scholarly journals An Inductive Sensing System to Measure In-Socket Residual Limb Displacements for People Using Lower-Limb Prostheses

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3840 ◽  
Author(s):  
Katrina Henrikson ◽  
Ethan Weathersby ◽  
Brian Larsen ◽  
John Cagle ◽  
Jake McLean ◽  
...  

The objective of this research was to assess the performance of an embedded sensing system designed to measure the distance between a prosthetic socket wall and residual limb. Low-profile inductive sensors were laminated into prosthetic sockets and flexible ferromagnetic targets were created from elastomeric liners with embedded iron particles for four participants with transtibial amputation. Using insights from sensor performance testing, a novel calibration procedure was developed to quickly and accurately calibrate the multiple embedded sensors. The sensing system was evaluated through laboratory tests in which participants wore sock combinations with three distinct thicknesses and conducted a series of activities including standing, walking, and sitting. When a thicker sock was worn, the limb typically moved further away from the socket and peak-to-peak displacements decreased. However, sensors did not measure equivalent distances or displacements for a given sock combination, which provided information regarding the fit of the socket and how a sock change intervention influenced socket fit. Monitoring of limb–socket displacements may serve as a valuable tool for researchers and clinicians to quantitatively assess socket fit.

Author(s):  
Breanna Holmes ◽  
Wenlong Zhang

Prosthetic sockets are static interfaces for dynamic residual limbs. As the user’s activity level increases, the volume of the residual limb can decrease by up to 11% and increase by as much as 7% after activity. Currently, volume fluctuation is addressed by adding/removing prosthetic socks to change the profile of the residual limb. However, this is impractical and time consuming. These painful/functional issues demand a prosthetic socket with an adjustable interface that can adapt to the user’s needs. This paper presents a prototype design for a dynamic soft robotic interface which addresses this need. The actuators are adjustable depending on the user’s activity level, and their structure provides targeted compression to the soft tissue which helps to limit movement of the bone relative to the socket. Testing of the prototype demonstrated promising potential for the design with further refinement. Work on embedded sensing and intelligent feedback control should be continued in future research in order to create a viable consumer product which can improve a lower limb amputee’s quality of life.


2001 ◽  
Author(s):  
Arie N. de Jong ◽  
Hans Winkel ◽  
Rick I. Ghauharali

2021 ◽  
Author(s):  
William Anderst ◽  
Goeran Fiedler ◽  
Kentaro Onishi ◽  
Gina McKernan ◽  
Tom Gale ◽  
...  

Abstract • Background: Among the challenges of living with lower limb loss is the increased risk of long-term health problems that can be either attributed directly to the amputation surgery and/or prosthetic rehabilitation or indirectly to a disability-induced sedentary lifestyle. These problems are exacerbated by poorly fit prosthetic sockets. There is a knowledge gap regarding how the socket design affects in-socket mechanics, and how in-socket mechanics affect patient-reported comfort and function. The objectives of this study are: 1) to gain a better understanding of how in-socket mechanics of the residual limb in transfemoral amputees are related to patient-reported comfort and function, 2) to identify clinical tests that can streamline the socket design process, and 3) to evaluate the efficacy and cost of a novel, quantitatively informed socket optimization process.• Methods: Users of transfemoral prostheses will be asked to walk on a treadmill wearing their current socket plus 8 different check sockets with designed changes in different structural measurements that are likely to induce changes in residual limb motion, skin strain, and pressure distribution within the socket. Dynamic biplane radiography and pressure sensors will be used to measure in-socket residual limb mechanics. Patient-reported outcomes will also be collected after wearing each socket. The effects of in-socket mechanics on both physical function and patient-reported outcomes (aim 1) will be assessed using a generalized linear model. Partial correlation analysis will be used to examine the association between research grade measurements and readily available clinical measurements (aim 2). In order to compare the new quantitative design method to the Standard of Care, patient reported outcomes and cost will be compared between the two methods, utilizing the Wilcoxon Mann-Whitney non-parametric test (aim 3).• Discussion: Knowledge on how prosthetic socket modifications affect residual bone and skin biomechanics itself can be applied to devise future socket designs, and the methodology can be used to investigate and improve such designs, past and present. Apart from saving time and costs, this may result in better prosthetic socket fit for a large patient population, thus increasing their mobility, participation, and overall health-related quality of life. • Trial registration: clinicaltrials.gov: NCT05041998


Proceedings ◽  
2019 ◽  
Vol 32 (1) ◽  
pp. 14
Author(s):  
Liang ◽  
Stewart ◽  
Bryan-Kinns

This paper presents research about design a textile-based stretch sensor for making a reliable sensing system for dance movement sensing. We examined sixteen textile-based conductive stretch sensors that were made with commercially produced conductive materials. Through the analysis of their sensitivity, linearity, hysteresis, responsiveness, and fatigue, a silver-plated conductive fabric, Technik-tex P130B, shows the best performance for dance movement sensing. Then, we tested the bonding technique, and washability of Technik-tex P130B-made sensors. The finding shows that bonding makes a noticeable impact on sensor performance. Both bonding and washing increase the sensor’s resistance. Technik-tex P130B on one side bonding has the best performance for dance movement sensing. This reliable and washable textile-based stretch sensor is utilised for dance bodysuit making for further development.


2020 ◽  
Vol 44 (5) ◽  
pp. 355-358 ◽  
Author(s):  
Eric Nickel ◽  
Kyle Barrons ◽  
Barry Hand ◽  
Alana Cataldo ◽  
Andrew Hansen

Background and Aim: During post-amputation recovery or rapid body mass change, residual limb volume can change quickly, requiring frequent adjustments or replacement of the socket to maintain fit. The aim of this pilot test was to evaluate the feasibility of using a three-dimensional-printed insert to extend the service life of a prosthetic socket after substantial residual limb volume loss. Technique: One research subject with a well-fitting transtibial prosthetic socket had an oversized socket fabricated to simulate substantial limb volume loss. The digital shapes of the oversized and well-fitting sockets were used to create a three-dimensional-printed insert to restore fit. Discussion: Two-minute walk test distance decreased when using the oversized socket without the insert, but not when using the socket with the insert. Socket comfort score was 8+ under all conditions. These results suggest that three-dimensional-printed inserts may be an effective method of extending the service life of prosthetic sockets when rapid limb volume loss occurs. Clinical relevance Three-dimensional (3D) printing gives prosthetists a new tool to manage large volume changes without refabricating entire sockets. Sockets can be fabricated in anticipation of volume gain/loss, using replaceable 3D-printed inserts to maintain fit and comfort.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Mohammad Reza Safari ◽  
Philip Rowe ◽  
Arjan Buis

Lower limb prosthetic socket shape and volume consistency can be quantified using MRI technology. Additionally, MRI images of the residual limb could be used as an input data for CAD-CAM technology and finite element studies. However, the accuracy of MRI when socket casting materials are used has to be defined. A number of six, 46 mm thick, cross-sections of an animal leg were used. Three specimens were wrapped with Plaster of Paris (POP) and the other three with commercially available silicone interface liner. Data was obtained by utilising MRI technology and then the segmented images compared to corresponding calliper measurement, photographic imaging, and water suspension techniques. The MRI measurement results were strongly correlated with actual diameter, surface area, and volume measurements. The results show that the selected scanning parameters and the semiautomatic segmentation method are adequate enough, considering the limit of clinical meaningful shape and volume fluctuation, for residual limb volume and the cross-sectional surface area measurements.


2012 ◽  
Vol 24 (1) ◽  
pp. 19-24 ◽  
Author(s):  
W. Lee Childers ◽  
Karen L. Perell-Gerson ◽  
Robert J. Gregor

2016 ◽  
Vol 41 (5) ◽  
pp. 527-531 ◽  
Author(s):  
Kay Mitton ◽  
Jai Kulkarni ◽  
Kenneth William Dunn ◽  
Anthony Hoang Ung

Background: This novel case report describes the problems of prescribing a prosthetic socket in a left transfemoral amputee secondary to chronic patellofemoral instability compounded by complex regional pain syndrome. Case Description and Methods: Following the amputation, complex regional pain syndrome symptoms recurred in the residual limb, presenting mainly with oedema. Due to extreme daily volume fluctuations of the residual limb, a conventional, laminated thermoplastic socket fitting was not feasible. Findings and Outcomes: An adjustable, modular socket design was trialled. The residual limb volume fluctuations were accommodated within the socket. Amputee rehabilitation could be continued, and the rehabilitation goals were achieved. The patient was able to wear the prosthesis for 8 h daily and to walk unaided indoors and outdoors. Conclusion: An adjustable, modular socket design accommodated the daily residual limb volume fluctuations and provided a successful outcome in this case. It demonstrates the complexities of socket fitting and design with volume fluctuations. Clinical relevance Ongoing complex regional pain syndrome symptoms within the residual limb can lead to fitting difficulties in a conventional, laminated thermoplastic socket due to volume fluctuations. An adjustable, modular socket design can accommodate this and provide a successful outcome.


Sign in / Sign up

Export Citation Format

Share Document