Investigation of a camera-based contactless pulse oximeter with time-division multiplex lightning on piglets for neonatological applications.

Objective: The purpose of the study is to create the basis for non-contact monitoring of premature babies in neonatal intensive care units.

Methods: A contactless pulse oximeter is presented which measures the arterial oxygen saturation and heart rate with a monochrome camera and a time division multiplex controlled illumination with three wavelengths (660 nm, 810 nm and 940 nm). The related hardware setup and the signal processing is described in detail. The newly developed technology as prototype was used for the first time on an animal model.

Results: Using the camera system and our new designed algorithm for further analysis, the detection of heartbeat and calculation of the oxygen saturation was evaluated. Under ideal conditions, heartbeat and respiration were separated clearly by flat breathing and only minor intervention. In this case, the saturation can be determined with an mean difference of 0.7%.

Conclusion: The general functionality of the sensor can be guaranteed by the results of the presented experiments under ideal conditions. The results allow a systematic improvement for the further development of contactless vital sign monitoring systems.

Significance: The results presented here are a major step towards the development of an incubator with non-contact sensor systems for use in the neonatal intensive care unit.