From Prototype to Clinical Workflow: Co-Developing a Wearable Hypomimia System for Parkinson's Disease

Area of Science:

• Biomedical Engineering
• Neurology
• Human-Computer Interaction

Background:

• Hypomimia, characterized by reduced facial expressiveness, is a common symptom in Parkinson's disease (PD).
• Current clinical assessments of hypomimia, often using the MDS-UPDRS, are subjective and may not capture the full spectrum of the condition.
• There is a need for objective, reliable methods to quantify hypomimia in real-world clinical settings.

Purpose of the Study:

• To develop and refine a wearable, cap-mounted device for objective hypomimia recording.
• To assess the usability and technical feasibility of the device during routine inpatient Parkinson's disease assessments.
• To improve the device through iterative, patient-centered design based on clinical feedback.

Main Methods:

• A co-development process involving four prototypes and clinician workflow analysis.
• Evaluation of Prototype 3 using the System Usability Scale (SUS) and free-text feedback.
• Patient-centered redesign leading to Prototype 4, followed by bench testing and usability assessment with a larger cohort.

Main Results:

• Bench testing confirmed stable operation, robust housing, and reliable Wi-Fi data streaming.
• Usability significantly improved from moderate (SUS 44.7) in Prototype 3 to good (SUS 80.0) in Prototype 4.
• The device achieved a mean effective sampling rate of 4.79 frames/s with 95.4% face detection accuracy.

Conclusions:

• The iterative, patient-centered design process was crucial for enhancing device usability.
• Technical robustness and user-centered design are essential for the clinical validation of wearable assessment tools.
• The developed wearable hypomimia capture device shows promise for integration into routine Parkinson's disease assessments.