Prior art

Patent Analysis of US12268475: Identifying Most Relevant Prior Art

For US Patent 12268475B2, titled "Wearable device for differential measurement on pulse rate and blood flow," the most relevant cited prior art, based on the earliest effective filing date and extensive disclosure of related subject matter by the same inventor and assignee, is US9164032B2.

Analysis of US9164032B2

• Full Citation: US9164032B2, "Non-invasive blood constituent measurement using light," invented by Mohammed N. Islam, assigned to Omni Medsci Inc.

• Publication/Filing Date:

  • Filing Date: December 17, 2013
  • Publication Date (Grant Date): October 20, 2015
  • Priority Date: December 31, 2012 (based on provisional application No. 61/747,569)
    (Note: The priority date of US12268475B2 is also December 31, 2012. This indicates that US9164032B2 and US12268475B2 likely stem from the same original disclosure and are part of the same patent family. While this impacts a strict "prior art" determination under 35 U.S.C. § 102 for independent inventions, for the purpose of this analysis as requested, its disclosures are examined.)

• Brief Description:
  US9164032B2 describes a system and method for non-invasive measurement of blood constituents using light. The system includes a light source (which can be a super-continuum source, laser diodes, or light-emitting diodes (LEDs)), a human interface configured to be placed on a user's body part, and a detector. A processor analyzes the detector's output to measure various blood constituents (e.g., glucose, HbA1c, ketone bodies) and other physiological parameters like heart rate and oxygen saturation. The patent emphasizes techniques for signal-to-noise ratio (SNR) improvement, including differential measurements, ambient light subtraction, and increasing light source power. It also describes determining if the human interface is properly worn by the user.

• Claims Potentially Anticipated Under 35 U.S.C. § 102:
  Despite the shared priority date, US9164032B2 discloses elements corresponding to the independent claims (1, 4, and 8) and their dependent claims of US12268475B2, as detailed below:

  • Claim 1 (Apparatus for differential measurement):

    • "apparatus adapted to be worn by a user": US9164032B2 describes a "human interface" for placement on a user's body part (e.g., finger, hand, wrist) and mentions "wearable components."
    • "plurality of biosensors": US9164032B2 discusses a system configurable with "multiple input ports for various types of sensors," implying a plurality of biosensors.
    • "measuring of the one or more physiological parameters comprises a differential measurement, and wherein the one or more physiological parameters comprises a pulse rate monitoring and a blood flow measurement": US9164032B2 explicitly mentions "differential measurement" for compensation (e.g., for skin interference, common mode noise) and states the system can measure "heart rate and oxygen saturation" (heart rate being equivalent to pulse rate, and blood flow being related to these measurements).
    • "light source comprising a plurality of light emitting diodes that are configured to generate an output optical light having one or more optical wavelengths": US9164032B2 lists "light emitting diodes" as a possible light source and mentions a "plurality of light sources."
    • "one or more lenses configured to receive at least a portion of the output optical light and to deliver a lens output light to tissue comprising skin": US9164032B2 refers to "lens system" for light delivery.
    • "detection system configured to receive at least a portion of the lens output light reflected from the tissue and to generate an output signal is indicative of the one or more physiological parameters that has a signal-to-noise ratio": US9164032B2 details a "detector" that "detects light from the human interface" (including reflected light) and mentions improving SNR.
    • "detection system is configured to be synchronized to the light source": US9164032B2 describes modulating the light source and using a lock-in amplifier or band-pass filter, which implies synchronization.
    • "comprises a plurality of detectors that are spatially separated from each other": US9164032B2 mentions "plurality of detectors, for example, to sample different locations on the body."
    • "at least one analog to digital converter is coupled to at least one of the plurality of detectors": US9164032B2 states that data from the detector is "digitized using an analog-to-digital converter."
    • "apparatus is configured to increase the signal-to-noise ratio by increasing light intensity of at least one of the plurality of light emitting diodes from an initial light intensity": US9164032B2 teaches that "Higher optical power densities may be used to increase the signal-to-noise ratio."

  • Claim 2 (Ambient light subtraction for SNR improvement):

    • US9164032B2 explicitly describes increasing SNR by using "two measurements: one with the light source on and one with the light source off. By subtracting the two measurements, the ambient light can be eliminated." This directly anticipates the method of comparing signals with LEDs off and on.

  • Claim 3 (Determining if device is worn):

    • US9164032B2 states, "the system can determine that the human interface is being worn or is in contact with the user, before taking measurements. The system can check if sufficient optical signal is being collected or if the signal matches characteristics of a human body." This anticipates determining if the device is worn.

  • Claim 4 (Wearable device with processor for SNR and worn detection):

    • This claim combines the "wearable device" aspect with the processor-controlled steps of ambient light subtraction and worn detection, all of which are disclosed in US9164032B2.

  • Claim 8 (System for device worn by user, with SNR increase by intensity):

    • This claim aligns closely with the elements discussed for Claim 1, including the light source, lenses, detection system, synchronization, spatially separated detectors, ADC, and the method of increasing SNR by increasing light intensity.

Given the comprehensive overlap in technical disclosure and the common priority date, US9164032B2 is highly relevant as it details the foundational technology upon which US12268475B2 is built.