The patellar tendon bar! Is it a necessary feature?

Eshraghi

et al. 2013

Sensors

This study presents the first investigation into the capability of fiber Bragg grating (FBG) sensors to measure interface pressure between the stump and the prosthetic sockets of a trans-tibial amputee. FBG element(s) were recoated with and embedded in a thin layer of epoxy material to form a sensing pad, which was in turn embedded in a silicone polymer material to form a pressure sensor. The sensor was tested in real time by inserting a heavy-duty balloon into the socket and inflating it by using an air compressor. This test was conducted to examine the sensitivity and repeatability of the sensor when subjected to pressure from the stump of the trans-tibial amputee and to mimic the actual environment of the amputee's Patellar Tendon (PT) bar. The sensor exhibited a sensitivity of 127 pm/N and a maximum FSO hysteresis of around ∼0.09 in real-time operation. Very good reliability was achieved when the sensor was utilized for in situ measurements. This study may lead to smart FBG-based amputee stump/socket structures for pressure monitoring in amputee socket systems, which will result in better-designed prosthetic sockets that ensure improved patient satisfaction.

“…PTB sockets are custom fabricated on a case-to-case basis [2]. Therefore, the fabrication process still relies largely on the techniques, skills, and experience of the prosthetist [7].…”

Section: Methodsmentioning

confidence: 99%

“…The product is then laminated. The final step is socket finishing [2]. Further details about the manufacturing procedures are provided by Radcliffe [20].…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Capability of Fiber Bragg Grating Sensors to Measure Amputees’ Trans-Tibial Stump/Socket Interface Pressures

Al-Fakih

Eshraghi

et al. 2013

Sensors

“…The clinicians need to be conscious about the effects of various suspension methods and prosthetic socket designs on residual limb and user satisfaction. The interface pressure of various prosthetic sockets has been evaluated [15,24,33-36]. The level of user satisfaction with a prosthesis is very much reliant on the appropriate pressure at the pressure-tolerant and pressure-relief areas of the residuum.…”

Section: Discussionmentioning

confidence: 99%

Clinical implication of interface pressure for a new prosthetic suspension system

Gholizadeh

BioMedical Engineering OnLine

Eshraghi

et al. 2014

BackgroundProsthesis suspension systems can alter the distribution of pressure within the prosthetic socket. This study evaluates a new suspension system for lower limb prostheses, and aims to compare the interface pressure and amputees’ satisfaction with the new system compared with a common prosthetic suspension system (pin/lock).MethodsTen transtibial amputees walked at a self-selected speed on a level ground with two different suspension systems, namely the pin/lock and HOLO system. The interface pressure was measured using the F-socket transducers at the proximal, middle and distal sites of residual limb. Furthermore, subjective feedback was logged to compare two systems.ResultsThe pressure was significantly higher at the proximal and distal areas with the pin/lock suspension system during the swing phase of gait (P < 0.05). Subjective feedback also showed traction at the stump with the pin/lock system. There were no significant differences in the pressure applied to the mid-anterior and mid posterior stump for both suspension systems. However, the lateral and medial sides exhibited higher pressure with the new system during stance phase.ConclusionsThe intention of this study was to deepen understanding on the effect of suspension system on the load distribution over the residual limb. The new coupling system was proved compatible with the pin/lock system in terms of suspending the leg and amputee’s satisfaction. On the other hand, the HOLO system could distribute the pressure more uniformly over the residual limb.

“…Since the mid-1960s, researchers have proposed a variety of measurement systems such as ESG based transducers [118–120], F-socket transducer arrays [121], and FEA [122–124] in order to understand the pressure distribution in this interface, leading to fabrication of amputee sockets that prevent discomfort and provide satisfactory results. Despite these technological advances in the existing socket design and the measurement systems, many amputees still complain that their prosthesis causes complications such as edema, pressure ulcers, skin irritation and dermatitis [125].…”

Section: Applicationsmentioning

confidence: 99%

The Use of Fiber Bragg Grating Sensors in Biomechanics and Rehabilitation Applications: The State-of-the-Art and Ongoing Research Topics

Al-Fakih

Adikan

2012

Sensors

141

In recent years, fiber Bragg gratings (FBGs) are becoming increasingly attractive for sensing applications in biomechanics and rehabilitation engineering due to their advantageous properties like small size, light weight, biocompatibility, chemical inertness, multiplexing capability and immunity to electromagnetic interference (EMI). They also offer a high-performance alternative to conventional technologies, either for measuring a variety of physical parameters or for performing high-sensitivity biochemical analysis. FBG-based sensors demonstrated their feasibility for specific sensing applications in aeronautic, automotive, civil engineering structure monitoring and undersea oil exploration; however, their use in the field of biomechanics and rehabilitation applications is very recent and its practicality for full-scale implementation has not yet been fully established. They could be used for detecting strain in bones, pressure mapping in orthopaedic joints, stresses in intervertebral discs, chest wall deformation, pressure distribution in Human Machine Interfaces (HMIs), forces induced by tendons and ligaments, angles between body segments during gait, and many others in dental biomechanics. This article aims to provide a comprehensive overview of all the possible applications of FBG sensing technology in biomechanics and rehabilitation and the status of ongoing researches up-to-date all over the world, demonstrating the FBG advances over other existing technologies.