Patent ID: 9682235
Date: 2017-06-20
CPC Classifications: A61M,A61N

Claim:
1. A medical device for use with a mechanical ventilator and breathing circuit coupled to a patient, said medical device comprising: a subcutaneous electrode pair positioned proximate at least one phrenic nerve in the neck of said patient; a stimulator/controller connected to said electrode pair via a lead cable, said stimulator/controller delivering electrical stimulation to said electrode pair at a pulse repetition rate, with a current and a waveform sufficient to at least partially activate the patient's diaphragm; an instrumented wye coupled to said patient and coupled to said mechanical ventilator via tubing of the breathing circuit, providing a wye flow measurement and a wye pressure measurement to said stimulator/controller; said stimulator/controller selecting one of several breaths defining a single selected breath; said stimulator/controller beginning stimulation at the beginning of an inspiratory event in response to an inspiratory trigger event, said event corresponding to a preset specific flow at said instrumented wye; said stimulator/controller ending stimulation at the end of an inspiratory event triggered by an end inspiratory trigger event, said event corresponding to a specific flow at said instrumented wye; said inspiratory event trigger and said end inspiratory event trigger together defining a duration for the stimulation within the inspiratory phase of said single selected breath; a power/work measuring device coupled to said instrumented wye measuring the instantaneous work throughout the inspiratory phase of said single selected breath, by comparing a predicted pressure at the wye and a measured pressure at the wye, and indicating work only if the predicted pressure differs from the measured pressure at said instrumented wye.