Pulsatile 3D-printed multilayer optical phantoms with microchannels for testing pulse oximeters

Understanding pigmentation's effect on pulse oximetry is critical amid evidence that pulse oximetry is less accurate for patients with pigmented skin. Optical phantoms can help validate oximeters, but commercial phantoms do not vary pigmentation. We develop a resin-based 3D printing method that generates mechanically flexible phantoms with tunable optical properties and <100 µm diameter channels. Using a reflectance-mode Maxim 86171 pulse oximeter, we evaluate how photoplethysmogram waveforms change as phantom pigmentation increases, and test an algorithm for estimating pigmentation from waveforms alone. 3D-printed phantoms can provide a platform for testing pulse oximeter performance across the spectrum of human pigmentation.