Next-Generation Remote Hand Assessments: Cross-Platform DIGITS Web Application

Abstract

Purpose: We have previously developed DIGITS, a platform for remote evaluation of range of motion, dexterity, and swelling of fingers for reducing barriers to accessing clinical resources. The current study was aimed at evaluating DIGITS across different devices with varied operating systems and camera resolutions using a single person's hands.

Methods: Our team has now developed a web application version of the DIGITS platform, which makes it accessible on any device that is equipped with a camera, including computers, tablets, and smartphones. In the present study, we aimed to validate this web application by comparing flexion and extension measurements on the same person's hands using three different devices with cameras of different resolutions. The absolute difference, SD, standard mean error, and intraclass correlation coefficient were calculated. Additionally, equivalency testing was performed using the confidence interval approach.

Results: Our findings indicated that the differences in degree measured between the devices ranged from 2° to 3° when digit extension was assessed (all hand landmarks are visible in the camera's direct view) and from 3° to 8° when digit flexion was assessed (some of the hand landmarks are hidden from view). The intraclass correlation coefficient of individual trials ranged from 0.82 to 0.96 for extension and 0.77 to 0.87 for flexion across all devices. Additionally, within a 90% confidence interval, our data showed equivalency with measurements using three different devices.

Conclusions: The absolute differences were within an acceptable 9° tolerance for measurements taken between devices for flexion and extension. Equivalency was observed for measurements of finger range of motion taken using DIGITS, regardless of devices, platforms, or camera resolutions.

Clinical relevance: In summary, the DIGITS web application has good test-retest reliability to generate data on finger range of motion for hand telerehabilitation. DIGITS can reduce costs to patients, providers, and health care facilities for conducting postoperative follow-up assessments.

Keywords: Computer vision; Hand surgery; Plastic surgery; Range of motion; Telerehabilitation.

Figure 1

Schematic of recording ROM data using the DIGITS web application in the clinical setting.

Figure 2

Illustration of the different hand positions from which the data were collected: A extension and palmar facing as well as B extension and ulnar facing. C Flexion and palmar facing as well as D flexion and ulnar facing.

Figure 3

The average degrees recorded by the DIGITS web application of the left or right hand at full flexion or extension positions using the following three devices: laptop, PC, and smartphone (phone).