Optimizing and validating an EMG-based fetal monitor to identify true preterm labor

External fetal monitoring is an irreplaceable clinical tool for moment to moment assessment of fetal well beingIt is performed by simultaneously measuring the fetal heart rate and uterine contractionsForyearsthe fetal heart rate has been measured using the Doppler ultrasound and uterine contractions have been assessed using the tocodynamometerTocoThe Doppler is an electronic stethoscope and the Toco is plunger driven device that measures the uterine shape change that occurs with a contractionBoth the Doppler and the Toco are unreliable in preterm and obese patientsToco only reports the timing of contractionsnot the contraction strengthand cannot distinguish between false and true laborOur overarching goal is to improve the reliability of fetal monitoringespecially for challenging patients such as obese or pretermor both obese and pretermFurtherwe will validate our method of determining if a patient is in true labor or false laborWe will accomplish this by applying new knowledge to an old technologyuterine EMGThe uterus emits bioelectrical signals with each contraction that can be detected by electromyographyEMGbut only recently has EMG technology approached the reliability of Toco in reporting contractionsThere are now four devices marketed for fetal monitoring that use this technologyand both use several ECG pads to record small uterine EMG signalsAlthough FDA clearedthe benefits of these devices over Doppler Toco methods are slightThere remains significant need to improve the reliability of fetal monitoringand especially to correctly identify contractions as true or false laborThis application is based on our advanced understanding of how the uterus generates coordinated contractions without a pacemaker or dedicated electrical conduction pathwaysWe show that contractions of the uterine muscle create an electric field that is directed perpendicular to the skinrather than parallel with the skinas has long been assumedTo efficiently observe these signalswe created a novel directional EMG sensorwe call thearea sensorOur prototype gatherstimes the uterine bioelectrical signalwhen compared to ECG pad type electrodesIn this workwe propose to first optimize sensor design to increase sensor efficiency and signalTo accomplish thiswe will vary the electrode sizewidthand surface area to createrelated designsthen test each design onphantomsmade of hydrogel that mimic human fatWe will then use the best design on preterm and obese patients to learn the monitoring capabilities in the most challenging patientsFinallywe will usesensors to directly observe how well the local contractions are synchronizedhighly synchronized predicts true laborunsynchronized predicts false laborThen we will check this prediction against that patient s progress over the ensuinghoursThese data will validate the ability to separate false and true laborwhich has never before been accomplished using noninvasive methods External fetal monitoring is used to assess the moment to moment health of unborn babies and is used to make important decisions regarding delivery and medical management of laborWe have designed a new method of fetal monitoring based on our novel sensors for electromyographyWe will further refine these sensors to optimize the design of our fetal monitor systemand noninvasively determine if any patient is in labor or not in labor