Socket size adjustments in people with transtibial amputation: Effects on residual limb fluid volume and limb-socket distance

McLean, Jake B.; Redd, Christian B.; Larsen, Brian G.; Garbini, Joseph L.; Brzostowski, Jacob T; Hafner, Brian J.; Sanders, Joan E.

doi:10.1016/j.clinbiomech.2019.02.022

Cited by 30 publications

(45 citation statements)

References 15 publications

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“…The clean polymer serves as an elastic covering, and the ferrous polymer serves as a target for an inductive sensing element that is placed within the wall of the socket during fabrication ( Figure 1 b). The inductive sensing element is a custom antenna made using flexible circuit board printing techniques and is embedded approximately 0.6 mm from the inside surface [ 15 ].…”

Section: Methodsmentioning

confidence: 99%

“…Inductive sensing eliminates the need for a line of sight. Inductive sensing elements have been incorporated into the socket, and a target attached to the user’s prosthetic liner [ 13 , 14 , 15 ]. An auto-adjusting socket that used an inductive sensor for feedback control maintained socket distance and appropriately responded to a change in set point during testing on amputee participants [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

“…A magnetically permeable target (e.g., iron powder) is structurally different than a conductive element. While the magnetically permeable design produced excellent results [ 15 ], numerous liners are used by the amputee population thus the model selected served only a limited number of users. A necessary next step is to extend from this success to create a more general fabrication technique so that many commercial liners can be made into “ferrous liner” products, increasing the number of prosthesis users who can use a socket with fit sensing.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Incorporating a Ferrous Polymer Target into Elastomeric Liners for Socket Fit Sensing in Prosthesis Users

Carter

Larsen

McLean

et al. 2020

Sensors

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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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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Incorporating a Ferrous Polymer Target into Elastomeric Liners for Socket Fit Sensing in Prosthesis Users

Carter

Larsen

McLean

et al. 2020

Sensors

Self Cite

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“…For example, the Infinite Socket™ adjustable, custommoulded, four-strut design combined with a textile brim and tensioner (LIM Innovations, San Francisco, CA, USA) and the RevoFit™ manual adjustable socket (RevoFit™, Steamboat Springs, CO, USA) both for transfemoral residual limbs, and the immediate fit socket system (iFIT Prosthetics, Pewaukee, WI, USA) for transtibial residual limbs. 92 A series of studies by Sanders et al [93][94][95][96] reveal interesting findings that may be used to develop a practical active panel socket for volume management without adversely affecting socket fit and comfort. The findings show that standing and low-intensity activity result in volume loss.…”

Section: Management Of Residual Limb Volume Fluctuationmentioning

confidence: 99%

Lower limb prosthetic interfaces

Safari

2020

Prosthetics &Amp; Orthotics International

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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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“…Two groups, at the Ohio Willow Wood Company and the University of Washington, have pursued inductive sensing in prosthetics. Researchers place an antenna within or on the prosthetic socket, and a target material on the user’s liner, [12,13,14,15] (Figure 1). An inductive sensing chip powers the antenna so that the system operates as an LC tank oscillator.…”

Section: Introductionmentioning

confidence: 99%

Thin Magnetically Permeable Targets for Inductive Sensing: Application to Limb Prosthetics

Weathersby

Gurrey

McLean

et al. 2019

Sensors

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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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Socket size adjustments in people with transtibial amputation: Effects on residual limb fluid volume and limb-socket distance

Cited by 30 publications

References 15 publications

Incorporating a Ferrous Polymer Target into Elastomeric Liners for Socket Fit Sensing in Prosthesis Users

Incorporating a Ferrous Polymer Target into Elastomeric Liners for Socket Fit Sensing in Prosthesis Users

Lower limb prosthetic interfaces

Thin Magnetically Permeable Targets for Inductive Sensing: Application to Limb Prosthetics

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