Back in early December Apple was granted a major patent relating to a Future Apple Watch that could monitor blood pressure. Today the U.S. Patent and Trademark Office officially granted Apple their second patent regarding this invention.

As a quick review of the base invention, Apple's patent generally relates to the measuring and monitoring of blood pressure. More specifically, embodiments may determine and apply one or more correction factors for calculating or adjusting a measured blood pressure to provide for a more accurate blood pressure measurement. This may be particularly beneficial with blood pressure measurement devices that may be worn by a user that non-invasively measure and monitor blood pressure of a user.

Further, Apple's invention provides non-invasive devices and methods for determining an pressure of blood within a cardiovascular system of a user. It may be desirable to reduce a bulkiness of current blood pressure measurement devices to make blood pressure measurements more convenient. While reducing the bulkiness of current blood pressure measurement devices may be desirable, doing so may come with additional challenges.

Apple's patent FIG. 4 below illustrates an exemplary device #10a that may measure blood pressure using applanation tonometry; FIG. 5 illustrates another exemplary device #10b that may measure blood pressure using oscillometry; FIG. 11 illustrates an exemplary device 1100 for detecting a band configuration/estimating a wrist circumference, and/or estimating a target artery depth.

Apple's patent FIG. 12 above illustrates an Apple Watch that includes an ultrasound transducer #1210 coupled with a band #1202. The ultrasound transducer may be configured to direct ultrasound energy toward the target artery #1201. The ultrasound transducer may be further configured to receive reflected ultrasound energy from the target artery to determine a depth of the target artery.

Apple's patent FIG. 14 above illustrates an exemplary device for estimating target artery depth. The band may support an actuator #1406 proximate the target artery #1407. One or more sensors #1408 may be provided that are configured to measure a parameter associated with an actuation amount of the actuator to determine a distance.

Apple further notes that band #1404 may include an actuator may be a fluid bladder in some embodiments. While illustrated as a fluid bladder, it should be understood that actuator may be a linear actuator in other embodiments.

Apple's second granted patent regarding blood pressure measurements introduces a series of 18 new patent claims that will better protect this invention. A Few of the new patent claims are presented below:

Patent Claim #1: "A wrist-worn device comprising: a pressure sensor for measuring a pressure signal from a target artery; an actuator coupled with the pressure sensor, wherein the actuator is configured to apply an applanation force to a wrist of a user during pressure measurement by the pressure sensor, and wherein the actuator comprises an actuator sensor for monitoring a displacement distance of a contact end of the actuator as it moves against the wrist of the user over a reconfiguration of the actuator, between a first configuration and a second configuration, that induces a variation in the applanation force applied to the wrist via the contact end of the actuator; and a processor coupled with the pressure sensor and the actuator, wherein the processor is configured to: monitor the pressure signal and the actuator sensor during an actuation of the actuator to identify an amount of the displacement distance of the contact end of the actuator as it moves against the wrist of the user that reconfigures the actuator from the first configuration to the second configuration or from the second configuration to the first configuration, wherein the second configuration of the actuator results in a desired variation in the pressure signal, and wherein the applanation force in the second configuration is greater than the applanation force in the first configuration; determine a correction factor based on the identified amount of the displacement distance of the contact end of the actuator as it moves against the wrist of the user; and calculate a blood pressure value based on the pressure signal from the pressure sensor and the correction factor."

Patent Claim #2: "The wrist-worn device of claim 1, wherein the processor monitors the pressure sensor during the actuation of the actuator to: identify initial contact or discontinuation of contact of the contact end of the actuator or the pressure sensor with the wrist of the user during the actuation of the actuator; and identify a mean arterial pressure of the target artery based on the pressure signal measured by the pressure sensor when the actuator is in the second configuration; and wherein the identified amount of the displacement distance of the contact end of the actuator as it moves against the wrist of the user corresponds to one of: actuation of the actuator from the initial contact of the contact end of the actuator or the pressure sensor with the wrist of the user to the second configuration of the actuator; or actuation of the actuator from the second configuration to the discontinuation of contact of the contact end of the actuator or the pressure sensor with the wrist of the user."

Patent Claim #13: "A method comprising: measuring a pressure signal from a target artery using a pressure sensor; using an actuator coupled with the pressure sensor to apply an applanation force against a wrist of a user during pressure measurement by the pressure sensor; monitoring, via an actuator sensor, a displacement distance of a contact end of the actuator as it moves against a wrist of the user over a reconfiguration of the actuator, between a first configuration and a second configuration, that induces a variation in the applanation force applied to the wrist via the contact end of the actuator; monitoring the pressure signal during an actuation of the actuator to identify the displacement distance of the contact end of the actuator as it moves against a wrist of the user that reconfigures the actuator from the first configuration to the second configuration or from the second configuration to the first configuration, wherein the second configuration results in a desired variation in the pressure signal, and wherein the applanation force in the second configuration is greater than the applanation force in the first configuration; determining a correction factor based on the identified amount of the displacement distance of the contact end of the actuator as it moves against a wrist of the user; calculating a blood pressure value using the pressure signal from the pressure sensor and the correction factor; and outputting the blood pressure value.

Patent Claim #14: "The method of claim 13, wherein the identification of the amount of the displacement distance of the contact end of the actuator as it moves against a wrist of the user comprises: identifying an initial contact or discontinuation of contact of the pressure sensor or the contact end of the actuator with the wrist of the user during the actuation of the actuator using pressure signals from the pressure sensor; and identifying a mean arterial pressure based on the pressure signal measured by the pressure sensor when the actuator is in the second configuration; and wherein the identified amount of the displacement distance of the contact end of the actuator as it moves against the wrist of the user corresponds to one of: actuation of the actuator from the initial contact of the pressure sensor or the contact end of the actuator with the wrist of the user to the second configuration of the actuator; or actuation of the actuator from the second configuration to the discontinuation of contact of the contact end of the actuator or the pressure sensor with the wrist of the user."

You could review our first granted report on this invention here. Apple's patent was never published as a patent application to keep this project secret. The record shows that Apple only filed a provisional patent, that wasn't made public, so as to secure the patent's future granting and to keep competitors in the dark.

Review Apple's current granted patent 10,881,307 to review the full list of new patent claims here.  

Apple's second granted patent regarding blood pressure monitoring is part of a larger project on this subject. Back on December 10, 2020, Patently Apple posted a patent application report titled "Apple Reveals an all-new Wearable Blood Pressure Device with an Inflatable Cuff and Controller Interface." The patent figures presented below are from that patent.

With the Apple Watch now being considered a "health" device with heart monitoring, fall detection, ECG and Blood Oxygen features, measuring blood pressure is definitely one of the major health features that Apple wants to one day introduce.

Samsung is trying to mirror what Apple is offering on their Watch for the Android world. Last week Samsung was granted a patent for an all-new wearable device having an exchangeable sensor that could detect a biomarker, such as lactic acid, body temperature, or blood pressure, as well as blood sugar level. We'll post a brief report on this later today. Patent FIG. 1 from that patent is presented below.