In our previous project, we created a smartphone-based device to measure blood pressure from your fingertip. The user holds this device at heart level and press on the sensor unit on the back of the phone with her fingertip and while pressing, the device records the blood volume oscillations and the applied finger pressure using a light and pressure sensor. Recorded data is transferred to the phone via a Bluetooth circuit and an Application running in the backend of the phone employs a computation algorithm to estimate brachial systolic and diastolic BP. This smartphone-based device is an add-on to the Phone to measure blood pressure conveniently. Unlike this smartphone-based BP monitoring device, in our new project, we created a standalone iPhone Application to measure blood pressure using existing sensors embedded in the phone. We used the front camera of an iPhone to measure the blood volume oscillations in the finger artery and strain gauge array under the screen, popularly referred to as 3D-Touch, to estimate the applied finger pressure. To measure BP using this application, the user has to perform three main steps:

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