Control of a Mechanical Ventilator Using the pre‐Bötzinger Complex

Abstract

Chronic mechanical respiratory support is critical for patients unable to breathe spontaneously, yet current mechanical ventilators fail to synchronize to the body's physiological needs. Ventilator asynchrony often results in ventilator induced lung injury to those on respiratory support. We are developing a patient‐triggered ventilator to provide respiratory support in a more physiologically synchronous manner than existing ventilation methods. Our system utilizes neurological activity within the brainstem, particularly in the pre‐Bötzinger complex (pre‐BötC), to control a ventilator with minimal latency between brainstem electrical activity and ventilation.In vivo experiments were performed on anesthetized mice. Extracellular recordings of the pre‐BötC neurons were made; pre‐BötC electrical activity was amplified and integrated. This integrated signal was then processed into a valve‐control signal. Constant air pressure was supplied to the valve; airway pressure (Paw) between the valve and a test lung was measured using a pressure transducer. Pre‐BötC, diaphragmatic EMG, and Paw data were visualized and recorded for analysis. System latency was determined by measuring the time between the onset of pre‐BötC inspiratory activity and the onset of resulting Paw inspiratory swings. The system was effective in using the pre‐BötC electrical activity to ventilate a test lung. The average system latency was 20 ± 10ms.Our preliminary findings demonstrate that a mechanical ventilator can be operated using the respiratory signal produced by the pre‐BötC. Further, the system operates with latency less than the delays reported for existing patient‐triggered ventilators.Funding source: SCRI