Wearable Device For Differential Measurement On Pulse Rate And Blood Flow
Patent No. US12268475 (titled "Wearable Device For Differential Measurement On Pulse Rate And Blood Flow") was filed by Omni Medsci Inc on Oct 25, 2024.
What is this patent about?
’475 is related to the field of wearable physiological monitoring devices, specifically those employing optical techniques to measure parameters like pulse rate and blood flow. The background acknowledges the increasing need for non-invasive monitoring solutions, particularly for conditions like diabetes, where frequent blood draws are inconvenient and potentially risky. Existing non-invasive methods often struggle with sensitivity and selectivity due to interfering signals from other blood constituents and skin artifacts.
The underlying idea behind ’475 is to improve the accuracy and reliability of wearable optical sensors by actively managing and compensating for noise. This is achieved by using a differential measurement of reflected light, synchronizing the light source and detection system, and employing a signal processing technique that compares signals obtained when the light source is on and off. The device also uses an algorithm to determine when it is actually being worn by the user, preventing false readings.
The claims of ’475 focus on a wearable device that uses a light source (LEDs) to illuminate tissue, a detection system to receive reflected light, and a processor to analyze the signal. The independent claims emphasize the device's ability to improve the signal-to-noise ratio by increasing light intensity and comparing signals obtained with the light source on and off. A key aspect is the device's capability to determine whether it is being worn based on the processed output signal.
In practice, the device operates by emitting light into the skin and measuring the reflected light using multiple spatially separated detectors. The synchronization between the light source and detection system, along with the analog-to-digital converters, ensures precise data acquisition. The signal processing algorithm then compares the signals obtained when the LEDs are on and off, effectively subtracting out ambient light and other sources of noise. This active noise cancellation significantly enhances the accuracy of the physiological parameter measurements.
’475 differentiates itself from prior approaches by actively managing noise through a combination of hardware and software techniques. Unlike passive systems that simply rely on filtering or signal averaging, this invention uses a differential measurement and a synchronized detection system to actively compensate for ambient light and other sources of interference. The wear detection algorithm further enhances reliability by ensuring that measurements are only taken when the device is properly positioned on the user's body, preventing spurious readings and improving the overall accuracy of the monitoring system.
How does this patent fit in bigger picture?
Technical landscape at the time
In the mid-2020s when ’475 was filed, wearable devices for physiological monitoring were at a time when signal processing techniques were commonly relied upon to enhance data quality due to limitations in sensor sensitivity and power constraints. At that time, systems commonly relied on algorithms to filter noise and compensate for motion artifacts, when hardware or software constraints made real-time data analysis non-trivial.
Novelty and Inventive Step
The examiner approved the application because the prior art, whether alone or combined, did not disclose specific limitations of the claims. For example, the prior art failed to teach an apparatus configured to increase the signal-to-noise ratio by increasing the light intensity of light emitting diodes, or a detection system configured to generate a first signal when the light emitting diodes are off, generate a second signal when the light emitting diodes are on, and increase the signal-to-noise ratio by comparing the first and second signals. Also, the prior art failed to teach a wearable device that generates a first output signal with a first signal-to-noise ratio when the light source is on, a second output signal with a second signal-to-noise ratio when the light source is off, and a third output signal using portions of the first and second output signals, where the third output signal has a higher signal-to-noise ratio and is associated with a physiological parameter. Furthermore, the prior art failed to teach measuring physiological parameters that change in response to hand or finger movements, and using this information to determine if the device is being worn.
Claims
This patent contains 20 claims, with independent claims 1, 8, and 15. The independent claims are generally directed to wearable devices or systems that use light sources and detectors to measure physiological parameters of a user. The dependent claims generally add further detail and limitations to the independent claims.
Key Claim Terms New
Definitions of key terms used in the patent claims.
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Date
Description
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US12268475
- Application Number
- US18927698
- Filing Date
- Oct 25, 2024
- Status
- Granted
- Expiry Date
- Dec 17, 2033
- External Links
- Slate, USPTO, Google Patents