Sensor device for optical measurement of biological properties
Inventors
Ben Ishay, Arik • Sarussi, Israel • May, Johanan • GURGOV, HASSID C.
Assignees
Publication Number
US-12193811-B2
Publication Date
2025-01-14
Expiration Date
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Abstract
A device, a substrate including a connection port. The substrate includes traces to enable a circuit of the substrate. The circuit is connected to the connection port. A light sensor mechanically and electrically attached respectfully to a first planar surface of the substrate and the circuit. A light source is mechanically and electrically attached respectively to the first planar surface and the circuit. The light source is located lateral to the light sensor at a first distance. A light signal of the light source emanates from the light source at an angle perpendicular to the first planar surface and a reflector mechanically attached to the first planar surface and located between the light sensor and the light source. The light signal is substantially reflected by the reflector away from the light sensor.
Core Innovation
The present invention discloses a structure for a sensor device designed for optical measurement of biological properties of a subject employing a reflective measurement technique. The structure includes reflection of the incident light of one or more light emitters by a reflector positioned in proper angle and distance relative to a light detector unit of the sensor device so that proper selection of the direction and distances substantially improves the magnitudes, the SNR and the AC/DC ratios of the measured optical signals. The invention provides configurations in which most of the light components reaching the light detector are reflected/scattered from perfused tissue layers while many components reflected/scattered from non-perfused near-surface tissue layers do not reach the detector.
The background identifies that reflective blood measurement techniques can suffer from low signal-to-noise ratios (SNR) and low AC/DC ratios due to direct surface reflections and reflections from non-perfused tissue layers which contribute baseline DC components. Attempts to overcome these limitations by increasing irradiated light power or number of light sources can increase noise and baseline DC, and therefore may not provide satisfying results. The invention addresses the need to improve the quality of optical signals measured by reflective blood measurement techniques to provide higher AC/DC ratios and improved SNR.
Claims Coverage
This patent includes one independent claim and three extracted inventive features corresponding to the main elements recited in the independent claim.
Substrate with connection port and circuit traces
A substrate including a connection port, wherein the substrate includes traces to enable a circuit of the substrate, wherein the circuit is connected to the connection port.
Light sensor and light source mounted to a first planar surface with lateral spacing
A light sensor mechanically and electrically attached respectively to a first planar surface of the substrate and the circuit; a light source mechanically and electrically attached respectively to the first planar surface and the circuit, wherein the light source is located lateral to the light sensor at a first distance, wherein a light signal of the light source emanates from the light source at an angle perpendicular to the first planar surface.
First and second reflectors configured to redirect emitted light to the sensor
A first reflector mechanically attached to the first planar surface such that the first reflector covers the light source and located between the light sensor and the light source; a second reflector mechanically attached to the first planar surface such that the second reflector surrounds the first reflector; wherein the light signal is substantially reflected by the first reflector towards the second reflector, and wherein the light signal is substantially reflected by the second reflector toward the light sensor.
Collectively, these inventive features define a device having a substrate with a connection port and traces, a light sensor and laterally spaced light source attached to a first planar surface with the emitted light signal, and an arrangement of concentric reflectors that substantially reflect the light signal from the light source toward the light sensor.
Stated Advantages
Substantially improves magnitudes, signal-to-noise ratio (SNR) and AC/DC ratios of the measured optical signals.
Reduces baseline DC components by preventing collection of light directly reflected from the organ surface and from non-perfused upper tissue layers.
Increases the proportion of detected light components scattered from perfused tissue layers, thereby enhancing blood-related pulsatile (AC) information in measured signals.
Mitigates optical signal distortions that may be induced in the measured signals due to movements of the body part/organ to which the sensor device is attached.
Documented Applications
Wearable devices to be worn over a portion of body segments, such as chest patch, head, neck, torso, or limbs (e.g., over the wrist, like a watch).
Optical measurement of blood-related properties including heart rate, blood flow, and arterial blood oxygen saturation.
Determination of blood-related analyte concentrations and parameters, explicitly including sugar (glucose), cholesterol, hemoglobin, bilirubin, and fat level.
Measurement of cardiac parameters such as blood pressure, cardiac output, and stroke volume; and measurements employing pulse oximetry and photoplethysmography (PPG) techniques.
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