JPH08313828A - Stereoendoscopic system - Google Patents

Abstract

PURPOSE: To make it possible to obtain the required natural presence feel by setting a preferable relation between a stereoendoscope and a head-on-mounting type stereodisplay device. CONSTITUTION: This stereoendoscopic system is provided with a stereoscopic rigid mirror 1 with which right and left video signals having a parallax of an observation section are obtd., a right video signal processor 2 which executes signal processing of the right video signals of the observation section obtd. by the stereoscopic rigid mirror 1, a left video signal processor 3 which executes the signal processing of the left video signals of the observation section obtd. by the stereoscopic rigid mirror 1, an HMD 4 which displays the stereoscopic images of the observation section mounted at the head of an observer and an HMD controller 5 which displays the stereoscopic images on this HMD 4 by the right and left video signals subjected to the signal processing with the right video signal processor 2 and the left video signal processor 3. The system described above satisfies the condition 0.4<β/α<2 (αis the field angle of the stereoscopic rigid mirror 1 and β is the visual angle of the HMD 4).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereoscopic endoscope for picking up left and right images having a parallax and having an elongated insertion portion, and a left and right image acquired by the stereoscopic endoscope to the left and right of an observer. The present invention relates to a stereoscopic endoscope system having a head-mounted stereoscopic display device that transmits to the eyes.

[0002]

2. Description of the Related Art In recent years, a minimally invasive procedure using an endoscope and a dedicated treatment instrument has become widespread in the field of medical surgery. Since it becomes possible to treat a disease which has conventionally required an open surgery under an endoscope, it is possible to reduce the social burden on the patient by shortening the hospitalization period. Therefore, endoscopic surgery, which is a minimally invasive procedure, is expected to continue to develop.

In this endoscopic surgery, a treatment tool is remotely operated while observing an image inside a body cavity acquired by an endoscope on a TV monitor or the like.

A problem in this case is difficulty in guiding the treatment tool. In particular, since information in the depth direction cannot be obtained with a conventional endoscope, guiding the treatment tool in the depth direction is unavoidable by trial and error, which causes a problem that the treatment takes time. Therefore, a stereoscopic endoscope system capable of providing information in the depth direction to an observer has been developed.

An observation system of a stereoscopic endoscope system is usually of a twin-lens type, and as shown in FIG. 6, an observation optical system for capturing left and right images of an observation region having a parallax with an elongated insertion portion. A stereoscopic endoscope 101 having a built-in image pickup element, a stereoscopic video signal processing device 102 that generates a stereoscopic image from the video signals of the left and right images from the stereoscopic endoscope 101, and stereoscopic video signal processing device 102 Stereoscopic display device 1 for displaying an image
It consists of 03.

In this stereoscopic endoscope system,
The observation optical system of the stereoscopic endoscope 101 forms an image of an object on the image pickup surface of the image pickup element. Various methods are used for the observation optical system in order to obtain left and right images having parallax. The left and right images acquired by the image pickup device are transmitted as video signals from the stereoscopic endoscope 101 to the stereoscopic video signal processing device 102. The stereoscopic video signal processing device 102 performs necessary signal processing corresponding to the stereoscopic display device 103 in the subsequent stage. The stereoscopic display device 103 forms left and right images on the display element based on the stereoscopic image sent from the stereoscopic video signal processing device 102.

There are various types of stereoscopic display devices 103 for separating left and right images and transmitting them to both eyes of an observer.

The two-lens type stereoscopic display device 103 is roughly divided into two types, one using a stationary TV monitor and the other a head called HMD (head mounting device). It is a wearable type. The advantages of the HMD over the stationary TV monitor are that the size of the field of view (the size of the image seen by the eye) is fixed at the time of use, and the size of the field of view can be arbitrarily selected in design. In a stationary TV monitor, the size of the field of view is not fixed because it depends on the viewing distance. However, in order to increase the field of view in a stationary TV monitor, the screen of the TV monitor must be enlarged, which causes a problem in installing the device. Therefore, it is practically difficult to obtain a certain field of view size or more.

On the other hand, in the HMD, a large field of view that cannot be obtained by a stationary TV monitor can be obtained by the size of the small element such as liquid crystal and the selection of the eyepiece optical system.

Therefore, in the endoscopic surgical operation by stereoscopic vision, a stereoscopic display device using a stationary TV monitor is currently the mainstream, but it is considered that the HMD will become popular in the future. In particular, the fixed size of the field of view and the high degree of freedom of selection, which are the advantages of the HMD described above, are important factors for achieving a natural presence in stereoscopic vision.

[0011] For example, USP4 is known as a prior art relating to a combination of a stereoscopic endoscope and a head-mounted stereoscopic display device.
651201 discloses a stereoscopic endoscope system including a head-mounted stereoscopic display device.

[0012]

However, the natural presence is not determined only by the stereoscopic display device 103, but is determined by the relationship with the stereoscopic endoscope 101 that serves as a stereoscopic image input device. There has been a problem that the preferable relationship between them has not been sufficiently examined and, as a result, a natural sense of reality cannot be obtained.

The present invention has been made in view of the above circumstances, and obtains a desired natural presence by setting a preferable relationship between the stereoscopic endoscope and the head-mounted stereoscopic surface device. It is an object of the present invention to provide a stereoscopic endoscope system capable of performing.

[0014]

A stereoscopic endoscope system of the present invention is a stereoscopic endoscope having an elongated insertion portion for picking left and right images having parallax, and the stereoscopic endoscope. In a stereoscopic endoscope system having a head-mounted stereoscopic display device that transmits the left and right images acquired in 1. to the left and right eyes of an observer, the condition 0.4 <β / α <2 (α is within the stereoscopic view) The angle of view of the endoscope, β, satisfies the viewing angle of the head-mounted stereoscopic display device), thereby setting a preferable relationship between the stereoscopic endoscope and the head-mounted stereoscopic display device, and the required natural It is possible to get a sense of reality.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 5 relate to an embodiment of the present invention, FIG. 1 is a block diagram showing the configuration of a stereoscopic vision system, FIG. 2 is a block diagram showing the configuration of the HMD of FIG. 1, and FIG. 1 is a conceptual diagram for explaining the operation of the stereoscopic vision system of FIG. 1, and FIG.
5 is a first explanatory view for explaining the definition of the viewing angle β of the HMD and the viewing angle α of the stereoscopic endoscope, and FIG. 5 illustrates the definition of the viewing angle β of the HMD and the viewing angle α of the stereoscopic endoscope in FIG. It is a second explanatory diagram to do.

As shown in FIG. 1, the stereoscopic endoscopic system of the present embodiment has a stereoscopic rigid endoscope 1 for obtaining left and right image signals having a parallax of an observed region, and an observation obtained by the stereoscopic rigid endoscope 1. A right video signal processing device 2 that processes the right video signal of the region, a left video signal processing device 3 that processes the left video signal of the observed region obtained by the stereoscopic rigid endoscope 1, and a head of the observer. HMD4 that is attached and displays a stereoscopic image of the observation site
And an HMD controller 5 for displaying a stereoscopic image on the HMD 4 by the left and right video signals processed by the right video signal processing 2 and the left video signal processing device 3.

The stereoscopic rigid endoscope 1 includes a scope portion 11 having a rigid insertion portion to be inserted into a body cavity, and a camera head portion which is used by being connected to the scope portion 11 and which captures left and right images having a parallax of an observation site. 12 and. In the scope section 11, the objective optical system 15 and the relay optical system 16 are constituted by one optical system which is axially symmetrical. Objective optical system 15
The image formed by is transmitted by a predetermined distance by the relay optical system 16, and at the rear end of the relay optical system 16, the objective optical system 17 of the camera head 12 spatially divides the pupil into two so that the parallax is reduced. A pair of left and right images are picked up by CCDs 18 and 19 as an image pickup means. The pair of left and right captured images is converted into an electric signal, processed by the right video signal processing 2 and the left video signal processing device 3 and converted into a general-purpose video signal such as NTSC, and then the HMD 4 is controlled by the HMD controller 5. A stereoscopic image is displayed on. In addition,
The HMD controller 5 controls the HMD 4 and supplies power.

As shown in FIG. 2, the HMD 4 is arranged at a position deviated from the line of sight of the right eye 21 of the observer, for example, and a liquid crystal display (LCD) 22 for displaying a right image of the observed region.
And an optical system 23 that transmits the right image displayed on the LCD 22 to the right eye 21, and the optical system 23 is configured by joining two prisms 25 and 26 with a half mirror surface 24 interposed therebetween. The concave mirror 28 of the lower prism 26 has a function of a magnifying lens. Then, the right image displayed on the LCD 22 is transmitted and enlarged and reflected by the concave mirror 28,
It is reflected by the half mirror surface 24 at a right angle and is supplied to the right eye 21. A liquid crystal shutter 29 is arranged at a position facing the right eye 21 of the optical system 23, and as shown in FIG. 1, a portion of the housing of the HMD 4 corresponding to the liquid crystal shutter 29 is a transparent portion 30. Then, when the liquid crystal shutter 29 is closed (non-transparent), L is set in the dark.
The image displayed on the CD 22 is magnified and observed, and the outside can be seen when the liquid crystal shutter 29 is opened (transmitted). The left eye side is also similarly configured.

In the stereoscopic vision endoscopic system of the present embodiment, FIG.
As shown in, the stereoscopic flexible endoscope 3 is replaced with the stereoscopic flexible endoscope 3
1 can also be connected. The stereoscopic flexible endoscope 31 includes an elongated insertion portion 32 that is inserted into a body cavity, and a distal end side of the insertion portion 32 is a bendable bending portion 33, and an operation portion provided at a proximal end of the insertion portion 32. The bending portion 33 can be bent by operating a bending operation knob (not shown) of 34. Inside the tip of the insertion portion 32, an optical system 35 which is divided into two parts, left and right, is built in. The left and right optical systems 35 each consist of an objective lens system 36 and a solid-state image sensor, such as a CCD 37. The video signal is transmitted to each of the left video signal processing device 3 and the right video signal processing device 2, and thereafter, the same processing as in the case of the stereoscopic rigid endoscope is performed.

The specifications of the HMD 4 and the stereoscopic endoscope which is the stereoscopic rigid endoscope 1 or the stereoscopic flexible endoscope 31 are as follows.

<HMD> HMD-A type: Viewing angle β = 36 ° Liquid crystal pixel number = 180,000 pixels HMD-B type: Viewing angle β = 50 ° Liquid crystal pixel number = 380,000 pixels HMD-C type: Viewing angle β = 70 ° Number of liquid crystal pixels = 600,000 pixels <Stereoscopic endoscope> Applicable area: abdominal cavity, abdominal cavity, brain joint, thoracic cavity insertion section type rigid rigid rigid rigid rigid soft angle of view α [°] 65 70 50 90 70 insert outer diameter D [mm] 12 10 4 4 10 Entrance pupil distance E [mm] 1.7 4 0.18 0.25 5 E / D 0.142 0.4 0.045 0.063 0.5 β / α [HMD-A type °] 0.55 0.51 0.72 0.4 0.51 β / α [HMD-B type °] 0.77 0.71 1 0.56 0.71 β / α [HMD-C type] 1.08 1 1.4 0.78 1 The operation of the present embodiment having such a configuration will be described.

FIG. 3 is a conceptual diagram for explaining the operation of the present embodiment. As shown in FIG. 3A, in order to obtain a natural sense of presence in endoscopic surgery, stereoscopic hardness is set. Mirror 1
Alternatively, it is desired that the image of the object 41 by the stereoscopic endoscope 40 which is the stereoscopic flexible endoscope 31 is reproduced by the eye 21 by the optical system 23 of the HMD 4 mounted on the human head. Therefore, as shown in FIG. 3B, it is desirable to create a state in which the human eyeball is provided as a virtual eyeball 42 at the tip of the insertion portion of the stereoscopic endoscope 40.

At this time, the most important thing is the relationship between the angle of view α of the stereoscopic endoscope 40 and the viewing angle β of the HMD. In the configuration of the present embodiment, the view angle α of the stereoscopic endoscope and the view angle β of the HMD are made substantially equal to each other so that a natural sense of reality can be obtained. If β / α = 1, the angle of the light beam entering the stereoscopic endoscope 40 from the object is equal to the angle of the light beam entering the eye 21 from the HMD, and the most natural sense of reality can be obtained. Even if it is not 1, if the range of the formula (1) is satisfied, no great discomfort will occur.

0.4 <β / α <2 (1) When β / α becomes 0.4 or less, the viewing angle β becomes narrow and the eye 2
The image of the object 41 shown in 1 is smaller than a desired size, and a sufficient sense of reality cannot be obtained. In this case, the observer feels that the image is insufficient, which is not desirable.

If β / α is 2 or more, the viewing angle β becomes wider, and the image of the object seen by the eye becomes larger than a desired size, resulting in excessive presence. In this case, the observer's fatigue is excessively increased during long-term use such as endoscopic surgery, which is not desirable. Therefore, the expression (1) is satisfied.

Next, the definition of the viewing angle β of the HMD 4 and the viewing angle α of the stereoscopic endoscope 40 used in the equation (1) will be described. HM
The viewing angle β of D4 and the viewing angle α of the stereoscopic endoscope 40 are HMD.
The value corresponding to the most peripheral portion of the endoscopic image displayed on the LCD 22 of No. 4 is used. FIG. 4 is a diagram showing the definition of the viewing angle β in the HMD 4. Figure 4 shows the HMD image when the endoscope is connected.
4 is displayed on the entire screen of the LCD 22.
The viewing angle β of D4 uses a value corresponding to the diagonal of the LCD 22 screen, and the angle of view α of the stereoscopic endoscope 40 is also the LCD 22 of the HMD4.
Use the value that corresponds to the diagonal of the screen. FIG. 5 shows a case where an image when the endoscope is connected is displayed on a part of the screen.
The viewing angle β of is not a diagonal value but a value corresponding to the maximum length of the endoscopic image, and the view angle α of the stereoscopic endoscope 40 is also a value corresponding to the maximum length of the image.

In addition to the above-mentioned conditions, it is desirable that the condition of the following expression (2) be satisfied.

0.043 <E / D <0.52 (2) where E is the entrance pupil distance of the left and right optical systems at the tip of the insertion portion of the stereoscopic endoscope 40, and D is the stereoscopic endoscope 40. The outer diameter of the insertion part.

The equation (2) will be described. Expression (2) is a condition for obtaining a natural three-dimensional effect. Assuming the state of FIG. 3B, there is a desirable relationship between the entrance pupil distance E corresponding to the human eye width and the object distance X. In actual human observation, the eye width is about 65 mm, and the observation distance that facilitates stereoscopic viewing is about 0.25 m to 3 m. In order to reproduce the ratio of the human eye width to the observation distance at the tip of the insertion portion of the stereoscopic endoscope, it is necessary to satisfy the following expression (3).

65/3000 <E / X <65/250 (3) In the case of endoscopic surgery, the object distance X is preferably assumed to be the distance at which the treatment is performed. Endoscopic surgery has spread to various parts of the human body. Generally, a large endoscope with an insertion part outer diameter D is used for a part such as abdominal cavity where a wide space can be secured. A thin endoscope is used in a region such as the brain where only a narrow space can be obtained. For this reason,
Assuming that the outer diameter D of the insertion portion and the object distance X are approximately proportional to each other, the relationship of the following expression (4) can be set empirically.

X = 2D (4) Equation (2) is derived by eliminating the object distance X from the above equations (3) and (4). That is, E / D of the equation (2) is determined only by the configuration of the stereoscopic endoscope 40. If the E / D is less than 0.043, the stereoscopic effect becomes too small, and 0.5
When it exceeds 2, the three-dimensional effect becomes too large, which is not preferable.

The reason why the stereoscopic display device is limited to the HMD4 is that the size of the visual field (viewing angle) is fixed and the degree of freedom of selection is high as described above, but the HMD is also used in the stationary type.
It is still desirable if observation conditions similar to those of 4 can be obtained.

Although the relationship between the stereoscopic endoscope 40 and the HMD 4 has been described above, the condition of the equation (2) shown above is determined by the stereoscopic endoscope 40 alone,
It is desirable to be satisfied regardless of the form of the stereoscopic display device. For this reason, it is desirable that the stereoscopic endoscope 40 having the elongated insertion portion and capturing the left and right images having parallax is configured to satisfy the expression (2).

Further, it is desirable that the scope part of the stereoscopic rigid endoscope 1 uses a pupil division type in which the optical system has only one optical axis. It is also known that the optical system consists of two optical systems having independent optical axes, but the entrance pupil distance E is the distance between the two optical systems, and the E / D value in the equation (2) is smaller than that in the pupil division equation. growing. For this reason, it is not preferable to set the value of E / D to the upper limit of 0.52 or less, which is a great constraint in mechanical design.

As described above, in the present embodiment, the view angle α of the stereoscopic endoscope 40 and the view angle β of the HMD are substantially equal to each other, or 0.4.
Since <β / α <2 is satisfied, a natural sense of reality can be obtained.

[Additional remarks] (Additional remark 1) A stereoscopic endoscope having a slender insertion portion for picking up left and right images having parallax, and left and right images acquired by the stereoscopic endoscope are left and right of an observer. In a stereoscopic endoscope system having a head-mounted stereoscopic display device that transmits to the eye, a stereoscopic endoscope system satisfying the following condition (1).

Condition (1): 0.4 <β / α <2 where α is the angle of view of the stereoscopic endoscope, and β is the angle of view of the head-mounted stereoscopic display device.

(Additional Item 2) The stereoscopic endoscope system according to Additional Item 1, wherein the following condition (2) is satisfied.

Condition (2): 0.043 <E / D <0.52, where E is the entrance pupil distance of the left and right optical systems at the tip of the insertion portion of the stereoscopic endoscope, and D is the stereoscopic endoscope. It is the outer diameter of the insertion part of the mirror.

(Additional Item 3) A stereoscopic endoscope which has a slender insertion portion and picks up left and right images having parallax, which satisfies the following condition (2).

Condition (2): 0.043 <E / D <0.52, where E is the entrance pupil distance of the left and right optical systems at the tip of the insertion portion of the stereoscopic endoscope, and D is the stereoscopic endoscope. It is the outer diameter of the insertion part of the mirror.

[0043]

As described above, according to the stereoscopic endoscope system of the present invention, a stereoscopic endoscope having an elongated insertion portion for picking left and right images having parallax, and the stereoscopic endoscope are provided. In a stereoscopic endoscope system having a head-mounted stereoscopic display device that transmits left and right images acquired by a mirror to the left and right eyes of an observer, the condition 0.4 <β / α <2 (α is the stereoscopic vision) Since the angle of view of the endoscope, β satisfies the angle of view of the head-mounted stereoscopic display device), it is possible to set a preferable relationship between the stereoscopic endoscope and the head-mounted stereoscopic display device, and the required natural There is an effect that a sense of reality can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a stereoscopic vision endoscopy system according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a configuration of the HMD in FIG.

FIG. 3 is a conceptual diagram illustrating the operation of the stereoscopic endoscopic system of FIG.

4 is a view angle β of the HMD and a view angle α of the stereoscopic endoscope in FIG.
Explanatory diagram for explaining the definition of

5 is a view angle β of the HMD and a view angle α of the stereoscopic endoscope in FIG.
Explanatory diagram illustrating the definition of

FIG. 6 is a configuration diagram showing a configuration of a conventional stereoscopic endoscopic system.

[Explanation of symbols]

 1 ... Stereoscopic rigid endoscope 2 ... Right image signal processing device 3 ... Left image signal processing device 4 ... HMD 5 ... HMD controller 11 ... Scope part 12 ... Camera head part 15, 17 ... Objective optical system 16 ... Relay optical system 18, 19 ... CCD 21 ... Right eye 22 ... LCD 23 ... Optical system 24 ... Half mirror surface 25, 26 ... Prism 28 ... Concave mirror 29 ... Liquid crystal shutter 30 ... Transparent part 31 ... Stereoscopic flexible mirror

Claims (1)

[Claims] 1. A stereoscopic endoscope having an elongated insertion portion for capturing left and right images having parallax, and a head for transmitting the left and right images acquired by the stereoscopic endoscope to the left and right eyes of an observer. A stereoscopic endoscope system having a part-mounted stereoscopic display device, which satisfies the following condition (1). Condition (1): 0.4 <β / α <2 where α is the angle of view of the stereoscopic endoscope and β is the angle of view of the head-mounted stereoscopic display device.