Design and Construction of a Sensor to Monitor Blood Parameters During Resuscitation

Abstract

When performed by professional medical staff, cardiopulimary resuscitation (CPR) is successful in resuscitating patients in less than 45% of cases. Even in cases where patients survive, brain damage due to partially hypoxic conditions is a significant cause of morbidity. Monitoring cerebral oxygenation during resuscitative procedures has the potential to improve effectiveness by providing real time feedback for attending medical personnel. This will enable quick and informed procedural alterations, especially when conditions do not allow use of the full breadth of medical technology. We present work towards a device capable of providing real time information concerning the cerebral oxygenation and perfusion of a patient. We have considered both direct monitoring of cerebral oxygenation and perfusion using a transcranial ultrasound/NIRS system and ultrasound based monitoring of carotid blood flow as a proxy for cerebral oxygenation and perfusion. Two studies were performed in a poly-trauma pig model to test the viability of carotid based blood flow monitoring during critical conditions. In both cases, blood flow was detectable until near death conditions at mean arterial pressures (MAP) as low as 28 mmHg. Additionally, heart rate was accurately measured across all experimental conditions. As a result of positive initial data, a custom transducer was designed to carry this project further into pig studies and eventually human based research studies.