User-driven Retrospectively Supervised Classification Updating (RESCU) System for Robust Upper Limb Prosthesis Control
Conditions: Amputation, Upper Limb
Sponsor: Infinite Biomedical Technologies

 
 
 
 
 
 
 
 
 
 
 
User-driven Retrospectively Supervised Classification Updating (RESCU) System for Robust Upper Limb 
Prosthesis Control   
NCT04043234 
December 29, 2023 
 

This study will compare the use of RESCU [Experimental] Prosthesis with a [Standard] pattern recognition 
prosthesis in a clinical setting and in unsupervised daily activity. The protocol will follow a single case 
experimental design (SCED) to compensate for the limited size of the patient population. Each of the participants 
will use the Standard and Experimental and systems over a 35-day period. The Standard system will include a 
multi-articulated hand, eight EMG electrodes, and a commercially-available pattern recognition controller. The 
RESCU system will also use the multi-articulated hand, similar to the Standard system, but will differ with respect 
to incorporating eight IBT Element Electrodes (as required for pattern recognition control) and the RESCU control 
software. 
Participants: We will recruit a total of 10 unilateral trans-radial amputees based on the inclusion and exclusion 
criteria noted in the Clinical Protocol. Note: the RESCU system is applicable to a range of amputation levels, but 
this study is focused on trans-radial amputees as they represent the largest population of users.  
Procedures: After informed consent and medical clearance are completed, participants will be fitted by the study 
prosthetist. 
On Day 0, the participant will be evaluated with the Standard prosthesis. A series of Measures (as defined in the 
next paragraph) will then be recorded. The participant will then take the prosthesis home for 1 week, and daily 
use data will be recorded. The participant will return to the clinic for Day 7 Measures and download of the daily 
use data. During this same session, the participant will be fit with the second system, instructed on the controller’s 
use, and Measures will be recorded. There will be no washout period as the prosthesis is expected to be in daily 
use. The participants will go home for a four-week period and return on Day 35 for a second set of Measures. 
At this time, the participant will be asked which prosthesis he/she prefers, and this will be the prosthesis that 
they return home with at the end of the study. 
There are limited functional outcome assessment options for the planned comparison. However, we will test 
functional measures at the clinic appointments, examine daily use data, and administer several qualitative 
surveys to assess participant outcomes. 
Measures (each appointment day): First, a validated measure of upper extremity impairment will be used: the 
Activities Measure for Upper Limb Amputees (AM-ULA). The AM-ULA is a clinician-graded measure of activity 
performance for adults with upper limb amputation that considers task completion, speed, movement quality, 
skillfulness of prosthetic use, and independence to quantify how functional an individual is while using their 
prosthesis. A higher score indicates overall greater prosthesis functionality. This test has been validated for 
normative data.  
Second, we will ask participants to record daily use data with the Standard and Experimental systems: 
Mean Daily Prosthesis Use Duration: Our hypothesis is that RESCU will improve prosthesis acceptance. In 
addition to the subjective measures used below, we will measure the mean duration of daily prosthesis use as a 
proxy for improved prosthesis acceptance. We will compare the mean daily use for the Standard and 
Experimental systems, hypothesizing that the Experimental system will be used more than the Standard system. 
This will be our primary outcome measure. 
Third, we will use a suite of validated survey instruments directly related to prosthesis use and satisfaction. 
These instruments are the Orthotics and Prosthetics User Survey Upper Extremity Functional Status (OPUS-
UEFS) [53], the Trinity Amputation Prosthesis Experience Scale (TAPES), and various Patient Reported 
Outcomes Measurement Information System (PROMIS) subscales (e.g., Pain Interference, Satisfaction Short 
Form 8a). In addition, we will report the percentage of participants that preferred the RESCU system. 
Statistics: Our primary outcome measure will be the mean daily prosthesis use duration. We hypothesize that 
the mean daily use for those using the Standard system will be increased from 4.0 to 6.0 hours. In order to detect 
such a difference, using a paired t-test calculating the mean difference between the use of the two systems, and 
assuming no period effect and no carryover effect, 10 pairs of measurements would be needed. A two-sided t-
test achieves 80% power to infer that the mean difference is not 0.00 when the total sample size of a 2x2 cross-
over design is 20 (10 patients), the actual mean difference is 2.00, the standard deviation of the paired 
differences is 3.00, and the significance level is 0.050. 
Data analysis: Data will be gathered and evaluated carefully by study team members without conflicts of interest 
to determine the distribution of all scores in the population studied and the variability of scores within and between 
uses of the two systems. We will specifically examine whether daily use improves by week of use. Personal 

characteristics will be used to stratify analyses as applicable. As stated above, we will compare the mean daily 
use duration of the two systems using a paired t-test, and attempt to determine if there is a period effect, i.e., 
trend over time. We will also test to assure that there is no sequence effect. We anticipate that the system 
preferred by the participant will also demonstrate an increased mean daily use duration.