Safety and Efficacy of Vibro-tactile Feedback for Patients Who Underwent Lower Limb Amputation

Study Overview
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Brief Summary
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Prosthetics research has grown recently, focusing on bionic approaches that restore bodily functions with technical aids. One method involves using prostheses with feedback systems, which measure physical parameters and provide additional information to the user. Saphenus has developed a feedback system called Suralis© that transfers pressure signals from the prosthetic sole to another body region. This clinical investigation aimed to determine if this system improves gait stability and walking. The study analyzed changes in gait and functional balance and gathered patient-reported measures to evaluate the quality of life. This research was open to individuals who have undergone below-knee amputation but no targeted re-innervation surgery and use prosthetics. Participants received the Suralis© feedback system, and the investigators assessed their walking activities. The system measures prosthetic foot sole pressure and converts it into digital signals, triggering vibration stimuli during the stance phase of walking. The investigators collected gait analyses and patient feedback to assess the impact of the feedback system on prosthetic management. The results will help us understand the benefits and effectiveness of this technology for people with amputation.

Detailed Description
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The investigators conducted a prospective, unblinded crossover trial to compare the effectiveness of a vibration intervention with no intervention. Participants were randomly assigned to one of two sequences: vibration intervention followed by no intervention or vice versa. The intervention involved using the Suralis© vibrotactile ground-contact feedback system for 60 days. The system transmitted ground contact information to the residual lateral thigh, providing sensory feedback. During the control phase, participants received no additional intervention. The washout period lasted seven days. The study collected data during four visits, assessing gait and patient-reported measures. Bayesian generalized linear mixed models were used for data analysis, considering fixed effects (intervention, sequence, and period) and random effects (individuality).

Official Title
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Safety and Efficacy of Vibro-tactile Feedback for Patients Who Underwent Lower Limb Amputation

Conditions
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Amputation of Lower Limb Below Knee, Unilateral

Intervention / Treatment
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* Device: vibrotactile ground-contact feedback


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: male, female, and diverse individuals unilateral transtibial amputation at least 18 months post surgery walking without aids possible signed informed consent form Exclusion Criteria: insufficient thigh sensation to distinguish between the two closest vibrotactile actuators an acute event that restricts the walking ability interfering lesions or painful conditions undergone targeted re-innervation surgery poor stump condition used a non-modular prosthesis used a prosthesis in poor condition conditions preventing safe participation or interfering with study objectives not able to not comply with the protocol

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Control-Vibration<br>Participants were assessed before and after 60 days of no additional intervention to any ongoing treatment, after seven days of washout, and after receiving 60 days of vibrotactile ground-contact feedback. | Device: vibrotactile ground-contact feedback<br>* Suralis®, Saphenus Medical Technology (Baden, Lower Austria, Austria)<br>|
| Active Comparator: Vibration-Control<br>Participants were assessed before and after receiving 60 days of vibrotactile ground-contact feedback, after seven days of washout, and after 60 days of no additional intervention to any ongoing treatment. | Device: vibrotactile ground-contact feedback<br>* Suralis®, Saphenus Medical Technology (Baden, Lower Austria, Austria)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Affected leg stance time treatment-change difference | Stance time of the prosthetic leg during walking over level ground and on a 518 cm instrumented walkway at a self-selected speed | Difference between the within-period changes of the 60-day control (C) and vibration (V) periods of the randomized controlled crossover trial, i.e., V(post - pre) - C(post - pre); three tries each assessment day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gait speed treatment-change difference | Average speed of walking over level ground and on a 518 cm instrumented walkway at a self-selected speed | Difference between the within-period changes of the 60-day control (C) and vibration (V) periods of the randomized controlled crossover trial, i.e., V(post - pre) - C(post - pre); three tries each assessment day | 
| Unaffected leg step length treatment-change difference | Step length of the non-prosthetic leg during walking over level ground and on a 518 cm instrumented walkway at a self-selected speed | Difference between the within-period changes of the 60-day control (C) and vibration (V) periods of the randomized controlled crossover trial, i.e., V(post - pre) - C(post - pre); three tries each assessment day | 
| Quality of life score treatment-change difference | EuroQol (EQ) 5-Dimension (5D) 3-Level (3L) version, visual analog scale (VAS) | Difference between the within-period changes of the 60-day control (C) and vibration (V) periods of the randomized controlled crossover trial, i.e., V(post - pre) - C(post - pre); once each assessment day | 
| Adverse effects frequency treatment difference | Patient diary documentation and interview regarding adverse effects | Difference in the event frequency during the 60-day control (C) and vibration (V) periods of the randomized controlled crossover trial, i.e., V - C; once each assessment day | 
| Timed up and go test time treatment-change difference | Stand up, walk 3 m, turn around, and sit down | Difference between the within-period changes of the 60-day control (C) and vibration (V) periods of the randomized controlled crossover trial, i.e., V(post - pre) - C(post - pre); three tries each assessment day | 
| 2 min walk test distance treatment-change difference | Walking distance in meters within a 2 min time frame | Difference between the within-period changes of the 60-day control (C) and vibration (V) periods of the randomized controlled crossover trial, i.e., V(post - pre) - C(post - pre); once each assessment day | 
| Four square step test time treatment-change difference | Do and reverse four steps over 90 cm long canes arranged in a cross configuration on the ground | Difference between the within-period changes of the 60-day control (C) and vibration (V) periods of the randomized controlled crossover trial, i.e., V(post - pre) - C(post - pre); three tries each assessment day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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lower limb amputation, somatosensory feedback, functional balance, gait performance, rehabilitation, four square step test