Dejan B Popović | Search PubMed

PubMed2005

The drawing test: assessment of coordination abilities and correlation with clinical measurement of spasticity.

OBJECTIVE: To assess the correlation between kinematic measures of movement (Drawing Test) and a clinical measure of spasticity (Ashworth Scale). DESIGN: Correlation study of Drawing Test and the Ashworth Scale scores. SETTING: Inpatient rehabilitation center. PARTICIPANTS: Forty-five poststroke hemiplegic subjects with various levels of spasticity (up to Ashworth Scale score of 3) and 8 able-bodied subjects with no sensorimotor deficits in their upper extremities. INTERVENTIONS: Subjects made self-paced, radial point-to-point movements between the left, and the right corners of a square (200 x 200 mm) on the surface of a drawing tablet. Hand coordinates were recorded from the mouse, which was attached to the hand. MAIN OUTCOME MEASURES: Correlation between (1) Drawing Test scores (time to perform the movement, radial [ y ] and tangential [ x ] distances between the end point of the movement and the target endpoint, standard error of the mean calculated as distances between the recorded path and its radial linear fit), and (2) Ashworth Scale scores. RESULTS: Drawing Test scores correlated highly with Ashworth Scale scores in 49 of 53 subjects, based on the multiple linear regression analysis. CONCLUSIONS: The Drawing Test, a quantitative metric of movement ability, correlated highly to the Ashworth Scale, a clinical measure of spasticity.

Adult↗

PubMed2005

Multi-field surface electrode for selective electrical stimulation.

We designed a 24-field array and an on-line control box that selects which and how many of 24 fields will conduct electrical charge during functional electrical stimulation. The array was made using a conductive microfiber textile, silver two-component adhesive, and the conductive ink imprint on the polycarbonate. The control box comprised 24 switches that corresponded one-to-one to the fields on the array. Each field could be made conductive or nonconductive by simple pressing of the corresponding push-button type switch on the control box. We present here representative results of the selectivity of the new electrode measured in three tetraplegic patients during functional electrical stimulation of the forearm. The task was to generate finger flexion and extension with minimal interference of the wrist movement during lateral and palmar grasps. Therapists determined the appropriate pattern that lead to effective grasping, lasting on average 5 min per stimulation channel in the first session. This optimal conductive pattern (size and shape) provided effective finger flexion and extension with minimal wrist flexion/extension and ulnar/radial deviations (<10 degrees). The optimal size and shape of the electrode in all cases had a branched pattern. The selection of the optimal stimulation site was achieved without moving the electrode. The size and shape were reproducible in the same subject from session to session, yet were different from subject to subject. The optimal electrode size and shape changed when subjects pronated and supinated their forearm. The control box includes a program that can dynamically change the number and sites of the conductive fields; hence, it is feasible to use this during functional movements. Subjects learned how to determine the optimal electrode pattern; hence, these electrodes could be effective for home usage.

Electric Stimulation↗