CN106073715B

CN106073715B - Red light vein enhancement display device and method

Info

Publication number: CN106073715B
Application number: CN201610483015.7A
Authority: CN
Inventors: 王潇
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2016-06-27
Filing date: 2016-06-27
Publication date: 2020-03-24
Anticipated expiration: 2036-06-27
Also published as: CN106073715A

Abstract

The invention discloses a red light vein enhancement display device and a method, wherein the device comprises a red light source, a scanning galvanometer and a driving circuit thereof, a focusing collimating lens, a detection module and a control module; the detection module comprises a converging lens, a red light filter and a red light detector. The red light source, the driving circuit and the detection module are respectively connected with the control module. The method of the invention utilizes the light beam emitted by the red light source to irradiate the target skin, judges whether veins exist under the irradiation position by detecting the backscattered light signal, then the control module modulates the light intensity of the red light according to the signal to distinguish the veins and tissues, and utilizes the scanning galvanometer to drive the light beam to scan the whole surface of the target skin, thereby finally enhancing the vein distribution. And respectively giving control modes under a continuous light mode and a pulse light mode by controlling the light intensity and the pulse of the monochromatic light output and the sampling time of the detector. Compared with the prior art, the device has a more compact and simpler structure on the premise of keeping the enhanced display effect.

Description

Red light vein enhancement display device and method

Technical Field

The invention relates to a vein display device and method, in particular to a red light vein enhancement display device and method, and belongs to the technical field of medical instruments.

Background

In the clinical diagnosis and treatment process, venipuncture is a common operation of medical workers, such as intravenous injection, blood drawing and blood testing and the like. At present, in the venipuncture process, the positioning of the vein is mainly determined by the observation of medical staff, the positioning is inaccurate, and particularly, when the puncture objects are infants, fat patients and patients with dark skin color, the puncture success rate is reduced due to too thin vein or unclear blood vessels, so that the pain of the patients and the disputes of doctors and patients are increased. Therefore, the vein enhancement display device is provided by an optical means, so that medical staff can observe the vein distribution visually, and the accurate positioning of the vein vessel is very important.

This problem is manifested around optical vein enhancement, and there are some related studies and products at home and abroad, which can be roughly divided into two categories. The first is to directly irradiate the skin with a red light source, and because hemoglobin in the venous vessels absorbs red light more strongly than surrounding tissues, the contrast between the distribution of the venous vessels and the surrounding tissues when observed by naked eyes is increased. Such as chinese patent publication nos. 203873737U and 102379699 a. This technique is simple in principle and structure, but has a limited reinforcing effect. The second type is that near-infrared light is utilized to irradiate the skin, because hemoglobin in vein blood vessels absorbs the near-infrared light more strongly than surrounding tissues, the distribution of the vein blood vessels under the target skin is obtained through an infrared detection system, and then the obtained vein distribution is projected in situ through a visible light projection mode. The projection method is divided into liquid crystal projection (e.g. chinese patent 103584836a) and laser projection (e.g. chinese patent 101156778A).

The first technology, which directly irradiates the skin with red light, enhances the contrast ratio by utilizing the strong absorption of veins to the red light, and has simple structure. However, the direct illumination of the surface light source lacks spatial modulation and temporal modulation, and has low resolution and limited contrast enhancement due to tissue scattering and the like. The second technology utilizes near infrared light detection and visible light in-situ projection display. The technology has the following greatest advantages compared with the first technology: (1) the resolution and accuracy of vein distribution detection are improved by using an image processing or signal processing method; (2) the contrast of the vein distribution display is improved by utilizing a visible light projection display mode. However, this technique uses a two-color light source, resulting in a complicated optical structure and high cost.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the single red light source is utilized to complete two functions of vein distribution detection and vein display, the advantages of the two technologies in the background technology are combined, the structure is simple, and the display enhancement effect is obvious.

The invention adopts the following technical scheme for solving the technical problems:

a red light vein enhancement display device comprises a red light source, a scanning galvanometer, a driving circuit of the scanning galvanometer, a detection module and a control module; the red light source, the drive circuit of the scanning galvanometer and the detection module are respectively connected with the control module;

the control module controls the red light source to output a red light beam, the red light beam is reflected to the surface of target skin to be scanned through the scanning galvanometer to generate backscattered light, the detection module detects backscattered light signals and transmits detection results to the control module, the control module judges whether veins exist or not according to the strength of the signals and modulates the light intensity of the output red light beam to distinguish veins and tissues, and the control module controls the scanning galvanometer to perform two-dimensional deflection through the driving circuit to drive the red light beam to scan the whole surface of the target skin.

As a further scheme of the device, the device also comprises a focusing collimation lens arranged between the red light source and the scanning galvanometer, and the red light beams emitted by the red light source are incident on the scanning galvanometer after passing through the focusing collimation lens.

As a preferred scheme of the device of the present invention, the detection module includes a converging lens, a red light filter and a red light detector; the converging lens is a common lens or a Fresnel lens, the red light filter is a filter for passing red light of a light source waveband, and the red light detector is a photoelectric detector sensitive to the red light source waveband.

As a preferable embodiment of the device of the present invention, the red light source is a laser light source emitting red light or a red LED light source.

As a preferable scheme of the device, the scanning galvanometer is a one-dimensional deflection MEMS galvanometer combination or a single two-dimensional deflection MEMS galvanometer.

A red light vein enhancement display method comprises the following steps:

step 1, a red light source emits a red light beam, and the red light beam is projected to the surface of target skin to be scanned through a scanning galvanometer;

step 2, generating back scattering light on the surface of the target skin to be scanned, receiving the back scattering light by a detection module, sending the detected red light signal to a control module by the detection module, and judging whether veins exist under the currently scanned target skin by the control module according to the intensity of the red light;

step 3, the control module modulates the output of the red light source and projects two red light beams with different light intensities to the surface of the target skin to distinguish veins and tissues;

and 4, controlling the driving circuit to drive the scanning galvanometer to deflect by the control module so as to drive the red light beams to scan the surface of the whole target skin, finishing the steps 1-3 at each position, and finally displaying the vein distribution of the whole target skin.

As a preferred embodiment of the method of the present invention, when the red light beam emitted by the red light source is continuous light, the control strategy of the control module is as follows: the red light intensity is modulated into two intensity levels by the control module, wherein one intensity is used for detecting veins and displaying tissues, and the other intensity is used for displaying veins; the red light detector utilizes time sampling and gain compensation to remove interference from the red light used for display.

As a preferred embodiment of the method of the present invention, when the red light beam emitted by the red light source is a pulse light, the control strategy of the control module is as follows: the control module controls the red light source to output two red light pulses, wherein one pulse is used for detecting veins, and the other pulse is used for distinguishing and displaying veins and tissues through light intensity modulation; the time sampling of the red detector is controlled to remove interference from the red pulses used for display.

As a preferable mode of the method of the invention, the mode of scanning the surface of the target skin by the red light beam is Lissajous scanning or raster scanning.

Compared with the prior art, the invention adopting the technical scheme has the following technical effects:

1. the red light vein enhancement display device and the method combine the advantages of the prior art, overcome the defects, and utilize a single red light source to complete two functions of vein distribution detection and vein display, so that the skin vein distribution can be enhanced and displayed in real time, medical staff can be helped to accurately observe and position the vein, and the puncture success rate is improved.

2. Compared with the existing optical vein enhancement technology, the red light vein enhancement display device and the method have the advantages of simple and compact structure and lower cost on the premise of ensuring the enhanced display effect with high contrast and resolution.

Drawings

Fig. 1 is a schematic structural diagram of a red vein enhancement display device according to the present invention.

FIG. 2 is a schematic representation of the Lissajous scan pattern of the scanning galvanometer in the apparatus of the present invention.

FIG. 3 is a schematic diagram of a raster scan pattern of a scanning galvanometer in the apparatus of the present invention.

FIG. 4 is a schematic diagram of the control timing of the apparatus in the continuous light mode according to the present invention.

FIG. 5 is a schematic diagram of the control timing of the apparatus for time-sharing sampling of the red light detector in the continuous light mode according to the present invention.

FIG. 6 is a schematic diagram of the control timing sequence of the apparatus in the pulsed light mode according to the present invention.

The device comprises a light source 1, a focusing collimating lens 2, a scanning galvanometer 3, a target skin 4, a back scattering light 5, a detection module 6, a collecting lens 6.1, a red light filter 6.2, a red light detector 6.3, a control module 7, a vein vessel 8 and a light beam scanning pattern 9.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

As shown in fig. 1, in the red vein enhancement display device provided by the present invention, a red light beam emitted from a red light source 1 passes through a focusing collimating lens 2, and is reflected to the surface of a target skin 4 by a scanning galvanometer 3, and a backscattered light 5 formed on the surface of the target skin 4 is received by a detection module 6. The detection module consists of a converging lens 6.1, a red light filter 6.2 and a red light detector 6.3. The control module 7 is connected with the red light source 1, the scanning galvanometer 3 and the detection module 6, and drives and synchronizes the work among the modules.

The red light source 1 selects a narrow spectrum red laser or red Light Emitting Diode (LED). The red laser diode or LED has the advantages of narrow spectrum, small volume, low energy consumption and the like, so that the red laser diode or LED is suitable for being used as a light source of the red vein enhancement display equipment. The light source wavelength is in the red band, and 635nm is a good choice. Compared with an LED, the laser diode has the advantages of higher modulation rate, narrower spectrum, smaller radiation angle and the like, and can ensure better resolution, simpler signal processing and longer working distance. While LEDs are less expensive, a balance between performance and cost is required in the selection.

The focusing collimator lens 2 is matched with the red light source 1 to ensure that the light beam is focused on the surface of the target skin 4. The size and quality of the focused spot determine the resolution and contrast of the display. The smaller the spot, the higher the resolution, but the more steps are required to scan the same size skin surface simultaneously, so the scan time is longer and the frame rate is reduced. The focused spot size is balanced according to the scan size and the scan time.

The scanning galvanometer 3 forms a deflection angle of 45 degrees with the incident beam, and the surface of the scanning galvanometer is plated with a red light wave band reflecting film, so that the horizontally incident red light beam is vertically projected to the surface of the skin. The function of the scanning galvanometer is to realize the deflection of the incident red light beam in two directions through the deflection of the scanning galvanometer 3, thereby completing the two-dimensional scanning of the light beam on the surface of the target skin. In consideration of energy consumption and structural compactness, the MEMS scanning galvanometer is selected as the scanning galvanometer, and compared with the traditional current detection type scanning galvanometer, the MEMS scanning galvanometer has the advantages of high selection speed, small volume, low energy consumption and the like. The MEMS galvanometers can be combined by selecting a pair of MEMS galvanometers with deflection directions perpendicular to each other, or a single MEMS galvanometer capable of deflecting in two directions perpendicular to each other can be selected.

The MEMS galvanometer is driven by the control module 7 to deflect according to a certain rule, so that the incident beam is deflected to repeatedly scan on the surface of the target skin 4 according to a specific beam scanning pattern 9, which has various scanning patterns such as lissajous and raster type, as shown in fig. 2 and 3. The driving mode of the MEMS galvanometer can be electromagnetic driving, electrostatic driving and the like.

In order to ensure the real-time performance of vein distribution display by considering the effect of human eye persistence, the scanning frame frequency of the MEMS galvanometer is selected to be more than 20HZ, and the frame frequency is selected by considering that the energy consumption of the MEMS galvanometer is lowest when the MEMS galvanometer works at the resonant frequency. For a target skin scan area of 50mm x 50mm, a projection height of 200mm requires a maximum scan mechanical deflection angle of the scan galvanometer of about 3.6 °.

The red light beam reflected by the scanning galvanometer 3 is backscattered by the surface of the target skin 4, and the backscattered light 5 is received by the detection module 6. The detection module comprises a converging lens 6.1, a red light filter 6.2 and a red light detector 6.3. The converging lens 6.1 enlarges the range of the red light detector 6.3 for receiving the backscattered light 5, improves the detection efficiency, and can select a Fresnel lens or a common optical lens. The red light filter 6.2 can filter out background light outside the red light wave band, and simplify subsequent signal processing. The red light detector 6.3 is selected from a photodiode or a triode sensitive to red light in a light source wave band. In the device, one detection module can be adopted, and the device can also be formed by a plurality of detection modules which are arranged in space. The plurality of detection modules are arranged in space, so that the fluctuation of the reflected light signal caused by the geometric shape and the position of the surface skin can be reduced.

Since deoxyhemoglobin in the venous blood vessels has strong absorption of red light, when the venous blood vessels are under the target skin irradiated by the red light beam, a large amount of red light is absorbed to result in weakening of the backscattered light 5. The detection module receives the backscattered light signals and transmits the backscattered light signals to the control module 7, the control module processes the signals, judges whether veins exist under the skin at the red light beam irradiation position according to the intensity of the signals, modulates the light intensity of the red light beam irradiating the position according to the signals, and displays vein blood vessels and surrounding tissues in a distinguishing mode. Under the drive of the scanning galvanometer, the light beam scans the whole target skin to finish the detection and display of all positions, and finally the enhanced display of the distribution of the vein 8 under the surface of the whole target skin is realized.

In the method for enhancing the display of the red veins, which is provided by the invention, because only a single light source is provided, the light source is used as a vein detection light source, and veins are contrastingly displayed by modulating the output light intensity. Corresponding light source and detector control methods are required to ensure that the two functions of vein detection and display are realized without mutual interference. And respectively corresponding to different control methods according to the fact that the light wave output by the light source is continuous light or pulse light.

1) The red light source outputs a continuous light whose intensity is modulated to two intensity levels, one intensity for detecting the veins and marking the surrounding tissue and the other intensity for marking the veins. The detector compensates for variations in detected light intensity by means of signal processing or gain. The control process is further explained by taking fig. 4 as an example, and the light source output is modulated into two light intensities by the control module, wherein one dark light is used for vein detection and simultaneously for tissue marking, and the other bright light is used for vein display. When the detected light beam moves to the vein, the control module adjusts the output light intensity to be bright and informs the detector that the current detected light is bright, and the detector proportionally reduces the gain to compensate. When the light beam leaves the vein, the control module dims the output light intensity and informs the detector that the current detection light is dim light, and the detector recovers to the original gain.

The other method is to control the sampling time of the detector to ensure that the detection and the display do not interfere with each other, in the method, the output light wave is divided into periods in time, the detector works in the sampling time of the detector in each period, the detector does not work except the sampling time, and veins are displayed through the light intensity change. As shown in fig. 5, the detector only samples when the control clock is high, and does not sample at other times, and the light source outputs light with two levels, one bright and one dark. When the light beam scans the skin, the light beam is kept in a bright state, when the detector detects veins at the sampling time, the control module modulates the output of the light source to be dark, in the next period, the light source is recovered to be bright, and the veins are continuously detected at the sampling time, and the light source is modulated to be dark. In this example, the vein is in two cycles. When the light beam moves out of the vein, the detector detects tissue at the time of use, and the control module modulates the light source output to be kept in a bright state.

2) The red light source outputs a light beam as a pulsed light wave, where a very short pulse is used for detection followed by a long pulse for display, and the detector samples during the short pulse. The short pulse has high brightness but very short time, and can not influence the detection of naked eyes due to the very short time. The long pulse has the brightness suitable for display and observation, the duration is long, the brightness is divided into two intensity levels of light and dark, the two intensity levels are used for marking veins and tissues respectively, and the dark level can also be used for directly closing the long pulse. The control time sequence is shown in fig. 6, in this example, the bright pulse is used for marking veins, the light source firstly emits short pulse light in one period, the detector samples, when the veins are judged, the control module modulates the light intensity of the long pulse to be bright, and when the detector detects that the veins are tissues, the control module modulates the light intensity of the long pulse to be dark.

Controlling the scanning galvanometer to deflect and drive the red light beams to scan the surface of the target skin, completing two steps of detecting veins and displaying veins at each position, then scanning the whole surface of the target skin position by position, and finally displaying the vein distribution of the whole surface of the target skin.

The above embodiments are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modifications made on the basis of the technical scheme according to the technical idea of the present invention fall within the protection scope of the present invention.

Claims

1. A red light vein enhancement display device is characterized by comprising a red light source, a scanning galvanometer, a driving circuit of the scanning galvanometer, a detection module and a control module; the red light source, the drive circuit of the scanning galvanometer and the detection module are respectively connected with the control module;

2. The red vein enhancement display device according to claim 1, further comprising a focusing collimating lens disposed between the red light source and the scanning galvanometer, wherein the red light beam emitted from the red light source is incident on the scanning galvanometer after passing through the focusing collimating lens.

3. The red vein enhancement display device according to claim 1 or 2, wherein the detection module comprises a converging lens, a red light filter and a red light detector; the converging lens is a common lens or a Fresnel lens, the red light filter is a filter for passing red light of a light source waveband, and the red light detector is a photoelectric detector sensitive to the red light source waveband.

4. The red vein enhancement display device according to claim 1 or 2, wherein the red light source is a laser light source emitting red light or a red LED light source.

5. The red vein enhancement display device according to claim 1 or 2, wherein the scanning galvanometer is a one-dimensional deflection MEMS galvanometer combination or a single two-dimensional deflection MEMS galvanometer.

6. A red light vein enhancement display method is characterized by comprising the following steps:

step 4, the control module controls the driving circuit to drive the scanning galvanometer to deflect, so that the red light beams are driven to scan the surface of the whole target skin, the steps 1-3 are completed at each position, and finally vein distribution of the whole target skin is displayed;

when the red light beam emitted by the red light source is continuous light, the control strategy of the control module is as follows: the red light beam scans the skin, the control module judges whether veins exist under the skin at the position of the red light beam according to the backscatter signal acquired by the detector, and the intensity of the emergent red light beam is modulated to mark the veins and common tissues respectively; the red light detector compensates the influence of the red light intensity on the vein detection signal by changing the gain;

when the red light beam emitted by the red light source is pulse light, the control strategy of the control module is as follows: the control module controls the red light source to output two red light pulses, wherein one pulse is used for detecting veins, and the other pulse is used for distinguishing and displaying veins and tissues through light intensity modulation; the time sampling of the red detector is controlled to remove interference from the red pulses used for display.

7. The red vein enhancement display method according to claim 6, wherein the red light beam is scanned on the target skin surface in a Lissajous scanning or raster scanning.