It would be possible to DIY this, it might be clunkier than most would expect and have worse battery life. *edit, found this eval kit by maxim https://www.dig

It would be possible to DIY this, it might be clunkier than most would expect and have worse battery life. *edit, found this eval kit by maxim https://www.digikey.com/en/products/detail/maxim-integrated/MAXREFDES103/11589120 https://www.digikey.com/en/products/detail/maxim-integrated/... Kinda expensive and not very open for an eval kit. The only somewhat difficult part is implementing the pulse oximetry signal chain and analysis software. Everything else is basic integration.