg/m2, ciprofloxacin given through the ANC nadir may be effective in preventing febrile morbidity. A prospective randomized trial is underway to evaluate this approach.

Temporal control on interval schedules: what determines the postreinforcement pause?

On fixed-interval or response-initiated delay schedules of reinforcement, the average pause following food presentation is proportional to the interfood interval. Moreover, when a number of intervals of different durations occur in a programmed cyclic series, postreinforcement pauses track the changes in interval value. What controls the duration of postreinforcement pauses under these conditions? Staddon, Wynne, and Higa (1991), in their linear waiting model, propose control by the preceding interfood interval. Another possibility is that delay to reinforcement, signaled by a key peck and/or stimulus change, determines the subsequent pause. The experiments reported here examined the role of these two possible time markers by studying the performance of pigeons under a chained cyclic fixed-interval procedure. The data support the linear waiting model, but suggest that more than the immediately preceding interfood interval plays a role in temporal control.

Convergent inputs to the inferior olive from the dorsal column nuclei and pretectum in the cat

The dorsal column nuclei (DCN) consist of an anatomically heterogeneous population of neurons, some of which project to the inferior olive and pretectum. Recent anatomical experiments on cats have shown that neurons in the parts of the pretectum which receive input from DCN also project to the inferior olive. Thus, DCN neurons provide an input to the inferior olive via both a direct DCN-olivary pathway and an indirect pathway through the pretectum. This connective situation provides a mechanism by which incoming somatic sensory information that is processed at different levels of the brainstem (i.e. DCN and pretectum) has access to the cerebellum by way of the inferior olive. It is of interest whether the two sets of differently processed information are conveyed to the same group of inferior olive neurons. Although DCN and pretectal projections to the inferior olive have been generally described, the relationship between the DCN targets in the inferior olive and those specifically from the DCN-recipient parts of the pretectum have not. To address this question, this study used single and double anterograde labeling strategies with a variety of tracers to compare the two targets in the inferior olive of cats. It was found that projections to the inferior olive from the DCN-recipient parts of the pretectum were located predominantly in the dorsal accessory portion of the inferior olive where they overlapped extensively with projections directly from DCN. These results provide evidence for a pathway by which sequentially processed somatic sensory information, first in the DCN and then in the pretectum, has access to the cerebellum by way of the same group of inferior olive neurons.

Prevention of parenting alterations for women with low social support

Parenting is a demanding role. Traditionally societies provide mechanisms for supporting major caregivers. For most parents the partner relationship is a source of refueling energy. In addition, often the extended family members provide support for the parent(s). In a prior research study dealing with early intervention where the family demonstrated double vulnerability, defined by pregnancy complications and social problems, we found the mothers most resistant to help were women who both had a lot of situational problems and few if any friends or family supporting them (Barnard et al. 1985). This finding prompted us to think about parents who did not have the supportive mechanisms cultures generally provide.

Cerebral vasospasm: theoretical causes, medical management, and nursing implications

Cerebral vasospasm is a potentially life-threatening complication following subarachnoid hemorrhage (SAH) from a ruptured cerebral artery aneurysm. Traditionally, vasospasm has been treated with a variety of medical interventions. However, surgical intervention with an extracranial to intracranial (EC/IC) bypass graft has yielded promising results in a limited group of patients. This article discusses the theoretical causes of cerebral vasospasm, its clinical presentation, diagnosis, and treatment modalities. Nursing interventions for the patient experiencing cerebral vasospasm are also presented.

Extracranial-intracranial bypass surgery

Although the indications and effectiveness of the operation remain controversial, extracranial-intracranial (EC-IC) bypass surgery has become a common method in the treatment of patients with cerebral vascular disease. The technical feasibility of the procedure and its low mortality and morbidity rates are well established. However, its usefulness remains unproven in a variety of clinical, angiographic and regional cerebral blood flow patterns. This discussion focuses on the purpose of EC-IC bypass surgery as well as the procedure itself and postoperative nursing care.

Rubin’s “Puerperal Change” Reconsidered

A preliminary study was conducted to examine if healthy new mothers exhibit Rubin's "Taking-in" and "Taking-hold" behaviors and attitudes and if these behaviors and attitudes change during the course of hospitalization. Twenty subjects were surveyed on each postpartal hospital day at a large, west coast urban hospital. While the women exhibited some of the behavior and attitude changes, the findings do not support the specific time aspects described by Rubin. Implications for nursing practice, education, and research are discussed.