Classification of Extremity Movements by Visual Observation of Signal Transforms

A low-cost quantitative continuous measurement of movements in the extremities of people with Parkinson's disease (PD) (McKay, 2019) provides the means to express the dysfunction of movements commonly seen in people with PD in the form of the signals of instrumentation capturing the three-dimensional position in space of the extremities during movements. The goal of the current protocol is to provide the means to obtain objective assessments of the signals and transforms of the output of our low-cost quantitative continuous measurement of movements in the extremities of people with PD (McKay, 2019; Harrigan, 2020). To attain this end, we sought to develop a method for 35 experts to blindly rate the signals and transforms of our quantitative continuous measurement of movements in the extremities of cohorts of people with PD and control and comparison groups (McKay, 2019; Harrigan, 2020; Ziegelman, 2020). Thus, we conducted an investigation to apply our accelerometry-based method for the acquisition of motion data for the twelve tasks (McKay, 2019) on 20 patients with PD, one patient with multiple system atrophy (MSA), and 8 healthy age- and sex-matched healthy individuals with typical development (TD). The original output from the instrumentation was stored on the laptop used for the study. Subsequent analysis has been restricted to the five repetitive tasks (3.4 Finger tapping, 3.5 Hand movements, 3.6 Pronation-supination movements of hands, 3.7 Toe tapping, 3.8 Leg agility) (Ziegelman 2021). The signals and the fast Fourier transforms (FFTs) and continuous wavelet transforms (CWTs) of the signals of the five repetitive items have been published (Harrigan 2020, 2022). We sought to develop a protocol to express the signals and the transforms of the five repetitive movements of each of the cohorts in a format suitable for blind rating by experts unfamiliar with the original data. In order to verify that each rater was qualified to participate as a rater, potential raters participated in weekly online research team meetings including instruction by a biomedical engineer and a mechanical engineer in the expression of output signals as FFTs and CWTs. Raters were asked to perform ratings independently without consultation with others. Because the research team of expert raters included people throughout the world, raters were allowed to view the images as long as they wanted. They were allowed to change ratings. They could take as much time as they wanted to complete and submit each set of ratings. The overall scheme of the and retest is presented in the attach Form-Link Master Sheet. Examples of the images on the panels for the participant with MSA (1960, 2352, 2822, and 3386) presented to the raters are provided to illustrate that part of the rating procedure. Raters were additionally provided a score sheet below each image panel to rate the presence or absence of deviations from a uniform rhythm (Hernandez, et al., MethodsX 2022; 9: 101739).