SBIR-STTR Award

The goal of the project is to develop a closed loop electrical muscle stimulation (CL-EMS) system to mitigate ICUacquired 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 asthe respiratory muscles impeding weaning from mechanical ventilation, leading to prolonged hospitalization andeventual short-term and long-term functional impairment and reduced quality of life. Currently, no effectivetreatment exists for ICUAW, and the focus is primarily on early mobility preventive measures. Current earlymobility program is executed by physical therapy and requires patient's cooperation and could not be performedimmediately after ICU admission in critically ill/mechanically ventilated patients. Therefore, there is highinterest 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 andelectrical 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 developedfor ICU use raising safety questions related to electromagnetic interference (EMI) with cardiac monitoringsystems as well as life sustaining equipment such as cardiac implanted electronic devices and externaldefibrillators; (2) the continuous presence of a skilled operator on site to set up the device and continuouslymonitor 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 couldreduce the risk of EMI. Additionally, we reasoned that using real-time muscle bioelectric feedback in responseto electric stimulation could create the basis for a closed loop system. A low noise EMS system showed promisingresults when tested with an ECG system. In addition, we find that the use of real-time bioelectric feedback isreliable in detecting muscle response to electrical stimulation. Therefore, in this project we will integrate abioelectric feedback device with a low noise EMS device to create a CL-EMS α-version that is safe for use in ICUsetting. In phase 1 R&D work related to the electrical design integration of the closed loop prototype system willbe completed. An α-version of the CL-EMS system will be built and tested for safety and efficacy in inducing aneffective muscle contraction. The validation process will include IEC testing and testing in healthy volunteers.

Public Health Relevance Statement:
80% of mechanically ventilated patients in the US develop some form of neuromuscular dysfunction resulting in ICUAW. Efforts to reduce this burden have been hindered by the lack of an effective tool facilitating the adoption of early mobility. The goal of the project is to develop a safe and easy to use electrical muscle stimulation device to facilitate the adoption of early mobility therapy within few hours of ICU admission.

Project Terms:

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 system that is safe for use in ICU setting. In phase 1 of this project, the electrical design integration of the closed loop prototype system was completed successfully - preliminary safety was validated in a clinical trial in healthy volunteers. In phase 2 a commercial prototype of the CL-EMS system will be built and tested for safety and feasibility in inducing an effective muscle contraction in the intended use setting. The validation process will include IEC testing and testing in critically ill patients.

Public Health Relevance Statement:
80% of mechanically ventilated patients in the US develop some form of neuromuscular dysfunction resulting in ICUAW. Efforts to reduce this burden have been hindered by the lack of an effective tool facilitating the adoption of early mobility. The goal of the project is to develop a safe and easy to use electrical muscle stimulation device to facilitate the adoption of early mobility therapy within few hours of ICU admission. Terms: