Apple's introduction of Touch ID was made by Vice President of Marketing Phil Schiller during an iPhone media event on September 10, 2013. Touch ID is a fingerprint recognition feature, designed and released by Apple and is currently available on the iPhone 5S, the iPhone 6 and iPhone 6 Plus, the iPad Air 2, and the iPad Mini 3. Apple's engineers have racked up a number of Biometric related patents that you could review in our specialized Archives. They cover the possibility of Touch ID expanding to the Mac and may eventually evolve to so that the sensors are either behind an iPhone/iPad display or on the backside of these devices hidden in the Apple logo. Today, a new Biometrics related patent surfaced in Europe with a whole new approach to bringing biometric ID to the Apple Watch.

Apple has filed a number of Apple Watch patents in Europe of late. We covered one in a June 12 report titled "New Apple Watch Patent Covers Wearable Multi-Modal Physiological Sensing System." The second patent was covered in our June 25 report titled "Apple Advances Future Apple Watch Heart Rate Sensor System." Today we've discovered Apple's third Apple Watch patent filing published in the last 30 days.

Apple's Patent Background

A light emitter and light sensor pair can be used to determine one or more characteristics of a user's vasculature. For example, a pulse oximeter employs a light emitter and a light sensor to measure the percentage of oxygenated blood in a subject.

Apple's Invention: User ID using Plethysmography

Apple invention relates to biometric identification based on Plethysmography. In examples of the present disclosure, light emitters and light sensors can be used to perform biometric identification of a user based on identifying characteristics of the user's vasculature. For example, light information can be obtained at one or more light sensors, and the information can be compared to stored information associated with a user identity. Based on the comparison, the user of the device can be identified as having the user identity.

In Apple's patent FIG. 1 noted below illustrates an electronic device #100 that performs biometric identification according to examples of the disclosure. A first light emitter #102 and a first light sensor #104 may be co-located on the electronic device. The first light emitter may emit light at a first wavelength /q. A second light emitter #106 and a second light sensor #108 may be co-located on the electronic device. The second light emitter may emit light at a second wavelength /...2. During use, the electronic device may be situated proximate to the skin #110 of a user. For example, the electronic device may be strapped to the user's wrist.

Each light emitter may emit light towards the user's skin such that a portion of the light is absorbed by the skin, the blood, and/or other parts of the user's body, and an additional portion of the light is reflected back to the co-located light sensor. The light sensor may generate information indicating an amount of light reflected. Such information can be used to determine how much of the light emitted by a co-located light emitter is absorbed by the blood of the user, which can further indicate the volume of blood present in the skin of the user. The volume of blood present in the skin can be a function of several factors, including the cyclical movement of blood to and from the skin and the particular physical characteristics of the vasculature of a user, among other possibilities.

Apple's patent FIG. 1 noted above illustrates an electronic device that performs biometric identification according to examples of the disclosure. The top graphic with the four sensors is a generic graphic showing that Apple's FIG. 1 takes the shape of the backside of the current Apple Watch; Apple's patent FIG. 5 illustrates a method of storing identifying light information to be used in identification of a user at a later time.

Apple notes in their filing that their patent FIG. 5 noted above illustrates a method of storing identifying light information to be used in identification of a user at a later time. "Motion information and light information may be received during a first time period (500, 502). A gesture may be determined from the motion information (504). Then, the light information may be stored in association with the determined identifying gesture and an identity of a user of the electronic device. This stored light information may be used to later identify the user of the electronic device."

According to Apple, a gesture and a first time period of the gesture may be determined based on the motion information. Stored gesture information and/or one or more heuristics may be used to determine a gesture from the motion information. For example, "motion information may indicate that the user rapidly moved a hand from their waist to the side of their head, and such a motion can be recognized as a gesture. More specifically, the gesture may be recognized as a gesture associated with the identification process."

Custom gesturing for the Apple Watch was also recently covered in a patent report regarding the sharing of information between two user's Apple Watches. So this is a consistent theme that Apple is working on.

Whether Apple's latest biometric ID system is to be used in conjunction with Touch ID or for another future application is unknown at this time.

Apple's biometric related patent was published today in Europe today and originally filed internationally in Q4 2013.

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