Development of a compact stand-alone esophageal pressure measurement device

Abstract

Mechanical ventilation requires optimal parameter setting for every single patient. For instance sufficient positive end-expiratory pressure (PEEP) may ensure oxygenation and prevent overdistension of lungs or alveolar collapse. To find optimal PEEP, transpulmonary pressure (airway pressure minus pleural pressure) guides as an indicator for both, chest wall mechanics and lung characteristic. Since measurement of pleural pressure is impractical in clinical routine, esophageal pressure can be used to estimate pleural pressure and may help to assure protective mechanical ventilation. We developed a PESO (derived from PESO = esophageal pressure) measurement system, which provides a compact stand-alone device to measure the esophageal pressure during mechanical ventilation of patients. In addition to the esophageal pressure, air way pressure is also measured to provide the synchronized data independent of the ventilator manufacturer. The device works with two commercial pressure transducers, whose signals are conditioned and digitized with an Arduino Nano microcontroller, which samples data with 62 kHz and transmits averaged data with 100 Hz to a mobile tablet PC, which acts as process, display and record unit. The compact system provides a working time of 5 hours. Therefore, the system supports the progress for mechanical ventilation research. This paper describes technical details as well as functionality.