Optical sensing device for heart rate and blood pressure monitor

Abstract

The invention discloses an optical sensing device for a heart rate and blood pressure monitor, comprising a light-emitting device, an optical lens, a photoelectric receiving tube and a light-shielding black frame, wherein the optical lens includes a light-gathering window above the light-emitting device and a photoelectric The light-transmitting window above the receiving tube; the light-shielding black frame is located above the light-emitting device and is set between the light-gathering window and the light-transmitting window; the light-gathering window adopts a Fresnel structure, which includes at least one transmission surface and one or more teeth composition of reflective surfaces. Due to the use of the oblique-axis Fresnel lens, it can achieve the purpose of concentrating and turning the light path with a relatively thin thickness. It concentrates the LED light and converges it to the measured point on the skin in an oblique direction, passing through the measured point. After being reflected by the blood vessels in the measuring point, it is received by the photoelectric receiving tube through the transparent window, thereby generating pulse and blood signals. The optical sensing device has the characteristics of strong signal, low noise, high sensitivity, accuracy, good reliability and the like.

Description

technical field [0001] The invention relates to the technical field of optical sensing devices, in particular to an optical sensing device used in heart rate and blood pressure monitors. Background technique [0002] With the increasing pressure of modern urban life, smoking and alcohol, overeating, obesity, insomnia, anxiety and other problems, the pressure on people's heart is also increasing, and the human heart rate carries a lot of information about the health status of the heart and body , Arrhythmia is facing a younger trend, if you do not pay attention to your own health, the consequences will be disastrous. The so-called arrhythmia refers to changes in the normal sequence of pulses that cause the heart to pump blood between the body. Since abnormal heart rhythms may only occur sporadically, it often takes long-term continuous monitoring to detect abnormal heart rhythms. Fast, accurate and smart heart rate and blood pressure monitors are necessary. [0003] The pat...

AI Technical Summary

Problems solved by technology

Such a sensor structure has several problems: 1. Because the light-emitting angle of the light-emitting device is relatively large, especially the smaller patch-type light emitters generally have a Lambertian distribution with a beam angle of 120 degrees, which only has a small A small part of the light will hit the desired detection position and be reflected by the blood vessel before being received by the light receiver

Most of the light is wasted where it is not needed, so the resulting signal strength is relatively weak

2. Due to the relatively large light-emitting angle of the light-emitting device, when some large-angle light passes through the transparent glass window in front of the light transmitter and light receiver, due to the light-guiding effect of the transparent glass window, this part of the light has the opportunity to be inside the window. Reflection and refraction back and forth, and then received by the light receiver, resulting in stray light, generating noise

These sensors in the prior art, due to their weak signal and high noise, have caused common technical problems such as low detection sensitivity, poor reliability, and inaccurate detection signals.

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