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Sanders JE, Vamos AC, Mertens JC, Allyn KJ, Larsen BG, Ballesteros D, Wang H, DeGrasse NS, Garbini JL, Hafner BJ, Friedly JL. An adaptive prosthetic socket for people with transtibial amputation. Sci Rep 2024; 14:11168. [PMID: 38750086 PMCID: PMC11096356 DOI: 10.1038/s41598-024-61234-9] [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: 01/20/2024] [Accepted: 05/01/2024] [Indexed: 05/18/2024] Open
Abstract
It is essential that people with limb amputation maintain proper prosthetic socket fit to prevent injury. Monitoring and adjusting socket fit, for example by removing the prosthesis to add prosthetic socks, is burdensome and can adversely affect users' function and quality-of-life. This study presents results from take-home testing of a motor-driven adaptive socket that automatically adjusted socket size during walking. A socket fit metric was calculated from inductive sensor measurements of the distance between the elastomeric liner surrounding the residual limb and the socket's inner surface. A proportional-integral controller was implemented to adjust socket size. When tested on 12 participants with transtibial amputation, the controller was active a mean of 68% of the walking time. In general, participants who walked more than 20 min/day demonstrated greater activity, less doff time, and fewer manual socket size adjustments for the adaptive socket compared with a locked non-adjustable socket and a motor-driven socket that participants adjusted with a smartphone application. Nine of 12 participants reported that they would use a motor-driven adjustable socket if it were available as it would limit their socket fit issues. The size and weight of the adaptive socket were considered the most important variables to improve.
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Affiliation(s)
- Joan E Sanders
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA.
| | - Andrew C Vamos
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Joseph C Mertens
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Katheryn J Allyn
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Brian G Larsen
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Daniel Ballesteros
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Horace Wang
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Nicholas S DeGrasse
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA, 98195, USA
| | - Joseph L Garbini
- Department of Mechanical Engineering, University of Washington, 3900 E Stevens Way NE, Box 352600, Seattle, WA, 98195, USA
| | - Brian J Hafner
- Department of Rehabilitation Medicine, University of Washington, 1959 NE Pacific St, Box 356490, Seattle, WA, 98195, USA
| | - Janna L Friedly
- Department of Rehabilitation Medicine, University of Washington, 325 Ninth Ave, Box 359612, Seattle, WA, 98104, USA
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Baldock M, Pickard N, Prince M, Kirkwood S, Chadwell A, Howard D, Dickinson A, Kenney L, Gill N, Curtin S. Adjustable prosthetic sockets: a systematic review of industrial and research design characteristics and their justifications. J Neuroeng Rehabil 2023; 20:147. [PMID: 37926807 PMCID: PMC10626671 DOI: 10.1186/s12984-023-01270-0] [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: 07/13/2023] [Accepted: 10/18/2023] [Indexed: 11/07/2023] Open
Abstract
BACKGROUND The prosthetic socket is a key component that influences prosthesis satisfaction, with a poorly fitting prosthetic socket linked to prosthesis abandonment and reduced community participation. This paper reviews adjustable socket designs, as they have the potential to improve prosthetic fit and comfort through accommodating residual limb volume fluctuations and alleviating undue socket pressure. METHODS Systematic literature and patent searches were conducted across multiple databases to identify articles and patents that discussed adjustable prosthetic sockets. The patents were used to find companies, organisations, and institutions who currently sell adjustable sockets or who are developing devices. RESULTS 50 literature articles and 63 patents were identified for inclusion, representing 35 different designs used in literature and 16 commercially available products. Adjustable sockets are becoming more prevalent with 73% of publications (literature, patents, and news) occurring within the last ten years. Two key design characteristics were identified: principle of adjustability (inflatable bladders, moveable panels, circumferential adjustment, variable length), and surface form (conformable, rigid multi-DOF, and rigid single DOF). Inflatable bladders contributed to 40% of literature used designs with only one identified commercially available design (n = 16) using this approach. Whereas circumferential adjustment designs covered 75% of identified industry designs compared to only 36% of literature devices. Clinical studies were generally small in size and only 17.6% of them assessed a commercially available socket. DISCUSSION There are clear differences in the design focus taken by industry and researchers, with justification for choice of design and range of adjustment often being unclear. Whilst comfort is often reported as improved with an adjustable socket, the rationale behind this is not often discussed, and small study sizes reduce the outcome viability. Many adjustable sockets lack appropriate safety features to limit over or under tightening, which may present a risk of tissue damage or provide inadequate coupling, affecting function and satisfaction. Furthermore, the relationship between design and comfort or function are rarely investigated and remain a significant gap in the literature. Finally, this review highlights the need for improved collaboration between academia and industry, with a strong disconnect observed between commercial devices and published research studies.
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Affiliation(s)
- Michael Baldock
- School of Health and Society at the University of Salford, Salford, UK.
| | - Nicolaas Pickard
- School of Health and Society at the University of Salford, Salford, UK.
| | - Michael Prince
- School of Health and Society at the University of Salford, Salford, UK
| | - Sarah Kirkwood
- School of Health and Society at the University of Salford, Salford, UK
| | - Alix Chadwell
- School of Health and Society at the University of Salford, Salford, UK
- School of Engineering at Newcastle University, Newcastle upon Tyne, UK
| | - David Howard
- School of Health and Society at the University of Salford, Salford, UK
| | - Alex Dickinson
- School of Engineering at the University of Southampton, Southampton, UK
| | - Laurence Kenney
- School of Health and Society at the University of Salford, Salford, UK
| | - Niamh Gill
- School of Health and Society at the University of Salford, Salford, UK
| | - Sam Curtin
- School of Health and Society at the University of Salford, Salford, UK.
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Weathersby EJ, Vamos AC, Larsen BG, McLean JB, Carter RV, Allyn KJ, Ballesteros D, Wang H, deGrasse NS, Friedly JL, Hafner BJ, Garbini JL, Ciol MA, Sanders JE. Performance of an auto-adjusting prosthetic socket during walking with intermittent socket release. J Rehabil Assist Technol Eng 2022; 9:20556683221093271. [PMID: 35558157 PMCID: PMC9087223 DOI: 10.1177/20556683221093271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 03/24/2022] [Indexed: 01/09/2023] Open
Abstract
Introduction A challenge in the engineering of auto-adjusting prosthetic sockets is to maintain stable operation of the control system while users change their bodily position and activity. The purpose of this study was to test the stability of a socket that automatically adjusted socket size to maintain fit. Socket release during sitting was conducted between bouts of walking. Methods Adjustable sockets with sensors that monitored distance between the liner and socket were fabricated. Motor-driven panels and a microprocessor-based control system adjusted socket size during walking to maintain a target sensed distance. Limb fluid volume was recorded continuously. During eight sit/walk cycles, the socket panels were released upon sitting and then returned to position for walking, either the size at the end of the prior bout or a size 1.0% larger in volume. Results In six transtibial prosthesis users, the control system maintained stable operation and did not saturate (move to and remain at the end of the actuator's range) during 98% of the walking bouts. Limb fluid volume changes generally matched the panel position changes executed by the control system. Conclusions Stable operation of the control system suggests that the auto-adjusting socket is ready for testing in users' at-home settings.
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Affiliation(s)
- Ethan J Weathersby
- Department of Bioengineering, University of
Washington, Seattle, WA, USA
| | - Andrew C Vamos
- Department of Bioengineering, University of
Washington, Seattle, WA, USA
| | - Brian G Larsen
- Department of Bioengineering, University of
Washington, Seattle, WA, USA
| | - Jake B McLean
- Department of Bioengineering, University of
Washington, Seattle, WA, USA
| | - Ryan V Carter
- Department of Bioengineering, University of
Washington, Seattle, WA, USA
| | - Katheryn J Allyn
- Department of Bioengineering, University of
Washington, Seattle, WA, USA
| | - Daniel Ballesteros
- Department of Bioengineering, University of
Washington, Seattle, WA, USA
| | - Horace Wang
- Department of Bioengineering, University of
Washington, Seattle, WA, USA
| | | | - Janna L Friedly
- Department of Rehabilitation
Medicine, University of
Washington, Seattle, WA, USA
| | - Brian J Hafner
- Department of Rehabilitation
Medicine, University of
Washington, Seattle, WA, USA
| | - Joseph L Garbini
- Department of Mechanical
Engineering, University of
Washington, Seattle, WA, USA
| | - Marcia A Ciol
- Department of Rehabilitation
Medicine, University of
Washington, Seattle, WA, USA
| | - Joan E Sanders
- Department of Bioengineering, University of
Washington, Seattle, WA, USA
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Mbithi FM, Chipperfield AJ, Steer JW, Dickinson AS. Developing a control framework for self-adjusting prosthetic sockets incorporating tissue injury risk estimation and generalized predictive control. Biomed Eng Lett 2021; 12:59-73. [DOI: 10.1007/s13534-021-00211-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/21/2021] [Accepted: 11/07/2021] [Indexed: 10/19/2022] Open
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Ko ST, Asplund F, Zeybek B. A Scoping Review of Pressure Measurements in Prosthetic Sockets of Transfemoral Amputees during Ambulation: Key Considerations for Sensor Design. SENSORS (BASEL, SWITZERLAND) 2021; 21:5016. [PMID: 34372253 PMCID: PMC8347332 DOI: 10.3390/s21155016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 07/11/2021] [Accepted: 07/14/2021] [Indexed: 02/05/2023]
Abstract
Sensor systems to measure pressure at the stump-socket interface of transfemoral amputees are receiving increasing attention as they allow monitoring to evaluate patient comfort and socket fit. However, transfemoral amputees have many unique characteristics, and it is unclear whether existing research on sensor systems take these sufficiently into account or if it is conducted in ways likely to lead to substantial breakthroughs. This investigation addresses these concerns through a scoping review to profile research regarding sensors in transfemoral sockets with the aim of advancing and improving prosthetic socket design, comfort and fit for transfemoral amputees. Publications found from searching four scientific databases were screened, and 17 papers were found relating to the aim of this review. After quality assessment, 12 articles were finally selected for analysis. Three main contributions are provided: a de facto methodology for experimental studies on the implications of intra-socket pressure sensor use for transfemoral amputees; the suggestion that associated sensor design breakthroughs would be more likely if pressure sensors were developed in close combination with other types of sensors and in closer cooperation with those in possession of an in-depth domain knowledge in prosthetics; and that this research would be facilitated by increased interdisciplinary cooperation and open research data generation.
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Affiliation(s)
- Siu-Teing Ko
- Research and Innovation, Össur, 110 Reykjavík, Iceland
| | - Fredrik Asplund
- Department of Machine Design, KTH Royal Institute of Technology, 10044 Stockholm, Sweden;
| | - Begum Zeybek
- Healthcare Innovation Centre, School of Health and Life Sciences, Teesside University, Middlesbrough TS1 3BX, UK;
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6
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Paternò L, Ibrahimi M, Rosini E, Menfi G, Monaco V, Gruppioni E, Ricotti L, Menciassi A. Residual limb volume fluctuations in transfemoral amputees. Sci Rep 2021; 11:12273. [PMID: 34112873 PMCID: PMC8192500 DOI: 10.1038/s41598-021-91647-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 05/31/2021] [Indexed: 11/08/2022] Open
Abstract
This study constitutes the first attempt to systematically quantify residual limb volume fluctuations in transfemoral amputees. The study was carried out on 24 amputees to investigate variations due to prosthesis doffing, physical activity, and testing time. A proper experimental set-up was designed, including a 3D optical scanner to improve precision and acceptability by amputees. The first test session aimed at measuring residual limb volume at 7 time-points, with 10 min intervals, after prosthesis doffing. This allowed for evaluating the time required for volume stabilization after prosthesis removal, for each amputee. In subsequent sessions, 16 residual limb scans in a day for each amputee were captured to evaluate volume fluctuations due to prosthesis removal and physical activity, in two times per day (morning and afternoon). These measurements were repeated in three different days, a week apart from each other, for a total of 48 scans for each amputee. Volume fluctuations over time after prosthesis doffing showed a two-term decay exponential trend (R2 = 0.97), with the highest variation in the initial 10 min and an average stabilization time of 30 min. A statistically significant increase in residual limb volume following both prosthesis removal and physical activity was verified. No differences were observed between measures collected in the morning and in the afternoon.Clinical Trials.gov ID: NCT04709367.
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Affiliation(s)
- Linda Paternò
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy.
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa, Italy.
| | - Michele Ibrahimi
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Elisa Rosini
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Giuseppe Menfi
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Vito Monaco
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa, Italy
- IRCCS Fondazione Don Carlo Gnocchi, 20148, Milan, Italy
| | | | - Leonardo Ricotti
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Arianna Menciassi
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
- Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa, Italy
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7
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Gao RZ, Ren CL. Synergizing microfluidics with soft robotics: A perspective on miniaturization and future directions. BIOMICROFLUIDICS 2021; 15:011302. [PMID: 33564346 PMCID: PMC7861881 DOI: 10.1063/5.0036991] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 01/19/2021] [Indexed: 05/12/2023]
Abstract
Soft robotics has gone through a decade of tremendous progress in advancing both fundamentals and technologies. It has also seen a wide range of applications such as surgery assistance, handling of delicate foods, and wearable assistive systems driven by its soft nature that is more human friendly than traditional hard robotics. The rapid growth of soft robotics introduces many challenges, which vary with applications. Common challenges include the availability of soft materials for realizing different functions and the precision and speed of control required for actuation. In the context of wearable systems, miniaturization appears to be an additional hurdle to be overcome in order to develop truly impactful systems with a high user acceptance. Microfluidics as a field of research has gone through more than two decades of intense and focused research resulting in many fundamental theories and practical tools that have the potentials to be applied synergistically to soft robotics toward miniaturization. This perspective aims to introduce the potential synergy between microfluidics and soft robotics as a research topic and suggest future directions that could leverage the advantages of the two fields.
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8
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Weathersby EJ, Garbini JL, Larsen BG, McLean JB, Vamos AC, Sanders JE. Automatic Control of Prosthetic Socket Size for People WithTranstibial Amputation: Implementation and Evaluation. IEEE Trans Biomed Eng 2020; 68:36-46. [PMID: 32386137 DOI: 10.1109/tbme.2020.2992739] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE The purpose was to design, implement, and test a control system for a motor-actuated, cable-panel prosthetic socket that automatically maintains socket fit by continuous adjustment of the socket size. METHODS Sockets with motor-driven adjustable panels were fabricated for participants with transtibial amputation. A proportional-integral control system was implemented to adjust socket size based on Socket Fit Metric (SFM) data collected by an inductive sensor embedded within the socket wall. The sensed distance was representative of limb-to-socket distance. Testing was conducted with participants walking on a treadmill to characterize the system's capability to maintain a set point and to respond to a change in the set point. RESULTS Test results from 10 participants with transtibial amputation showed that the Integral of Absolute Error (IAE) to maintain a set point ranged from 0.001 to 0.046 mm with a median of 0.003 mm. When the set point was changed, IAE errors ranged from 0.001 to 0.005 mm, with a median of 0.003 mm. An IAE of 0.003 mm corresponded to approximately a 0.08% socket volume error, which was considered clinically acceptable. CONCLUSION The capability of the control system to maintain and respond to a change in set point indicates that it is ready for evaluation outside of the laboratory. SIGNIFICANCE Integration of the developed control system into everyday prostheses may improve quality of life of prosthesis users by relieving them of the burden of continually adjusting socket size to maintain fit.
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9
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Safari R. Lower limb prosthetic interfaces: Clinical and technological advancement and potential future direction. Prosthet Orthot Int 2020; 44:384-401. [PMID: 33164655 DOI: 10.1177/0309364620969226] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The human-prosthesis interface is one of the most complicated challenges facing the field of prosthetics, despite substantive investments in research and development by researchers and clinicians around the world. The journal of the International Society for Prosthetics and Orthotics, Prosthetics and Orthotics International, has contributed substantively to the growing body of knowledge on this topic. In celebrating the 50th anniversary of the International Society for Prosthetics and Orthotics, this narrative review aims to explore how human-prosthesis interfaces have changed over the last five decades; how research has contributed to an understanding of interface mechanics; how clinical practice has been informed as a result; and what might be potential future directions. Studies reporting on comparison, design, manufacturing and evaluation of lower limb prosthetic sockets, and osseointegration were considered. This review demonstrates that, over the last 50 years, clinical research has improved our understanding of socket designs and their effects; however, high-quality research is still needed. In particular, there have been advances in the development of volume and thermal control mechanisms with a few designs having the potential for clinical application. Similarly, advances in sensing technology, soft tissue quantification techniques, computing technology, and additive manufacturing are moving towards enabling automated, data-driven manufacturing of sockets. In people who are unable to use a prosthetic socket, osseointegration provides a functional solution not available 50 years ago. Furthermore, osseointegration has the potential to facilitate neuromuscular integration. Despite these advances, further improvement in mechanical features of implants, and infection control and prevention are needed.
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Affiliation(s)
- Reza Safari
- Health and Social Care Research Centre, University of Derby, Derby, UK
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10
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Carter RV, Larsen BG, McLean JB, Garbini JL, Sanders JE. Incorporating a Ferrous Polymer Target into Elastomeric Liners for Socket Fit Sensing in Prosthesis Users. SENSORS 2020; 20:s20195620. [PMID: 33019604 PMCID: PMC7582797 DOI: 10.3390/s20195620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/15/2020] [Accepted: 09/24/2020] [Indexed: 11/16/2022]
Abstract
Liner-to-socket distance measurement using inductive sensing may be an effective means to continuously monitor socket fit in people using trans-tibial prostheses. A practical limitation, however, is a means to incorporate a thin uniform-thickness layer of conductive or magnetically permeable target material into the wide range of prosthetic liner products that people with limb amputation commonly use. In this paper, a method is presented whereby a 0.50-mm thickness ferrous polymer made from a SEEPS polymer and iron powder that is formed adjacent to a 0.25-mm thick non-ferrous layer of SEEPS polymer is assembled between two sheets of elastic fabric material. Bench testing showed that the fabrication procedure achieved a root-mean-square error in the thickness of this construct of 58 μm, helping to create a consistent calibration result over the entire surface. The original fabric backing of an off-the-shelf prosthetic liner was removed and replaced with the developed construct. When worn in the shoe of an able-bodied participant for 7.5 h per day for 28 days, the sensor well maintained the shape of its calibration curve at the start of wear, but a distance offset (shifting of the y-intercept) was introduced that increased during the initial approximately 12 days of wear. When the distance offset was corrected, for the primary distance range of clinical interest for this application (0.00–5.00 mm), the sensor maintained its calibration within 4.4%. Before being used in clinical application for liner-to-socket distance monitoring, new ferrous liners may need to be pre-worn so as to achieve a consistent distance reference.
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11
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Towards Management of Residual Limb Volume: Monitoring the Prosthetic Interface Pressure to Detect Volume Fluctuations—A Feasibility Study. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10196841] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
(1) Motivation: Variations in the volume of the residual limb negatively impact various aspects of prosthesis use including the prosthetic socket fit. Although volume adjustment systems mitigate corresponding fit problems to some extent, some users still find the management of these systems challenging. With the ultimate goal of creating a feedback system that assists users with the management of their volume adjustment systems, this study demonstrates the feasibility of detecting variations in the volume of the residual limb. (2) Methods: Measurements of the interface force at the bottom of the prosthetic socket were used as indicators of variations in the volume of the residual limb. Force sensitive resistors (FSRs) were placed at the bottom of participants’ prosthetic sockets to monitor the interface limb–socket force as participants walked on a flat surface. Two phases of experiments were carried out: The first phase considered variations simulated by three prosthetic sock plies, established the feasibility of detecting variations in the volume of the limb based on the interface force, and further determined the locations at which the interface force could be used to detect variations in the limb’s volume. Having validated the effectiveness of the proposed method in the first phase, the second phase was carried out to determine the smallest detectable variation of the limb’s volume using the proposed method. In this phase, variations simulated by one and two prosthetic sock plies were considered. Four and three volunteers with transtibial amputations participated in the first and the second phases, respectively. (3) Results: Results of the first phase showed that an increase in the volume of the limb resulted in a decrease in the force measured at the distal location of the prosthetic sockets of all participants; however, the smallest detected variation could not be statistically confirmed.
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12
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Ibrahimi M, Paternò L, Ricotti L, Menciassi A. A Layer Jamming Actuator for Tunable Stiffness and Shape-Changing Devices. Soft Robot 2020; 8:85-96. [PMID: 32456553 DOI: 10.1089/soro.2019.0182] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Changing the shape and the stiffness of a device in a dynamic and controlled way enables important advancements in the field of robotics and wearable robotics. Variable stiffness materials and technologies can be used to address this challenge. In particular, layer jamming actuation is a very promising technology, featured by high efficiency and low cost. In this article, a stiffness- and shape-changing device based on a novel mechanism including a multiple-chamber structure is proposed. It allows to effectively modulate the shape and stiffness of a device, by activating two jamming chambers while pressurizing/depressurizing one or more interposed inflatable chambers. Prototypes with a size of 45 × 270 mm2 and an average thickness ranging from 4.4 to 13 mm were developed and their ability to undergo a stiffness change over two orders of magnitude was demonstrated. The prototypes were also able to change their shape according to the position and inflation level of the interposed inflatable chambers, thus resulting in an overall deflection >10 mm. The possibility to wear the system as an orthotic brace was also demonstrated: this technology increased the patient comfort in static positions, yet keeping a supportive function when needed (e.g., in dynamic conditions). The device working principle highlighted in this article could also be exploited in other domains, for example, to build walking soft robots, prostheses, or grippers, as demonstrated through additional tests.
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Affiliation(s)
- Michele Ibrahimi
- The Biorobotics Institute, Scuola Superiore di Studi Universitari e di Perfezionamento Sant'Anna, Pontedera, Italy.,Department of Excellence in Robotics & AI, Scuola Superiore di Studi Universitari e di Perfezionamento Sant'Anna, Pontedera, Italy
| | - Linda Paternò
- The Biorobotics Institute, Scuola Superiore di Studi Universitari e di Perfezionamento Sant'Anna, Pontedera, Italy.,Department of Excellence in Robotics & AI, Scuola Superiore di Studi Universitari e di Perfezionamento Sant'Anna, Pontedera, Italy
| | - Leonardo Ricotti
- The Biorobotics Institute, Scuola Superiore di Studi Universitari e di Perfezionamento Sant'Anna, Pontedera, Italy.,Department of Excellence in Robotics & AI, Scuola Superiore di Studi Universitari e di Perfezionamento Sant'Anna, Pontedera, Italy
| | - Arianna Menciassi
- The Biorobotics Institute, Scuola Superiore di Studi Universitari e di Perfezionamento Sant'Anna, Pontedera, Italy.,Department of Excellence in Robotics & AI, Scuola Superiore di Studi Universitari e di Perfezionamento Sant'Anna, Pontedera, Italy
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13
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Gupta S, Loh KJ, Pedtke A. Sensing and actuation technologies for smart socket prostheses. Biomed Eng Lett 2019; 10:103-118. [PMID: 32175132 DOI: 10.1007/s13534-019-00137-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/17/2019] [Accepted: 10/26/2019] [Indexed: 01/20/2023] Open
Abstract
The socket is the most critical part of every lower-limb prosthetic system, since it serves as the interfacial component that connects the residual limb with the artificial system. However, many amputees abandon their socket prostheses due to the high-level of discomfort caused by the poor interaction between the socket and residual limb. In general, socket prosthesis performance is determined by three main factors, namely, residual limb-socket interfacial stress, volume fluctuation of the residual limb, and temperature. This review paper summarizes the various sensing and actuation solutions that have been proposed for improving socket performance and for realizing next-generation socket prostheses. The working principles of different sensors and how they have been tested or used for monitoring the socket interface are discussed. Furthermore, various actuation methods that have been proposed for actively modifying and improving the socket interface are also reviewed. Through the continued development and integration of these sensing and actuation technologies, the long-term vision is to realize smart socket prostheses. Such smart socket systems will not only function as a socket prosthesis but will also be able to sense parameters that cause amputee discomfort and self-adjust to optimize its fit, function, and performance.
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Affiliation(s)
- Sumit Gupta
- 1Department of Structural Engineering, University of California-San Diego, La Jolla, CA 92093-0085 USA
| | - Kenneth J Loh
- 1Department of Structural Engineering, University of California-San Diego, La Jolla, CA 92093-0085 USA
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Weathersby EJ, Gurrey CJ, McLean JB, Sanders BN, Larsen BG, Carter R, Garbini JL, Sanders JE. Thin Magnetically Permeable Targets for Inductive Sensing: Application to Limb Prosthetics. SENSORS (BASEL, SWITZERLAND) 2019; 19:E4041. [PMID: 31546816 PMCID: PMC6767675 DOI: 10.3390/s19184041] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/04/2019] [Accepted: 09/12/2019] [Indexed: 11/16/2022]
Abstract
The purpose of this research was to create a thin ferrous polymer composite to be used as a target for inductive sensing in limb prosthetics. Inductive sensors are used to monitor limb-to-socket distance in prosthetic sockets, which reflects socket fit. A styrene-ethylene-ethylene/propylene-styrene (SEEPS) polymer was mixed with iron powder at three concentrations (75, 77, 85 wt%), and thin disk-shaped samples were fabricated (0.50, 0,75, 1.00 mm thickness). For 85 wt% samples of 0.50 mm thickness, which proved the best combination of high signal strength and low target volume, inductive sensor sensitivity ranged from 3.2E5 counts/mm at 0.00-1.00 mm distances to 7.2E4 counts/mm at 4.00-5.00 mm distances. The application of compressive stress (up to 425 kPa) introduced an absolute measurement error of less than 3.3 μm. Tensile elasticity was 282 kPa, which is comparable to that of commercial elastomeric liners. Durability testing in the shoe of an able-bodied participant demonstrated a change in calibration coefficient of less than 3.8% over two weeks of wear. The ferrous polymer composite may facilitate the development of automatically adjusting sockets that use limb-to-socket distance measurement for feedback control.
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Affiliation(s)
- Ethan J Weathersby
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA 98195-5061, USA.
| | - Clement J Gurrey
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA 98195-5061, USA.
| | - Jake B McLean
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA 98195-5061, USA.
| | - Benjamin N Sanders
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA 98195-5061, USA.
| | - Brian G Larsen
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA 98195-5061, USA.
| | - Ryan Carter
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA 98195-5061, USA.
| | - Joseph L Garbini
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA 98195-5061, USA.
| | - Joan E Sanders
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Box 355061, Seattle, WA 98195-5061, USA.
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Paterno L, Ibrahimi M, Gruppioni E, Menciassi A, Ricotti L. Sockets for Limb Prostheses: A Review of Existing Technologies and Open Challenges. IEEE Trans Biomed Eng 2018; 65:1996-2010. [PMID: 29993506 DOI: 10.1109/tbme.2017.2775100] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In the prosthetics field, one of the most important bottlenecks is still the human-machine interface, namely the socket. Indeed, a large number of amputees still rejects prostheses or points out a low satisfaction level, due to a sub-optimal interaction between the socket and the residual limb tissues. The aim of this paper is to describe the main parameters (displacements, stress, volume fluctuations and temperature) affecting the stump-socket interface and reducing the comfort/stability of limb prostheses. In this review, a classification of the different socket types proposed in the literature is reported, together with an analysis of advantages and disadvantages of the different solutions, from multiple viewpoints. The paper then describes the technological solutions available to face an altered distribution of stresses on the residual limb tissues, volume fluctuations affecting the stump overtime and temperature variations affecting the residual tissues within the socket. The open challenges in this research field are highlighted and the possible future routes are discussed, towards the ambitious objective of achieving an advanced socket able to self-adapt in real-time to the complex interplay of factors affecting the stump, during both static and dynamic tasks.
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Sang Y, Li X, Luo Y. Characteristics of a volume-adjustable compression chamber for transradial prosthetic interface. Proc Inst Mech Eng H 2016; 230:650-60. [DOI: 10.1177/0954411916645132] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 03/21/2016] [Indexed: 11/16/2022]
Abstract
In the transradial limb–socket contact interface, the physiological properties and prosthetic operating habits of the residual limb might affect the comfort and functionality of the prosthesis. To enhance the comfort and functionality of the interface, a frame-type socket with four volume-adjustable compression chambers was proposed for the transradial amputation level. The contact pressure of the limb–socket interface was adjusted by the volume changes in the chambers and controlled by a vacuum pump and the corresponding control system. The parameters of the chamber were designed in accordance with the biomechanics of the forearm soft tissue. The chamber with a negative stiffness characteristic was theoretically compared with the chamber with a positive stiffness characteristic. The results showed that the former had a superior performance to the latter in safety and pump performance requirements. A physical model of the transradial frame-type prosthetic interface was also manufactured with four negative stiffness chambers. The experimental results showed that this new prosthetic interface achieved more fitting time and better performance in comfort and functionality than the fixed frame-type socket. This new prosthetic interface with volume-adjustable compression chambers might be an alternative choice for transradial amputees.
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Affiliation(s)
- Yuanjun Sang
- State Key Laboratory of Mechanical System and Vibration, Institute of Biomedical Manufacturing and Life Quality Engineering, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Xiang Li
- State Key Laboratory of Mechanical System and Vibration, Institute of Biomedical Manufacturing and Life Quality Engineering, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yun Luo
- State Key Laboratory of Mechanical System and Vibration, Institute of Biomedical Manufacturing and Life Quality Engineering, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
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Sanders JE, Cagle JC, Harrison DS, Myers TR, Allyn KJ. How does adding and removing liquid from socket bladders affect residual-limb fluid volume? JOURNAL OF REHABILITATION RESEARCH AND DEVELOPMENT 2013; 50:845-60. [PMID: 24203546 DOI: 10.1682/jrrd.2012.06.0121] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Adding and removing liquid from socket bladders is a means for people with limb loss to accommodate residual-limb volume change. We fit 19 people with transtibial amputation using their regular prosthetic socket with fluid bladders on the inside socket surface to undergo cycles of bladder liquid addition and removal. In each cycle, subjects sat, stood, and walked for 90 s with bladder liquid added, and then sat, stood, and walked for 90 s again with the bladder liquid removed. The amount of bladder liquid added was increased in each cycle. We used bioimpedance analysis to measure residual-limb fluid volume. Results showed that the preferred bladder liquid volume was 16.8 +/- 8.4 mL (mean +/- standard deviation), corresponding with 1.7% +/- 0.8% of the average socket volume between the bioimpedance voltage-sensing electrodes. Residual-limb fluid volume driven out of the residual limb when bladder liquid was added was typically not recovered upon subsequent bladder liquid removal. Of the 19 subjects, 15 experienced a gradual residual-limb fluid volume loss over the test session. Care should be taken when implementing adjustable socket technologies in people with limb loss. Reducing socket volume may accentuate residual-limb fluid volume loss.
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Affiliation(s)
- Joan E Sanders
- University of Washington, 3720 15th Ave NE, Seattle, WA 98195.
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Sanders JE, Harrison DS, Cagle JC, Myers TR, Ciol MA, Allyn KJ. Post-doffing residual limb fluid volume change in people with trans-tibial amputation. Prosthet Orthot Int 2012; 36:443-9. [PMID: 22588848 PMCID: PMC4423811 DOI: 10.1177/0309364612444752] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Residual limb volume may change after doffing, affecting the limb shape measured and used as a starting point for socket design. OBJECTIVES The purpose of this study was to compare residual limb fluid volume changes after doffing for different test configurations. STUDY DESIGN The study was a repeated measures experimental design with three conditions (Sit, Liner, and Walk). METHODS Residual limb fluid volume on 30 people with trans-tibial amputation was measured using bioimpedance analysis. Three tests were conducted--Sit: sit for 10 minutes, remove the prosthesis, socks and liner, sit for 10 minutes; Liner: sit for 10 minutes, remove the prosthesis and socks but not the liner, sit for 10 minutes; Walk: conduct sit, stand and walk activities for 30 minutes, remove the prosthesis, socks and liner, sit for 10 minutes. RESULTS The percentage fluid volume increase after doffing was significantly higher for Walk (2.8%) than for Sit (1.8%) (p = 0.03). The time to achieve a maximum or stable fluid volume was shorter for Liner (4.3 min) than for Sit (6.6 min) (p = 0.03). CONCLUSIONS Activity before doffing intensified the post-doffing limb fluid volume increase. Maintaining a liner after doffing caused limb fluid volume to stabilize faster than removing the liner. Clinical relevance To minimize residual limb volume increase before casting or imaging, practitioners should have patients sit with their prosthesis donned for 10 minutes. Leaving a liner on the residuum will not reduce the post-doffing volume increase, but it will help to more quickly achieve a consistent limb fluid volume.
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Affiliation(s)
- Joan E Sanders
- University of Washington, Box 355061, 3720 15th Ave NE, Seattle, WA 98195, USA.
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