CN107981855B

CN107981855B - Blood flow imaging device and endoscope

Info

Publication number: CN107981855B
Application number: CN201711478459.2A
Authority: CN
Inventors: 邱建军; 陈云亮
Original assignee: Sonoscape Medical Corp
Current assignee: Sonoscape Medical Corp
Priority date: 2017-12-29
Filing date: 2017-12-29
Publication date: 2024-06-25
Anticipated expiration: 2037-12-29
Also published as: CN107981855A

Abstract

The invention discloses a blood flow imaging device, comprising: a light source device, an imaging lens, an image information separating device, a focusing device and a processing device; the light source device emits a laser beam and an incoherent light beam to an observation object; the imaging lens is positioned on a transmission path of reflected light of the laser beam reflected by the observed object and reflected light of the incoherent light beam reflected by the observed object; separating the light signals corresponding to the reflected light of the laser beam and the reflected light of the incoherent light beam into the laser beam and the incoherent light beam by an image information separating device, and converting the separated laser beam into an electric signal corresponding to the laser beam; the focusing device generates a focusing instruction according to the separated incoherent light beam to drive the imaging lens to automatically focus; the processing device generates a two-dimensional blood flow velocity image of the observed object by utilizing the electric signals corresponding to the laser beams; the device can separate incoherent light beams from light signals to realize automatic focusing, and the invention also discloses an endoscope.

Description

Blood flow imaging device and endoscope

Technical Field

The invention relates to the technical field of auxiliary medical diagnosis, in particular to a blood flow imaging device and an endoscope.

Background

Due to the scattered or reflected laser beam of the object under observation, a randomly distributed granular pattern, i.e. "speckle", is formed on the imaging surface due to interference. The degree of blurring of the speckle pattern is related to the velocity of movement of scattering particles (e.g., red blood cells) in the object under observation and can be quantitatively characterized by the speckle contrast (i.e., the ratio of the standard deviation of the intensity to the mean of the intensity). The greater the velocity of the scattering particle movement, the lower the speckle contrast. Based on the principle, the laser speckle blood flow imaging can reconstruct a two-dimensional blood flow velocity distribution image by calculating speckle contrast in each spatial region in the speckle image. The laser speckle imaging does not need scanning, and has the characteristics of high spatial resolution and high time resolution.

However, since the speckle pattern formed by laser illumination masks the structural information of the observation object, there is caused a problem that it is often difficult to perform auto-focusing in the case of laser illumination. In the past, it is common practice to perform manual focusing under illumination of white light or incoherent light of other colors, and then switch to laser illumination to perform laser speckle blood flow imaging. But it has the following disadvantages: before laser speckle blood flow imaging, illumination light is required to be switched from laser to incoherent illumination light, optical focusing is carried out under incoherent illumination, and then the illumination light is switched to laser illumination, so that laser speckle blood flow imaging is carried out, and the operation process is complicated and inconvenient.

Therefore, how to achieve accurate real-time focusing when performing laser speckle blood imaging is a technical problem that needs to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide a blood flow imaging device and an endoscope, which can realize automatic focusing when a laser beam and an incoherent light beam are simultaneously irradiated, simplify user operation and improve user experience.

In order to solve the above technical problems, the present invention provides a blood flow imaging device, including: a light source device, an imaging lens, an image information separating device, a focusing device and a processing device; wherein:

The light source device emits a laser beam and an incoherent light beam to an observation object;

The imaging lens is located on a transmission path of reflected light of the laser beam reflected by the observation object and reflected light of the incoherent light beam reflected by the observation object;

The image information separating device separates the light signals corresponding to the reflected light of the laser beam and the reflected light of the incoherent light beam into the laser beam and the incoherent light beam, and converts the separated laser beam into an electric signal corresponding to the laser beam;

The focusing device generates a focusing instruction according to the separated incoherent light beam to drive the imaging lens to automatically focus;

the processing device generates a two-dimensional blood flow velocity image of the observation object using the laser beam corresponding to the electric signal.

Optionally, the image information separation device is a color image sensor; the wavelength bands of the corresponding laser beam and incoherent light beam do not overlap.

Optionally, the image information separation device includes: a first monochromatic image sensor, a second monochromatic image sensor and a spectroscopic device; wherein,

A filter in the light splitting device separates the optical signal into a laser beam and an incoherent light beam;

the first monochromatic image sensor is used for converting the separated laser beams into electric signals corresponding to the laser beams and outputting the electric signals to the processing device;

The second monochromatic image sensor is used for converting the separated incoherent light beam into an electric signal corresponding to the incoherent light beam and outputting the electric signal to the processing device.

Optionally, the image information separation device includes: a third monochromatic image sensor, a fourth color image sensor and a spectroscopic device; wherein,

The third monochromatic image sensor is used for converting the separated laser beams into electric signals corresponding to the laser beams and outputting the electric signals to the processing device;

The fourth color image sensor is configured to convert the separated incoherent light beam into an electrical signal corresponding to the incoherent light beam, and output the electrical signal to the processing device.

Optionally, the image information separation device includes: a dichroic mirror and a fifth monochromatic image sensor; wherein,

The dichroic mirror is used for transmitting laser beams in the optical signals and reflecting incoherent light beams;

The fifth monochromatic image sensor is used for converting the laser beam transmitted by the dichroic mirror into an electric signal corresponding to the laser beam and outputting the electric signal to the processing device.

Optionally, the focusing device includes: a focus calculation circuit, a motor control circuit, and a transmission section; wherein the conveying component is fixedly connected with the imaging lens;

The focusing calculation circuit is used for calculating an image definition value by utilizing the electric signals corresponding to the incoherent light beams and determining driving parameters of the motor control circuit according to the image definition value;

And the motor control circuit is used for controlling the transmission component to drive the imaging lens to move along the direction perpendicular to the imaging lens according to the driving parameter.

Optionally, the focusing device includes: a focus detection light path, a focus calculation circuit, a motor control circuit and a transmission part; wherein the conveying component is fixedly connected with the imaging lens;

the focusing detection light path is used for dividing the optical signal for filtering the laser beam into two paths of light paths and respectively calculating corresponding phases;

the focusing calculation circuit is used for calculating the phase difference of the phase to determine the driving parameter of the motor control circuit;

Optionally, the conveying component is a rack-and-pinion conveying component or a screw conveying component.

Optionally, the processing device further includes: and a display unit for displaying the two-dimensional blood flow velocity image.

Optionally, the light source device further includes: an optical coupling device and a light guide fiber; wherein,

The optical coupling device is used for coupling the laser beam and the incoherent light beam;

the light guide fiber is used for transmitting the coupled light beam and transmitting the coupled light beam to the observation object at the light transmitting end of the light guide fiber.

The present invention also provides an endoscope including: a blood flow imaging device as claimed in any one of the preceding claims.

The present invention provides a blood flow imaging device, comprising: a light source device, an imaging lens, an image information separating device, a focusing device and a processing device; the light source device emits a laser beam and an incoherent light beam to an observation object; the imaging lens is positioned on a transmission path of reflected light of the laser beam reflected by the observed object and reflected light of the incoherent light beam reflected by the observed object; separating the light signals corresponding to the reflected light of the laser beam and the reflected light of the incoherent light beam into the laser beam and the incoherent light beam by an image information separating device, and converting the separated laser beam into an electric signal corresponding to the laser beam; the focusing device generates a focusing instruction according to the separated incoherent light beam to drive the imaging lens to automatically focus; the processing device generates a two-dimensional blood flow velocity image of the observed object by utilizing the electric signals corresponding to the laser beams;

the blood flow imaging device separates the laser beam and the incoherent light beam in the optical signal through the image information separating device, so that the focusing device can perform automatic focusing operation according to the received incoherent light beam, and therefore automatic focusing is performed when the laser beam and the incoherent light beam are simultaneously irradiated, user operation is simplified, and user experience is improved; the invention also discloses an endoscope, which has the beneficial effects and is not repeated here.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

Fig. 1 is a block diagram of a blood flow imaging device according to an embodiment of the present invention;

FIG. 2 is a schematic diagram showing a color filter matrix of a color image sensor according to an embodiment of the present invention;

FIG. 3 is a block diagram illustrating another blood flow imaging apparatus according to an embodiment of the present invention;

FIG. 4 is a block diagram of a blood flow imaging apparatus according to an embodiment of the present invention;

Fig. 5 is a block diagram of still another blood flow imaging apparatus according to an embodiment of the present invention.

Detailed Description

The core of the invention is to provide a blood flow imaging device which can realize automatic focusing when a laser beam and an incoherent light beam are irradiated simultaneously, so that the user operation is simplified and the user experience is improved; another core of the present invention is to provide an endoscope.

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1, fig. 1 is a block diagram illustrating a blood flow imaging apparatus according to an embodiment of the present invention; the blood flow imaging device (may be simply referred to as a device) may include: a light source device 2, an imaging lens 3, an image information separation device 5, a focusing device 6, and a processing device 7; wherein:

the light source device 2 emits a laser beam and an incoherent light beam to the observation target 101;

The imaging lens 3 is located on a transmission path of reflected light of the laser beam reflected by the observed object 101 and reflected light of the incoherent light beam reflected by the observed object 101;

the image information separating device 5 separates the light signals corresponding to the reflected light of the laser beam and the reflected light of the incoherent light beam into the laser beam and the incoherent light beam, and converts the separated laser beam into the electric signals corresponding to the laser beam;

the focusing device 6 generates a focusing instruction according to the separated incoherent light beam to drive the imaging lens 3 to automatically focus;

the processing device 7 generates a two-dimensional blood flow velocity image of the observation target using the laser beam corresponding to the electric signal.

The present embodiment does not limit the intensities of the laser beam and the incoherent light beam emitted from the light source device 2. For example, parameter information such as intensities of the laser beam and the incoherent light beam is not limited. The user can set according to the actual application condition. In the present embodiment, the light source device 2 includes a laser light source module for emitting a laser beam and an incoherent light source module for emitting an incoherent light beam. The specific constituent structures of the two light source modules are not limited in this embodiment, and may be, for example, an existing light source module structure. Specifically, the laser light source module may be composed of a laser driving circuit 9 and a laser 8, and emit a laser beam through the laser 8. The incoherent light source module may be composed of an incoherent light driving circuit 11 and incoherent light 10, and emit a laser beam through the incoherent light 10. The parameter information of the two beams can be controlled by the processing means 7. The present embodiment is not limited to the installation position of the light source device 2 as long as it can irradiate the observation target 101.

The present embodiment is not limited to the transmission form of the laser beam and the incoherent light beam, for example, the two light beams may be transmitted through separate light paths and respectively irradiated onto the observation object 101, or the two light beams may be combined, that is, coupled and then transmitted together and irradiated onto the observation object 101.

In order to enhance the irradiation effect, the light source device 2 may preferably further include: an optical coupling device 12 and a light guiding fiber 13; wherein the optical coupling device 12 is used for coupling the laser beam and the incoherent light beam; the light guiding fiber 13 is used for transmitting the coupled light beam, and transmitting the coupled light beam to an observation object at the light transmitting end of the light guiding fiber 13. The optical coupling device 12 is located at the output end of the laser 8 and the incoherent light 10, the output end of the optical coupling device 12 is connected with the input end of the light guiding fiber 13, and the light emitting end of the light guiding fiber 13 emits the coupled light beam to the observation object. The optical coupling device 12 and the light guiding fiber 13 are arranged in a position and form as shown in fig. 1.

Specifically, the light beam emitted from the laser light 8 and the incoherent light 10 is combined by the optical coupling device 12, transmitted through the light guide fiber 13, and emitted from the light emitting end to irradiate an observation object (the observation object is denoted by 101 in fig. 1).

It can also be seen from fig. 1 that the observation object 101, the imaging lens 3, and the image information separating apparatus 5 are disposed on a straight line, i.e., arranged along the imaging transmission path of the light beam. An aperture 4 may also be provided between the imaging lens 3 and the observation object 101 to control the amount of light entering the imaging lens 3. The present embodiment is not particularly limited in the model and structure of the imaging lens 3 and the diaphragm 4. Can be selected according to actual requirements.

In the prior art, when the blood flow imaging device focuses, the illumination mode needs to be switched, namely, the blood flow imaging device needs to focus under white light illumination and then switch back to laser illumination for imaging. If the imaging object is subjected to shaking caused by breathing and the like in the laser illumination imaging process, the laser blood flow image is blurred, the blood flow speed calculation is inaccurate, and the focusing process is tedious and inconvenient to operate. In order to avoid the situation, automatic focusing is needed, and the premise of realizing automatic focusing is that laser and incoherent light can be allowed to illuminate simultaneously, namely the device can perform image processing when the laser and the incoherent light are illuminated simultaneously to realize the imaging of a two-dimensional blood velocity image of an observation object, and at the moment, the situation of laser illumination can be focused without frequently switching illumination light.

In order to image the two-dimensional blood velocity image of the observation target by performing image processing when both the light beams are irradiated at the same time, it is necessary to separate the light signal corresponding to the laser beam and the light signal corresponding to the incoherent light beam from the reflected light beam of the observation target 101, that is, to separate the light signal corresponding to the reflected light of the laser beam and the reflected light of the incoherent light beam into the laser beam and the incoherent light beam. The separated laser beams can be further converted into electric signals corresponding to the laser beams, and a two-dimensional blood flow velocity image of the observation object is generated according to the electric signals; and realizing an automatic focusing process by utilizing the separated incoherent light beams. In this embodiment, the image information separating device 5 is used to separate the optical signals corresponding to the reflected light of the laser beam and the reflected light of the incoherent light beam into the laser beam and the incoherent light beam, and convert the separated laser beam into the electrical signal corresponding to the laser beam, and output the electrical signal to the processing device 7 to perform imaging of the two-dimensional blood velocity image, and output the separated incoherent light beam to the focusing device 6 to enable the focusing device 6. The problem that in the prior art, an image of an observation object is shot by using one single-color image sensor, because focusing cannot be performed under the condition of simultaneously having a laser beam and an incoherent light beam, focusing can only be performed by utilizing incoherent light irradiation firstly, and after focusing is completed, the image is switched back to a laser light source module to irradiate the observation object 101 by utilizing laser light, so that a two-dimensional blood flow velocity image of the observation object 101 is generated by utilizing an electric signal corresponding to the laser light beam can be solved.

The present embodiment is not limited to the specific configuration of the image information separation device 5, as long as it can separate an optical signal corresponding to the reflected light of the laser beam and the reflected light of the incoherent light beam into the laser beam and the incoherent light beam, that is, has a beam separation function. For example, the image information separation device 5 may be one color image sensor, or a plurality of monochrome image sensor-coupled spectroscopic members, or a monochrome image sensor, a color image sensor-coupled spectroscopic member, or a plurality of color image sensor-coupled spectroscopic members, or a single monochrome image sensor-coupled spectroscopic member, or the like. The present embodiment is not limited to the specific configuration of the spectroscopic unit, either, as long as beam splitting (e.g., having a transmission and reflection function) can be achieved. For example, a dichroic mirror, a filter, a dichroic sheet, or the like may be used.

The light reflected by the observation object 101 passes through the aperture 4 and the imaging lens 3, is received by the image information separation device 5, separates an optical signal corresponding to the reflected light of the laser beam and the reflected light of the incoherent light beam into a laser beam and an incoherent light beam, and converts the separated laser beam into an electrical signal corresponding to the laser beam to be output to the processing device 7. The conversion of the separated laser beam into the laser beam corresponding electrical signal may be performed by an image sensor. Specifically, when the user uses the color image sensor, not only the separated laser beam but also the separated incoherent light beam may be converted into an electric signal corresponding to the laser beam, and the processing device 7 may generate the reflected light image of the observation object 101 or the physiological parameter of the observation object 101, for example, the blood volume, the blood oxygen saturation, and the like, using the electric signal corresponding to the incoherent light beam.

Since the electric signal converted by the laser beam and the electric signal converted by the incoherent light beam can be obtained when the color image sensor is included in the image information separating apparatus 5 in the present embodiment. In this case, the processing device 7 can generate a two-dimensional blood flow velocity image of the observation target or a reflected light image of the observation target or a physiological parameter of the observation target from the two electrical signals. The imaging of a plurality of different observation modes can be realized at the same time, namely, focusing is carried out without switching back to a white light irradiation mode, and focusing can be carried out in real time, namely, the problem that focusing feedback mechanism exists in the prior art when the motion of an observation object in the axial direction exceeds the depth of field range of an imaging system is solved. The image information separating device 5 in this embodiment is provided at a position capable of receiving an optical signal corresponding to the reflected light of the laser beam and the reflected light of the incoherent light beam, that is, on a transmission path of the reflected light of the laser beam and the reflected light of the incoherent light beam. Reference may be made in particular to fig. 1, which may be arranged in line with the object of view 101, the aperture 4, the imaging lens 3.

The present embodiment does not limit the focusing frequency of the focusing device 6. The focusing device can be real-time focusing or timing focusing. The present embodiment is also not limited to the focusing principle of the focusing device 6, and is not limited to the specific structure of the focusing device 6. For example, the separated incoherent light beam may be subjected to a series of processes according to the phase focusing principle to achieve focusing, or the incoherent light beam transmitted to the processing device 7 may be subjected to focusing according to the image sharpness principle according to the corresponding electric signal. The focusing device 6 can generate a focusing command according to a focusing result to drive the imaging lens 3 to move to a position corresponding to the focusing command, and adjust the distance between the imaging lens and the image information separation device 5 so as to realize automatic focusing.

The focusing device 6 can feed back to the processing device 7 after focusing is completed, so that the processing device 7 can acquire clear laser beam corresponding electric signals or laser beam corresponding electric signals and incoherent light beam corresponding electric signals after focusing is completed, and further can perform subsequent image analysis. For example, when focusing is completed, the focusing device 6 transmits a focusing completion signal to the CPU30 in the processing device 7, and the CPU30 receives the signal and transmits a control signal to the image capturing control circuit, which controls the electronic shutter speed, frame rate, electronic gain, and the like of the image information separating device 5 under the control of the CPU30 to acquire corresponding electrical signal data. The image processing circuit 33 in the processing device 7 generates a two-dimensional blood flow velocity image using the laser beam corresponding to the electric signal (the algorithm such as reconstructing the two-dimensional blood flow velocity image and acquiring the blood flow velocity value may refer to the related art specifically), generates a reflected light image of the observation object using the incoherent light beam corresponding to the electric signal, or calculates the physiological parameter of the observation object (the physiological parameter of the observation object is not limited in this embodiment, and for example, the blood volume, the blood oxygen saturation, and the like may refer to the related art specifically for the calculation method of each parameter). That is, the embodiment can simultaneously perform a plurality of imaging modes such as laser speckle blood flow imaging, endogenous light imaging/white light imaging and the like, and simultaneously acquire a plurality of important physiological parameters such as blood flow velocity, blood volume, blood oxygen saturation and the like. The present embodiment is not limited to the specific position set by the processing device 7.

Further, in order to increase the flexibility of the blood flow imaging device for processing the object of view 101, optionally, referring to fig. 1, the processing device 7 may further comprise a mode switching power supply 31. Specifically, the CPU30 transmits a control signal for switching the observation mode to the mode switching circuit 31 according to the operation of the user to control the illumination mode of the light source device 2, for example: under the condition of a laser speckle blood imaging mode, the laser 8 is turned on, and the incoherent light 10 is turned off; in incoherent light imaging mode (i.e., two-dimensional blood flow velocity image), the laser 8 is off and the incoherent light 10 is on; in a mode in which laser speckle blood flow imaging is performed simultaneously with incoherent light imaging, the laser light 8 and incoherent light 10 are turned on simultaneously.

In order to enable separation, the wavelengths of the laser beam and the incoherent light beam are different in this embodiment. The laser beam and the incoherent light beam are simultaneously irradiated and mutually noninterfere, so that focusing is not needed under incoherent light, and then the laser beam is switched to laser illumination for speckle imaging, thereby facilitating imaging. Especially under the condition of long-time observation, the automatic focusing can be performed at certain intervals without switching to white light illumination.

The blood flow imaging device of the embodiment not only can be used for an imaging system with the objective lens as a fixed-focus lens, but also can be used for an imaging system with the objective lens as a zoom lens, so that real-time focusing of laser speckle blood flow imaging is realized.

Based on the above technical scheme, the blood flow imaging device provided by the embodiment of the invention separates the laser beam and the incoherent light beam in the optical signal through the image information separating device, so that the focusing device can perform automatic focusing operation according to the received incoherent light beam, thereby realizing automatic focusing when the laser beam and the incoherent light beam are simultaneously irradiated, simplifying user operation and improving user experience.

Referring to fig. 1, in order to simplify the structure of the blood flow imaging device, the blood flow imaging device can implement two modes simultaneously, that is, process the electric signal corresponding to the laser beam and the electric signal corresponding to the incoherent light beam simultaneously. The image information separating device 5 in this embodiment is specifically a color image sensor; the wavelength bands of the corresponding laser beam and incoherent light beam do not overlap.

The color image sensor of the present embodiment is not limited to the type, and may be, for example, a CMOS color image sensor, and the corresponding image capturing control circuit is the CMOS control circuit 32. In the following, for the sake of explanation corresponding to fig. 1, CMOS color image sensors will be described as examples, but this is not a limitation. In particular, the arrangement position of the color image sensor may refer to fig. 1.

After passing through the aperture 4 and the imaging lens 3, the light reflected by the observation object 101 is received by a color image sensor, and the light signal is converted into an electric signal to be output to the processor 7. The color filter matrix of the color image sensor is constituted by, for example, a bayer pattern as shown in fig. 2. The image of the observation target 101 captured by the color image sensor is a RAW image in which light from the laser light 8 and incoherent light 10 reflected by the observation target is transmitted through the color filter matrix; wherein the RAW image contains all photo information of the original photo file before entering the camera image processor after the image sensor generates.

In addition, the wavelength band of the laser light 8 in the light source device 2 does not overlap with the wavelength band of the incoherent light 10, and in the color filter matrix composed of, for example, the bayer pattern shown in fig. 2, the laser light 8 can only transmit one filter of the R, G, B three colors of filters, while the incoherent light 10 can only transmit one or two filters of the R, G, B three colors of filters different from the filter through which the laser light 8 is transmitted.

Preferably, the laser 8 is red laser light that can only pass through the R filter, and the incoherent light 10 is narrow-band green light that can only pass through the G filter, or narrow-band blue light that can only pass through the B filter, or light obtained by combining the two narrow-band lights in a certain ratio.

The red wave light can ensure the reflected or dispersed laser intensity, is favorable for obtaining blood flow velocity distribution information and improves the signal-to-noise ratio of blood flow images; blue and green incoherent light are located at the hemoglobin absorption peak, and thus images generated by the G channel, B channel, or a combination of both can be used to highlight vascular structures. The combination of the coherent light and the incoherent light can be skillfully utilized to carry out multi-mode imaging, or the blood flow velocity information of the blood vessel region and the non-blood vessel region can be respectively obtained through an image segmentation and image fusion algorithm.

The following describes the operation of the present embodiment in a specific configuration in fig. 1:

The image processing circuit 33 in the processing device 7 processes an image of the observation target 101 taken by the color image sensor. For example, assuming that the laser light 8 is red light, the incoherent light 10 is light formed by combining green light and blue light in a certain proportion, and in a mode in which laser speckle blood flow imaging and incoherent light imaging are performed simultaneously, the image processing circuit 33 extracts gray values from pixel positions corresponding to an R filter matrix from a RAW image of the color image sensor to form a new image SPEC, which is used for calculating a blood flow velocity and reconstructing a two-dimensional blood flow velocity image in laser speckle blood flow imaging, and extracts gray values from pixel positions corresponding to a G filter matrix and a B filter matrix from the RAW image of the color image sensor to form two new G images GN1, GN2 and a new B image BN, which are used for calculating parameters such as a blood volume, a blood oxygen saturation, and the like and reconstructing a corresponding two-dimensional image. In addition, since there are two G filters in a2×2 bayer filter matrix, a new G image GN is obtained by averaging the images GN1 and GN 2.

Specifically, the blood flow velocity may be calculated from the image SPEC by using a sliding spatial window, by using a sliding time window, or by a combination of both. Taking the case of calculating the blood flow velocity using a sliding spatial window as an example, first, using a spatial window of size n×n, calculating the mean value and standard deviation of the gray values of each pixel of the image SPEC in a spatial neighborhood of size n×n, and calculating the ratio of the standard deviation and the mean value, thereby calculating a value called speckle contrast; according to the calculation method, sliding the space window in a space region of the image SPEC, and calculating a speckle contrast value of the region where the space window is located at the same time, so that the whole image region of the image SPEC is traversed, and a speckle contrast image is obtained; the inverse of the square of the speckle ratio value at each pixel position of the above-mentioned speckle ratio image is calculated or a quantitative formula calculation using the speckle ratio value and the electric field autocorrelation function is used to obtain the blood flow velocity value at the corresponding pixel position, thereby reconstructing a two-dimensional blood flow velocity image. The method of calculating parameters such as blood volume, blood oxygen saturation, and the like from the image GN and the image BN can be referred to the prior art.

Further, the two-dimensional blood flow velocity information, the two-dimensional blood oxygen saturation information, physiological parameter information, and the like of the observation target 101 may be obtained and stored by the data storage circuit 34. For subsequent viewing.

Further, optionally, the processing device further includes: and the display component is used for displaying the image of the observation object corresponding to the laser beam and/or the image of the observation object corresponding to the incoherent light beam. The display means may display an image corresponding to the current operation mode.

The present embodiment is not limited to the specific form of the display means, and may be, for example, the display 35, a display screen, a projection device, or the like. When the image of the observation target corresponding to the laser beam and the image of the observation target corresponding to the incoherent light beam can be displayed by the display means, in order to improve the display efficiency, the image of the observation target corresponding to the laser beam and the image of the observation target corresponding to the incoherent light beam can be simultaneously displayed in one display means. I.e. a split screen display may be selected. For example, the display 35 displays a two-dimensional blood flow velocity image and a blood oxygen saturation image in a split screen. The present embodiment is not limited to the proportion of split screens, and may be equally distributed, for example. Of course, the user can also select to display after image fusion processing.

Based on the above technical scheme, the blood flow imaging device provided by the embodiment utilizes the focusing device to realize automatic focusing when the laser beam and the incoherent light beam are simultaneously irradiated, so that the user operation is simplified; and the laser beam and the incoherent light beam can respectively extract the corresponding electric signals of the laser beam and the incoherent light beam after simultaneously irradiating the object to be detected, thereby realizing simultaneous imaging of the laser beam and the incoherent light beam.

Referring to fig. 3, in order to improve the resolution of the laser beam corresponding to the electrical signal. The image information separation apparatus 5 in this embodiment includes: a first monochromatic image sensor 5a, a second monochromatic image sensor 5b, and a spectroscopic device 40; wherein,

The filter 40a in the spectroscopic device 40 separates the optical signal into a laser beam and an incoherent light beam;

a first monochrome image sensor 5a for converting the separated laser beam into an electric signal corresponding to the laser beam and outputting the electric signal to the processing device 7;

the second monochromatic image sensor 5b is configured to convert the separated incoherent light beam into an incoherent light beam corresponding electrical signal and output the incoherent light beam to the processing device 7.

For example, the filter 40a may reflect an incoherent light beam in the optical signal and transmit a laser beam (as shown in fig. 3); of course, the filter 40a may transmit an incoherent light beam in the optical signal and reflect the laser beam. The present embodiment is not limited thereto as long as the optical signal can be separated into a laser beam and an incoherent light beam. The first monochromatic image sensor 5a is disposed on the transmission path of the separated laser beam, and the second monochromatic image sensor 5b is disposed on the transmission path of the separated incoherent light beam.

Taking fig. 3 as an example, the specific process is as follows: the optical filter 40a of the spectroscopic device 40 reflects light from the laser beam 8 out of the reflected light from the observation object 101 that has passed through the aperture 4 and the imaging lens 3, and causes the light to enter the monochrome image sensor 5b; the filter 40a transmits light, which is reflected from the observation target 101 and passes through the aperture 4 and the imaging lens 3, which is a component of the incoherent light 10, and allows the light to enter the monochromatic image sensor 5a.

The position of the optical filter 40a in the spectroscopic device 40 may be as shown in fig. 3, and the present embodiment is not limited thereto, and may be set according to practical situations, as long as light transmitted and reflected by the optical filter can enter the corresponding monochrome image sensor.

Since the monochrome image sensor does not have a color filter matrix, the original resolution of the optical system is easier to maintain. Therefore, in the embodiment, the separation of the laser beam and the incoherent light beam is realized by adopting two monochromatic image sensors, so that the original resolution of the optical system can be maintained. And since the monochrome image sensor does not have a color filter matrix, the wavelength range selection freedom of the corresponding laser is higher than that of using the color image sensor. In this embodiment, the laser may be any wavelength in the visible light range, or may be near infrared laser.

The following describes the operation of the device with the specific structure shown in fig. 3:

the image processing circuit 33 processes images of the image of the observation target 101 taken by the monochrome image sensor 5a and the monochrome image sensor 5 b. For example, assuming that the laser light 8 is red light, the incoherent light 10 is light formed by combining green light and blue light in a certain proportion, in a mode in which laser speckle blood flow imaging and incoherent light imaging are performed simultaneously, an image captured by the monochromatic image sensor 5b is used for calculating a blood flow velocity and reconstructing a two-dimensional blood flow velocity image in the laser speckle blood flow imaging, and an image captured by the monochromatic image sensor 5a is used for generating a two-dimensional incoherent light observation image.

The blood flow velocity may be calculated from the image captured by the monochrome image sensor 5b by using a sliding spatial window calculation, by using a sliding time window calculation, or by a combination of both. Taking the case of calculating the blood flow velocity using a sliding spatial window as an example, first, using a spatial window of size n×n, calculating the mean value and standard deviation of each pixel gradation value of an image captured by the monochrome image sensor 5b in a spatial neighborhood of size n×n, and calculating the ratio of the standard deviation and the mean value, thereby calculating a value called speckle contrast; according to the calculation method, sliding the space window in the space region of the image shot by the monochromatic image sensor 5b, and calculating the speckle contrast value of the region where the space window is located, so as to traverse the whole image region of the image shot by the monochromatic image sensor 5b and obtain a speckle contrast image; and calculating the inverse of the square of the speckle contrast value at each pixel position of the speckle contrast image to obtain the blood flow velocity value at the corresponding pixel position, thereby reconstructing a two-dimensional blood flow velocity image.

Thus, according to the above method, a two-dimensional blood flow velocity image, a two-dimensional incoherent light image, or the like of the observation target 101 is obtained, and an image corresponding to the current operation mode can be stored by the data storage circuit 34 and displayed on the display 35. For example, in a mode in which laser speckle blood flow imaging is performed simultaneously with incoherent light imaging, the display 35 displays a two-dimensional blood flow velocity image in a split screen with an incoherent light image generated by absorption of incoherent light by an endogenous acoustic bolus. That is, the processing means 7 performs corresponding processing on the images from the monochrome image sensor 5a and the monochrome image sensor 5b according to the operation mode selected by the user, and stores and displays the processing results.

Referring to fig. 4, in order to distinguish the superficial blood vessels from the middle blood vessels. The image information separation apparatus 5 in this embodiment includes: a third monochrome image sensor 5d, a fourth color image sensor 5c, and a spectroscopic device 40; wherein,

a third monochrome image sensor 5d for converting the separated laser beam into an electric signal corresponding to the laser beam and outputting the electric signal to the processing device 7;

A fourth color image sensor 5c for converting the separated incoherent light beam into an incoherent light beam corresponding electrical signal and outputting the incoherent light beam to the processing device 7.

For example, the filter 40a may reflect an incoherent light beam in the optical signal and transmit a laser beam (as shown in fig. 4); of course, the filter 40a may transmit an incoherent light beam in the optical signal and reflect the laser beam. The present embodiment is not limited thereto as long as the optical signal can be separated into a laser beam and an incoherent light beam. The third monochrome image sensor 5d is disposed on the transmission path of the separated laser beam, and the fourth color image sensor 5c is disposed on the transmission path of the separated incoherent light beam.

Taking fig. 4 as an example, the specific process is as follows: the optical filter 40a of the spectroscopic device 40 transmits light of the component from the laser light 8 out of the reflected light reflected from the observation object 101 and passing through the aperture 4 and the imaging lens 3, and causes the light to enter the monochrome image sensor 5d; the filter 40a reflects light from the incoherent light 10 out of the reflected light from the observation target 101 and having passed through the aperture 4 and the imaging lens 3, and allows the light to enter the color image sensor 5c.

Since the reflected light of the blue light and the green incoherent light is received by the monochromatic image sensor, a monochromatic image is formed for observing the physiological state of the biological tissue. The gray scale of this monochrome image reflects the extent to which blue and green light are absorbed by the absorbing clusters in the biological tissue. The advantage of this approach is the high resolution, but the disadvantage is that the effect of the separate action of blue and green light cannot be distinguished from the monochromatic image, i.e. the shallow and middle blood vessels cannot be distinguished. The color image sensor 5c is used in this embodiment, which has the advantage that the shallow blood vessel and the middle blood vessel can be separated by image processing (the penetration depth of blue light is shallow for imaging the shallow blood vessel, and the penetration depth of green light is relatively deep for imaging the middle blood vessel), so that the disease diagnosis can be performed. The corresponding resolution reduction problem in this case can compensate for the partial resolution loss by interpolation algorithms.

The position of the optical filter 40a in the spectroscopic device 40 may be as shown in fig. 4, and the present embodiment is not limited thereto, and it may be set according to practical situations, as long as light transmitted and reflected by the optical filter can enter the corresponding monochrome image sensor.

The following describes the operation of the device with the specific structure shown in fig. 4:

The image processing circuit 33 processes images of the image of the observation target 101 taken by the monochrome image sensor 5d and the color image sensor 5 c. For example, assuming that the laser beam 8 is red light, the incoherent light 10 is light formed by combining green light and blue light in a certain proportion, in a mode in which laser speckle blood flow imaging and incoherent light imaging are performed simultaneously, an image captured by the monochromatic image sensor 5d is used for calculating a blood flow velocity and reconstructing a two-dimensional blood flow velocity image in the laser speckle blood flow imaging, and an image captured by the color image sensor 5c is used for calculating parameters such as a blood volume, a blood oxygen saturation, and the like and reconstructing a corresponding two-dimensional image.

Thus, according to the above method, two-dimensional blood flow velocity information, two-dimensional blood oxygen saturation information, and the like of the observation target 101 are obtained, and it is possible to store the two-dimensional blood flow velocity information, the two-dimensional blood oxygen saturation information, and the like by the data storage circuit 34, and to display an image corresponding to the current operation mode on the display 35. For example, in a mode in which laser speckle blood flow imaging is performed simultaneously with incoherent light imaging, the display 35 displays a two-dimensional blood flow velocity image and an oxygen saturation image in a split screen manner. The processing means 7 performs corresponding processing on the images from the monochrome image sensor 5d and the color image sensor 5c according to the operation mode selected by the user, and stores and displays the processing results.

Referring to fig. 5, the image information separating apparatus 5 of the present embodiment includes: a dichroic mirror 51 and a fifth monochromatic image sensor 52; wherein,

A dichroic mirror 51 for transmitting a laser beam in the optical signal and reflecting an incoherent light beam;

A fifth monochromatic image sensor 52 for converting the laser beam transmitted by the dichroic mirror into a laser beam corresponding electrical signal and outputting the laser beam to the processing device 7.

Among them, the dichroic mirror (Dichroic Mirrors) is also called a dichroic mirror, and is commonly used in laser technology. It is characterized by almost complete transmission of light of a certain wavelength and almost complete reflection of light of other wavelengths. This embodiment uses this characteristic of the dichroic mirror to separate the laser beam and the incoherent light beam in the optical signal. Specifically, the dichroic mirror 51 transmits a laser beam in the optical signal, and reflects an incoherent light beam. The fifth monochrome image sensor 52 is disposed on the transmission path of the laser beam transmitted by the dichroic mirror. The incoherent light beam reflected by the dichroic mirror enters the focusing device 6, so that the focusing device 6 generates a focusing instruction according to the incoherent light beam to drive the imaging lens to automatically focus.

Referring to fig. 1, the focusing device 6 includes: a focus calculation circuit 20, a motor control circuit 21, and a transmission section 22; wherein the transfer member 22 is fixedly connected with the imaging lens 3;

a focus calculation circuit 20 for calculating an image sharpness value using the electric signal corresponding to the incoherent light beam, and determining a driving parameter of the motor control circuit 21 based on the image sharpness value;

The motor control circuit 21 is used for controlling the transmission part 22 to drive the imaging lens 3 to move along the direction vertical to the imaging lens according to the driving parameters.

Specifically, the specific structure of the specific conveying member 22 is not limited in this embodiment, as long as it can drive the imaging lens 3 to move in the vertical imaging lens direction under the drive of the motor control circuit 21. Alternatively, the transfer member 22 may be a rack and pinion transfer member or a screw transfer member. Please refer to fig. 1, which shows a transmission part composed of a rack 22a of a gear 22 b. Namely, the motor control circuit 21 controls the gear 22b to rotate, the gear 22b drives the rack 22a to move up and down, and then the imaging lens 3 fixedly connected with the rack 22a is driven to move up and down along the direction vertical to the imaging lens, so that automatic focusing is realized.

The present embodiment is not limited to the specific configuration of the specific focus calculation circuit 20 and the motor control circuit 21, and reference may be made to the related art.

Please refer to fig. 1, which illustrates a specific focusing principle by taking a color image sensor as an example: the focus calculation circuit 20 in the focus device 6 performs image sharpness value calculation such as gradient calculation on a G color channel image, a B color channel image, or a new image formed by combining the G color channel image and the B color channel image of the color image sensor in a certain conversion manner, and controls the motor control circuit 21 according to the image sharpness value, and the motor control circuit 21 controls the gear 22B of the motor 22 to rotate clockwise or counterclockwise according to the control of the focus calculation circuit 20, thereby driving the rack 22a of the motor 22 to move upward or downward. The imaging lens 3 is fixed to the rack 22, and thereby moves by the movement of the rack 22a, achieving focusing.

When focusing is completed, the focusing calculation circuit 20 sends a focusing completion signal to the CPU in the processing device 7, and after receiving the signal, the CPU sends a control signal to the CMOS control circuit 32, and the CMOS control circuit 32 controls the electronic shutter speed, frame rate, electronic gain, and the like of the color image sensor under the control of the CPU.

Referring to fig. 5, in order to further improve focusing accuracy, phase focusing may be used. The focusing device 6 in this embodiment specifically includes: a focus detection optical path 23, a focus calculation circuit 20A, a motor control circuit 21, and a transmission member 22; wherein the transfer member 22 is fixedly connected with the imaging lens 3;

the focusing detection light path 23 is used for dividing the optical signal of the filtered laser beam into two paths of light paths and respectively calculating corresponding phases;

A focus calculation circuit 20A for calculating a phase difference of the phases to determine a driving parameter of the motor control circuit 21;

The present embodiment is not limited to a specific configuration of the focus detection optical path 23, the focus calculation circuit 20A, and the motor control circuit 21, and reference may be made to the related art.

Please refer to fig. 5, which illustrates a specific focusing principle by taking a color image sensor as an example:

The autofocus device 6 performs focus control by phase calculation. The input light to the focus detection optical path 23 is from the light reflected by the beam splitter or the dichroic mirror. In the following, an example of a spectroscopic sheet is described, for example, in which the spectroscopic sheet splits illumination light reflected from the observation target 101 and passing through the imaging lens 3 and the aperture 4, and guides the split illumination light into the focus detection optical path 23. The focus detection optical path 23 filters out the light of the laser beam band out of the light from the light splitting sheet 24 by an optical filter, and the focus detection optical path 23 may be an optical path in which the light of the light from the light splitting sheet 24 and the light of the laser beam band is split into two light beams, and a converging lens and a phase detection device are disposed on the optical paths of the two light beams, for example. The focus calculation circuit 20A calculates the phase difference of the phases detected by the phase detection means, thereby determining the direction and distance the imaging lens 3 needs to adjust, and sends this information to the motor control circuit 21, and the motor control circuit 21 controls the direction and angle of rotation of the gear 22b of the motor 22 according to the control of the focus calculation circuit 20A, and the rack 22a moves the imaging lens 3 upward or downward under the drive of the gear 22 b. Thereby, the imaging lens 3 realizes the auto focus according to the control of the auto focus device 6A.

In the embodiment, the automatic focusing algorithm carries out phase calculation on the image generated or derived by incoherent light, so that the masking of laser speckles on the structural information of the image of the observed object is effectively avoided, and the focusing accuracy is ensured.

The endoscope provided by the embodiment of the present invention is described below, and the endoscope described below and the blood flow imaging device described above can be referred to correspondingly.

The present invention also provides an endoscope including: the blood flow imaging device as described in any of the above embodiments.

The blood flow imaging device and the endoscope provided by the invention are described in detail above. The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present invention and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.

Claims

1. A blood flow imaging device, comprising: a light source device, an imaging lens, an image information separating device, a focusing device and a processing device; wherein:

2. The blood flow imaging device of claim 1, wherein the image information separation device is a color image sensor; the wavelength bands of the corresponding laser beam and incoherent light beam do not overlap.

3. The blood flow imaging apparatus according to claim 1, wherein the image information separation apparatus includes: a first monochromatic image sensor, a second monochromatic image sensor and a spectroscopic device; wherein,

4. The blood flow imaging apparatus according to claim 1, wherein the image information separation apparatus includes: a third monochromatic image sensor, a fourth color image sensor and a spectroscopic device; wherein,

5. The blood flow imaging apparatus according to claim 1, wherein the image information separation apparatus includes: a dichroic mirror and a fifth monochromatic image sensor; wherein,

6. The blood flow imaging device of claim 3 or 4, wherein the focusing device comprises: a focus calculation circuit, a motor control circuit, and a transmission section; wherein the conveying component is fixedly connected with the imaging lens;

and the motor control circuit is used for controlling the transmission component to drive the imaging lens to move along the direction vertical to the imaging lens according to the driving parameter.

7. The blood flow imaging device of claim 1, wherein the focusing device comprises: a focus detection light path, a focus calculation circuit, a motor control circuit and a transmission part; wherein the conveying component is fixedly connected with the imaging lens;

8. The blood flow imaging device of claim 6, wherein the delivery member is a rack and pinion delivery member or a lead screw delivery member.

9. The blood flow imaging device of claim 7, wherein the delivery member is a rack and pinion delivery member or a lead screw delivery member.

10. The blood flow imaging device of claim 1, wherein the processing device further comprises: and a display unit for displaying the two-dimensional blood flow velocity image.

11. The blood flow imaging device of claim 1, wherein the light source device further comprises: an optical coupling device and a light guide fiber; wherein,

12. An endoscope, comprising: a blood flow imaging device according to any one of claims 1 to 11.