阅读说明：本技术 用于二维腹腔镜的三维成像转换器 (Three-dimensional imaging converter for two-dimensional laparoscope ) 是由 周平 杨子 顾承 蔡维嘉 于 2019-09-24 设计创作，主要内容包括：用于二维腹腔镜的三维成像转换器,包括连接器和三维成像转换模块,三维成像转换模块包括依次设置的物镜-Ⅱ、微透镜阵列和图像传感器,二维腹腔镜的二维成像经物镜-Ⅱ和微透镜阵列投射在图像传感器。本发明使用三维成像转换器外接于二维腹腔镜成像硬杆的目镜端,将物体经二维腹腔镜所成的二维像再次成像为含有位置与方向信息的新的像,对新的像进行后处理即可得到物体的三维信息。具体应用时,三维成像转换器可接装在二维腹腔镜上,通过后处理算法获得被测物的三维信息,不应用时,将三维成像转换器从二维腹腔镜上拆卸,原二维腹腔镜仍可实现原功能。(The three-dimensional imaging converter for the two-dimensional laparoscope comprises a connector and a three-dimensional imaging conversion module, wherein the three-dimensional imaging conversion module comprises an objective lens-II, a micro lens array and an image sensor which are sequentially arranged, and two-dimensional imaging of the two-dimensional laparoscope is projected on the image sensor through the objective lens-II and the micro lens array. The invention uses the three-dimensional imaging converter to be externally connected with the eyepiece end of the imaging hard rod of the two-dimensional laparoscope, the two-dimensional image formed by the object through the two-dimensional laparoscope is imaged into a new image containing position and direction information again, and the three-dimensional information of the object can be obtained by post-processing the new image. When the three-dimensional imaging converter is not applied, the three-dimensional imaging converter is detached from the two-dimensional laparoscope, and the original two-dimensional laparoscope can still realize the original functions.)

1. A three-dimensional formation of image converter for two-dimensional peritoneoscope, characterized by includes connector (10) and three-dimensional formation of image conversion module (3), three-dimensional formation of image converter passes through connector (10) butt joint in the eyepiece end of two-dimensional peritoneoscope (2), three-dimensional formation of image conversion module (3) are including the objective lens-II (6), microlens array (7) and image sensor (9) that set gradually, the two-dimensional formation of two-dimensional peritoneoscope (2) is through objective lens-II (6) and microlens array (7) projection at image sensor (9), wherein each part satisfies following restraint:

a) the distance parameter between the objective lens II (6) and the ocular lens (5) is equal to the focal length of the objective lens II (6);

b) the distance parameter between the objective lens-II (6) and the micro lens array (7) is equal to the focal length of the objective lens-II (6);

c) the distance between the microlens array (7) and the image sensor (9) is equal to the focal length of the microlenses;

d) f number matching requirement:

the element image of the light field image refers to an image of the microlenses of the microlens array (7) on the image sensor (9).

2. The three-dimensional imaging transducer for two-dimensional laparoscope as recited in claim 1, wherein the diameter of the element image of the light field image is equivalent to the diameter of the microlens.

3. The three-dimensional imaging converter for two-dimensional laparoscopes as claimed in claim 1, wherein a relay lens (8) is further arranged between the microlens array (7) and the image sensor (9), satisfying the following constraints:

e) the distance between the relay lens (8) and the micro lens array (7) is equal to the sum of the focal length of the relay lens and the focal length of the micro lens;

f) the distance between the relay lens (8) and the image sensor (9) is equal to the relay lens focal length.

4. The three-dimensional imaging converter for two-dimensional laparoscope as claimed in claim 3, characterized in that the distance between the relay lens (8) and the microlens array (7) is equivalent to the relay lens focal length.

5. The three-dimensional imaging transducer for two-dimensional laparoscope as claimed in any of claims 1-4, wherein the F-number matching is performed by adjusting the diameter of the beam projected by the two-dimensional laparoscope (2) on the objective lens-II (6) through the optical 4F system.

Technical Field

The invention belongs to the technical field of optical imaging and computer vision, relates to imaging detection, and discloses a three-dimensional imaging converter for a two-dimensional laparoscope.

Technical Field

Compared with the traditional operation scheme, the laparoscopic minimally invasive surgery has obvious advancement in the aspects of reducing peripheral complications in the operation period, accelerating postoperative recovery, enhancing the safety of patients and the like. The laparoscope is a medical instrument with a miniature camera, is used as an auxiliary instrument for laparoscopic minimally invasive surgery, and has very important performance.

At present, two-dimensional laparoscope is commonly used in laparoscopic surgery, and three-dimensional laparoscope is not popularized yet. In laparoscopic surgery, a doctor needs to make many delicate surgical operations and has a very accurate judgment on the depth, and the lack of two-dimensional laparoscopic depth information reduces the ability of the surgeon to confirm the position and size of an anatomical structure, limits the sensitivity of the operation in the surgery, and further affects the diagnosis and the effect of the surgery. The current three-dimensional imaging technology is mainly divided into three categories: binocular stereo vision imaging, structured light imaging and light field imaging. The existing three-dimensional laparoscopes in the market are all products based on the binocular stereoscopic vision principle. In the binocular stereo imaging technology, an object is shot through two imaging devices with known parameters and spatial positions, the projection positions of all spatial points in the two imaging devices are obtained corresponding to double optical paths in a three-dimensional laparoscope in the prior art, and three-dimensional information of the object point relative to the imaging devices can be obtained by combining the parameters and the spatial positions of the imaging devices. The three-dimensional laparoscope based on binocular stereo vision is limited by a narrow application space, belongs to a short-baseline three-dimensional imaging system, and belongs to passive imaging, so that the three-dimensional measurement precision is difficult to improve, which is also a main reason that the existing three-dimensional laparoscope in the current market has no measurement function. The main principle of the structured light imaging technology is that a light plane with a certain structure is projected on the surface of an object to be measured through a projector, the characteristics of the structured light are extracted from a shot image, and the three-dimensional information of the surface profile of the object relative to an imaging device is obtained through calculation. Since the structured light imaging technology requires the projection of multiple images, the real-time performance of the laparoscopic system cannot be achieved, and therefore, no three-dimensional laparoscope adopting the technology is available in the market. The micro-lens array is used for light field imaging, light rays converged to an imaging plane by a traditional camera are re-dispersed to obtain a light field image, the position information and the direction information of the light rays can be recorded simultaneously, the light field image is processed to obtain three-dimensional information of an object, the light field imaging is a technology which is gradually matured in recent years, and no three-dimensional laparoscope product based on the light field imaging technology exists yet.

Although the application of the two-dimensional laparoscope improves the diagnosis and operation conditions, the two-dimensional laparoscope lacks depth information and is not beneficial to doctors to judge more accurately in the diagnosis and operation processes, so the three-dimensional laparoscope is a hot project researched and developed at present. Compared with the existing three-dimensional laparoscope based on binocular stereo vision, the light field imaging technology has the advantage of realizing the measurement function, and is a development approach of the future three-dimensional laparoscope. In addition, most of the existing equipment of the medical institution is a two-dimensional laparoscope system, and the cost for replacing the equipment with the three-dimensional laparoscope is high, so that the upgrading of the equipment into the three-dimensional laparoscope on the basis of the existing two-dimensional laparoscope is a more acceptable way for hospitals.

Disclosure of Invention

The invention aims to solve the problems that: the two-dimensional laparoscope imaging lacks depth information and cannot meet the use requirement, and the existing three-dimensional laparoscope is deficient in precision and real-time, so that a new three-dimensional laparoscope needs to be researched to meet the use requirement. Meanwhile, the problem of equipment replacement cost is also considered, and improvement and upgrading are carried out on the basis of original equipment.

The technical scheme of the invention is as follows: a three-dimensional imaging converter for two-dimensional peritoneoscope, including connector and three-dimensional imaging conversion module, three-dimensional imaging converter passes through the connector butt joint and holds at the eyepiece of two-dimensional peritoneoscope, and three-dimensional imaging conversion module is including the objective lens-II, microlens array and the image sensor that set gradually, and the two-dimensional imaging of two-dimensional peritoneoscope is projected at image sensor through objective lens-II and microlens array, and wherein each part satisfies following constraint:

a) the distance parameter between the objective lens-II and the ocular lens is equal to the focal length of the objective lens-II;

b) the distance parameter between the objective lens-II and the micro lens array is equal to the focal length of the objective lens-II;

c) the distance between the microlens array and the image sensor is equal to the focal length of the microlenses;

d) f number matching requirement:

the element image of the light field image refers to an image of the microlenses of the microlens array (7) on the image sensor (9).

Further, according to the optical imaging principle, the elemental image diameter of the light field image may be equivalent to the diameter of the microlens.

Further, a relay lens is arranged between the micro-lens array and the image sensor, and the following constraints are met:

e) the distance between the relay lens and the micro lens array is equal to the sum of the focal length of the relay lens and the focal length of the micro lens;

f) the distance between the relay lens and the image sensor is equal to the relay lens focal length.

Since the focal length of the microlenses is small, the distance between the relay lens and the microlens array can be equivalent to the focal length of the relay lens.

Furthermore, when F number matching is carried out, the diameter of a light beam projected on the objective lens-II by the two-dimensional laparoscope is adjusted through the optical 4F system, so that the requirement of F number matching can be met.

Aiming at the problems in the prior art, the invention provides a three-dimensional imaging converter based on a light field imaging technology on the basis of the existing two-dimensional laparoscope. And a three-dimensional imaging converter is externally connected with an eyepiece end of the imaging hard rod of the two-dimensional laparoscope, and a two-dimensional image formed by the object through the two-dimensional laparoscope is imaged into a new image containing position and direction information again. And post-processing the new image to obtain the three-dimensional information of the object. When the three-dimensional imaging converter is not applied, the three-dimensional imaging converter is detached from the two-dimensional laparoscope, the original two-dimensional laparoscope can still be normally used, and the original function is realized.

Drawings

Fig. 1 is a schematic structural diagram of a three-dimensional imaging transducer for a two-dimensional laparoscope according to the present invention.

Fig. 2 is a second schematic structural diagram of a three-dimensional imaging converter for a two-dimensional laparoscope according to the present invention.

FIG. 3 is a schematic diagram of the F-number matching principle.

Fig. 4 is a schematic diagram of an optical 4F system.

Fig. 5 is a schematic mechanical diagram of the converter of the present invention.

Detailed Description

The invention relates to a three-dimensional imaging converter for a two-dimensional laparoscope, in particular to a device which can be arranged at an eyepiece end of an imaging hard rod of the two-dimensional laparoscope and converts a two-dimensional image of the laparoscope into an image containing three-dimensional information. The technology of the invention can be used in the field of medical detection, industrial detection and other fields.

The three-dimensional imaging converter of the invention is composed of a three-dimensional imaging conversion module 3 and a connector 10. In the present invention, the connector 10 is used to physically connect the three-dimensional imaging conversion module 3 with the eyepiece 5 of the two-dimensional laparoscope 2, so that two-dimensional imaging can be stably transmitted between the two. As shown in fig. 1, the three-dimensional imaging conversion module 3 for the two-dimensional laparoscope 2 according to the present invention may be composed of three parts, i.e., an objective lens-ii 6, which is an objective lens and is written as an objective lens-ii, for distinguishing from the objective lens of the two-dimensional laparoscope, and a microlens array 7, and an image sensor 9. When the three-dimensional imaging conversion module 3 is connected with the two-dimensional laparoscope 2, one side of an objective lens-II 6 of the three-dimensional imaging conversion module 3 is butted with one side of an ocular lens 5 of the two-dimensional laparoscope 2. The objective 4 of the two-dimensional laparoscope 2 is positioned at the same side as the object 1 to be measured.

As shown in fig. 2, the three-dimensional imaging conversion module 3 for the two-dimensional laparoscope 2 proposed by the present invention can also be composed of four parts, namely an objective lens-ii 6, a microlens array 7, a relay lens 8 and an image sensor 9. When the three-dimensional imaging conversion module 3 is connected with the two-dimensional laparoscope 2 through the converter 10, one side of the objective lens-II 6 of the three-dimensional imaging conversion module 3 is butted with one side of the ocular lens 5 of the two-dimensional laparoscope 2. The objective 4 of the two-dimensional laparoscope 2 is positioned at the same side as the object 1 to be measured.

The three-dimensional imaging conversion module 3 of the invention is equivalent to a light field camera, and no matter the three-dimensional imaging conversion module composed of three parts or four parts is adopted, the three-dimensional imaging of the object to be measured 1 can be realized through the post-processing of the image formed by the three-dimensional imaging conversion module, and the post-processing of the imaging of the light field camera is the prior art and is not detailed. The parameters of each part of the three-dimensional imaging conversion module, the distance parameters between each part and the distance parameters between the objective lens II 6 and the ocular lens 5 have influence on the three-dimensional imaging performance. In order to obtain high imaging performance of the three-dimensional imaging conversion module, the three-dimensional imaging conversion module of the invention needs to meet the following requirements:

a) the distance parameter between objective lens-II 6 and eyepiece 5 is equal to the focal length of objective lens-II 6.

b) The distance parameter between objective lens-II 6 and microlens array 7 is equal to the focal length of objective lens-II 6.

c) For a three-dimensional imaging conversion module 3 consisting of three parts, the distance between the microlens array 7 and the image sensor 9 is equal to the focal length of the microlenses.

d) For the three-dimensional imaging conversion module 3 composed of four parts, the distance between the relay lens 8 and the micro lens array 7 is equal to the sum of the focal length of the relay lens and the focal length of the micro lens. This distance may also be equal to the relay focal length due to the smaller microlens focal length.

e) For the three-dimensional imaging conversion module 3 composed of four parts, the distance between the relay lens 8 and the image sensor 9 is equal to the relay lens focal length.

f) F number matching requirement: as shown in fig. 3, the parameters between the three-dimensional imaging conversion module 3 and the components of the two-dimensional laparoscope 2 are required to satisfy the following relationships:

as shown in FIG. 3, the focal length of objective lens-II 6 is f_clFocal length of the microlens is f_MLAThe elemental image of the light-field image is defined as the image of the microlens on the image sensor 9, the elemental imageHas a diameter d'. The two-dimensional laparoscope 2 projects a beam on the objective II 6 with a diameter D_e. In the calculation, since the diameter d ' of the elemental image is substantially equal to the diameter d of the microlens, the diameter d ' of the elemental image may be replaced with the diameter d ' of the microlens.

Among the above parameters, the focal length of the objective lens-ii 6 is usually fixed and is not freely adjustable, the focal length of the microlens and the diameter of the element image of the light field image are related to the processing condition of the microlens array, and processing according to the F number matching requirement brings higher cost. Through analysis, the diameter of the projection beam of the two-dimensional laparoscope 2 on the objective lens-II 6 is equal to the diameter of the ocular lens 3 of the two-dimensional laparoscope 2 when the diameter of the projection beam of the two-dimensional laparoscope 2 is not adjusted, so that when the F number matching cannot meet the requirement, the diameter D of the projection beam of the two-dimensional laparoscope 2 on the objective lens-II 6 can be adjusted by adopting a 4F system commonly used in optics_eThe 4F system principle is shown in fig. 4.

It should be noted that the precise satisfaction of the constraints a) to f) described above allows to obtain a three-dimensional image of the object 1 to be measured with optimal performance. The small error which does not satisfy the above conditions may affect the imaging performance, but the three-dimensional imaging of the object to be measured 1 may still be realized through the post-processing algorithm corresponding to the light field camera.

The following describes the embodiments of the present invention with reference to the drawings. The three-dimensional imaging converter with relay lens for two-dimensional laparoscope is taken as an example for explanation.

The principle machine of the three-dimensional imaging conversion method for the two-dimensional laparoscope shown in the embodiment is shown in fig. 5, and an endoscope, i.e. the two-dimensional laparoscope, is used. On the basis of the structure of a principle machine, optical parameters are processed according to the constraint conditions of all distance parameters in the scheme of the invention, a connector 10 connected with a two-dimensional laparoscope is designed and manufactured on one side of an objective lens-II 6 of a three-dimensional imaging conversion module 3, and the connector 10 and the three-dimensional imaging conversion module 3 are assembled into a three-dimensional converter for the two-dimensional laparoscope. The two-dimensional laparoscope used in this embodiment is a two-dimensional laparoscope rigid rod manufactured by Shenda corporation, wherein the objective lens 4 is located at the right end of the two-dimensional laparoscope of FIG. 5, facing the object to be photographed, and the eyepiece lens 5 is located at the left end of the two-dimensional laparoscope of FIG. 5, and is butted with the objective lens-II 6. Objective lens-II 6 is a convex lens with a focal length of 50mm and a diameter of 30 mm. The microlens array is formed by arranging 110 × 165 microlenses, each having a diameter of 0.136mm and a focal length of 0.93 mm. The relay lens is selected with the amplification ratio of 1:1, and the focal length is 15 mm.