Apple has filed a great number of patents relating to possible future blood pressure monitoring to Apple Watch like this one. Rumors of such a feature has also been rumored for years by Bloomberg's Mark Gurman. Yet the feature has yet to come to market.

This week the U.S. Patent and Trademark Office officially published a patent application patent from Samsung that relates to bringing Blood Pressure monitoring to future devices such as the Galaxy Watch, notebooks, an interesting entry called a "Watch Phone," tablets and more. For the sake of this patent, Samsung chose to present Blood Pressuring Monitoring on future foldable devices, as noted in the patent figures presented below.  

Samsung's invention covers a display device capable of detecting a photoplethysmography signal using an image display panel and measuring biometric information such as a user's blood pressure.

Embodiments of the present disclosure also provide a display device capable of increasing Signal-to-Noise Ratio (SNR) and biometric information measurement accuracy by setting and correcting light sensing conditions used to detect biosignals such as pulse wave signals in real time according to the touch shape and touch area of a user's body part.

According to an embodiment of the present disclosure, there is provided a display device including: display pixels arranged in a display area of a display panel; light sensing pixels arranged in the display area; a display scan driver configured to cause the display pixels to emit light; a light sensing scan driver configured to cause the light sensing pixels to sense light; and a main driving circuit configured to measure a user's biometric information by using light sensing signals provided from the light sensing pixels, wherein the main driving circuit senses the user's touch area when the user's biometric information is measured, and sets a biometric information measurement area and a measurement condition, which includes an emission color and an emission luminance, according to a shape of a sensed touch area and touch area information to measure the user's biometric information.

According to embodiments of the present disclosure, when light output from an image display pixel is reflected from a part of the body such as a user's finger, the reflected light is sensed by a light sensing pixel of the display panel, to detect biometric information such as the user's blood pressure. This way, biometric information such as the user's blood pressure can be detected using the display panel of the display device.

According to the embodiments of the present disclosure, biometric information can be measured by setting and correcting light sensing conditions for detecting biosignals such as pulse wave signals in real time according to the touch shape and touch area of a user's body part. Accordingly, the SNR for biometric information measurement can be increased and the user's biometric information can be more accurately measured according to the characteristics of the user's body part, such as the face, scalp, and finger blood vessels.

Samsung's patent FIG. 11 is a diagram showing an image display screen and a body part touch area detection process during a biometric information measurement period; FIG. 13 is a diagram showing a process of setting a biometric information measurement area in a body part touch area.

Samsung's patent FIGS. 18 & 21 illustrates two foldable devices (book-style and flip-style) that Samsung is considering for their future blood pressure monitoring feature; FIG. 15 is a graph for illustrating a method of calculating blood pressure from the biometric information.

With both Apple and Samsung racing to bring new health features to their respective devices, it'll be interesting to see which company will be first to bring this feature to market.