Method and system for monitoring depth of muscle relaxation of a patient

A system for monitoring depth of muscle relation of a patient, the system comprising:

• a stimulator configured to apply a series of stimulations to a nerve of the patient;
• a sensor device configured to measure muscle responses of the patient to the series of stimulations;
• a non-transitory storage medium storing a stimulation mode indicator that indicates a stimulation mode for the stimulator and/or a stimulus current indicator of at least one of a maximal stimulus current, a supramaximal stimulus current, and a submaximal stimulus current for the patient, wherein the maximal stimulus current is a current at which a maximal muscle response is produced from stimulating the nerve, the supramaximal stimulus current is greater than or equal to the maximal stimulus current, and the submaximal stimulus current is less than the maximal stimulus current;
• a controller configured to:
• control the stimulator to apply the series of stimulations to the nerve of the patient at varying stimulus currents and the sensor device to measure muscle responses to the series of stimulations to determine at least one of the maximal stimulus current, the supramaximal stimulus current, and a submaximal stimulus current for the patient;
• control the stimulator to periodically apply a train-of-four (TOF) stimulation to the nerve of the patient at the supramaximal stimulus current and measure a TOF response to the TOF stimulations to the nerve of the patient at the supramaximal stimulus current;
• compare the measured TOF response to a supramax response threshold;
• upon identifying that the measured TOF response to the TOF stimulations is at least equal to the supramax response threshold:
• periodically apply a TOF stimulation to the nerve of the patient at the submaximal stimulus current and measure a submax TOF responses to monitor the depth of muscle relaxation of the patient;
• and
• store a submaximal stimulation mode indicator in the non-transitory storage medium.