User ratings of prosthetic usability and satisfaction in VA study to optimize DEKA Arm

Abstract

Abstract-The Department of Veterans Affairs study to optimize the DEKA Arm provided feedback to inform optimization of the gen 2 (second-generation) prototype and evaluate the gen 3 (third-generation) prototype. This article summarizes recommendations to improve gen 2 and reports satisfaction and usability ratings of gen 2 and gen 3. Data were collected from 39 subjects; 37 subjects were included in this analysis. Of the subjects, 24 were fit with gen 2 (8 radial configuration [RC], 6 humeral configuration [HC], and 10 shoulder configuration [SC]), 13 were fit with gen 3 (4 RC, 5 HC, and 4 SC), and 5 were fit with both. Usability and satisfaction were evaluated using the Trinity Amputation and Prosthesis Experience Scale (TAPES) and study-specific usability and satisfaction scales. Descriptive statistics were examined and prototypes compared using Wilcoxon rank-sum. Results were stratified by configuration level and outcomes compared by prototype. Satisfaction and usability were greater for gen 3 than gen 2. Overall TAPES scores were similar; however, scores of the TAPES aesthetic satisfaction subscale were higher for gen 3. Compared with gen 2 users, gen 3 users were more satisfied with appearance, grips, and doffing and rated overall usability higher. Features of gen 3, including weight, external cables and wires, hand covering, and fingernails, would benefit from further optimization.

User and clinician perspectives on DEKA Arm: Results of VA study to optimize DEKA Arm

“…The DEKA Arm (both gen 2 and gen 3) is available in three configurations: radial configuration (RC), humeral configuration (HC), and shoulder configuration (SC) (see Figure 1 in Resnik and Borgia in this issue for gen 2 and gen 3 SC prototypes [4]). The SC has 10 powered degrees of freedom and additional passive degrees of freedom [5][6] (Table 1).…”

“…Three iterations of foot controls (see Figure 2 in Resnik and Borgia in this issue [4]) were used: force sensitive resistors (FSRs); inertial measurement units (IMUs) during gen 2 (IMU-1); and a refined version of the IMU in gen 3 (IMU-2) that did not require an external arm control interface (ACI) unit worn on the ankles and had new features, including the ability to detect walking motion and to automatically put the arm into standby (called Walk Detect).…”

“…In addition, an audible, vibratory tactor "buzzed" to indicate changing between hand and arm modes, moving into or out of standby mode, changing grips, and changing grip pressure. The Luke User Interface (LUI) introduced in gen 2 displayed information about grip, mode, power, battery charge, and system faults (see Figure 3 in Resnik and Borgia in this issue [4]). In gen 3, the LUI was replaced with an embedded wrist display (see Figure 3 in Resnik and Borgia in this issue [4]) that had light-emitting diode (LED) displays for grip, low battery, mode notification, and system faults, as well as indicators for Walk Detect and over-angle limit detect.…”

“…The Luke User Interface (LUI) introduced in gen 2 displayed information about grip, mode, power, battery charge, and system faults (see Figure 3 in Resnik and Borgia in this issue [4]). In gen 3, the LUI was replaced with an embedded wrist display (see Figure 3 in Resnik and Borgia in this issue [4]) that had light-emitting diode (LED) displays for grip, low battery, mode notification, and system faults, as well as indicators for Walk Detect and over-angle limit detect. DEKA designed inflatable bladders to be used inside transhumeral (TH) sockets to increase skeletal stabilization or for use inside X-frames to provide pressure relief [8].…”

Is a prosthetic arm customized PRADA? A critical perspective on the social aspects of prosthetic arms

“…A study of user reviews of the Dean Kamen (DEKA) Arm -one of the most advanced prosthetic arms -by the US Department of Veterans Affairs (2014) reported that as many as 30% of the people were dissatisfied, mainly due to issues linked to optimization (Resnik and Matthew 2014). Unlike other electronic gadgets that can be identically mass produced, optimal use of a prosthetic arm is not just about the list of capacities of the device, but is also about how suitable and how safe it is for each user.…”