Design and validation of a handheld capnography device for cardiopulmonary assessment based on the Arduino platform

The design of a handheld capnography device is in great demand because of its effective and practical uses in all cardiac arrest resuscitations, according to the recommendation of the American Heart Association. Herein, a handheld capnography device that can be used in clinical settings and the home environment is reported. The proposed device was developed by using an infrared CO2 sensor, Arduino Mega2560, and a high-resolution display (2.8"). Furthermore, two rechargeable batteries (7.6V, 0.99A) and a secure digital card with a capacity of 16GB were incorporated to increase the portability and usability of the device. Algorithms were implemented to measure standard features, namely, inspired CO2 (ICO2), end-tidal CO2 (EtCO2), and respiratory rate (RR). The features of 15 healthy subjects were recorded by using the developed prototype and the standard capnography device (CapnostreamTM20 Model CS08798). Validation was performed with Bland-Altman plots. Findings revealed that mean differences ± standard deviations for the set limits of ICO2, EtCO2 and RR were 0.29 ± 1.30 millimeters of mercury (mmHg), 0.15 ± 1.77 mmHg and 0.40 ± 0.97 breaths per minute (bpm), respectively. Most of the differences among device measurements across all features fell within the 95% limits of agreement. Thus, the developed device may help manage respiratory distress conditions in and outside of a hospital setting.