A Novel Instrument to Address Freezing of Gait in Parkinson's Patients

Project Summary/Abstract Introduction. Parkinson’s Disease (PD) is a common neurodegenerative disorder that affects 1 million Americans and 10 million individuals worldwide. One of the most debilitating and impactful symptoms of PD is Freezing of Gait (FOG). FOG, defined as an episodic absence or marked reduction of forward progression of the feet despite the intention to walk, is a common motor symptom of PD. FOG is a “mysterious phenomenon” with a pathophysiology that is not fully understood. FOG decreases quality of life and activity level, and leads to loss of independence and injurious falls. Surgical and pharmacological treatments are often ineffective in reducing FOG; however, alternate interventions can be more efficacious. External prompts, such as auditory, visual, or tactile cues, have been shown to help, but outcomes are mixed due to the individualized nature of FOG—different cues are more or less effective depending on the individual and their present circumstances. The ParkinSense System. The body-worn ParkinSense system will help PD patients prevent FOG and resume ambulation when FOG occurs. The miniature, wireless ParkinSense instrument will be easily attachable to existing prescription or nonprescription eyeglasses, or can be worn as a low-profile band under a cap or hat. Using sophisticated on-board six degrees-of-freedom inertial sensing and online processing algorithms, the ParkinSense system will automatically detect FOG and provide an individually calibrated and optimized combination of cues, including: auditory (speech, music, or rhythmic beats), visual (transverse lines or a grid in the visual field), and/or vibrotactile cues. The ParkinSense system also includes a limb-worn unit to perform supplemental sensing and cueing directly to a leg. The ParkinSense system will enable delivery of multiple types of cues alone or in any combination. Cueing can be provided automatically in response to a FOG event, manually (controlled by the wearer), or continuously. Cue delivery (for example, the amplitude and frequency of the tactile cues) can be optimized to provide maximum efficacy, unobtrusiveness, and comfort for individual users. Further, the ParkinSense system will have the capability to adapt its cues; for instance, the cue rhythm can match the functional step cadence of the wearer in order to maximize response. The ParkinSense system will track FOG occurrence over time and the efficacy of each provided cue. These data will be used to further and continuously personalize the system for each user; ParkinSense will become more effective for an individual as it is used. Finally, ParkinSense will have a remote reporting capability that will allow clinicians to monitor their patients health status over time (e.g., activity level, FOG occurrence, and adherence to device use). Phase I Results. A ParkinSense prototype was designed, built, and evaluated by collecting data on patients with PD using a FOG-inducing protocol. The ParkinSense system algorithms were shown to detect FOG with high accuracy. A mixed-methods formative user-acceptance study demonstrated high acceptance, usability, and enthusiasm for the ParkinSense system. All Phase I objectives were achieved.