CN106994006A - Bimodal imaging system - Google Patents

Abstract

A dual-mode imaging system, including: a laser light source, a beam splitter, a spectrometer, a reference arm, a microscope objective lens, an irregular right-angle triangular prism with an acoustic focusing groove on a right-angle side, a regular right-angle triangular prism, and a water-immersed high-speed The scanning galvanometer and the ultrasonic probe, wherein: the light beam generated by the laser light source passes through the variable diaphragm, the first lens, the pinhole diaphragm and the second lens arranged between the laser light source and the beam splitter and enters the beam splitter, and the light beam passes through A part of the beam behind the beam splitter enters the reference arm, and another part of the beam passes through the beam splitter and enters the microscope objective to form a focused beam. Right-angle side injection, the system structure of the present invention is simplified, the stability of the system is increased, and the cost of the system is reduced at the same time.

Description

Dual Mode Imaging System

technical field

The invention relates to a technique in the field of microscopic imaging, in particular to a dual-mode imaging system.

Background technique

The principle of optical coherence microscopy (OCM) is similar to that of optical coherence tomography, which is based on the backscattering light characteristics of incident photon tissue, and detects the back reflection or scattering intensity of incident photons at different depths of biological tissue. In this way, the tissue microstructure information within a certain depth range can be obtained, and then the two-dimensional or three-dimensional structural information of biological tissues can be obtained through horizontal scanning. Optical-Resolution Photoacoustic Microscopy (OR-PAM) is mainly based on the distribution characteristics of light absorption by absorbers in biological tissues. The tissue absorbs light energy to generate ultrasonic signals, which are detected by ultrasonic transducers to obtain Subtle changes in the morphological and functional parameters of the absorber and images of pathological states.

OCM imaging technology uses weakly coherent interference signals of tissue scattered photons to detect changes in the back reflection or scattering intensity of incident photons at different depths inside biological tissues. It can provide high longitudinal resolution and high contrast structural imaging, but it cannot provide blood Important functional parameters of microvessels such as oxygen saturation, oxygen metabolism and hemoglobin content. OR-PAM is based on the difference in the light absorption coefficients of oxygenated hemoglobin and deoxygenated hemoglobin in different bands, which are important components in blood, and can realize effective position-specific functional imaging and quantify metabolic-related hemoglobin concentration, SO ₂ and total hemoglobin concentration and other key physiological and functional parameters in clinical diagnosis.

Contents of the invention

Aiming at the fact that the existing technology cannot realize large-scale high-speed high-resolution imaging of living animals, the sub-imaging system is optical coherence tomography, and there is a serious shortage of lateral resolution in microvascular imaging, especially in capillary detection in the early stage of tumor development. A dual modality imaging system.

The present invention is achieved through the following technical solutions:

The invention includes: a laser light source, a beam splitter, a spectrometer, a reference arm, a microscope objective lens, an irregular right-angle triangular prism with an acoustic focus groove on a right-angle side, a regular right-angle triangular prism, a water-immersion high-speed scanning vibrating mirror and an ultrasonic probe , wherein: the slopes of the irregular right-angle triangular prism and the regular right-angle triangular prism are bonded together, an aluminum film layer is arranged between the two slopes of the irregular right-angle triangular prism and the regular right-angle triangular Fitted and opposite to the acoustic focusing groove, the beam generated by the laser light source passes through the variable diaphragm, the first lens, the pinhole diaphragm and the second lens arranged between the laser light source and the beam splitter and enters the beam splitter in sequence, and passes through A part of the beam behind the beam splitter enters the reference arm, and another part of the beam passes through the beam splitter and enters the microscope objective to form a focused beam. The object is scanned from the right-angle side and enters the water-immersed high-speed scanning galvanometer. The ultrasonic signal generated on the surface of the object is collected by the ultrasonic probe after passing through the water-immersed high-speed scanning galvanometer, the acoustic focusing groove and the regular right-angled triangular prism. The generated backscattered light returns along the original optical path and combines with the beam in the reference arm to generate an interference signal, and the interference signal enters the spectrometer through the beam splitter.

A first reflector and a photodetector are arranged between the second lens and the beam splitter, and the first reflector injects a part of the beam splitted from the second lens into the photodetector.

The reference arm includes a focusing lens, a first fiber coupler and a second reflecting mirror arranged in sequence.

The maximum pulse energy of the beam emitted by the laser light source is greater than 20μJ, the repetition frequency is greater than 5KHz, and the pulse width is less than 10ns.

The center frequency of the ultrasonic probe is greater than 30MHz, the -6dB bandwidth is greater than 50%, the sensitivity is greater than -220dB, and the delay line is 4.25μs.

Both the right angle sides of the regular right-angle triangular prism and the irregular right-angle triangular prism are larger than 15 mm, and the hypotenuses are larger than 21.2 mm.

The diameter of the acoustic focusing groove is 9mm, the radius of curvature is greater than 7.07mm, and the center depth is greater than 2.2mm.

The working frequency of the water-immersed high-speed scanning galvanometer has a fast axis greater than 25KHz, a slow axis greater than 2KHz, a mirror diameter greater than 1 mm, and a vibration period greater than 10 ^-11 s.

technical effect

Compared with the prior art, the system structure of the present invention is simplified, the system stability is increased, and the cost of the system is reduced at the same time. More integrated, light and sound achieve the purpose of coaxiality, which greatly improves the signal-to-noise ratio and sensitivity of the system's detection, and combines the transmission, scanning and transmission of light and sound in one system.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Figure 2 is an imaging comparison chart;

Among the figure: (a) is the common device imaging; (b) is the imaging of the present invention;

In the figure: 1 laser light source, 2 iris diaphragm, 3 first lens, 4 pinhole diaphragm, 5 second lens, 6 first reflector, 7 photoelectric detector, 8 beam splitter, 9 focusing lens, 10 The first optical fiber coupler, 11 the second mirror, 12 large-aperture microscope objective lens, 13 irregular right-angle triangular prism, 14 regular right-angle triangular prism, 15 aluminum film layer, 16 water immersion high-speed scanning vibrating mirror, 17 acoustic focusing concave Tank, 18 ultrasonic signal, 19 water tank, 20 ultrasonic probe, 21 signal amplifier, 22 control acquisition computer, 23 spectrometer, 24 second fiber coupler, 25 focusing objective lens.

detailed description

As shown in Figure 1, the present embodiment comprises: a laser light source 1, a beam splitter 8, a spectrometer 23, a reference arm, a large-aperture microscopic objective lens 12, an irregular right-angled triangular prism 13 that is provided with an acoustic focusing groove 17 on a right-angled side, Regular right-angle triangular prism 14, water immersion type high-speed scanning vibrating mirror 16 and ultrasonic probe 20, wherein: irregular right-angle triangular prism 13 and the slope of regular right-angle triangular prism 14 are bonded, irregular right-angle triangular prism 13 and regular right-angle triangular prism An aluminum film layer 15 is arranged between the two slopes of 14, and the ultrasonic probe 20 is attached to the right-angle side of the regular right-angled triangular prism 14 and is opposite to the acoustic focusing groove 17. The variable diaphragm 2, the first lens 3, the pinhole diaphragm 4 and the second lens 5 between the beam splitters 8 enter the beam splitter 8, and a part of the beam passing through the beam splitter 8 enters the reference arm, and the other part of the beam Sequentially pass through the beam splitter 8 and enter the large-aperture microscopic objective lens 12 to form a focused beam. The high-speed scanning galvanometer 16 scans the object, and the ultrasonic signal 18 generated on the object surface is collected by the ultrasonic probe 20 after passing through the water-immersion high-speed scanning galvanometer 16, the acoustic focusing groove 17 and the regular right-angle triangular prism 14, and the ultrasonic signal generated on the surface of the object The backscattered light returns along the original optical path and combines with the light beam in the reference arm to generate an interference signal, and the interference signal enters the spectrometer 23 through the beam splitter 8 .

A first reflector 6 and a photodetector 7 are arranged between the second lens 5 and the beam splitter 8 , and the first reflector 6 splits a part of the light emitted by the second lens 5 into the photodetector 7 . The reference arm includes a focusing lens 9 , a first fiber coupler 10 and a second mirror 11 arranged in sequence. A focusing objective lens 25 and a second fiber coupler 24 are sequentially arranged between the beam splitter 8 and the spectrometer 23 .

The water-immersed high-speed scanning galvanometer 16 , the regular right-angle triangular prism 14 , the irregular right-angle triangular prism 13 and the ultrasonic probe 20 are all immersed in the water tank 19 .

The maximum pulse energy of the beam emitted by the laser light source 1 is greater than 20μJ, the repetition frequency is greater than 5KHz, the pulse width is less than 10ns, and it can provide a wide spectrum band with a wavelength of 500-980nm. The center frequency of the ultrasonic probe 20 is greater than 30MHz, the -6dB bandwidth is greater than 50%, the sensitivity is greater than -220dB, and the delay line is 4.25μs. Both the right angles of the regular right-angled triangular prism 14 and the irregular right-angled triangular prism 13 are greater than 15 mm, and the hypotenuses are greater than 21.2 mm. The diameter of the acoustic focusing groove 17 is 9mm, the radius of curvature is greater than 7.07mm, and the center depth is greater than 2.2mm. The working frequency of the water-immersed high-speed scanning galvanometer 16 has a fast axis greater than 25KHz and a slow axis greater than 2KHz. Its mirror diameter is greater than 1mm, and its vibration period is greater than 10 ^-11 s. It can obtain an optical sweep angle of 80°.

The ultrasonic signal collected by the ultrasonic probe 20 is transmitted to the control acquisition computer 22 through the signal amplifier 21, and the interference signal collected by the spectrometer 23 is also transmitted to the control acquisition computer 22, and the two-dimensional and three-dimensional dual-mode display is reconstructed in the control acquisition computer 22. Microstructure-function image.

As shown in Figure 2, this device can realize rapid microvascular imaging of superficial diseases in vivo, and the imaging is clearer than that of ordinary devices, which greatly promotes the application process of this technology in pre-clinical transformation. Water as the acoustic signal transmission medium exists in the photoacoustic system, so in this design, the acoustic signal theoretically only transmits through the secondary interface between the quartz glass and the aluminum film to the probe interface. According to the incident and refraction angles of the acoustic signal, the aluminum film and the quartz glass Acoustic impedance, the transmittance of the sound wave in this design is 97.5%, after the second transmission, the detection efficiency of 95% can still be obtained, and the sensitivity is increased by about 12.3%.

Compared with the existing technology, the system structure of this device is simplified, the system stability is increased, and the cost of the system is reduced at the same time, which is very beneficial to the productization of the system and the user's use and operation, and effectively reduces the attenuation in the process of sound wave transmission. More integrated, the light and sound achieve the purpose of coaxial concentricity, which greatly improves the signal-to-noise ratio and sensitivity of the system's detection, and integrates the transmission, scanning and transmission of light and sound in one system.

The above specific implementation can be locally adjusted in different ways by those skilled in the art without departing from the principle and purpose of the device. The protection scope of the device is subject to the claims and is not limited by the above specific implementation. Each implementation within the scope is bound by this device.

Claims (8)

1. A dual-mode imaging system, characterized in that it comprises: a laser light source, a beam splitter, a spectrometer, a reference arm, a microscopic objective lens, an irregular right-angled triangular prism with an acoustic focusing groove on a right-angled side, a regular right-angled triangular Prisms, water-immersed high-speed scanning galvanometers and ultrasonic probes, wherein: the inclined surfaces of the irregular right-angled triangular prism and the regular right-angled triangular prism are bonded, and an aluminum film is arranged between the two inclined surfaces of the irregular right-angled triangular prism and the regular right-angled triangular prism layer, the ultrasonic probe is attached to the right-angle side of the regular right-angle triangular prism and is opposite to the acoustic focusing groove, and the beam generated by the laser light source passes through the variable diaphragm, the first lens, and the pinhole arranged between the laser light source and the beam splitter in sequence The diaphragm and the second lens enter the beam splitter, a part of the beam passing through the beam splitter enters the reference arm, and the other part of the beam passes through the beam splitter and enters the microscope objective to form a focused beam, which enters the irregular right-angle triangular prism The right-angled side of the object is ejected from the other right-angled side with the acoustic focusing groove and enters the water-immersed high-speed scanning galvanometer to scan the object. The ultrasonic signal generated on the surface of the object passes through the water-immersed high-speed scanning galvanometer, the acoustic focusing groove and The regular right-angle triangular prism is collected by the ultrasonic probe. The backscattered light generated on the surface of the object returns along the original optical path and combines with the beam in the reference arm to generate an interference signal. The interference signal enters the spectrometer through the beam splitter. 2. The dual-mode imaging system according to claim 1, wherein a first reflector and a photodetector are arranged between the second lens and the beam splitter, and the first reflector connects the second lens A part of the emitted light after splitting enters the photodetector. 3. The dual-mode imaging system according to claim 2, wherein the reference arm comprises a focusing lens, a first fiber coupler and a second mirror arranged in sequence. 4. The dual-mode imaging system according to claim 1, wherein the maximum pulse energy of the beam emitted by the laser light source is greater than 20 μJ, the repetition frequency is greater than 5 KHz, and the pulse width is less than 10 ns. 5. The dual-mode imaging system according to claim 1, wherein the center frequency of the ultrasonic probe is greater than 30MHz, the -6dB bandwidth is greater than 50%, the sensitivity is greater than -220dB, and the delay line is 4.25μs. 6. The dual-mode imaging system according to claim 1, characterized in that, the right angles of the regular right-angled triangular prism and the irregular right-angled triangular prism are both greater than 15 mm, and the hypotenuses are greater than 21.2 mm. 7. The dual-mode imaging system according to claim 6, wherein the diameter of the acoustic focusing groove is 9mm, the radius of curvature is greater than 7.07mm, and the center depth is greater than 2.2mm. 8. The dual-mode imaging system according to claim 1, characterized in that, the fast axis of the working frequency of the water-immersion high-speed scanning galvanometer is greater than 25KHz, the slow axis is greater than 2KHz, the mirror diameter is greater than 1mm, and the vibration period Greater than 10 ^-11 s.