I want to develop a health care app using Android smart watch devices that have an optical heart rate sensor. Examples of such devices are: Samsung gear live, Moto360, LG G watch R, etc.
To do this, I need the raw PPG signal data from those devices, but I found that the Android API only supports heart rate data by BPM unit.
Does anyone know if the raw signal data is accessible, and if so, how do I get access to that data?
Yes, it is possible (at least on a Samsung mobile device such as the S5, S6 etc.).
See this link: http://developer.samsung.com/galaxy#sensor-extension
From the Samsung website:
The HRM Sensor is located on the rear panel of the phone. If you place your finger, measurement starts. The photoplethysmogram(PPG) signal means the amount back of IR / RED light that reflected from blood vessel in the finger.
Use Samsung's SDK and it will give you the raw values (values range from 0 to ~64600 if I remember correctly).
Yes, It is possible to do that. I have answered a similar question here :Android Wear: How to get raw PPG data?
Basically, try to follow these steps:
1- Get the sensor type (represented by a number) of your PPG sensor (it is a constant that describes the sensor). This can be done by listing all the available sensors on your device:
List<Sensor> sensorList = mSensorManager.getSensorList(Sensor.TYPE_ALL);
for (Sensor currentSensor : sensorList) {
Log.d("List sensors", "Name: "+currentSensor.getName() + " /Type_String: " +currentSensor.getStringType()+ " /Type_number: "+currentSensor.getType());
}
2- Then, try to find the sensorType of your PPG sensor. In your output, you will find one of the sensors containing the word ppg in it's type. For instance here is what the ppg sensor of my Huawei watch 2 looks like:
Name: AFE4405 light Sensor /Type_String: com.huawei.watch.ppg /Type_Number: 65537
3-Register your listener using the the type_number of your ppg sensor, mine is 65537 so I would do this:
sensorManager.registerListener(this,sensorManager.getDefaultSensor(65537),SensorManager.SENSOR_DELAY_NORMAL);
No, I have searched rigorously to extract the raw values but wasn't successful. AsteroidOS (asteroidos.org/) is a custom rom for few compatible watches, even after going through the entire source code, I could only find a single place where the Heart Rate Monitor was used.
Implementation File
https://github.com/AsteroidOS/android_frameworks_native/blob/e88bdd18c91c313b2102445eb5eb6213814bc124/libs/gui/Sensor.cpp
The reason I feel why It wouln't work because the Hear Rate is computed by the Hard Ware internally.
For experimental purposes you could build your own PPG sensor externally
www.sparkfun.com/products/11574
and connect it to aurdino.
Or could search for some wireless PPG sensor and build one of your own.
