Objective: The objective of this study is to evaluate algorithms in a medical device for l-dopa delivery and monitoring. This wearable medical device will measure the effectiveness of l-dopa dosage by quantifying the rigidity and tremors of the patient, receiving cues from the caregiver, and by estimating dopamine blood concentration through measuring its concentration in the interstitial skin fluid.

Background: This ongoing project studies the safety and effectiveness of closed loop medical device algorithms for delivering an optimal l-dopa dosage throughout the day. These algorithms assume a family of medical devices able to measure the effectiveness of l-dopa dosage by quantifying body tremors through several methods including recognizing voice tremors, measuring body kinematics, detecting body tremors, receiving caregiver or patient feedback, and by estimating dopamine concentration in the blood through interstitial fluid measurement.

Methods: Human body kinematics models were developed where tremors and rigidity are assume to be time delay function of the dopamine concentration in the blood due to the brain blood barrier accounting for differences of concentration in the brain versus in the blood, time delay effects due pharmacology of the l-lopa medication. Normalization algorithms are deployed to take into account feedback from caregivers or the patient. Degree of body rigidity and tremors may be evaluated differently by different persons. Data fusion techniques are used to merge measurements and cues from different sources. Mathematical issues related to stability, state controlability and obserservability were studied.

Results: We modeled a closed loop l-dopa pumping device using Matlab/Octave. Our simulation results provided an estimation of safety margins for the implementation of closed loop l-dopa pump algorithm in software, and other trade-offs that may be relevant for fine tuning by a clinician.

Conclusions: Closed loop l-dopa pump devices are a technology similar to closed loop glucose infusion pumps. However the implementation challenges are much more complex as it is currently impossible to continuously evaluate the concentration of dopamine in the brain in a noninvasive and cost effective manner. The present study provides guidance towards the implementation of these devices.

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MDS Abstracts - https://www.mdsabstracts.org/abstract/efficacy-and-safety-of-a-l-dopa-delivery-and-monitoring-medical-device/