Near infrared imaging using laser arrays with distributed bragg reflectors

Abstract

A smart phone or tablet includes laser diodes, at least some of which may be pulsed and generate near-infrared light and include Bragg reflectors to direct light to tissue / skin. An array of laser diodes generates near-infrared light and has an assembly in front of the array that forms the light into a plurality of spots on the tissue / skin. A receiver includes detectors that receive light reflected from the tissue / skin. An infrared camera receives light reflected from the tissue / skin and generates data based on the received light. The smart phone or tablet is configured to generate a two-dimensional or three-dimensional image using at least part of the data from the infrared camera.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a Continuation of U.S. application Ser. No. 16 / 016,649 filed Jun. 24, 2018 (now U.S. Pat. No. 10,213,113), which is a Continuation of U.S. application Ser. No. 15 / 860,065 filed Jan. 2, 2018 (now U.S. Pat. No. 10,098,546), which is a Continuation of U.S. application Ser. No. 15 / 686,198 filed Aug. 25, 2017 (now U.S. Pat. No. 9,861,286), which is a Continuation of U.S. application Ser. No. 15 / 357,136 filed Nov. 21, 2016 (now U.S. Pat. No. 9,757,040), which is a Continuation of U.S. application Ser. No. 14 / 651,367 filed Jun. 11, 2015 (now U.S. Pat. No. 9,500,635), which is the U.S. national phase of PCT Application No. PCT / US2013 / 075736 filed Dec. 17, 2013, which claims the benefit of U.S. provisional application Ser. No. 61 / 747,477 filed Dec. 31, 2012 and U.S. provisional application Ser. No. 61 / 754,698 filed Jan. 21, 2013, the disclosures of which are hereby incorporated by reference in their entirety.[0002]This applicat...

AI Technical Summary

Benefits of technology

This patent describes a device that uses near-infrared light to monitor important physiological parameters, such as blood glucose levels. The device uses a special light source and a light detection system that can be attached to dental equipment or worn on the user's wrist or ear. The device generates a beam of light that is directed to the tissue, where it is reflected and captured by detectors. By analyzing the reflected light and increasing the intensity of the light source, the device can improve the signal-to-noise ratio and provide a non-invasive measure of blood glucose levels.

Problems solved by technology

Despite these advances, dental decay continues to be the leading cause of tooth loss.

Moreover, such lesions are difficult to detect in the early stages of development.

Leaving these lesions untreated may potentially lead to cavities reaching the dentine and pulp and perhaps eventually causing tooth loss.

However, detection using these methods may be somewhat subjective; and, by the time that caries are evident under visual and tactile examination, the disease may have already progressed to an advanced stage.

Also, because of the ionizing nature of x-rays, they are dangerous to use (limited use with adults, and even less used with children).

Although x-ray methods are suitable for approximal surface lesion detection, they offer reduced utility for screening early caries in occlusal surfaces due to their lack of sensitivity at very early stages of the disease.

This technique may be difficult to quantify due to an uneven light distribution inside the tooth.

However, the image provided by QLF may be difficult to assess due to relatively poor contrast between healthy and infected areas.

Moreover, QLF may have difficulty discriminating between white spots and stains because both produce similar effects.

Stains on teeth are commonly observed in the occlusal sites of teeth, and this obscures the detection of caries using visible light.

However, several challenges have arisen in these efforts.

Second, the non-invasive procedures have often transmitted or reflected light through the skin, but skin has many spectral artifacts in the near-infrared that may mask the glucose signatures.

Moreover, the skin may have significant water and blood content.

These difficulties become particularly complicated when a weak light source is used, such as a lamp.

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