Wearable Devices Comprising Semiconductor Diode Light Sources With Improved Signal-To-Noise Ratio

What is this patent about?

’790 is related to the field of wearable physiological monitoring devices and, more broadly, to optical remote sensing. The background of the invention lies in the increasing need for non-invasive methods to measure physiological parameters, such as blood glucose levels, which traditionally require drawing blood. The patent addresses the challenges of achieving adequate sensitivity and selectivity in non-invasive measurements, particularly when dealing with spectral artifacts from skin and other blood constituents.

The underlying idea behind ’790 is to use a synchronized light source and detection system in a wearable device to measure physiological parameters. The device shines light onto the skin, measures the reflected light, and analyzes it to determine the levels of various physiological parameters. A key aspect is improving the signal-to-noise ratio by synchronizing the detection with the light source, increasing the light intensity, and using change detection to compare signals when the light source is on versus off.

The claims of ’790 focus on a wearable device that measures physiological parameters based on reflected light from tissue. The device includes a light source with multiple LEDs or semiconductor diodes, lenses to deliver the light to the skin, and a detection system synchronized with the light source. The independent claims emphasize the use of spatially separated detectors, analog-to-digital converters, and techniques to enhance the signal-to-noise ratio, such as increasing light intensity and comparing signals with the light source on and off.

In practice, the wearable device would be placed on the wrist or the back of the hand. As the user stretches their hand or moves their fingers, the physiological parameters being measured (e.g., blood flow, blood constituents) change, and these changes are detected by the optical system. The synchronization between the light source and the detection system is crucial for minimizing noise and improving the accuracy of the measurements. The device also incorporates object identification capabilities, suggesting potential applications beyond just physiological monitoring.

’790 differentiates itself from prior approaches by using a combination of techniques to improve signal quality. Unlike systems that rely on simple light transmission or reflection, this invention actively synchronizes the light source and detection, dynamically adjusts light intensity, and employs change detection. The use of multiple spatially separated detectors and analog-to-digital converters further enhances the system's ability to extract meaningful signals from noisy data. This combination of features aims to provide a more reliable and accurate non-invasive method for monitoring physiological parameters compared to existing solutions.