scholarly journals A Cost-Effective Inertial Measurement System for Tracking Movement and Triggering Kinesthetic Feedback in Lower-Limb Prosthesis Users

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1844
Author(s):  
McNiel-Inyani Keri ◽  
Ahmed W. Shehata ◽  
Paul D. Marasco ◽  
Jacqueline S. Hebert ◽  
Albert H. Vette
Keyword(s):  
Lower Limb ◽  
Balance Control ◽  
Low Cost ◽  
Feedback System ◽  
Inertial Measurement ◽  
Upper Limb Prosthesis ◽  
Kinesthetic Feedback ◽  
Kinesthetic Illusion ◽  
Limb Prosthesis ◽  
Lower Limb Prostheses

Advances in lower-limb prosthetic technologies have facilitated the restoration of ambulation; however, users of such technologies still experience reduced balance control, also due to the absence of proprioceptive feedback. Recent efforts have demonstrated the ability to restore kinesthetic feedback in upper-limb prosthesis applications; however, technical solutions to trigger the required muscle vibration and provide automated feedback have not been explored for lower-limb prostheses. The study’s first objective was therefore to develop a feedback system capable of tracking lower-limb movement and automatically triggering a muscle vibrator to induce the kinesthetic illusion. The second objective was to investigate the developed system’s ability to provide kinesthetic feedback in a case participant. A low-cost, wireless feedback system, incorporating two inertial measurement units to trigger a muscle vibrator, was developed and tested in an individual with limb loss above the knee. Our system had a maximum communication delay of 50 ms and showed good tracking of Gaussian and sinusoidal movement profiles for velocities below 180 degrees per second (error < 8 degrees), mimicking stepping and walking, respectively. We demonstrated in the case participant that the developed feedback system can successfully elicit the kinesthetic illusion. Our work contributes to the integration of sensory feedback in lower-limb prostheses, to increase their use and functionality.

A Haptic Feedback System for Lower-Limb Prostheses

2008 ◽  
Vol 16 (3) ◽  
pp. 270-277 ◽  
Author(s):  
R.E. Fan ◽  
M.O. Culjat ◽  
Chih-Hung King ◽  
M.L. Franco ◽  
R. Boryk ◽  
...  
Keyword(s):  
Lower Limb ◽  
Haptic Feedback ◽  
Feedback System ◽  
Lower Limb Prostheses

scholarly journals Technology in Rehabilitation: Evaluating the Single Leg Squat Exercise with Wearable Inertial Measurement Units

2017 ◽  
Vol 56 (02) ◽  
pp. 88-94 ◽  
Author(s):  
Tomás E. Ward ◽  
Eamonn Delahunt ◽  
Brian Caulfield ◽  
Darragh F. Whelan ◽  
Martin A. O'Reilly
Keyword(s):  
Lumbar Spine ◽  
Lower Limb ◽  
Low Cost ◽  
Objective Evaluation ◽  
Inertial Measurement Units ◽  
Lower Limb Injury ◽  
Inertial Measurement ◽  
Increased Risk ◽  
Measurement Units ◽  
Single Leg Squat

SummaryBackground: The single leg squat (SLS) is a common lower limb rehabilitation exercise. It is also frequently used as an evaluative exercise to screen for an increased risk of lower limb injury. To date athlete/patient SLS technique has been assessed using expensive laboratory equipment or subjective clinical judgement; both of which are not without shortcomings. Inertial measurement units (IMUs) may offer a low cost solution for the objective evaluation of athlete/patient SLS technique.Objectives: The aims of this study were to determine if in combination or in isolation IMUs positioned on the lumbar spine, thigh and shank are capable of: (a) distinguishing between acceptable and aberrant SLS technique; (b) identifying specific deviations from acceptable SLS technique.Methods: Eighty-three healthy volunteers participated (60 males, 23 females, age: 24.68 +/− 4.91 years, height: 1.75 +/− 0.09 m, body mass: 76.01 +/− 13.29 kg). All participants performed 10 SLSs on their left leg. IMUs were positioned on participants’ lumbar spine, left shank and left thigh. These were utilized to record tri-axial accelerometer, gyroscope and magnetometer data during all repetitions of the SLS. SLS technique was labelled by a Chartered Physiotherapist using an evaluation framework. Features were extracted from the labelled sensor data. These features were used to train and evaluate a variety of random-forests classifiers that assessed SLS technique.Results: A three IMU system was moderately successful in detecting the overall quality of SLS performance (77% accuracy, 77% sensitivity and 78% specificity). A single IMU worn on the shank can complete the same analysis with 76% accuracy, 75% sensitivity and 76% specificity. Single sensors also produce competitive classification scores relative to multi-sensor systems in identifying specific deviations from acceptable SLS technique.Conclusions: A single IMU positioned on the shank can differentiate between acceptable and aberrant SLS technique with moderate levels of accuracy. It can also capably identify specific deviations from optimal SLS performance. IMUs may offer a low cost solution for the objective evaluation of SLS performance. Additionally, the classifiers described may provide useful input to an exercise biofeed-back application.

scholarly journals The reversible adjustable coupling: A lightweight and low-cost alignment component for the lower limb prosthesis

2017 ◽  
Vol 4 ◽  
pp. 205566831770642
Author(s):  
Kazuhiko Sasaki ◽  
Jutamat Pinitlertsakun ◽  
Pakwan Nualnim ◽  
Gary Guerra ◽  
Yuttapichai Sansook ◽  
...  
Keyword(s):  
Low Income ◽  
Lower Limb ◽  
External Rotation ◽  
Low Cost ◽  
Low Income Countries ◽  
Strength Tests ◽  
Lower Limb Prosthesis ◽  
Repetitive Loading ◽  
Limb Prosthesis ◽  
Anterior Posterior

Background The alignment of the lower limb prosthesis is an integral part of the prosthetic fitting. A properly aligned prosthesis contributes to optimal gait and overall function of the patient. The current offering of alignment componentry is expensive for low-income countries. The purpose of this study was to develop a lightweight and low-cost alignment coupler for the lower limb prosthesis. Methods An alignment coupler called the reversible adjustable coupling was designed and manufactured. Measurements of total anterior/posterior and medial/lateral and rotation in prostheses were recorded and mechanical testing performed. Swiftness and difficulty of use was also recorded. Results The reversible adjustable coupling permitted acceptable ranges of anterior/posterior and medial/lateral translation and 30° of internal and external rotation of prosthetic componentry. Repetitive loading of the coupling at a speed of 1 Hz under 1.28 kN load for 2000 cycles was successful, as were static and strength tests. Discussion The coupler provided acceptable ranges of anterior/posterior and medial/lateral and rotation adjustment and is acceptable for potential use in the alignment of both exoskeletal and endoskeletal prosthesis. The final weight of the component was 166 g and cost of $55.00 USD is affordable for low-income countries for use in clinical and educational settings.

scholarly journals Towards an estimation of 3D efforts in lower limb prosthesis socket using low-cost, gauge-based acquisition system

2020 ◽  
Vol 23 (sup1) ◽  
pp. S7-S9
Author(s):  
A. Altamirano ◽  
D. Jacquot ◽  
D. Mangenot ◽  
C. Villa ◽  
E. Vacherand ◽  
...  
Keyword(s):  
Lower Limb ◽  
Low Cost ◽  
Acquisition System ◽  
Lower Limb Prosthesis ◽  
Limb Prosthesis

Examination of Tactor Configurations for the Design of Vibrotactile Feedback Systems for Use in Lower-Limb Prostheses

2018 ◽  
Author(s):  
Sam Shi ◽  
Matthew J. Leineweber ◽  
Jan Andrysek
Keyword(s):  
Lower Limb ◽  
Negative Relationship ◽  
Feedback System ◽  
Elevated Pressure ◽  
Intensity Level ◽  
Response Accuracy ◽  
Feedback Systems ◽  
Vibrotactile Feedback ◽  
Lower Limb Prosthesis ◽  
Lower Limb Prostheses

Vibrotactile feedback may be able to compensate for the loss of sensory input in lower-limb prosthesis users. Designing an effective vibrotactile feedback system would require that users could perceive and correctly respond to vibrotactile stimuli applied by the tactors. Our study explored three key tactor configuration variables (i.e. vibratory intensity, prosthetic pressure, spacing between adjacent tactors) through two experiments. The vibration propagation experiment investigated the effects of tactor configurations on vibratory amplitude at the prosthesis-limb interface. Results revealed a positive relationship between vibratory amplitude and intensity, and a negative relationship between vibratory amplitude and prosthetic pressure. The vibrotactile perception experiment investigated the effects of tactor configurations on user response accuracy, and found that greater spacing between tactors, and higher prosthetic pressure resulted in more accurate responses from the subjects. These findings inform the design of a vibrotactile feedback system for use in lower-limb prostheses: 1) the tactors may be best placed in areas of slightly elevated pressure at the prosthesis-limb interface; 2) a higher vibratory intensity level should improve performance for vibrotactile feedback systems; and 3) more spacing between adjacent tactors improves user response accuracy.

A Lower Limb Prosthesis Haptic Feedback System for Stair Descent

2017 ◽  
Author(s):  
Astrini Sie ◽  
Jonathan Realmuto ◽  
Eric Rombokas
Keyword(s):  
Lower Limb ◽  
Haptic Feedback ◽  
The Body ◽  
Lower Limbs ◽  
Prosthetic Limbs ◽  
Stair Descent ◽  
Lower Limb Prosthesis ◽  
Limb Prosthesis ◽  
Flat Ground ◽  
Lower Limb Prostheses

Though there are a variety of prosthetic limbs that address the motor deficits associated with amputation, there has been relatively little progress in restoring sensation. Prosthetic limbs provide little direct sensory feedback of the forces they encounter in the environment, but “closing the loop” between sensation and action can make a great difference in performance [1]. For users of lower limb prostheses, stair descent is a difficult and dangerous task. The difficulty in stair descent can be attributed to three different factors: 1) Absence of tactile and haptic sensations at the bottom of the foot. Although force on the prosthetic socket provides some haptic feedback of the terrain being stepped on, this feedback does not provide information on the location of the staircase edge. 2) Insufficient ankle flexion of lower limb prostheses. Dorsiflexion of the physiological ankle during stair descent is about 27°. Even prostheses that provide active dorsiflexion provide less than this number, and regular prostheses provide almost no ankle dorsiflexion. The first two factors are analogous to the sensation of stair descent for someone without amputation wearing ski boots. 3) Prosthetic feet are optimized for flat-ground walking, offering undesirable energy storage at ankle flexion and energy return at toe-off. This can result in unwanted extra energy at the end of stance phase, propelling the user forward down the stairs. Most lower limb prosthesis designs focus on flat ground walking, but there has been less progress in addressing the challenges of stair descent. One technique that users of prosthetic lower limbs can use for addressing these challenges is to employ an “overhanging toe” foot placement strategy. Under this strategy, the edge of the staircase is used as a pivot point for the foot to roll over the stair. This reduces the need for ankle flexion by allowing the knee and hip to compensate, and avoids storing energy in the prosthetic spring. This strategy is dynamic, and requires the user to know the amount of toe overhang to adjust the movement of the rest of the body. Most haptic devices built to assist individuals wearing prostheses focus on upper extremity tasks [2–4] or standing and walking [5,6]. Whereas previous lower limb sensory replacement systems have targeted standing measures, here we focus on stair descent. The system provides cues of the stair edge location via vibrotactile stimulations on the thigh.

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