Ah, my mistake.
The CORE was made with Littmann, it’s quality is sub par and their audio processing is rubbish. It only has BLE for data streaming, but as pairing is involved, it’s encrypted.
My father has both the CORE and the newer CORE 500 which has the analog output I mentioned.
It’ audio processing is far superior to the CORE and it features ECG as well.
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The project was canned, so nothing happened with all the work. If funding was available we might have gone to market.