WO2019181553A1

WO2019181553A1 - Surgical microscope system

Info

Publication number: WO2019181553A1
Application number: PCT/JP2019/009267
Authority: WO
Inventors: 大月　知之
Original assignee: ソニー株式会社
Priority date: 2018-03-22
Filing date: 2019-03-08
Publication date: 2019-09-26

Abstract

The present technique relates to a surgical microscope system which enables a microscope tube to be made smaller. This surgical microscope system includes: a microscope optical system for observing a biological tissue which is an object to be observed; and a tomographic information acquisition optical system for acquiring tomographic information of the biological tissue using interference between the reflection of observation light that is emitted on the biological tissue and reference light that is not emitted onto the biological tissue. The tomographic information acquisition optical system has an optical path length adjustment unit that adjusts an optical path length of the reference light. This technique can be applied to a surgical microscope system.

Description

Surgical microscope system

[Technical Field] The present technology relates to a surgical microscope system, and more particularly to a surgical microscope system in which a microscope barrel can be miniaturized.

For example, when acquiring a tomographic image of an eye during ophthalmic surgery with a tomogram acquisition device such as OCT (Optical Coherence Tomography) mounted on a microscope, depending on the technique, it may be relatively fast, following the movement of the surgical instrument. In some cases, it is desirable to change the acquisition range of tomographic images. Such a request for a high-speed acquisition range change includes a change in the depth direction, that is, a position adjustment of the acquisition range in the depth direction.

However, in a microscope system equipped with an OCT, the depth direction at the time of tomographic image acquisition, that is, the acquisition range in the optical axis direction is generally adjusted by moving the position of the microscope barrel in the optical axis direction. Therefore, it was difficult to change the acquisition range at high speed.

On the other hand, for example, as a microscope system equipped with an OCT, a technique for changing the acquisition range in the depth direction when acquiring a tomographic image by moving the light emission area for the OCT optical scanning path in the optical axis direction Has also been proposed (see, for example, Patent Document 1). If this technique is used, it is possible to change the tomographic image acquisition range in the depth direction at a relatively high speed as compared with the case of moving the position of the microscope barrel.

Japanese Patent No. 5587395

However, in the technique described in Patent Document 1, it is possible to change the acquisition range of the tomographic image at a relatively high speed, but it is necessary to provide a drive unit for moving the light emission area inside the microscope barrel. The microscope barrel becomes large.

The present technology has been made in view of such a situation, and enables a reduction in the size of a microscope barrel.

A surgical microscope system according to one aspect of the present technology includes a microscope optical system for observing a biological tissue that is an observation target, reflected light of observation light irradiated on the biological tissue, and reference light that is not irradiated on the biological tissue. A tomographic information acquisition optical system for acquiring tomographic information of the living tissue using the interference, and the tomographic information acquisition optical system includes an optical path length adjustment unit that adjusts an optical path length of the reference light.

In one aspect of the present technology, a surgical microscope system includes a microscope optical system for observing a biological tissue that is an observation target, reflected light of observation light that is irradiated on the biological tissue, and reference that is not irradiated on the biological tissue A tomographic information acquisition optical system for acquiring tomographic information of the living tissue using interference with light, and an optical path length adjustment unit for adjusting an optical path length of the reference light in the tomographic information acquisition optical system Is provided.

According to one aspect of the present technology, the microscope barrel can be reduced in size.

Note that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is a figure which shows the structural example of a surgical microscope system. It is a figure which shows the structural example of an image information acquisition part. It is a figure which shows the structural example of an optical path length adjustment part. It is a figure which shows the structural example of an optical path length adjustment part. It is a figure explaining the interlock control of an OCT focus position and a tomographic image acquisition range. It is a flowchart explaining a tomographic information acquisition process. It is a figure which shows the structural example of a computer.

Hereinafter, embodiments to which the present technology is applied will be described with reference to the drawings.

<First Embodiment>
<Configuration example of surgical microscope system>
This technique changes the acquisition range in the depth direction of tomographic information by changing the optical path length of reference light for acquiring tomographic information in a surgical microscope system. As a result, a mechanism for changing the acquisition range in the depth direction of the tomographic information can be provided outside the microscope barrel, so that the microscope barrel can be reduced in size.

FIG. 1 is a diagram illustrating a configuration example of an embodiment of a surgical microscope system to which the present technology is applied.

The surgical microscope system 11 shown in FIG. 1 is for observing a site such as a patient's eye, which is a surgical target, before or during surgery.

This surgical microscope system 11 has a function of acquiring tomographic information indicating a tomographic image of a site to be observed, that is, a site to be operated by, for example, an OCT (optical coherence tomography), and a microscope observation such as a bright field of the site to be observed. It has the function to acquire the front image obtained by this.

It should be noted that any observation target may be used as long as it is a living tissue, but in the following, in order to simplify the explanation, a case where the observation target living tissue is a patient's eye will be described as an example.

The surgical microscope system 11 includes an image information acquisition unit 21, an image processing unit 22, and a display unit 23.

The image information acquisition unit 21 includes a microscope with a tomographic image acquisition function, and acquires image information of the eye to be operated and supplies it to the image processing unit 22.

Specifically, the image information acquisition unit 21 uses, as image information, a tomographic image of the eye to be operated, that is, a tomographic image that is an image of a cross section of the eye, or a front image obtained by microscopic observation of the eye to be operated. get.

The microscopic observation here is, for example, bright field observation, phase difference observation, fluorescence observation, etc., but the description will be continued below assuming that the eye to be operated is observed in the bright field.

In addition, the image information acquisition unit 21 may acquire a tomographic image of a specified tomographic plane, acquire tomographic information of a wide range of eyes as volume data, and specify a position (tomographical fault) in the volume data. Plane) tomographic image may be generated by synthesis. In addition, a continuous tomographic image acquired in a certain time range may be acquired as a moving image.

The image processing unit 22 controls the display of display information on the display unit 23 based on the image information supplied from the image information acquisition unit 21 and controls the operation of the image information acquisition unit 21.

The image processing unit 22 includes an image recognition unit 31, an interface unit 32, a control unit 33, and a display information generation unit 34.

The image recognition unit 31 performs image recognition processing on the image information supplied from the image information acquisition unit 21, that is, a tomographic image or a front image, and supplies the recognition result to the control unit 33. For example, in the image recognition process, a region such as a predetermined part of a surgical target eye or a surgical tool is recognized from image information.

The interface unit 32 acquires various types of information by accepting an input operation by the user or communicating with other surgical devices, and supplies the information to the control unit 33.

The control unit 33 controls each unit of the surgical microscope system 11 using the recognition result supplied from the image recognition unit 31 and the information supplied from the interface unit 32 as necessary.

The display information generation unit 34 processes the image information supplied from the image information acquisition unit 21 under the control of the control unit 33 and generates display information.

For example, the display information may be a tomographic image or a front image itself, or may be an image in which information indicating a menu, a tomographic position, or the like is superimposed on these images. The display information generation unit 34 supplies the generated display information to the display unit 23.

The display unit 23 includes a display device such as a liquid crystal display, and displays the display information supplied from the display information generation unit 34.

<Configuration example of image information acquisition unit>
Next, a configuration example of the image information acquisition unit 21 illustrated in FIG. 1 will be described.

The image information acquisition unit 21 is configured as shown in FIG. 2, for example.

2 includes a light source 61, a coupler 62, an optical path length adjusting unit 63, a light receiving unit 64, and a microscope barrel 65. The image information acquiring unit 21 shown in FIG.

Also, inside the microscope barrel 65, a collimating lens 71, a scanning unit 72, an OCT focus lens 73, an objective lens 74, and a microscope optical system 75 are provided.

Here, the light source 61 to the microscope barrel 65, in particular, the light source 61, the coupler 62, the optical path length adjusting unit 63, the light receiving unit 64, the collimating lens 71, the scanning unit 72, the OCT focus lens 73, and the objective lens 74 are used for surgery. It is provided as a configuration for obtaining a tomographic image of the target eye EY11. That is, the OCT is configured by the light source 61 to the objective lens 74.

The microscope barrel 65 is used not only for obtaining a tomographic image but also for obtaining a front image of the eye EY11. That is, a microscope for observing the eye EY11 with a microscope is configured by the objective lens 74 and the microscope optical system 75 provided in the microscope barrel 65, a light source (not shown), an image sensor, and the like. It is a microscope barrel.

The coupler 62 is made of a 2 × 2 optical fiber coupler and includes an optical fiber 81 and an optical fiber 82.

Further, a light source 61 is connected to one end of the optical fiber 81, and a collimator lens 71 is connected to the other end of the optical fiber 81.

The light source 61 is a light source that outputs observation light and reference light at the time of tomographic image acquisition, and the collimator lens 71 collects light incident from the optical fiber 81 and makes it incident on the scanning unit 72 or scan. This is an optical lens that guides light incident from the section 72 to the optical fiber 81.

In contrast, the light receiving unit 64 is connected to one end of the optical fiber 82, and the optical path length adjusting unit 63 is connected to the other end of the optical fiber 82.

The light receiving unit 64 includes, for example, an image sensor, and the optical path length adjusting unit 63 is an optical path length adjusting mechanism that adjusts the optical path of incident light.

In the coupler 62, when light enters one end of the optical fiber 81, a part of the light is guided to the other end of the optical fiber 81, and the remaining light is on the other end side of the optical fiber 81. To the end of the optical fiber 82.

That is, after the light incident on one end of the optical fiber 81 travels through the optical fiber 81, the direction of the other end of the optical fiber 81 and the optical fiber at the joint between the optical fiber 81 and the optical fiber 82 Branches in the direction of the end of the optical fiber 82 on the other end side of 81.

Similarly, when light is incident on one end of the optical fiber 82, a part of the light is guided to the other end of the optical fiber 82, and the remaining light is on the other end side of the optical fiber 82. To the end of the optical fiber 81.

Therefore, for example, when obtaining a tomographic image of a predetermined surface of the eye EY11, that is, tomographic information, a part of the light output from the light source 61 is light that passes through the optical fiber 81 and is applied to the eye EY11. It enters the collimating lens 71 as observation light.

Then, the observation light incident on the collimating lens 71 is collected by the collimating lens 71 and irradiated to the eye EY11 through the scanning unit 72, the OCT focus lens 73, and the objective lens 74.

Then, a part of the observation light irradiated to the eye EY11 is reflected by a portion that becomes a reflection surface of the eye EY11, and the optical fiber is passed through the objective lens 74, the OCT focus lens 73, the scanning unit 72, and the collimating lens 71. 81.

When observation light, more specifically, reflected light of observation light, enters the optical fiber 81 from the collimator lens 71, a part of the observation light passes through the inside of the optical fiber 81, and then passes through the optical fiber 82 at the coupling portion. The light advances to the fiber 82 and enters the light receiving unit 64.

An optical system that guides the observation light output from the light source 61 to the light receiving unit 64, that is, an optical system including the coupler 62, the collimating lens 71, the scanning unit 72, the OCT focus lens 73, and the objective lens 74, The observation optical system 91 is used when acquiring a tomographic image by OCT.

Hereinafter, the optical path of the observation light passing through the observation optical system 91, that is, the optical path of the observation light from the light source 61 to the light receiving unit 64 will be particularly referred to as a sample arm. Hereinafter, the optical path length of the observation light is also referred to as the length of the sample arm or the optical path length of the sample arm.

Further, at the time of acquiring a tomographic image, the light that travels to the optical fiber 82 instead of the observation light among the light output from the light source 61 becomes the reference light. This reference light is light that is used to acquire a tomographic image, but is not irradiated to the eye EY11 to be observed.

That is, after the reference light is output from the light source 61, it passes through the inside of the optical fiber 81, proceeds to the optical fiber 82 side at the coupling portion with the optical fiber 82, and is arranged on the optical path of the reference light. Led to.

Further, the reference light incident on the optical path length adjusting unit 63 is reflected at the end inside the optical path length adjusting unit 63 and enters the optical fiber 82. That is, the reference light that has entered the optical path length adjustment unit 63 from the optical fiber 82 is reflected by the end inside the optical path length adjustment unit 63 and returns to the optical fiber 82.

The reference light incident on the optical fiber 82 from the optical path length adjustment unit 63 passes through the optical fiber 82 as it is and enters the light receiving unit 64.

An optical system that guides the reference light output from the light source 61 to the light receiving unit 64, that is, an optical system including the coupler 62 and the optical path length adjusting unit 63, is a reference optical system 92 at the time of tomographic image acquisition by OCT. The

Also, the observation optical system 91 and the reference optical system 92 constitute a tomographic information acquisition optical system 101 for acquiring a tomographic image (tomographic information) of the surgical target, that is, the eye EY11 to be observed.

Hereinafter, the optical path of the reference light passing through the reference optical system 92, that is, the optical path of the reference light from the light source 61 to the light receiving unit 64 will be particularly referred to as a reference arm. Hereinafter, the optical path length of the reference light is also referred to as a reference arm length or a reference arm optical path length.

When acquiring a tomographic image, observation light and reference light are incident on the light receiving unit 64. The light receiving unit 64 receives the observation light and the reference light incident from the optical fiber 82, performs photoelectric conversion, and outputs a signal indicating image information obtained as a result, that is, a signal indicating a tomographic image, as tomographic information. The image information acquisition unit 21 generates a tomographic image based on the tomographic information at a plurality of positions in the eye EY11 output from the light receiving unit 64. For example, the tomographic image is an image of a cross section of the eye EY11 parallel to the optical axis of the objective lens 74.

In the image information acquisition unit 21, a tomographic image is acquired using interference between the observation light and the reference light. Therefore, the surface of the eye EY11 where the length of the sample arm is equal to the length of the reference arm is the tomographic image acquisition surface, and more specifically, the tomographic image acquisition surface, more specifically, the region near the tomographic image acquisition surface is the reflective surface. Sometimes, an image of the tomographic image acquisition surface (reflection surface) of the eye EY11 is obtained as a tomographic image. Here, the tomographic image acquisition plane of the eye EY11 is a plane perpendicular to the optical axis of the observation optical system 91 in the eye EY11, more specifically the optical axes of the OCT focus lens 73 and the objective lens 74.

Specifically, at the time of tomographic image acquisition, a three-dimensional space near the tomographic image acquisition surface including the tomographic image acquisition surface, that is, a three-dimensional region irradiated with the observation light is set as the tomographic image acquisition range, and the eye EY11 The image information of the tomographic image acquisition range is acquired as a tomographic image (tomographic information). In other words, the tomographic image acquisition range is a region from which tomographic information is acquired by the eye EY11.

Hereinafter, the direction of the optical axis of the OCT focus lens 73 and the objective lens 74, that is, the vertical direction in FIG. 2 is also referred to as the Z direction. In addition, directions perpendicular to the Z direction and orthogonal to each other are also referred to as an X direction and a Y direction.

For example, the length in the Z direction of the tomographic image acquisition range, that is, the range in the Z direction as the acquisition target of the tomographic image is a range having a predetermined length centered on the tomographic image acquisition surface.

As described above, the interference between the observation light and the reference light is used for obtaining the tomographic image. Therefore, by adjusting the length (optical path length) of the sample arm or reference arm, it is possible to adjust the position (range) in the Z direction of the tomographic image acquisition range, that is, the position in the depth direction of the tomographic image acquisition surface. It is.

The image information acquisition unit 21 does not adjust the optical path length of the sample arm, makes the optical path length of the reference arm variable, and adjusts it to an appropriate length so that the position in the Z direction of the tomographic image acquisition range can be arbitrarily set. The position can be set.

In contrast, the position adjustment in the XY direction of the tomographic image acquisition range is realized by scanning the observation light in the X direction or the Y direction by the scanning unit 72. This is because the position (range) in the XY direction where the observation light is irradiated on the eye EY11 is the position (range) in the XY direction of the tomographic image acquisition range.

In this example, the scanning unit 72 is composed of a pair of scan mirror 111-1 and scan mirror 111-2 which are arranged so that the reflecting surfaces face each other in parallel. Such a scanning unit 72 functions as an OCT scanning system that scans observation light in the X and Y directions, that is, a scanner.

For example, the observation light from the collimator lens 71 is reflected by the scan mirror 111-1, further reflected by the scan mirror 111-2, and guided to the OCT focus lens 73. Hereinafter, the scan mirror 111-1 and the scan mirror 111-2 are also simply referred to as the scan mirror 111 when it is not necessary to distinguish between them.

When adjusting the position of the tomographic image acquisition range in the X and Y directions, the optical path of the observation light is changed by rotating the pair of scan mirrors 111, so that the observation light can be irradiated to an arbitrary position in the XY direction of the eye EY11. It can be done.

Further, the focusing position of the observation light in the Z direction, that is, the focus position of the observation light can be adjusted by the OCT focus lens 73.

The OCT focus lens 73 is arranged on the optical path of the observation light to constitute the observation optical system 91, but is not an optical element constituting an optical system for observing the eye EY11 in bright field. That is, the OCT focus lens 73 is not disposed on the optical path of light for observing the eye EY11 in bright field. Therefore, for example, even when tomographic information is acquired during bright field observation, the focus position of the observation light can be adjusted without affecting the bright field observation by using the OCT focus lens 73.

In the following, the focus position of the observation light in the Z direction is particularly referred to as the OCT focus position.

For example, the OCT focus lens 73 is composed of a variable focus lens whose shape (lens shape) changes according to an applied voltage. When the shape of the OCT focus lens 73 changes, the refractive power of the OCT focus lens 73, that is, the focal position, changes, so that the OCT focusing position also changes.

Here, an example in which the OCT focusing position is adjusted by changing the refractive power of the OCT focus lens 73 will be described. However, the OCT focus position may be adjusted by changing the position of the OCT focus lens 73 in the Z direction, or the refractive power of the OCT focus lens 73 and the change of the position in the Z direction may be adjusted. May be combined to adjust the OCT focusing position.

Furthermore, a microscope optical system 75 for bright-field observation of the eye EY11 is provided inside the microscope barrel 65.

For example, the microscope optical system 75 includes an illumination system and an imaging optical system. When acquiring a front image of the eye EY11, illumination light output from a light source (not shown) passes through the illumination optical system and the objective lens 74 of the microscope optical system 75. Through the eye EY11 to be observed. The illumination light reflected by the surface of the eye EY11 becomes bright field observation light, and the bright field observation light passes through the objective lens 74 and the imaging optical system of the microscope optical system 75 to an image sensor (not shown). And incident.

The image sensor receives the bright field observation light incident from the imaging optical system and photoelectrically converts the bright field observation light, thereby capturing a front image that is a bright field image of the eye EY11.

<Configuration example of optical path length adjustment unit>
By the way, in a general microscope system equipped with an OCT, as a method of changing the position in the Z direction of the tomographic image acquisition range, that is, the range in the depth direction of OCT imaging, the entire microscope column corresponding to the microscope column 65 is used. A method for moving the lens in the Z direction and a method for moving the lens corresponding to the collimating lens 71 in the optical axis direction are employed. In any of these methods, the position of the tomographic image acquisition range in the Z direction is adjusted by adjusting at least the optical path length of the sample arm.

However, in the method of moving the entire microscope barrel, since the microscope barrel is heavy, it is difficult to move the microscope barrel at high speed, and the position of the tomographic image acquisition range in the Z direction cannot be changed at high speed.

On the other hand, in the method of moving the lens corresponding to the collimating lens 71 in the optical axis direction, a driving unit that moves the lens in the Z direction is required. However, if the driving unit is not provided inside the microscope barrel, This is disadvantageous in reducing the size of the microscope barrel.

Therefore, in the present technology, the position of the tomographic image acquisition range in the Z direction can be adjusted by adjusting only the optical path length of the reference arm by the optical path length adjustment unit 63 without adjusting the optical path length of the sample arm. .

In the present technology, since only the optical path length of the reference arm is adjusted, the optical path length adjustment unit 63 for adjusting the optical path length can be disposed outside the microscope barrel 65, thereby the microscope barrel 65. A configuration advantageous for downsizing is realized. That is, the microscope barrel 65 can be reduced in size. In particular, in the example illustrated in FIG. 2, the optical path length adjustment unit 63 is disposed on the optical path of the reference light and outside the microscope barrel 65, so that the microscope barrel 65 is downsized.

As described above, in the OCT, the portion of the eye EY11 that has the same optical path length as that of the reference arm in the sample arm is used as a tomographic image acquisition surface, and a tomographic image in the tomographic image acquisition range including the tomographic image acquisition surface is captured The

Therefore, the optical path length of the reference arm may be changed in adjusting the position in the Z direction of the tomographic image acquisition range, that is, the range in the depth direction (Z direction) from which tomographic images are acquired.

In the image information acquisition unit 21, the optical path length of the reference arm is adjusted by the optical path length adjustment unit 63. For example, the optical path length adjustment unit 63 can be configured as shown in FIGS. 3 and 4. 3 and 4, the same reference numerals are given to the portions corresponding to those in FIG. 2, and description thereof will be omitted as appropriate.

For example, in the example illustrated in FIG. 3, the optical path length adjustment unit 63 includes a collimating lens 201, a reference mirror 202, and a driving unit 203.

Here, the collimating lens 201 and the reference mirror 202 are arranged on the optical path of the reference light, and in particular, the collimating lens 201 is arranged at the end portion of the optical fiber 82.

Therefore, the reference light guided by the optical fiber 82 and incident on the optical path length adjustment unit 63 is condensed by the collimator lens 201 and incident on the reference mirror 202.

Furthermore, the reference light that has entered the reference mirror 202 from the collimator lens 201 is reflected by the reference mirror 202 and enters the optical fiber 82 via the collimator lens 201. The reference light incident on the optical fiber 82 in this way enters the light receiving unit 64 through the optical fiber 82.

In the optical path length adjustment unit 63, the reference mirror 202 whose arrangement position is variable is arranged on the optical path of the reference light, and the optical path length of the reference light is adjusted by changing the arrangement position of the reference mirror 202. .

Specifically, the optical path length adjusting unit 63 physically moves the reference mirror 202 disposed on the optical path of the reference light in a direction parallel to the traveling direction of the reference light, that is, in the direction indicated by the arrow A11 in the drawing. A drive unit 203 is provided.

When the drive unit 203 moves the reference mirror 202, the distance from the collimating lens 201 to the reference mirror 202 changes, so that the optical path length of the reference light, that is, the optical path length of the reference arm changes.

For example, in the example shown in FIG. 4, the optical path length adjustment unit 63 includes a delay line 231, a collimator lens 232, and a reference mirror 233.

Here, the delay line 231, the collimating lens 232, and the reference mirror 233 are arranged on the optical path of the reference light. In particular, a delay line 231 is disposed at the end portion of the optical fiber 82, and a collimator lens 232 is disposed between the delay line 231 and the reference mirror 233.

Therefore, the reference light guided by the optical fiber 82 and incident on the optical path length adjusting unit 63 enters the collimator lens 232 via the delay line 231, is condensed by the collimator lens 232, and enters the reference mirror 233. .

Furthermore, the reference light that has entered the reference mirror 233 from the collimator lens 232 is reflected by the reference mirror 233 and enters the optical fiber 82 via the collimator lens 232 and the delay line 231. The reference light incident on the optical fiber 82 in this way enters the light receiving unit 64 through the optical fiber 82.

For example, the delay line 231 is configured by a device called an optical delay line, and the delay line 231 can electrically control the delay of the reference light, that is, adjust the optical path length of the reference light.

Specifically, for example, when a voltage signal or a current signal is supplied to the delay line 231, the refractive index inside the delay line 231 changes, thereby changing the optical path length of the reference light, that is, the optical path length of the reference arm.

When the optical path length of the reference arm is adjusted by the delay line 231, the optical path length can be adjusted at a higher speed than when the reference mirror 202 is physically moved as shown in FIG.

In the optical path length adjusting unit 63, the optical path length of the reference arm is adjusted by combining the configuration for moving the reference mirror as shown in FIG. 3 and the configuration using the delay line as shown in FIG. Alternatively, the optical path length of the reference arm may be adjusted by other configurations. Therefore, for example, in the optical path length adjusting unit 63 shown in FIG. 4, the arrangement position of the reference mirror 233 may be variable.

If the optical path length of the reference arm is adjusted by the configuration (mechanism) shown in FIGS. 3 and 4 as described above, the position in the Z direction of the tomographic image acquisition range is faster than the method of moving the entire microscope barrel. Can be adjusted.

<About adjusting the OCT focus position>
Also, a general microscope system equipped with OCT controls the focus position during bright-field observation with a microscope, that is, controls the OCT focus position independently of focus control during bright-field observation. Some are configured to be able to.

In such a case, for example, a plurality of types of focus lenses corresponding to the OCT focus lens 73 are prepared, and any one of these focus lenses is selectively arranged on the optical path of the observation light, so that the OCT focus position is obtained. In general, it is configured to change the above. In other words, the OCT focusing position is adjusted by exchanging the focus lens arranged on the sample arm.

As another example of the adjustment method of the OCT focusing position in a general microscope system equipped with an OCT, a fixed-shaped focus lens corresponding to the OCT focus lens 73 is moved in the optical axis direction to thereby move the OCT. A method for adjusting the in-focus position is also known.

However, with these methods, it is difficult to continuously adjust the OCT focus position at a high speed, for example, by changing the OCT focus position by following the movement of the surgical instrument.

Therefore, in the image information acquisition unit 21, a variable focus lens is employed as the OCT focus lens 73 in order to make it possible to electrically control the focus changing mechanism. As described above, the lens shape of the OCT focus lens 73 can be changed by electrical control. As a result, the refractive power of the OCT focus lens 73 changes, and as a result, the OCT focus position changes.

If such a variable focus lens is used as the OCT focus lens 73, the OCT focusing lens 73 is replaced at a higher speed than when the OCT focus lens 73 is replaced or when the OCT focus lens 73 is moved in the optical axis direction. The focal position can be changed. Thereby, for example, the OCT focusing position can be adjusted continuously at a high speed following the surgical instrument used for the operation of the eye EY11.

<Linking the adjustment of the tomographic image acquisition range and the OCT focusing position>
Some general microscope systems equipped with an OCT include a mechanism for adjusting a tomographic image acquisition range and a mechanism for adjusting an OCT focusing position.

However, since these mechanisms are controlled independently of each other, for example, when the position of the tomographic image acquisition range is adjusted in the Z direction, the OCT focusing position is not adjusted. In some cases, the position was outside the acquisition range.

In this case, the position in which the surgeon pays attention, that is, the position in the tomographic image acquisition range, and the OCT focusing position become large in the Z direction, and the operator cannot focus on the focus. That is, the tomographic image may be blurred.

For example, as shown in FIG. 5, it is assumed that a tomographic image is acquired by irradiating the eye EY11 with a beam BM11 as observation light. In FIG. 5, parts corresponding to those in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted as appropriate.

In FIG. 5, the vertical direction in the figure is the Z direction, and the position indicated by the arrow Q11 in the Z direction is the OCT focusing position. This OCT in-focus position is a position where the beam BM11 which is the observation light is most converged in the Z direction, that is, a position where the beam diameter of the beam BM11 is the smallest.

Further, the range indicated by the arrow Q12 is the Z direction range of the tomographic image acquisition range, and the position indicated by the arrow Q13 is the Z direction of the tomographic image acquisition range among the Z direction range of the tomographic image acquisition range. The center position of the range. The position indicated by the arrow Q13 is the tomographic image acquisition plane.

In particular, in the example of FIG. 5, the OCT focusing position is located on the tomographic image acquisition surface. In this state, since the OCT focusing position is located within the tomographic image acquisition range, a clear tomographic image in focus on the tomographic image acquisition surface can be obtained.

Here, an example is shown in which the OCT focusing position is a position on the tomographic image acquisition plane, but the OCT focusing position is not within the tomographic image acquisition plane but is positioned within the tomographic image acquisition range. If so, a clear tomographic image can be obtained. Therefore, the OCT focusing position is not limited to the position on the tomographic image acquisition surface, and may be any position as long as it is within the tomographic image acquisition range.

Now, from the state illustrated in FIG. 5, for example, it is assumed that the control unit 33 controls the optical path length adjustment unit 63 while the OCT focusing position is fixed, and changes the position in the Z direction of the tomographic image acquisition range.

In such a case, since the OCT focusing position does not change and the tomographic image acquisition range moves in the Z direction, it is not guaranteed that the OCT focusing position is located within the tomographic image acquisition range after adjustment of the tomographic image acquisition range. .

That is, when only one of the OCT focusing position and the tomographic image acquisition range is adjusted, the OCT focusing position may be located outside the tomographic image acquisition range. As a result, the tomographic image obtained by the image information acquisition unit 21 may become unclear.

Therefore, the surgical microscope system 11 can obtain a focused and clear tomographic image by controlling the OCT focusing position and the tomographic image acquisition range to be adjusted in conjunction with each other. That is, it is possible to obtain a tomographic image focused on the position focused by the operator.

Specifically, in the surgical microscope system 11, the operation of the optical path length adjustment unit 63 is controlled by the control unit 33, and the optical path length of the reference arm is adjusted.

Therefore, since the control unit 33 grasps the optical path length of the reference arm, the position in the Z direction of the tomographic image acquisition range determined with respect to the optical path length of the reference arm, that is, the Z direction in which the tomographic image is to be acquired. It is possible to specify a range.

The control unit 33 also controls the OCT focus lens 73, that is, adjusts the OCT focusing position.

Therefore, since the control unit 33 knows not only the position in the Z direction of the tomographic image acquisition range but also the OCT focusing position, the OCT focusing is always performed so that the OCT focusing position is located within the tomographic image acquisition range. The position and the tomographic image acquisition range can be changed in conjunction with each other. In other words, the control unit 33 controls the optical path length adjustment unit 63 and the OCT focus lens 73 so that the OCT focus position is always within the tomographic image acquisition range.

Note that the OCT focusing position may be adjusted to be a fixed position within the tomographic image acquisition range, such as a position on the tomographic image acquisition surface. That is, in this case, the controller 33 controls the adjustment of the OCT focusing position and the position of the tomographic image acquisition range so that the relative position of the OCT focusing position with respect to the tomographic image acquisition range is always the same position. become.

Further, for the purpose of sharpening the tomographic image, a plurality of positions within the tomographic image acquisition range are sequentially set as the OCT focusing positions, and the tomographic information is acquired for each of the plurality of OCT focusing positions. Good. That is, the OCT in-focus position may be scanned in the Z direction within the tomographic image acquisition range while the position of the tomographic image acquisition range is fixed.

In this case, if the image information acquisition unit 21 performs image processing based on the tomographic information obtained for each OCT in-focus position to obtain one final tomographic information, a clear tomographic image can be obtained. Will be able to.

<Description of fault information acquisition processing>
Subsequently, the operation of the surgical microscope system 11 will be described. That is, hereinafter, tomographic information acquisition processing performed by the surgical microscope system 11 will be described with reference to the flowchart of FIG. This tomographic information acquisition process is started when acquisition of tomographic information is instructed by an operator, for example.

In addition, when the tomographic information acquisition process is started, light is output from the light source 61.

A part of the light output from the light source 61 is irradiated to the eye EY11 through the optical fiber 81, the collimating lens 71, the scanning unit 72, the OCT focus lens 73, and the objective lens 74 as observation light.

The observation light reflected by the eye EY11 enters the light receiving unit 64 via the objective lens 74, the OCT focus lens 73, the scanning unit 72, the collimating lens 71, the optical fiber 81, and the optical fiber 82.

On the other hand, the remaining part of the light output from the light source 61 branches from the optical fiber 81 to the optical fiber 82 and becomes reference light. Then, the reference light enters the optical path length adjustment unit 63 through the optical fiber 82, is reflected by the reference mirror in the optical path length adjustment unit 63, and enters the optical fiber 82 again. Further, the reference light that has entered the optical fiber 82 from the optical path length adjustment unit 63 passes through the optical fiber 82 and enters the light receiving unit 64.

When the observation of the eye EY11 by the OCT is started in this manner, in step S11, the control unit 33 determines the tomographic image acquisition range and the OCT focusing position.

For example, the control unit 33 determines whether the OCT in-focus position is a tomographic image based on information indicating a tomographic plane designated by an operator or the like supplied from the interface unit 32 or a recognition result supplied from the image recognition unit 31. The tomographic image acquisition range and the OCT focusing position are determined so as to be located within the acquisition range.

In step S12, the control unit 33 controls the scanning unit 72, which is a scanning system, based on the tomographic image acquisition range determined in step S11.

For example, the control unit 33 controls the scanning unit 72 to set the scan mirror 111 in a predetermined manner so that the observation light is irradiated to the region of the tomographic image acquisition range determined in step S11 in the eye EY11 in the XY direction (XY plane). Rotate (rotate) the angle.

In step S13, the control unit 33 controls the optical path length adjustment unit 63 based on the tomographic image acquisition range determined in step S11 to adjust the optical path length of the reference arm.

For example, when the optical path length adjustment unit 63 has the configuration shown in FIG. 3, the control unit 33 drives the drive unit so that the actual tomographic image acquisition range is the tomographic image acquisition range determined in step S11 in the Z direction. The reference mirror 202 is moved by controlling 203.

For example, when the optical path length adjustment unit 63 has the configuration shown in FIG. 4, the control unit 33 sets the actual tomographic image acquisition range in the Z direction to be the tomographic image acquisition range determined in step S <b> 11. A voltage is applied to the delay line 231 to adjust the optical path length of the reference arm.

By the processing of step S12 and step S13, the tomographic image acquisition range determined in step S11 is set as the acquisition target region of the tomographic image (tomographic information), and the tomographic information is acquired.

In step S14, the control unit 33 controls the OCT focus lens 73 based on the OCT focusing position determined in step S11.

For example, the control unit 33 changes the refractive power of the OCT focus lens 73 by applying a voltage signal determined with respect to the OCT focus position determined in step S11 to the OCT focus lens 73. As a result, the observation light is condensed at the OCT in-focus position determined in step S11.

As a result of the processing in steps S11 to S14 described above, interlocking control of the OCT focusing position and the tomographic image acquisition range is realized.

In step S15, the image information acquisition unit 21 acquires tomographic information.

That is, by the processing so far, the observation light is irradiated on the tomographic image acquisition range determined in step S11 and reflected within the tomographic image acquisition range, and the reference light reflected by the optical path length adjustment unit 63 and Is incident on the light receiving portion 64.

The light receiving unit 64 receives incident observation light and reference light, performs photoelectric conversion, and outputs the tomographic information obtained as a result. The image information acquisition unit 21 acquires the tomographic information output from the light receiving unit 64 in this way. Further, the image information acquisition unit 21 constructs (generates) a tomographic image and volume data from the tomographic information obtained in each of a plurality of tomographic image acquisition ranges as necessary, and the image recognition unit 31 and the display information generation unit 34. To supply.

In step S16, the control unit 33 determines whether to end the acquisition of tomographic information.

For example, when the operator has operated the interface unit 32 to instruct the end of tomographic information acquisition or when a tomographic image instructed by the operator or the like has been obtained, it is determined that acquisition of tomographic information is to end. The

If it is determined in step S16 that the acquisition of tomographic information has not been completed yet, the process returns to step S11, and the above-described process is repeated. In this case, for example, in order to obtain the tomographic information of each region in the range designated by the operator, the new region is taken as the tomographic image acquisition range and the tomographic information is obtained. That is, the tomographic information is acquired by shifting the tomographic image acquisition range.

On the other hand, when it is determined in step S16 that the acquisition of tomographic information is to be terminated, each part of the surgical microscope system 11 stops the operation for acquiring the tomographic information, and the tomographic information acquiring process is ended.

As described above, the surgical microscope system 11 determines the OCT focusing position and the tomographic image acquisition range, and acquires tomographic information according to the determination. Thus, a clear tomographic image can be obtained by controlling the OCT focusing position and the adjustment of the tomographic image acquisition range in conjunction with each other.

As described above, according to the present technology, the optical path length of the reference arm is adjusted by adjusting the optical path length of the reference arm, thereby adjusting the range (region) in the Z direction as the acquisition target of the tomographic information. The optical path length adjusting unit 63 can be arranged outside the microscope barrel 65. Thereby, the microscope barrel 65 can be reduced in size while adjusting the Z direction of the tomographic image acquisition range at high speed.

<Example of computer configuration>
By the way, the above-described series of processing can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software is installed in the computer. Here, the computer includes, for example, a general-purpose personal computer capable of executing various functions by installing a computer incorporated in dedicated hardware and various programs.

FIG. 7 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processing by a program.

In the computer, a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, and a RAM (Random Access Memory) 503 are connected to each other via a bus 504.

An input / output interface 505 is further connected to the bus 504. An input unit 506, an output unit 507, a recording unit 508, a communication unit 509, and a drive 510 are connected to the input / output interface 505.

The input unit 506 includes a keyboard, a mouse, a microphone, an image sensor, and the like. The output unit 507 includes a display, a speaker, and the like. The recording unit 508 includes a hard disk, a nonvolatile memory, and the like. The communication unit 509 includes a network interface or the like. The drive 510 drives a removable recording medium 511 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

In the computer configured as described above, the CPU 501 loads the program recorded in the recording unit 508 to the RAM 503 via the input / output interface 505 and the bus 504 and executes the program, for example. Is performed.

The program executed by the computer (CPU 501) can be provided by being recorded in a removable recording medium 511 as a package medium, for example. The program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

In the computer, the program can be installed in the recording unit 508 via the input / output interface 505 by attaching the removable recording medium 511 to the drive 510. Further, the program can be received by the communication unit 509 via a wired or wireless transmission medium and installed in the recording unit 508. In addition, the program can be installed in the ROM 502 or the recording unit 508 in advance.

The program executed by the computer may be a program that is processed in time series in the order described in this specification, or in parallel or at a necessary timing such as when a call is made. It may be a program for processing.

The embodiments of the present technology are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present technology.

For example, the present technology can take a cloud computing configuration in which one function is shared by a plurality of devices via a network and is jointly processed.

Further, each step described in the above flowchart can be executed by one device or can be shared by a plurality of devices.

Further, when a plurality of processes are included in one step, the plurality of processes included in the one step can be executed by being shared by a plurality of apparatuses in addition to being executed by one apparatus.

Furthermore, the present technology can be configured as follows.

(1)
A microscope optical system for observing a biological tissue to be observed;
A tomographic information acquisition optical system for acquiring tomographic information of the biological tissue using interference between reflected light of observation light irradiated on the biological tissue and reference light not irradiated on the biological tissue;
The tomographic information acquisition optical system includes an optical path length adjustment unit that adjusts an optical path length of the reference light.
(2)
The said optical path length adjustment part is a surgery microscope system as described in (1) arrange | positioned outside the lens-barrel of the microscope in which the said microscope optical system was provided.
(3)
The surgical microscope system according to (1) or (2), wherein the tomographic information acquisition optical system further includes a focus lens that adjusts a focus position of the observation light in an optical axis direction of the tomographic information acquisition optical system.
(4)
The surgical microscope system according to (3), wherein the focus lens is a variable focus lens.
(5)
A controller that controls the optical path length adjustment unit and the focus lens so that the in-focus position is located in the region of the biological tissue that is to be acquired by the tomographic information, which is determined by the optical path length of the reference light; The surgical microscope system according to (3) or (4).
(6)
The surgical microscope system according to any one of (1) to (5), wherein the optical path length adjustment unit includes an optical delay line disposed on an optical path of the reference light.
(7)
The optical path length adjustment unit includes a mirror arranged on the optical path of the reference light and having a variable arrangement position, and adjusts the optical path length of the reference light by changing the arrangement position of the mirror. The surgical microscope system according to any one of 1) to (6).
(8)
The surgical microscope system according to any one of (1) to (7), wherein the living tissue is an eye.

11 surgical microscope system, 21 image information acquisition unit, 33 control unit, 61 light source, 62 coupler, 63 optical path length adjustment unit, 64 light receiving unit, 65 microscope barrel, 72 scanning unit, 73 OCT focus lens, 74 objective lens , 75 microscope optical system, 101 tomographic information acquisition optical system

Claims

A microscope optical system for observing a biological tissue to be observed;
A tomographic information acquisition optical system for acquiring tomographic information of the biological tissue using interference between reflected light of observation light irradiated on the biological tissue and reference light not irradiated on the biological tissue;
The tomographic information acquisition optical system includes an optical path length adjustment unit that adjusts an optical path length of the reference light.
The surgical microscope system according to claim 1, wherein the optical path length adjusting unit is disposed outside a microscope barrel provided with the microscope optical system.
The surgical microscope system according to claim 1, wherein the tomographic information acquisition optical system further includes a focus lens that adjusts a focus position of the observation light in an optical axis direction of the tomographic information acquisition optical system.
The surgical microscope system according to claim 3, wherein the focus lens is a variable focus lens.
A controller that controls the optical path length adjustment unit and the focus lens so that the in-focus position is located in the region of the biological tissue that is to be acquired by the tomographic information, which is determined by the optical path length of the reference light; The surgical microscope system according to claim 3.
The surgical microscope system according to claim 1, wherein the optical path length adjustment unit includes an optical delay line disposed on an optical path of the reference light.
The optical path length adjustment unit includes a mirror arranged on the optical path of the reference light and having a variable arrangement position, and adjusts the optical path length of the reference light by changing the arrangement position of the mirror. Item 2. The surgical microscope system according to Item 1.
The surgical microscope system according to claim 1, wherein the living tissue is an eye.