Closed Loop Electrical Muscle Stimulation System (CL-EMS) with improved safety for ICU environment to mitigate ICU Acquired Weakness

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Project Summary/Abstract The goal of the project is to develop a closed loop electrical muscle stimulation (CL-EMS) system to mitigate ICU acquired weakness (ICUAW). Multifactorial in origin (extended period of bed rest, acute inflammatory state, exposure to multiple pharmacological agents such as neuromuscular blockers, antibiotics, and corticosteroids), ICUAW starts within few hours of ICU admission, affects the limbs, particularly the lower extremities as well as the respiratory muscles impeding weaning from mechanical ventilation, leading to prolonged hospitalization and eventual short-term and long-term functional impairment and reduced quality of life. Currently, no effective treatment exists for ICUAW, and the focus is primarily on early mobility preventive measures. Current early mobility program is executed by physical therapy and requires patient’s cooperation and could not be performed immediately after ICU admission in critically ill/mechanically ventilated patients. Therefore, there is high interest in being able to intervene early via non-volitional exercise strategies. One such promising strategy is “Electrical Muscle Stimulation” (EMS). EMS passively activates muscles using skin-surface electrodes and electrical pulses. Clinical data from the literature support the use of EMS as a tool for early rehabilitation. However, technical limitations prevented widespread adoption of EMS in ICUs: (1) no EMS device is developed for ICU use raising safety questions related to electromagnetic interference (EMI) with cardiac monitoring systems as well as life sustaining equipment such as cardiac implanted electronic devices and external defibrillators; (2) the continuous presence of a skilled operator on site to set up the device and continuously monitor the treatment session (by assessing physiological feedback from the patient and making adjustments) increase the workload and cost of the intervention. We reasoned that an EMS device with low electric noise could reduce the risk of EMI. Additionally, we reasoned that using real-time muscle bioelectric feedback in response to electric stimulation could create the basis for a closed loop system. A low noise EMS system showed promising results when tested with an ECG system. In addition, we find that the use of real-time bioelectric feedback is reliable in detecting muscle response to electrical stimulation. Therefore, in this project we will integrate a bioelectric feedback device with a low noise EMS device to create a CL-EMS α-version that is safe for use in ICU setting. In phase 1 R&D work related to the electrical design integration of the closed loop prototype system will be completed. An α-version of the CL-EMS system will be built and tested for safety and efficacy in inducing an effective muscle contraction. The validation process will include IEC testing and testing in healthy volunteers.