Optical coherence tomography endoscope probe and imaging system

Abstract

The present invention provides an optical coherence tomography endoscope probe and an imaging system. An optical coherence tomography endoscope probe comprises a protective sleeve, an optical fiber, a gradient refractive index mirror group and a spectroscope. One end of the protective sleeve is a closed end, and the inner end surface of the closed end is a reflective surface. The gradient refractive index mirror group is accommodated in the protective sleeve. The spectroscope is arranged at one end of the gradient refractive index mirror group away from the optical fiber, and the spectroscope is used to divide the detection light into a first detection light and a second detection light. The first detection light is reflected from one side of the protective sleeve through the spectroscope, and the second detection light is transmitted to the reflective surface and reflected by the reflective surface. The above optical coherence tomography endoscope probe and imaging system can improve the imaging quality.

Description

Technical Field

[0001] The invention relates to an endoscope component, in particular to an optical coherence tomography endoscope probe and an imaging system. Background Art

[0002] An endoscope is a medical detection instrument that can be inserted into the human body cavity or internal organs for direct observation, diagnosis and treatment.

[0003] Optical coherence tomography (OCT) is a non-invasive, high-resolution biomedical imaging technology that can be measured in vivo. It can achieve three-dimensional imaging of biological tissue structures at a depth of 1 to 2 mm. OCT is an optical imaging technology that has higher image resolution than imaging technologies such as magnetic resonance imaging and ultrasound imaging. The resolution can reach submicron to more than ten microns. However, due to the limitation of the penetration depth of light in biological tissues, the imaging depth of OCT is lower than that of imaging technologies such as ultrasound, and is only on the order of millimeters.

[0004] In order to overcome the problem of shallow OCT imaging depth, researchers combined OCT with endoscopic imaging to form endoscopic OCT. Endoscopic OCT uses an endoscopic probe to penetrate the detection light deep into the tissue being tested, thereby realizing the detection of blood vessels, gastrointestinal tract, trachea and other lumens in the human body, playing an important role in assisting doctors in vascular stents, vulnerable plaque detection and early diagnosis of cancer.

[0005] In conventional OCT systems, when the OCT probe rotates at high speed, the twisting of the optical fiber will cause real-time changes in the polarization state of the sample light, while the polarization state of the reference light remains unchanged, causing the intensity of the interference signal to change with the polarization difference, thus affecting the imaging quality. Summary of the invention

[0006] The object of the present invention is to provide an optical coherence tomography endoscope probe and an imaging system capable of improving imaging quality.

[0007] An optical coherence tomography endoscopic probe, comprising:

[0008] A protective sleeve, one end of which is a closed end, and the inner end surface of the closed end is a reflecting surface;

[0009] An optical fiber, used for incident detection light, housed in the protective sleeve;

[0010] a gradient refractive index mirror assembly, housed in the protective sleeve, the gradient refractive index mirror assembly being disposed at one end of the optical fiber and used for receiving and converging the detection light; and

[0011] A beam splitter is disposed at one end of the gradient refractive index mirror assembly away from the optical fiber, and the beam splitter is used to split the detection light into a first detection light and a second detection light. The first detection light is reflected from one side of the protective sleeve through the beam splitter, and the second detection light is transmitted to the reflection surface and reflected by the reflection surface.

[0012] In one embodiment, the reflective surface is provided with a high reflective film layer.

[0013] In one embodiment, the beam splitter is a beam splitter prism.

[0014] In one embodiment, the beam splitter prism includes a first side surface, a second side surface and a third side surface, the first side surface is arranged opposite to the gradient refractive index lens group, light enters the beam splitter prism from the first side surface, the light is reflected by the second side surface, and exits the beam splitter prism from the third side surface and exits through the side wall of the protective sleeve.

[0015] In one embodiment, a side wall of the protective sleeve is provided with a transmissive portion, and the transmissive portion is a plane.

[0016] In one embodiment, the third side surface is parallel to the transmissive portion of the protective sleeve.

[0017] In one embodiment, the third side surface is bonded to the transmissive portion of the protective sleeve by an optical adhesive layer.

[0018] In one embodiment, the optical path between the inner axis of the reflection surface and the center point of the second side surface of the beam splitter prism is equal to the optical path between the focus of the first detection light and the center point of the second side surface of the beam splitter prism.

[0019] An optical coherence tomography system comprises a circulator, a coupler, a balanced detector, a host and an optical coherence tomography endoscope probe. Light enters the optical coherence tomography endoscope probe through the circulator and the coupler, is reflected by the optical coherence tomography endoscope probe, and is transmitted to the host through the balanced detector.

[0020] In one embodiment, the detection light is irradiated to the optical coherence tomography endoscope probe via the circulator and the coupler, and the interference signal returned from the optical coherence tomography endoscope probe is divided into two paths via the coupler, one path goes to the balanced detector, and the other path goes to the balanced detector via the circulator, and the signal collected by the balanced detector is transmitted to the host.

[0021] In the above optical coherence tomography imaging system, since the reference arm optical path and the sample arm optical path of the optical coherence tomography imaging endoscope probe are both located in the protective sleeve. When the endoscope probe rotates at high speed, the polarization states of the reference arm optical path and the sample arm optical path change in real time, and there will be no difference in the polarization state. Therefore, the intensity of the interference signal will not change, ensuring the imaging quality of the imaging system. In addition, the reference arm and the sample arm will not cause dispersion mismatch, thereby improving the longitudinal resolution of the above optical coherence tomography imaging system and improving the imaging quality.

[0022] Moreover, in the above-mentioned optical coherence tomography endoscope probe, both the sample arm and the reference arm pass through the optical fiber, and the difference in the length of the optical fiber will not cause the optical path difference between the sample light and the reference light. Therefore, in the above-mentioned endoscope probe, the sample arm and the reference arm will not have differences due to different optical fibers. Therefore, each time the probe is replaced, the operator does not need to debug the optical path size of the sample arm, which is convenient and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of an optical coherence tomography system according to this embodiment;

[0024] Figure 2 Based on Figure 1 Schematic diagram of the structure of the optical coherence tomography endoscope probe shown.

[0025] The description of the reference numerals is as follows: 10, optical coherence tomography system; 11, circulator; 12, coupler; 13, balanced detector; 14, host; 100, optical coherence tomography endoscope probe; 110, protective sleeve; 111, closed end; 112, transmission part; 113, reflecting surface; 120, optical fiber; 130, gradient refractive index mirror assembly; 140, spectroscope; 141, first side surface; 142, second side surface; 143, third side surface; 20, measured tissue; L, detection light; L1, first detection light; L2, second detection light. DETAILED DESCRIPTION

[0026] Although the present invention can be easily embodied in different forms of embodiments, only some of the specific embodiments are shown in the drawings and will be described in detail in this specification. It should be understood that this description should be regarded as an exemplary illustration of the principles of the invention and is not intended to limit the invention to that described herein.

[0027] Thus, a feature indicated in this specification will be used to illustrate one of the features of an embodiment of the present invention, rather than implying that each embodiment of the present invention must have the described feature. In addition, it should be noted that this specification describes many features. Although some features can be combined together to illustrate possible system designs, these features can also be used in other combinations that are not explicitly described. Thus, unless otherwise stated, the described combinations are not intended to be limiting.

[0028] In the embodiments shown in the drawings, the indications of directions (such as up, down, left, right, front and back) used to explain the structure and movement of various elements of the present invention are not absolute but relative. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the description of the positions of these elements changes, the indications of these directions also change accordingly.

[0029] The preferred embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings of this specification.

[0030] See also Figure 1 The present application provides an optical coherence tomography system. The optical coherence tomography system 10 of the present embodiment includes a circulator 11, a coupler 12, a balanced detector 13, a host 14, and an optical coherence tomography endoscope probe 100. The detection light enters the optical coherence tomography endoscope probe 100 through the circulator 11 and the coupler 12, is reflected by the optical coherence tomography endoscope probe 100, and is transmitted to the host 14 through the balanced detector 13. After being processed by the host 14, the detection image generated by the detection light is finally displayed.

[0031] In the above-mentioned optical coherence tomography system 10, the detection light emitted by the light source 15 is irradiated into the optical coherence tomography endoscopic probe 100 through the circulator 11 and the coupler 12. The interference signal returned from the optical coherence tomography endoscopic probe 100 is divided into two paths through the coupler 12, one path goes to the balanced detector 13, and the other path goes to the balanced detector 13 through the circulator 11. The signal collected by the balanced detector 13 is transmitted to the host 14, and after OCT data processing, a tomographic structure image of the measured tissue 20 is obtained.

[0032] The detection light emitted by the detection light is divided into a reference arm optical path and a sample arm optical path by a circulator 11 and a coupler 12, and the respective return lights are then combined by the coupler 12 to form an interference signal and received by a balanced detector 13. In the above optical coherence tomography imaging system 10, the polarization difference and dispersion mismatch introduced when the reference arm and the sample arm are branched can be eliminated, and the imaging quality can be improved. In addition, the above optical coherence tomography imaging system 10 can avoid the problem of the reference arm needing to be adjusted, which is convenient for doctors to operate.

[0033] Please also see Figure 1and Figure 2 An optical coherence tomography endoscopic probe 100 includes a protective sleeve 110, an optical fiber 120, a gradient refractive index mirror set 130 and a beam splitter 140. The optical fiber 120, the gradient refractive index mirror set 130 and the beam splitter 140 are all disposed in the protective sleeve 110.

[0034] The protective sleeve 110 can be used to provide a cylindrical accommodation space for accommodating the optical fiber 120, the gradient refractive index lens assembly 130 and the beam splitter 140. The protective sleeve 110 can be cylindrical or in other shapes. And the protective sleeve 110 can be a glass tube or a rubber tube.

[0035] One end of the protective sleeve 110 is a closed end 111. The closed end 111 is the front end of the protective sleeve 110. The front end of the protective sleeve 110 is closed to protect the endoscopic probe 100, prevent liquid from entering the endoscopic probe 100, and also prevent the probe from falling off and entering the human body cavity.

[0036] The optical fiber 120 is used to input light. Specifically, in the optical coherence tomography endoscope probe of this embodiment, the optical fiber 120 is used to input detection light. The optical fiber 120 is accommodated in the protective sleeve 110. In addition, the optical fiber 120 is a single-mode optical fiber 120.

[0037] The gradient refractive index mirror assembly 130 is an optical imaging element designed and manufactured using a medium with a gradient refractive index. The gradient refractive index mirror assembly 130 is disposed at one end of the optical fiber 120 and is used to receive the detection light emitted from the optical fiber 120. The gradient refractive index mirror assembly 130 is used to converge the detection light L. The optical axis of the gradient refractive index mirror assembly 130 coincides with the optical axis of the light, and the detection light is converged by the gradient refractive index mirror assembly 130.

[0038] The beam splitter 140 is disposed at one end of the gradient refractive index mirror assembly 130 away from the optical fiber 120. The beam splitter 140 is used to split the detection light L into two parts, namely, the first detection light L1 and the second detection light L2. Most of the detection light is reflected by the beam splitter 140 to become the first detection light L1, and the other part of the detection light is transmitted through the beam splitter 140 to become the second detection light L2.

[0039] The protective sleeve 110 is provided with a transmission portion 112. The transmission portion 112 is used to transmit light. When the protective sleeve 110 is a transparent tube, each position of the protective sleeve 110 can transmit light. It can be understood that in other embodiments, the protective sleeve 110 can also be a non-transparent tube. When the protective sleeve 110 is a non-transparent tube, the transmission portion 112 is a local area on the side wall of the protective sleeve 110. The transmission portion 112 is a transparent area that can transmit the first detection light L1. The first detection light L1 is transmitted out of the protective sleeve 110 from the transmission portion 112. The first detection light L1 is reflected out of the protective sleeve 110 and irradiated on the measured tissue 20. The first detection light L1 is scattered by the measured tissue 20 and returns to the optical fiber 120 to form a sample light.

[0040] Specifically in this embodiment, the transmission portion 112 of the protective sleeve 110 is a square area. In addition, the transmission portion 112 can also be other shapes. The shape and area size of the transmission portion 112 can be designed according to the shape and size of the transmission light spot to meet the transmission requirements of all light.

[0041] The transmission part 112 is in a planar shape. The first detection light L1 is emitted through the planar transmission part 112 to avoid astigmatism after the first detection light L1 is emitted. The protective sleeve 110 is provided at the step part on both sides of the transmission part 112. The step part connects the transmission part 112 and the cylindrical surface of the protective sleeve 110.

[0042] The inner end surface of the closed end 111 of the protective sleeve 110 is a reflective surface 113. Specifically, the reflective surface 113 is a high reflective surface. The reflective surface 113 is used to reflect the reference light.

[0043] The second detection light L2 transmits the beam splitter 140, propagates to the closed end 111 of the protective sleeve 110, and is reflected back to the optical fiber 120 by the reflection surface 113 as the reference light. The sample light scattered back by the measured tissue 20 and the reference light are coupled to form an interference signal, which is received by the balanced detector and transmitted to the host for processing.

[0044] The beam splitter 140 is disposed opposite to the transmission portion of the protection tube 110 so that the first detection light L1 is emitted through the transmission portion. Specifically in this embodiment, the beam splitter 140 is a beam splitter prism.

[0045] The beam splitter prism plays the role of light path deflection and light splitting. On the one hand, the beam splitter prism turns the direction of the light beam from the direction along the optical axis of the protective sleeve 110 to nearly perpendicular to the direction of the optical axis, so as to realize the irradiation of the side tissue 20 to be measured. On the other hand, the second side edge 142 of the beam splitter prism is not coated or coated with a partial reflective film, so as to realize the transmission of the second detection light L2 and the light splitting of the first detection light L1 and the second detection light L2. Therefore, in the above-mentioned endoscope probe, the beam splitter prism can play the role of light path deflection and light splitting without adding additional devices. The structure of the above-mentioned endoscope probe 100 is simple and compact, and the volume is reduced.

[0046] The beam splitter prism includes a first side surface 141, a second side surface 142, and a third side surface 143. The first side surface 141 is disposed opposite to the optical fiber 120. The first side surface 141 can be connected to the gradient refractive index mirror assembly 130 through an optical adhesive layer. The optical adhesive layer can minimize the scattering of the detection light between the gradient refractive index mirror assembly 130 and the beam splitter 140. It can be understood that the optical adhesive layer can be a UV adhesive layer.

[0047] The detection light L enters the beam splitter prism from the first side surface 141. The first detection light L1 is reflected from the second side surface 142 to the third side surface 143, and is emitted from the third side surface 143. The third side surface 143 is arranged opposite to the transmission part 112. The beam splitter prism and the transmission part 112 are bonded and connected by an optical adhesive layer. It can be understood that the optical adhesive layer can be an optical ultraviolet adhesive layer.

[0048] Furthermore, the optical path between the inner axis of the reflecting surface 113 and the center point of the second side surface 142 of the beam splitter prism is equal to the optical path between the focus of the first detection light L1 and the center point of the second side surface 142 of the beam splitter prism. Alternatively, the optical path between the inner axis of the reflecting surface 113 and the center point of the second side surface 142 of the beam splitter prism is slightly smaller than the optical path between the focus of the first detection light L1 and the center point of the second side surface 142 of the beam splitter prism. That is, the optical path size of the sample light is the same as the optical path size of the reference light. The length of the sample arm matches the length of the reference arm. According to the above optical path size relationship, it can be ensured that the zero optical path difference position with the highest imaging signal-to-noise ratio is near the focus of the sample light, thereby improving the imaging quality.

[0049] Since the refractive index difference between the transmissive portion 112 of the protective sleeve 110 and the beam splitter prism is small, the two interfaces are glued together with the help of an optical adhesive layer, which can reduce the reflection noise of the detection light at the interface and improve the imaging quality.

[0050] Specifically in this embodiment, the transmission portion 112 of the protective sleeve 110 is a plane, and the detection light is transmitted through the transmission portion 112, and will not diverge in the radial direction of the protective sleeve 110, so that the detection light can be prevented from diverging in the transmission portion 112, and the light spot of the detection light is guaranteed to maintain its original shape. When the light spot of the detection light is circular, the light spot of the emitted detection light is still circular. In addition, a high-transmittance film layer can also be provided on the surface of the transmission portion 112. The high-transmittance film layer can be used to increase the transmittance of the detection light and improve the imaging quality.

[0051] Furthermore, the third side surface 143 of the beam splitter prism is parallel to the plane where the transmission portion 112 is located. The first detection light L1 will not diverge, and the spot size and shape of the first detection light L1 will not change, thereby ensuring the accuracy of the first detection light L1 line and improving the imaging quality.

[0052] In summary, the above optical coherence tomography system has at least the following advantages over the traditional optical coherence tomography system:

[0053] First, in the above optical coherence tomography imaging system 10, since the reference arm optical path and the sample arm optical path of the optical coherence tomography imaging endoscope probe 100 are both located inside the endoscope probe. When the endoscope probe rotates at high speed, the polarization states of the reference arm optical path and the sample arm optical path change in real time, and there will be no difference in the polarization state. Therefore, the intensity of the interference signal will not change, ensuring the imaging quality of the imaging system. In addition, the reference arm and the sample arm will not cause dispersion mismatch, thereby improving the longitudinal resolution of the above optical coherence tomography imaging system and improving the imaging quality.

[0054] Moreover, in the above-mentioned optical coherence tomography endoscopic probe 100, both the sample arm and the reference arm pass through the optical fiber 120, and the difference in length of the optical fiber 120 will not cause the optical path difference between the sample arm and the reference arm. Therefore, in the above-mentioned endoscopic probe, the sample arm and the reference arm will not have differences due to different optical fibers 120. Therefore, every time the probe is replaced, the operator does not need to debug the optical path size of the sample arm, which is convenient and easy to operate.

[0055] Furthermore, in the above-mentioned endoscope probe, the beam splitter prism can play the role of light path deflection and beam splitting, without the need for additional devices, and the structure of the above-mentioned endoscope probe is simple and compact, and the volume is reduced. In addition, the first detection light L1 is emitted through the planar transmission part 112, which avoids the astigmatism phenomenon after the first detection light L1 is emitted. The accuracy of the first detection light L1 line is guaranteed, and the imaging quality is improved.

[0056] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. An optical coherence tomography endoscope probe, characterized in that: include: A protective sleeve, one end of which is a closed end, and the inner end surface of the closed end is a reflecting surface; An optical fiber, used for incident detection light, housed in the protective sleeve; A gradient refractive index mirror assembly is housed in the protective sleeve, and the gradient refractive index mirror assembly is disposed at one end of the optical fiber and is used to receive and converge the detection light; and A beam splitter is disposed at one end of the gradient refractive index mirror assembly away from the optical fiber, the beam splitter is used to split the detection light into a first detection light and a second detection light, the first detection light is reflected from one side of the protective sleeve through the beam splitter, and the second detection light is transmitted to the reflection surface and reflected by the reflection surface; the beam splitter is a beam splitter prism; The beam splitter prism includes a first side surface, a second side surface, and a third side surface. The detection light enters the beam splitter prism from the first side surface, and the beam splitter prism is used to split the detection light into a first detection light and a second detection light. The first detection light is reflected from the second side surface to the third side surface and emitted from the third side surface. The second detection light is transmitted through the second side surface, propagates to the closed end of the protective sleeve, and is reflected back to the optical fiber by the reflection surface to serve as reference light.

2. The optical coherence tomography endoscopic probe according to claim 1, characterized in that: The reflective surface is provided with a high reflective film layer.

3. The optical coherence tomography endoscopic probe according to claim 1, characterized in that: The side wall of the protection sleeve is provided with a transmissive portion, and the transmissive portion is a plane.

4. The optical coherence tomography endoscopic probe according to claim 3, characterized in that: The third side surface is parallel to the transmission portion of the protection sleeve.

5. The optical coherence tomography endoscopic probe according to claim 3, characterized in that: The third side surface is bonded to the transmission portion of the protective sleeve via an optical adhesive layer.

6. The optical coherence tomography endoscopic probe according to claim 1, characterized in that: The optical path between the inner axis of the reflecting surface and the center point of the second side surface of the beam splitter prism is equal to the optical path between the focus of the first detection light and the center point of the second side surface of the beam splitter prism.

7. An optical coherence tomography system, characterized in that: The optical coherence tomography endoscope comprises a circulator, a coupler, a balanced detector, a host and the optical coherence tomography endoscope probe according to any one of claims 1 to 6, wherein light enters the optical coherence tomography endoscope probe through the circulator and the coupler, is reflected by the optical coherence tomography endoscope probe, and is transmitted to the host through the balanced detector.

8. The optical coherence tomography system according to claim 7, characterized in that: The detection light is irradiated into the optical coherence tomography endoscope probe via the circulator and the coupler. The interference signal returned from the optical coherence tomography endoscope probe is divided into two paths via the coupler, one path goes to the balanced detector, and the other path goes to the balanced detector via the circulator. The signal collected by the balanced detector is transmitted to the host.

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