Great. Other options are veterinary grade or biological or farm grade; whichever is cheaper.
Medical grade can be expensive as if intended to be used by real people, transducers often have to be verifiably sterile, even if just for use on the skin; sterilizing it ups the cost.
For home monitoring, there are also simpler things to build, many are also re-purposed COTS gear:
non-contact IR thermal sensor to watch for fever or hypothermia, or if kitchen burners are left on unattended
gas sensors to check if gas is turned off or if the pilot light blows
motion sensors [ to set alarms when Alzheimer patients wake up in the middle in the night and decide to go anywhere]
web cams, used to visually observe elderly or disabled patients, usually on -demand when an alarm goes off
There are Chinese grade EKG monitors that are cheap and meant for individual use, rarely used in the West, but very practical for the niche its fills: you can then send screen caps jpgs or video mpegs to the doc for analysis:
The patient just grasps the thing, puts their finger on the metal strip on the side of the device and then the tracing is stored in memory.