Hello, how are you?
I worked on a similar project about 6 years ago.
The project performed ECG reading from electrodes, the data was processed in a microcontroller and sent via bluetooth to an Android app.
Since that a lot has evolved. I'm sure that this idea can be carried out with greater precision and quality today.
I understand that this project involves 3 main modules:
1 - Signal collection and treatment.
This is certainly the most complex part, the analog circuit to filter and amplify the ECG requires a lot of attention. The skin is a huge antenna for noise, but the academic literature has good methods that can be used.
2 - Transmission of information
I used a Microchip uC for signal treatment and an independent bluetooth module (incompatible with the most current protocols). A solution with Arduino and a newer Bluetooth module would work well, or (and this is my suggestion) an ESP32 module, which has more processing than an Arduino and built-in wifi and bluetooth modules.
3 - Information Display
An Android APP to view the data. But what would be interesting for your project? Real-time values? Graphic?
I understand that it is a long term project and that requires trust in the contracted professional. Feel free to get in touch. We can talk and you evaluate if I am the right person for your project.