Blood flow imaging device and endoscopeTechnical Field
The utility model relates to an auxiliary medical diagnosis technical field, in particular to blood flow imaging device and endoscope.
Background
Due to the laser beam scattered or reflected by the observation object, a granular pattern, i.e., "speckle", is formed in random distribution on the imaging plane 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 observed object 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 motion, 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 the speckle contrast in each space region in the speckle image. The laser speckle imaging does not need scanning and has the characteristics of high spatial resolution and high temporal resolution.
However, since the speckle pattern formed by laser illumination masks structural information of the observation object, there is a problem that it is often difficult to perform auto-focusing in the case of laser illumination. Conventionally, it is common practice to perform manual focusing under white light or incoherent light of other colors, and then to switch to laser illumination to perform laser speckle blood flow imaging. However, it has the following disadvantages: that is, before laser speckle blood flow imaging, the illumination light needs to be switched from laser to incoherent illumination light, optical focusing is performed under incoherent illumination, and then the illumination light is switched to laser illumination to perform laser speckle blood flow imaging, so that the operation process is complicated and inconvenient.
Therefore, how to achieve accurate real-time focusing in laser speckle blood flow imaging is a technical problem to be solved by those skilled in the art.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a blood flow image device and endoscope can realize carrying out auto focus when laser beam and incoherent light beam shine simultaneously, simplifies user operation, improves user experience.
In order to solve the above technical problem, the utility model provides a blood flow imaging device, include: the device comprises a light source device, an imaging lens, an image information separation 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 positioned on a transmission path of reflected light of the laser light beam reflected by the observation object and reflected light of the incoherent light beam reflected by the observation object;
separating the 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 by the image information separation 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 observation object by using the laser beam corresponding to the electric signal.
Optionally, the image information separating device is a color image sensor; the corresponding wavelength bands of the laser beam and the incoherent light beam do not overlap.
Optionally, the image information separating device includes: the first monochromatic image sensor, the second monochromatic image sensor and the light splitting device; wherein,
a filter in the light splitting device splits 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;
and the second monochromatic image sensor is used 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.
Optionally, the image information separating device includes: the third monochrome image sensor, the fourth color image sensor and the light splitting device; wherein,
a filter in the light splitting device splits the optical signal into a laser beam and an incoherent light beam;
the third monochromatic image sensor is used for converting the separated laser beam into an electric signal corresponding to the laser beam and outputting the electric signal to the processing device;
and the fourth color image sensor is used for converting the separated incoherent light beams into incoherent light beam corresponding electric signals and outputting the incoherent light beam corresponding electric signals to the processing device.
Optionally, the image information separating device includes: a dichroic mirror and a fifth monochrome image sensor; wherein,
the dichroic mirror is used for transmitting the laser beam in the optical signal and reflecting the incoherent light beam;
and the fifth monochromatic image sensor is used for converting the laser beams transmitted by the dichroic mirror into electric signals corresponding to the laser beams and outputting the electric signals to the processing device.
Optionally, the focusing device includes: a focusing calculation circuit, a motor control circuit and a transmission component; wherein the transmission component is fixedly connected with the imaging lens;
the focusing calculation circuit is used for calculating an image definition value by utilizing the electric signal corresponding to the incoherent light beam and determining a driving parameter of the motor control circuit according to the image definition value;
and the motor control circuit is used for controlling the conveying part to drive the imaging lens to move along the direction vertical to the imaging lens according to the driving parameters.
Optionally, the focusing device includes: a focusing detection optical path, a focusing calculation circuit, a motor control circuit and a transmission component; wherein the transmission component is fixedly connected with the imaging lens;
the focusing detection light path is used for dividing the optical signal of the filtered laser beam into two paths and respectively calculating corresponding phases;
the focusing calculation circuit is used for calculating the phase difference of the phases to determine the driving parameters of the motor control circuit;
and the motor control circuit is used for controlling the conveying part to drive the imaging lens to move along the direction vertical to the imaging lens according to the driving parameters.
Optionally, the transmission part is a rack and pinion transmission part or a screw transmission part.
Optionally, the processing apparatus further includes: a display unit configured to display the two-dimensional blood flow velocity image.
Optionally, the light source device further includes: an optical coupler 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 optical fiber is used for transmitting the coupled light beam and transmitting the coupled light beam to the observation object at the light emitting end of the light guide optical fiber.
The utility model also provides an endoscope, include: a blood flow imaging apparatus as claimed in any one of the preceding claims.
The utility model provides a blood flow image device, include: the device comprises a light source device, an imaging lens, an image information separation device, a focusing device and a processing device; a 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 light beam reflected by the observed object and reflected light of the incoherent light beam reflected by the observed object; separating the 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 by the image information separation 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 an observation object by utilizing the laser beam corresponding to the electric signal;
therefore, the blood flow imaging device separates the laser beam and the incoherent light beam in the optical signal through the image information separation device, so that the focusing device can perform automatic focusing operation according to the received incoherent light beam, automatic focusing is performed when the laser beam and the incoherent light beam are irradiated simultaneously, user operation is simplified, and user experience is improved; the utility model also discloses an endoscope has above-mentioned beneficial effect, no longer gives unnecessary details here.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a block diagram of a blood flow imaging apparatus according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a color filter matrix of a color image sensor according to an embodiment of the present invention;
fig. 3 is a block diagram of 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 illustrating a structure of another blood flow imaging apparatus according to an embodiment of the present invention.
Detailed Description
The core of the utility model is to provide a blood flow imaging device, which can realize automatic focusing when laser beams and incoherent light beams are irradiated simultaneously, simplify user operation and improve user experience; the other core of the utility model is to provide an endoscope.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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 obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a block diagram of a blood flow imaging apparatus according to an embodiment of the present invention; the blood flow imaging apparatus (which may be simply referred to as an apparatus) may include: a light source device 2, an imaging lens 3, an image information separating 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 object 101;
the imaging lens 3 is located on a transmission path of reflected light of the laser light beam reflected by the observed object 101 and reflected light of the incoherent light beam reflected by the observed object 101;
the image information separation 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 an electric signal 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 by using the laser beam in response to the electric signal.
However, the intensity of the laser beam and the incoherent light beam emitted from the light source device 2 is not limited in the present embodiment. Such as, but not limited to, the intensity of the laser beam and the incoherent light beam. 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 present embodiment does not limit the specific structure of the two light source modules, 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 emits 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 emits a laser beam through the incoherent light 10. The parameter information of the two light beams can be controlled by the processing means 7. The present embodiment does not limit the position where the light source device 2 is disposed, as long as it can illuminate the observation target 101.
The transmission form of the laser beam and the incoherent light beam is not limited in this embodiment, and for example, the two light beams may be transmitted through independent optical paths and respectively irradiated onto the observation object 101, or the two light beams may be combined, that is, coupled and transmitted together and irradiated onto the observation object 101.
In order to enhance the illumination effect, preferably, the light source device 2 may further include: a light coupling device 12 and a light guide fiber 13; wherein, the optical coupling device 12 is used for coupling the laser beam and the incoherent light beam; and a light guide fiber 13 for transmitting the coupled light beam and emitting the coupled light beam to an observation object at a light emitting end of the light guide fiber 13. Wherein, the optical coupling device 12 is located at the output ends 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 guide fiber 13, and the light emitting end of the light guide fiber 13 emits the coupled light beam to the observation object. The arrangement position and form of the optical coupling device 12 and the light guiding fiber 13 can be referred to fig. 1.
Specifically, the light beams emitted from the laser light 8 and the incoherent light 10 are combined by the optical coupling device 12, transmitted through the light guide optical fiber 13, and emitted at the light emitting end to irradiate the observation target (the observation target 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 device 5 are arranged in a straight line, i.e., arranged along the imaging transmission path of the light beam. A diaphragm 4 may also be provided between the imaging lens 3 and the observation target 101 to control the amount of light entering the imaging lens 3. The present embodiment does not specifically limit the types and structures of the imaging lens 3 and the diaphragm 4. The selection can be made according to actual requirements.
In the prior art, when focusing, the blood flow imaging device needs to switch the illumination mode, that is, the blood flow imaging device needs to focus under white light illumination first and then switch back to laser illumination for imaging. If the imaging object shakes due to breathing in the laser illumination imaging process, the laser blood flow image is blurred, the blood flow velocity is not accurately calculated, and the focusing process is complicated and inconvenient. In order to avoid such a situation, it is necessary to realize automatic focusing, which is based on the premise that laser light and incoherent light can be simultaneously illuminated, that is, the device can perform image processing to image a two-dimensional blood flow velocity image of an observation object when the laser light and incoherent light are simultaneously illuminated, and in this case, it is not necessary to frequently switch the illumination light to adjust the focus of the laser illumination.
In order to perform image processing to form a two-dimensional blood flow velocity image of an observation target when both are irradiated simultaneously, it is necessary to be able to separate an optical signal corresponding to laser light and an optical signal corresponding to incoherent light, that is, to separate an optical signal corresponding to reflected light of the laser light beam and reflected light of the incoherent light beam into a laser light beam and an incoherent light beam, in a reflected light beam of the observation target 101. The separated laser beams can be converted into corresponding electric signals of the laser beams, and a two-dimensional blood flow velocity image of the observed object is generated according to the electric signals; and the separated incoherent light beams are used for realizing the automatic focusing process. In this embodiment, the image information separation device 5 is adopted to separate the 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, convert the separated laser beam into an electrical signal corresponding to the laser beam and output the electrical signal to the processing device 7 for imaging of the two-dimensional blood flow velocity image, and output the separated incoherent light beam to the focusing device 6 so as to enable the focusing device 6 to focus the image. The problem that in the prior art, a monochrome image sensor is used for shooting an image of an observed object, and focusing cannot be performed under the condition that a laser beam and an incoherent light beam exist at the same time, so that focusing can be performed only by using the incoherent light beam after being irradiated by incoherent light, and the laser light source module is switched back after focusing is completed to irradiate the observed object 101 by using laser light, so that a two-dimensional blood flow velocity image of the observed object 101 is generated by using the laser light beam corresponding to an electric signal.
The present embodiment does not limit the specific structure of the image information separating device 5, as long as the optical signal corresponding to the reflected light of the laser beam and the reflected light of the incoherent light beam can be separated into the laser beam and the incoherent light beam, that is, the optical signal has a beam separating function. For example, the image information separating device 5 may be a color image sensor, or a plurality of monochrome image sensors combined with a light splitting element, or a monochrome image sensor, a color image sensor combined with a light splitting element, or a plurality of color image sensors combined with a light splitting element, or a monochrome image sensor combined with a light splitting element, or the like. Here, the present embodiment also does not limit the specific structure of the spectroscopic component as long as the beam splitting (for example, having the transmission and reflection functions) can be realized. For example, it may be a dichroic mirror, or a filter, or a splitter, etc.
The light reflected by the observation target 101 passes through the aperture 4 and the imaging lens 3, is received by the image information separating 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 the laser beam and the incoherent light beam, converts the separated laser beam into an electric signal corresponding to the laser beam, and outputs the electric signal to the processing device 7. Wherein, converting the separated laser beam into the electric signal corresponding to the laser beam can be completed by the image sensor. Specifically, when the user uses the color image sensor, the separated laser beam may be converted into an electric signal corresponding to the laser beam, and the separated incoherent light beam may be converted into an electric signal corresponding to the incoherent light beam, and the processing device 7 may generate a reflected light image of the observation target 101 or a physiological parameter of the observation target 101, such as blood volume, blood oxygen saturation, or the like, using the electric signal corresponding to the incoherent light beam.
Since the electrical signal into which the laser light beam is converted and the electrical signal into which the incoherent light beam is converted 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 may generate a two-dimensional blood flow velocity image of the observation target, a reflected light image of the observation target, or a physiological parameter of the observation target from the two electrical signals. The method can realize the imaging of a plurality of different observation modes at the same time, namely focusing is carried out when the white light irradiation mode does not need to be switched back, and the focusing can be carried out in real time, namely, a focusing feedback mechanism is provided, so that the problem that the focusing is out of focus when the movement of an observation object in the axial direction exceeds the depth of field range of an imaging system in the prior art is solved. In the present embodiment, the image information separating device 5 is disposed 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. Specifically, fig. 1 may be referred to, and may be arranged in line with the observation target 101, the diaphragm 4, and the imaging lens 3.
The present embodiment does not limit the focusing frequency of the focusing device 6. It may be real-time focusing or timing focusing. The present embodiment also does not limit the principle of focusing by the focusing device 6, and further does not limit the specific structure of the focusing device 6. For example, the separated incoherent light beam may be focused by performing a series of processing according to the phase focusing principle, or the incoherent light beam transmitted to the processing device 7 may be focused according to the electric signal corresponding to the incoherent light beam by using the image definition principle. The focusing device 6 can generate a focusing instruction according to the focusing result to drive the imaging lens 3 to move to a position corresponding to the focusing instruction, and adjust the distance between the imaging lens and the image information separating device 5 to realize automatic focusing.
The focusing device 6 can feed back to the processing device 7 after focusing is completed, and then the processing device 7 can obtain clear electric signals corresponding to the laser beams or electric signals corresponding to the laser beams and electric signals corresponding to the incoherent light beams after focusing is completed, so that subsequent image analysis can be performed. For example, when focusing is completed, the focusing device 6 sends a signal of completion of focusing to the CPU30 in the processing device 7, the CPU30 receives the signal and sends a control signal to the image capturing control circuit, and the image capturing control circuit controls the electronic shutter speed, the frame rate, the electronic gain, and the like of the image information separating device 5 under the control of the CPU30 to acquire corresponding electric signal data. The image processing circuit 33 in the processing device 7 generates a two-dimensional blood flow velocity image by using the laser beam corresponding to the electrical signal (specifically, the algorithm for reconstructing the two-dimensional blood flow velocity image and obtaining the blood flow velocity value may refer to the prior art), and generates a reflected light image of the observation object or calculates a physiological parameter of the observation object by using the incoherent light beam corresponding to the electrical signal (the embodiment does not limit the physiological parameter of the observation object, and may be, for example, blood volume, blood oxygen saturation, etc., and the prior art may be referred to as a calculation method of each parameter specifically). 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 simultaneously acquire a plurality of important physiological parameters such as blood flow velocity, blood volume, blood oxygen saturation, and the like. The present embodiment does not limit the specific position set by the processing device 7.
Further, in order to improve the flexibility of the blood flow imaging apparatus in processing the observation object 101, optionally, referring to fig. 1, the processing apparatus 7 may further include a mode switching unit 31. Specifically, the CPU30 transmits a control signal for switching the observation mode to the mode switching circuit 31 in accordance with an operation by the user to control the illumination mode of the light source device 2, for example: under the condition of the laser speckle blood flow imaging mode, the laser 8 is turned on, and the incoherent light 10 is turned off; in the incoherent light imaging mode (i.e., two-dimensional blood flow velocity image), the laser 8 is turned off, and the incoherent light 10 is turned on; in the mode where laser speckle blood flow imaging and incoherent light imaging are performed simultaneously, the laser light 8 and the incoherent light 10 are turned on simultaneously.
To enable separation, the laser beam and the incoherent light beam in this embodiment are of different wavelengths. The laser beam and the incoherent light beam are irradiated at the same time and are not interfered with each other, so that focusing is not required under the incoherent light, and then the laser beam is switched to laser illumination for speckle imaging, so that the imaging is more convenient and faster. Especially under the condition of long-time observation, the automatic focusing can be carried out at certain time intervals without switching to white light illumination.
The blood flow imaging device of the embodiment can be used for an imaging system with an objective lens as a fixed-focus lens and an imaging system with an objective lens as a zoom lens, and realizes real-time focusing of laser speckle blood flow imaging.
Based on the above technical solution, in the blood flow imaging apparatus provided in this embodiment, the image information separation apparatus separates the laser beam and the incoherent light beam in the optical signal, so that the focusing apparatus can perform the automatic focusing operation according to the received incoherent light beam, thereby implementing automatic focusing when the laser beam and the incoherent light beam are irradiated simultaneously, simplifying the user operation, and improving the user experience.
Referring to fig. 1, in order to simplify the structure of the blood flow imaging apparatus and enable the blood flow imaging apparatus to simultaneously implement two modes, i.e. simultaneously processing the electrical signal corresponding to the laser beam and the electrical signal corresponding to the incoherent light beam. The image information separation 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 present embodiment does not limit the type of the color image sensor, 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 description, for the sake of description with reference to fig. 1, a CMOS color image sensor is used as an example, but it is needless to say that the present invention is not limited thereto. Specifically, the position of the color image sensor may be referred to fig. 1.
The light reflected by the observation target 101 passes through the aperture 4 and the imaging lens 3, is received by the color image sensor, and is converted into an electrical signal to be output to the processor 7. The color filter matrix of the color image sensor is composed of, 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 the light beams of the laser light 8 and the incoherent light 10 reflected from the observation target have passed through the color filter matrix; the RAW image includes all the photo information of the original image file after being generated by the image sensor and before entering the camera image processor.
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 a color filter matrix formed of, for example, a bayer pattern shown in fig. 2, the laser light 8 can transmit only one filter of R, G, B three-color filters, while the incoherent light 10 can transmit only one or two filters of R, G, B three-color filters different from the filter through which the laser light 8 has transmitted.
Preferably, the laser light 8 is red laser light which can only pass through the R filter, and the incoherent light 10 is narrow-band green light which can only pass through the G filter, narrow-band blue light which can only pass through the B filter, or light obtained by combining the two kinds of narrow-band light in a certain ratio.
The red wave light can ensure the intensity of reflected or dispersed laser, is beneficial to obtaining blood flow velocity distribution information and improves the signal-to-noise ratio of blood flow images; blue and green incoherent light is located at the hemoglobin absorption peak, and thus images generated by the G channel, the B channel, or a combination of both can be used to highlight vascular structures. The combination of coherent light and incoherent light can be skillfully utilized to carry out multi-mode imaging, or the blood flow velocity information of a blood vessel region and a non-blood vessel region can be respectively obtained through an image segmentation and image fusion algorithm.
The operation of this embodiment is described below with a specific structure in fig. 1:
the image processing circuit 33 in the processing device 7 processes an image from the observation target 101 captured by the color image sensor. For example, the laser 8 is red light, the incoherent light 10 is light formed by combining green light and blue light according to a certain proportion, in a mode that laser speckle blood flow imaging and incoherent light imaging are simultaneously carried out, the image processing circuit 33 extracts gray values at pixel positions corresponding to R filter matrixes from a RAW image of the color image sensor to form a new image SPEC, the new image SPEC is used for calculating blood flow velocity and reconstructing a two-dimensional blood flow velocity image in laser speckle blood flow imaging, and gray values at pixel positions corresponding to G filter matrixes and B filter matrixes are respectively extracted from the RAW image of the color image sensor to form two new G images GN1 and GN2 and a new B image BN, and the new G images are used for calculating parameters such as blood volume and blood oxygen saturation and reconstructing the corresponding two-dimensional image. In addition, since there are two G filters in one 2 × 2 bayer filter matrix, a new G image GN is obtained by averaging the images GN1 and GN 2.
Specifically, the blood flow velocity calculated from the image SPEC may be calculated using, for example, a sliding spatial window, may be calculated using a sliding temporal window, or may be a combination of the two. Taking the example of calculating the blood flow velocity using a sliding spatial window, first, a mean value and a standard deviation of the gray values of each pixel of the image SPEC in a spatial neighborhood of size N × N are calculated using a spatial window of size N × N, and a ratio of the standard deviation and the mean value is calculated, thereby calculating a value called speckle contrast; sliding the space window in the space area of the image SPEC according to the calculation method, and calculating the speckle contrast value of the area where the space window is located, so as to traverse the whole image area of the image SPEC and obtain a speckle contrast image; and calculating the reciprocal of the square of the speckle contrast ratio value at each pixel position of the speckle contrast image or calculating by using a quantitative formula of the speckle contrast ratio value and the electric field autocorrelation function 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 refer to the related art.
Further, alternatively, two-dimensional blood flow velocity information of the observation target 101 obtained, two-dimensional blood oxygen saturation information physiological parameter information, and the like may be stored by the data storage circuit 34. For subsequent viewing.
Further, optionally, the processing apparatus further includes: and a display part 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 does not limit the specific form of the display component, and may be, for example, the display 35, or may be 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, 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 in order to improve the display efficiency. I.e. a split screen display can 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 manner. The present embodiment does not limit the ratio of split screens, and may be equally distributed, for example. Of course, the user may select to perform the image fusion processing and then display the image.
Based on the 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 after the laser beam and the incoherent light beam irradiate the object to be detected simultaneously, the electric signal corresponding to the laser beam and the electric signal corresponding to the incoherent light beam are respectively extracted, so that the laser beam and the incoherent light beam are imaged simultaneously.
Referring to fig. 3, in order to improve the resolution of the laser beam corresponding to the electrical signal. The image information separating device 5 in the present embodiment includes: a first monochrome image sensor 5a, a second monochrome image sensor 5b, and a light splitting device 40; wherein,
a filter 40a in the light splitting device 40 splits 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 a laser beam-corresponding electric signal and outputting the same to the processing device 7;
and a second monochrome image sensor 5b 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 the incoherent light beam in the optical signal and transmit the laser light beam (as shown in fig. 3); of course, the filter 40a may transmit the incoherent light beam in the optical signal and reflect the laser beam. This embodiment is not limited to this, as long as the optical signal can be separated into a laser beam and an incoherent light beam. The first monochrome image sensor 5a is disposed on the transmission path of the split laser light beam, and the second monochrome image sensor 5b is disposed on the transmission path of the split incoherent light beam.
Taking fig. 3 as an example, the specific process is as follows: the filter 40a of the spectroscopic device 40 reflects the light of the component from the laser light 8 out of the reflected light from the observation target 101 and having passed through the aperture 4 and the imaging lens 3, and causes the partial light to enter the monochrome image sensor 5 b; the filter 40a transmits the light of the component from the incoherent light 10 out of the reflected light reflected from the observation target 101 and passed through the aperture 4 and the imaging lens 3, and causes the partial light to enter the monochrome image sensor 5 a.
The position of the optical filter 40a in the light splitting device 40 can be as shown in fig. 3, but the present embodiment does not limit this, and it can be set according to actual conditions as long as the transmitted and reflected light can enter the corresponding monochrome image sensor.
Since the monochrome image sensor has no color filter matrix, it is easier to maintain the original resolution of the optical system. Therefore, in the embodiment, the two monochromatic image sensors are adopted to realize the separation of the laser beam and the incoherent light beam, and the original resolution of the optical system can be maintained. And since the monochrome image sensor has no color filter matrix, the degree of freedom in selecting the wavelength range of the corresponding laser light is higher than that of using a color image sensor. In this embodiment, the laser may be a laser having any wavelength in the visible light range, or may be a near-infrared laser.
The following describes the operation process with the specific structure in fig. 3:
the image processing circuit 33 processes images of the image of the observation target 101 captured by the monochrome image sensors 5a and 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 ratio, 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 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 calculation of the blood flow velocity from the image captured by the monochrome image sensor 5b may be, for example, calculation using a sliding spatial window, calculation using a sliding temporal window, or a combination of both. Taking the example of calculating the blood flow velocity using a sliding spatial window, first, using a spatial window of size N × N, a mean value and a standard deviation of the gray values of each pixel in a spatial neighborhood of size N × N of the image captured by the monochrome image sensor 5b are calculated, and a ratio of the standard deviation and the mean value is calculated, thereby calculating a value called speckle contrast; according to the above calculation method, the spatial window is slid in the spatial area of the image photographed by the monochrome image sensor 5b, and the speckle contrast ratio value of the area where the spatial window is located is calculated at the same time, thereby traversing the whole image area of the image photographed by the monochrome image sensor 5b to 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, and obtaining 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, and the like of the observation target 101 are obtained, and can be stored by the data storage circuit 34, and an image corresponding to the current operation mode is 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 and an incoherent light image generated by absorption of incoherent light by an endogenous acoustic chromophore. That is, the processing device 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, to distinguish between superficial vessels and middle vessels. The image information separating device 5 in the present embodiment includes: a third monochrome image sensor 5d, a fourth color image sensor 5c, and a light splitting device 40; wherein,
a filter 40a in the light splitting device 40 splits the optical signal into a laser beam and an incoherent light beam;
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;
and 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 the incoherent light beam in the optical signal and transmit the laser light beam (as shown in fig. 4); of course, the filter 40a may transmit the incoherent light beam in the optical signal and reflect the laser beam. This embodiment is not limited to this, 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 split laser light beam, and the fourth color image sensor 5c is disposed on the transmission path of the split incoherent light beam.
Taking fig. 4 as an example, the specific process is as follows: the filter 40a of the spectroscopic device 40 transmits the light of the component from the laser light 8 out of the reflected light from the observation target 101 and having passed through the aperture 4 and the imaging lens 3, and causes the partial light to enter the monochrome image sensor 5 d; the filter 40a reflects the light of the component of the incoherent light 10 out of the reflected light from the observation target 101 and having passed through the diaphragm 4 and the imaging lens 3, and makes the part of the light enter the color image sensor 5 c.
The reflected light of the incoherent blue light and green light is received by the monochromatic image sensor to form a monochromatic image for observing the physiological state of the biological tissue. The gray scale of this monochrome image reflects the degree of absorption of blue and green light by the absorbing color clusters in the biological tissue. This approach has the advantage of high resolution, but has the disadvantage of not distinguishing the effects of the blue and green light contributions from the monochromatic image, i.e. the superficial and middle vessels. The color image sensor 5c is used in the present embodiment, which has the advantage that the superficial blood vessels and the middle blood vessels can be distinguished by means of image processing (the blue light has a shallow penetration depth for imaging the superficial blood vessels; the green light has a relatively deep penetration depth for imaging the middle blood vessels), and is used for disease diagnosis. The corresponding resolution reduction problem in this case can be compensated for by an interpolation algorithm for a partial resolution loss.
The position of the optical filter 40a in the light splitting device 40 can be as shown in fig. 4, but the present embodiment does not limit this, and it can be set according to actual conditions as long as the transmitted and reflected light can enter the corresponding monochrome image sensor.
The following describes the operation process with the specific structure in fig. 4:
the image processing circuit 33 processes images of the image of the observation target 101 captured by the monochrome image sensor 5d and the color image sensor 5 c. For example, the laser 8 is red light, the incoherent light 10 is light formed by combining green light and blue light according to a certain ratio, in a mode that laser speckle blood flow imaging and incoherent light imaging are performed simultaneously, an image shot by the monochromatic image sensor 5d is used for calculating blood flow velocity and reconstructing a two-dimensional blood flow velocity image in the laser speckle blood flow imaging, and an image shot by the color image sensor 5c is used for calculating parameters such as blood volume and blood oxygen saturation 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 can be stored by the data storage circuit 34, and an image corresponding to the current operation mode is displayed on the display 35. For example, in a mode in which laser speckle blood flow imaging and incoherent light imaging are performed simultaneously, the display 35 displays a two-dimensional blood flow velocity image and a blood oxygen saturation image in a split manner. The processing device 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 device 5 of the present embodiment includes: dichroic mirror 51 and fifth monochrome image sensor 52; wherein,
a dichroic mirror 51 for transmitting the laser beam in the optical signal and reflecting the incoherent light beam;
a fifth monochrome image sensor 52 for converting the laser beam transmitted by the dichroic mirror into a laser beam-corresponding electric signal and outputting the same to the processing device 7.
Among them, Dichroic Mirrors (Dichroic Mirrors) are also called Dichroic Mirrors, and are commonly used in laser technology. It features that it is almost completely transparent to light with certain wavelength and almost completely reflective to light with other wavelength. This embodiment uses this characteristic of the dichroic mirror to separate the laser beam and the incoherent light beam in the optical signal. Specifically, dichroic mirror 51 transmits the laser beam in the optical signal, and reflects the incoherent light beam. The fifth monochrome image sensor 52 is disposed on the transmission path of the laser light 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 conveyance member 22; wherein, the transmission part 22 is fixedly connected with the imaging lens 3;
a focusing calculation circuit 20 for calculating an image sharpness value by using the electric signal corresponding to the incoherent light beam, and determining a driving parameter of the motor control circuit 21 according to the image sharpness value;
and 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 present embodiment does not limit the specific structure of the conveying member 22, that is, it can drive the imaging lens 3 to move along the direction perpendicular to the imaging lens under the driving of the motor control circuit 21. Alternatively, the transmission member 22 may be a rack and pinion transmission member, or may be a screw transmission member. Please refer to fig. 1, i.e. the gear 22b and the rack 22 a. 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 further drives the imaging lens 3 fixedly connected with the rack 22a to move up and down along the direction vertical to the imaging lens, so that automatic focusing is realized.
The present embodiment does not limit the specific structures of the 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 focusing calculation circuit 20 in the focusing device 6 calculates an image sharpness value, such as a gradient calculation, of a G color channel image of the color image sensor, a B color channel image, or a new image formed by combining the G color channel image and the B color channel image 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 focusing calculation circuit 20, thereby moving the rack 22a of the motor 22 upward or downward. The imaging lens 3 is fixed to the rack 22, and thus moves by the movement of the rack 22a, and focusing is achieved.
When focusing is completed, the focus calculation circuit 20 transmits a signal of completion of focusing to the CPU in the processing device 7, the CPU receives the signal and transmits a control signal to the CMOS control circuit 32, and the CMOS control circuit 32 controls the electronic shutter speed, the frame rate, the 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 the focusing accuracy, phase focusing may be utilized. In this embodiment, the focusing device 6 includes: a focus detection optical path 23, a focus calculation circuit 20A, a motor control circuit 21, and a conveyance member 22; wherein, the transmission part 22 is fixedly connected with the imaging lens 3;
a focusing detection optical path 23, configured to divide the optical signal with the filtered laser beam into two optical paths, and calculate corresponding phases respectively;
a focus calculation circuit 20A for calculating a phase difference of the phases to determine a drive parameter of the motor control circuit 21;
and 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 present embodiment does not limit the specific structure of the conveying member 22, that is, it can drive the imaging lens 3 to move along the direction perpendicular to the imaging lens under the driving of the motor control circuit 21. Alternatively, the transmission member 22 may be a rack and pinion transmission member or a screw transmission member. Please refer to fig. 1, i.e. the gear 22b and the rack 22 a. 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 further drives the imaging lens 3 fixedly connected with the rack 22a to move up and down along the direction vertical to the imaging lens, so that automatic focusing is realized.
The present embodiment does not limit the specific configurations of the focus detection optical path 23, the focus calculation circuit 20A, and the motor control circuit 21, which can refer 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 light reflected by a dichroic mirror or a beam splitter. The following description will be made taking a spectroscope as an example, and the spectroscope splits illumination light reflected from the observation target 101 and passing through the imaging lens 3 and the diaphragm 4, and guides the split illumination light to the focus detection optical path 23. The focus detection optical path 23 may filter, by an optical filter, light in the laser beam wavelength band out of the light from the spectroscope 24, and the focus detection optical path 23 may be an optical path in which, for example, the light from the spectroscope 24, from which the light in the laser beam wavelength band has been filtered, is divided into two light beams, and a condensing lens and a phase detection device are disposed on the optical paths of the two light beams. The focus calculation circuit 20A calculates the phase difference of the phases detected by the phase detection means, thereby determining the direction and distance in which the imaging lens 3 needs to be adjusted, and sends this information to the motor control circuit 21, 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 by the drive of the gear 22 b. Thereby, the imaging lens 3 realizes autofocus in accordance with the control of the autofocus device 6A.
In the embodiment, the automatic focusing algorithm performs phase calculation on the image generated or derived by the incoherent light, so that the covering of the laser speckle on the structural information of the image of the observed object is effectively avoided, and the focusing accuracy is ensured.
The following describes an endoscope provided by embodiments of the present invention, and the endoscope described below and the blood flow imaging device described above are referred to in correspondence.
The utility model also provides an endoscope, include: a blood flow imaging apparatus as claimed in any preceding embodiment.
The blood flow imaging device and the endoscope provided by the present invention are described in detail above. The principles and embodiments of the present invention have been explained herein using specific examples, and the above descriptions of the embodiments are only used to help understand the method and its core ideas of the present invention. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, the present invention can be further modified and modified, and such modifications and modifications also fall within the protection scope of the appended claims.