Low-Complexity System and Algorithm for an Emergency Ventilator Sensor and Alarm

TL;DR

This paper presents a low-cost, easy-to-implement electronic sensor and alarm system for emergency pressure-cycled ventilators, capable of estimating vital metrics and alerting malfunctions, suitable for resource-limited settings.

Contribution

It introduces a novel low-complexity signal processing algorithm using nonlinear recursive envelope trackers for ventilator monitoring.

Findings

Accurately estimates pressure and respiratory rate.

Operates on low-resource microcontrollers.

Provides reliable alarm functionality.

Abstract

In response to the shortage of ventilators caused by the COVID-19 pandemic, many organizations have designed low-cost emergency ventilators. Many of these devices are pressure-cycled pneumatic ventilators, which are easy to produce but often do not include the sensing or alarm features found on commercial ventilators. This work reports a low-cost, easy-to-produce electronic sensor and alarm system for pressure-cycled ventilators that estimates clinically useful metrics such as pressure and respiratory rate and sounds an alarm when the ventilator malfunctions. A low-complexity signal processing algorithm uses a pair of nonlinear recursive envelope trackers to monitor the signal from an electronic pressure sensor connected to the patient airway. The algorithm, inspired by those used in hearing aids, requires little memory and performs only a few calculations on each sample so that it can run on nearly any microcontroller.