Body cavity interior observing apparatus

According to a body cavity interior observing apparatus of the present invention, a non-tracked region to be displayed can be switched between a first non-tracked region and a second non-tracked region which is larger than the first non-tracked region, and in a search for an affected area in which it is preferable to track a treating instrument in order to consistently align the position of treating instrument to the central part of the screen, the first non-tracked region having a smaller non-tracked region is selected, while in a treatment of an affected area in which a treating instrument is moved in a wide range of area, the second non-tracked region having a larger non-tracked region is selected, thereby an appropriate monitor screen can be provided in searching for an affected area and in treating an affected area.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a body cavity interior observing apparatus, in particular, a body cavity interior observing apparatus for performing various treatments while an image of a body cavity interior of an object to be examined is displayed on a monitor.

2. Description of the Related Art

A laparoscopic apparatus is a body cavity interior observing apparatus, and after a trocar (penetrating instrument) is stabbed into the body cavity interior through a abdominal part surface of a patient, and a laparoscope inserting section is inserted into the body cavity interior with help of the trocar as a guide, the laparoscopic apparatus is used to perform various treatments such as a treatment of adhesion while displaying a presence or absence of adhesion of a body cavity interior, or an image of a body part of an object to be examined such as ovarian tumor and hysteromyoma on a monitor. The laparoscope is held by a movable holder which is mounted to a fixing section to be maintained in a fixed state in clinical practice (for example, see Japanese Patent Application Laid-Open No. H8-164148).

In clinical practices that use such a laparoscopic apparatus, in order to observe a body part of an object to be examined which is actually treated at the central part of a monitor screen, a position of a distal end portion of a treating instrument which is located inside of a body cavity is detected so that the distal end portion of the treating instrument can be tracked to constantly align the position of the distal end portion to the central part of an image displayed on a monitor. The tracking mechanism described in the Japanese Patent Application Laid-Open No. H8-164148 includes a magnetic three-dimensional position sensor which is mounted to a part of laparoscope located outside of a patient's body. The magnetic three-dimensional position sensor includes a magnet source which is mounted to the laparoscope, and a magnetic sensor which is mounted to a treating instrument, and is configured to obtain position information of the distal end portion of the treating instrument located inside of a body cavity by calculating the position of the distal end portion of the treating instrument, which is used for a treatment and is located in the body, from a mount position of the magnetic sensor outside of the body by using a rotation/translation coordinate transformation.

In a laparoscopic apparatus having the tracking mechanism, as the treating instrument moves, an observation image which is displayed on a monitor screen continuously moves, resulting in that, every time the treating instrument is moved for operations of various treatments and examinations of an affected area, the monitor screen wobbles, which may be troublesome for a practitioner in observing or treating of an affected area.

Japanese Patent Application Laid-Open No. H9-266882 discloses a laparoscopic apparatus which solves such a trouble. In the laparoscopic apparatus, a monitor screen is divided into a central non-tracked region and an outer tracked region which surrounds the non-tracked region, so that when a treating instrument moves into the tracked region out of the non-tracked region, a tracking function is turned on to move an image of the treating instrument to the central part of the monitor screen, while when the treating instrument is located in the non-tracked region, the tracking function is turned off to prevent the wobble of the observation image.

SUMMARY OF THE INVENTION

However, the laparoscopic apparatus disclosed in the above Japanese Patent Application Laid-Open No. H9-266882 is convenient since the screen does not wobble in treating an affected area by moving a treating instrument in a wide range area because the size of the non-tracked region is larger than that of the monitor screen, but the laparoscopic apparatus is inconvenient in an operation to search for the affected area because it is preferable to track the treating instrument to consistently align the position of the treating instrument to the central part of the screen. This trouble can be solved by switching the entire screen to the tracked region, but this makes the tracking function effective to every subtle movement (vibration) of the treating instrument and so the monitor screen slightly moves all the time, which makes it difficult for a practitioner to watch the image.

The present invention was made in view of the above described background, and one object of the present invention is to provide a body cavity interior observing apparatus which can provide an appropriate monitor screen both in searching for an affected area and in treating an affected area.

In order to achieve the above object, a first aspect of the present invention provides a body cavity interior observing apparatus, comprising: a treating instrument which is inserted into a body cavity interior of an object to be examined by using a penetrating instrument as a guide; an observing section which is mounted to an opening portion of a body wall of the object; a monitor which displays an image of the body cavity interior picked up by the observing section; a marker position detecting device for detecting a position of a marker attached to the treating instrument or the penetrating instrument from the image which shows the body cavity interior picked up by the observing section; and a tracking device for tracking the position of the marker detected by the marker position detecting device to align the position of the marker to a central part of a screen of the monitor, wherein a screen of the monitor is divided into a tracked region and a non-tracked region, and when the marker is located in the non-tracked region, the tracking device does not work, and the non-tracked region to be displayed is switched between a first non-tracked region which is positioned generally at the central part of the screen of the monitor and a second non-tracked region which is larger than the first non-tracked region.

According to the first aspect of the present invention, the screen of the monitor is divided into a tracked region and a non-tracked region, and also, the non-tracked region to be displayed can be switched between a first non-tracked region which is positioned generally at the central part of the screen of the monitor and a second non-tracked region which is larger than the first non-tracked region.

In a search for an affected area in which it is preferable to track a treating instrument in order to consistently align the position of treating instrument to the central part of the screen, the first non-tracked region having a smaller non-tracked region is selected. Thus, when the marker goes out of the smaller first non-tracked region, the marker is located in a tracked region, thereby a tracking function is turned on for any slight movement of the marker. This makes it possible to consistently align the position of the treating instrument to the central part of the screen in a search for an affected area. The tracking function is not turned on for subtle movements and vibrations of the treating instrument in the first non-tracked region. As a result, the monitor screen does not move, which provides a screen that is easy to watch for a practitioner. To the contrary, in a treatment of an affected area in which a treating instrument is moved in a wide range of area, the second non-tracked region having a larger non-tracked region is selected. Thus, even when a marker moves in the second non-tracked region having a larger area, the screen does not move, which makes the treatment of the affected area easy to perform for a practitioner. As a result, a body cavity interior observing apparatus of the present invention can provide an appropriate monitor screen in searching for an affected area and in treating an affected area.

A second aspect of the present invention provides the body cavity interior observing apparatus according to the first aspect, wherein the tracking device includes: a trimming device for trimming an image to obtain a predetermined region so that the position of the marker which is detected by the marker position detecting device is positioned at the central part of the screen of the monitor; and a magnifying device for magnifying the predetermined region trimmed by the trimming device at a predetermined magnification rate to be displayed on the monitor.

According to a body cavity interior observing apparatus of the present invention, a non-tracked region to be displayed can be switched between a first non-tracked region and a second non-tracked region which is larger than the first non-tracked region, and in a search for an affected area in which it is preferable to track a treating instrument in order to consistently align the position of treating instrument to the central part of the screen, the first non-tracked region having a smaller non-tracked region is selected, while in a treatment of an affected area in which a treating instrument is moved in a wide range of area, the second non-tracked region having a larger non-tracked region is selected, thereby an appropriate monitor screen can be provided in searching for an affected area and in treating an affected area.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, preferable embodiments of a body cavity interior observing apparatus according to the present invention will be explained below with reference to the accompanying drawings.

FIG. 1is a system configuration diagram of an embodiment of a body cavity interior observing apparatus10of the present invention, andFIG. 2is a diagram illustrating a clinical situation using the body cavity interior observing apparatus10.

As shown inFIG. 1andFIG. 2, the body cavity interior observing apparatus10includes a treating instrument12, a trocar (penetrating instrument)14, an observation unit (observing section)16, a video signal processor18, and a monitor20. Instead of the observation unit16, an endoscope or a rigid endoscope which picks up an image of a body cavity interior may be used as an observing section.

The treating instrument12is used to treat an affected area in a body cavity26of an object to be examined24who is lying on an operating table22, and is provided with an operating section30which is operated by an operator28. In the treating instrument12, an inserting section32is connected to a distal end of the operating section30, and a forceps34is provided to a distal end of the inserting section32.

The inserting section32of the treating instrument12is, as shown inFIG. 2, inserted into the body cavity26by using a trocar14as a guide, with the trocar14being stabbed through a surface of an abdominal part42of the object24. The trocar14includes a metallic hollow tube44having a sharpened distal end, and a flexible holding tube46which is provided at a proximal end of the hollow tube44. The trocar14is inserted into the body cavity26by the operator28who holds the holding tube46and stabs the trocar14through the abdominal part42with directing the sharpened distal end of the hollow tube44downward as the forefront thereof and thereby the hollow tube44is inserted in the body cavity26.

The observation unit16is, as shown inFIG. 1, formed into a generally cylindrical shape, and is fixed to an opening part43which is formed by cutting the abdominal part42near the position stabbed by the trocar14. The observation unit16includes, a unit body48which is formed into a generally cylindrical shape as shown inFIG. 2, and a nut section50which is threadedly engaged with a male screw part49of the unit body48to sandwich and press the abdominal wall (abdominal skin) between and against the unit body48. The sandwich and press allows the observation unit16to be fixed to the opening part43.

The unit body48includes a plurality of LEDs (light emitting diode)52, a battery54, an observation optical system60having a lens56and a CCD (charge-coupled device)58, and a video signal transmitting section62for wirelessly transmitting video signals, therein. The plurality of LEDs52are arranged along the circumference of an identical circle about the central axis of the unit body48with an equal space therebetween. A receiving recess64for receiving the LEDs52is sealed by a plate66such as a transparent plate or a light scattering plate. The observation optical system60is disposed so that the optical axis thereof is aligned with the central axis of the unit body48. A transparent plate68is disposed in front of the lens56of the observation optical system60, which seals the storage recess70of the observation optical system60.

The battery54is a button cell for a smaller size and weight of the unit. The battery54can be replaced with a new one after a cap72which is removably mounted to the upper surface of the unit body48is removed. The battery54supplies power to the LEDs52, the CCD58, and the video signal transmitting section62as shown inFIG. 3, and also supplies power to a video signal processing section74which processes the output signal from the CCD58into a video signal. The video signal processing section74is also built in the unit body48shown inFIG. 2.

According to the observation unit16having a configuration described above, the LEDs52illuminate an object to be observed36, so that the optical image of the object to be observed is focused on the CCD58via the lens56. The output signal from the CCD58is processed by the video signal processing section74into a video signal which is transmitted to the video signal processor18shown inFIG. 1via an antenna76of the video signal transmitting section62. That is, the observation unit16achieves the functions for illuminating, picking up images, and transmitting video signals by using the built-in battery54.

The video signal transmitted to the video signal processor18is, as shown inFIG. 3, received by an antenna80of a video signal receiving section78. The received video signal is, after the distortion of the lens56is corrected by a distortion correction controlling section82, output to a marker tracking controlling section90which includes a marker position detecting section (a marker position detecting device)84, a trimming section (a trimming device)86, and a magnifying section (a magnifying device)88.

Now, the marker tracking controlling section90will be explained below.

The observation optical system60of the observation unit16shown inFIG. 2is the one which has a large field of view for observation over the entire body cavity26, since the observation unit16is fixed to the opening portion of the body wall43. However, if the entire region, the image of which is picked up by the observation optical system60having a large field of view for observation (for example, a view angle of 170 degree), is displayed on the monitor20, there is a problem that the image of the site near the distal end portion of the treating instrument or trocar14, which is the point the operator truly needs to observe, is displayed as a small region.

In order to avoid the problem, as shown inFIG. 2, a marker M having a color which is completely different from the body color (for example: green) is attached to the forceps34of the treating instrument12. In an image processing by a marker tracking controlling section90, the position of the marker M is detected by the marker position detecting section84ofFIG. 3. Next, the processed image is trimmed to obtain a predetermined region by the trimming section86so that the marker M is positioned at the central part of the screen of the monitor20. Then, the image region is magnified at a predetermined magnification rate by the magnifying section88to be displayed on the monitor20. The magnification rate is adjusted by operating a magnification rate adjusting knob19of the video signal processor18. The image processing as described above allows the image of the site the operator truly needs to observe to be widely displayed on the monitor20, thereby the problem in using an observation optical system having a large field of view for observation can be eliminated. That is, since the observation optical system can be used while being fixed to the opening portion of the body wall43without any operation of the observation unit16by an operator, the number of operators can be reduced without any disadvantage for clinical practices. Even if the position of the marker M is changed by an operation of the treating instrument12, since the marker position detecting section84consistently tracks the marker M, the image near the marker M can be magnified to be observed at all time. The marker M may be attached to the distal end of the trocar14.

The video signal processor18of the embodiment includes an alteration switch92. The alteration switch92selectively switches the video signal to be output to the monitor20between the video signal only after distortion correction and the video signal magnified after the automatic tracking of the marker M. When the latter signal is selected, an image near the marker M is magnified and observed on the monitor20, while the former signal is selected, an image of the entire region which is picked up by the observation optical system60having a large field of view can be observed on the monitor20, which is convenient in understanding the position of the forceps34of the treating instrument12relative to the entire body cavity26.

Meanwhile, the marker position detecting section84of the body cavity interior observing apparatus10of the embodiment includes a pixel extracting section94, and a calculating section96.

The pixel extracting section94extracts a pixel group which has the same color as that of the green marker M attached to the treating instrument12from the image showing the body cavity interior which is picked up by the observation unit16. The calculating section96then calculates the position of the center of gravity of the pixel group as the position of the marker M. In this way, only the circuits of the pixel extracting section94and the calculating section96which are built in the marker position detecting section84enable a detection of the position of the marker M, thereby the distal end portion of the treating instrument12can be detected by a simple configuration without adding other machine apparatus.

Specifically, the pixel extracting section94extracts, as the pixel group, the pixels where the output values of the color components which are included in the green color of the marker M are larger than the output values of the color components which are not included in the green color of the marker M by a predetermined threshold or more, among the output values of R, G, B which are output from the CCD58of the observation unit16via the video signal transmitting section62.

Next, a calculation example by the calculating section96will be explained below.

The center of gravity Cgof the green color region can be obtained by the following formula, provided that the pixel value of the color c={r, g, b} in the coordinate (x, y) is f(x, y, c):

Cg=[Cg,xCg,y]=[∑i=1W/5⁢∑j=1H/5⁢5⁢i·hg⁡(5⁢i,5⁢j)∑i=1W/5⁢∑j=1H/5⁢hg⁡(5⁢i,5⁢j)∑i=1W/5⁢∑j=1H/5⁢5⁢j·hg⁡(5⁢i,5⁢j)∑i=1W/5⁢∑j=1H/5⁢hg⁡(5⁢i,5⁢j)]t,⁢⁢hg⁡(x,y)={1if⁢⁢f⁡(x,y,g)>f⁡(x,y,r)+tg,r⁢⁢and⁢f⁢(x,y,g)>f⁡(x,y,b)+tg,b0else.[Formula⁢⁢1]
where t is transposition, and W and H are the number of pixels in the horizontal and vertical direction of laparoscope input images, respectively. The tg, rand tg, bare the threshold parameters used in detecting the green color. In calculating the center of gravity, in this system, the detection is performed for every five pixels in row and column directions in order to reduce the cost involved in the calculation. The detection, however, may be performed for every pixel.

FIG. 4shows a (determined) green color region based on the set threshold parameters tg, rand tg, b. The horizontal axis ofFIG. 4represents a G-R pixel value difference, and the vertical axis represents a G-B pixel value difference.

When the marker M is set to be yellow, similarly, the center of gravity Cyof the yellow color region can be obtained by the following formula:

Cy=[Cy,xCy,y]=[∑i=1W/5⁢∑j=1H/5⁢5⁢i·hy⁡(5⁢i,5⁢j)∑i=1W/5⁢∑j=1H/5⁢hy⁡(5⁢i,5⁢j)∑i=1W/5⁢∑j=1H/5⁢5⁢j·hy⁡(5⁢i,5⁢j)∑i=1W/5⁢∑j=1H/5⁢hy⁡(5⁢i,5⁢j)]t,⁢⁢hy⁡(x,y)={1if⁢⁢f⁡(x,y,g)>f⁡(x,y,b)+tg,b⁢⁢and⁢f⁢(x,y,r)>f⁡(x,y,b)+tr,b0else.[Formula⁢⁢2]
where tg, b, tr, bare the threshold parameters used in detecting the yellow color.

FIG. 5shows a (determined) yellow color region based on the set threshold parameters tg, band tr, b. The horizontal axis ofFIG. 5represents a G-B pixel value difference, and the vertical axis represents a R-B pixel value difference.

As described above, since the calculating section96calculates the center of gravity for each color region having green color and yellow color respectively, even when two treating instruments12are simultaneously inserted, the positions of the distal ends of the two treating instruments12can be detected respectively.

Moreover, as described above, since the pixel extracting section94extracts, as the pixel group, the pixels where the output values of the color components which are included in the color of the marker M are larger than the output values of the color components which are not included in the color of the marker M by a predetermined threshold or more, among the output values of R, G, B which are output from the CCD58of the observation unit16, the truly needed pixels, that is the color of the marker M, can be extracted.

Meanwhile, the video signal processor18is provided with a region separating section108which separates a screen of the monitor20into a tracked region100and a non-tracked region (a first non-tracked region)102as shown inFIG. 6, and also separates a screen of the monitor20into a tracked region104and a non-tracked region (a second non-tracked region)106as shown inFIG. 7. The non-tracked region102ofFIG. 6is a rectangular region which is surrounded by a boundary line L1shown by a chain double-dashed line and is generally located at the center of the screen of the monitor20, and the tracked region100is the strip region located outside of the non-tracked region102. Similarly, the non-tracked region106shown inFIG. 7is larger than the non-tracked region102shown inFIG. 6and is a rectangular region surrounded by a boundary line L2shown by a chain double-dashed line, and the tracked region104is the strip region located outside of the non-tracked region106.

In the region separating section108, depending on a selection signal from a manual switch110, the first separated state shown inFIG. 6or the second separated state shown inFIG. 7is selected, and in either selected state, the trimming section86is controlled so that: when the center of gravity Cg of the marker portion M is located in the non-tracked region102or106, the trimming section86is controlled to stop its function, and; when the center of gravity Cg of the marker portion M is located in the tracked region100or104, the trimming section86is controlled to operate, so that the center of gravity Cg of the marker portion M is aligned to the central part of the screen of the monitor20.

Next, actions of the body cavity interior observing apparatus10having the configuration described above will be explained below.

First, in a search for an affected area in which it is preferable to track the treating instrument12in order to consistently align the position of the treating instrument12to the central part of the screen of the monitor20, the separated state with the non-tracked region102ofFIG. 6which has a smaller non-tracked region is selected by using the manual switch110.

Thus, in searching for an affected area, when the marker portion M goes out of the non-tracked region102having a smaller region, the marker portion M is positioned in a tracked region100, thereby a tracking function of the trimming section86is turned on for any slight movement of the marker portion M. This makes it possible to consistently align the position of the treating instrument12to the central part of the screen in searching for an affected area. The tracking function is not turned on for subtle movements and vibrations of the treating instrument12in the non-tracked region102. As a result, the screen of the monitor20does not move due to the subtle movements and vibrations of the treating instrument12, which provides a screen which is easy to watch for a practitioner.

Next, in a treatment of an affected area in which the treating instrument12is moved in a wide range of area, the separated state with the non-tracked region106ofFIG. 7which has a larger non-tracked region is selected by using the manual switch110. Thus, even when the marker portion M moves in the non-tracked region104having a larger area, the screen does not move, which makes the treatment of the affected area easy for a practitioner.

Therefore, according to the body cavity interior observing apparatus10of the embodiment, an appropriate monitor screen can be provided in searching for an affected area and in treating an affected area.