US 10874304

US Patent 10,874,304: Near Infrared Measurement Device with Enhanced Signal-to-Noise Ratio

Title: Semiconductor source based near infrared measurement device with improved signal-to-noise ratio

Assignee: Omni Medsci Inc

Inventor: Mohammed N. Islam

Filing Date: October 31, 2019

Issue Date: December 29, 2020

Abstract:
A measurement system or wearable device for physiological parameters is described. This device utilizes a light source with multiple semiconductor sources (e.g., LEDs) that emit near-infrared light between 700 nm and 2500 nm. The system is designed to improve the signal-to-noise ratio by increasing the light intensity from at least one semiconductor source and/or by comparing multiple receiver outputs. For wearable devices, the system can capture light when LEDs are off (first signal) and when at least one LED is on (second signal), and then difference these signals to further enhance the signal-to-noise ratio. The output signal represents a non-invasive measurement of blood constituents in tissue, and can be processed using techniques like Fourier transforms. The system can communicate with a smartphone or tablet for display, storage, and transmission of processed data to a remote device.

Plain-Language Overview of Independent Claims:

US Patent 10,874,304 contains seven independent claims (claims 1, 9, 14, 19, 23, 27, and 33).

Independent Claim 1:
This claim describes a wearable measurement device that includes a light source with several light-emitting diodes (LEDs) for measuring physiological parameters. The device generates a near-infrared optical beam (700-2500 nm) by modulating at least one LED. This beam is delivered to tissue, and the reflected light is received by a receiver with multiple spatially separated detectors and analog-to-digital converters, which produce at least two outputs. The device improves the signal-to-noise ratio by comparing these two receiver outputs and/or by increasing the intensity of the light from at least one LED. It generates an output signal representing a non-invasive measurement of blood within the tissue.

Independent Claim 9:
This claim is similar to Claim 1, describing a wearable measurement device with LED light sources for physiological parameter measurement using near-infrared light (700-2500 nm). It highlights improving the signal-to-noise ratio by increasing LED light intensity. The receiver has multiple detectors, with one detector positioned at different distances from two distinct LEDs, allowing for comparison of the received light from these LEDs to generate the output signal. The receiver is synchronized to the LED modulation, using a lock-in technique to detect the modulation frequency.

Independent Claim 14:
This claim also pertains to a wearable measurement device with LED light sources for physiological measurements using near-infrared light (700-2500 nm). It focuses on improving the signal-to-noise ratio by increasing LED light intensity and by comparing at least two receiver outputs from spatially separated detectors. It further specifies that one detector is situated at different distances from two LEDs, enabling the generation and comparison of signals responsive to light from each LED to form the final output signal. The receiver is synchronized to the LED modulation, employing a lock-in technique for frequency detection.

Independent Claim 19:
This claim describes a wearable measurement device with a light source comprising multiple LEDs for physiological parameter measurement using a near-infrared optical beam (700-2500 nm). The device includes a receiver that captures ambient light when the LEDs are off (first signal) and captured light (including reflected tissue light) when at least one LED is on (second signal). The signal-to-noise ratio is improved by subtracting the first signal from the second signal and by differencing at least two receiver outputs. Additionally, increasing the LED light intensity further improves the signal-to-noise ratio. The device generates an output signal for non-invasive blood measurements.

Independent Claim 23:
This claim is directed to a wearable device similar to Claim 19, using LED light sources and near-infrared optical beams (700-2500 nm) for physiological parameter measurement. The receiver captures light both when LEDs are off (first signal) and when at least one is on (second signal). The signal-to-noise ratio is enhanced by subtracting the first and second signals and by differencing two receiver outputs from spatially separated detectors. The claim also includes improving the signal-to-noise ratio by increasing the light intensity of at least one LED, and generating an output signal for non-invasive blood measurements.

Independent Claim 27:
This claim details a measurement system (which may be wearable) with a light source featuring multiple semiconductor sources that generate a near-infrared optical beam. The system improves its signal-to-noise ratio by increasing the light intensity from at least one of these semiconductor sources. An apparatus receives and delivers an analysis output beam to a sample. A receiver processes the reflected or transmitted analysis beam, generates an output signal, and synchronizes with the light source. The system also includes a smartphone or tablet for receiving, processing, storing, displaying, and wirelessly transmitting the output signal, as well as a remote device for receiving, processing, and storing the transmitted data, including a history of the received status over time.

Independent Claim 33:
This claim focuses on a wearable device designed for use with a smartphone or tablet. It includes a measurement device with multiple semiconductor light sources for physiological parameter measurement. The measurement device generates a modulated input optical beam with one or more optical wavelengths, delivers it to tissue, and receives a reflected portion. The receiver captures light when the semiconductor sources are off (first signal) and when at least one is on (second signal), and synchronizes with the modulation. The signal-to-noise ratio is improved by differencing the first and second signals and by increasing the light intensity from at least one semiconductor source. The device generates an output signal for non-invasive blood measurements and is configured to communicate with the smartphone or tablet, which processes, stores, displays, and transmits the output signal wirelessly.