JP2003245242A - Shape detector for endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shape detector for an endoscope which achieves an accurate display of the actual shape of the insertion tube with a simple structure. <P>SOLUTION: The mid point dPmi of an arc is determined by interpolation processing with respect to detection points Pi and Pi<SB>+1</SB>of a source coil arranged within the insertion tube and when the length of the arc is almost equal to the interval in the actual arrangement of the source coil, the mid point dPmi is set as a virtual point or when it is much smaller than the interval, a point Pvi extended from the mid point of the segment Pi-Pi<SB>+1</SB>in the direction of connecting it and the mid point dPmi of the arc is set as the virtual point. This allows the accurate detection of the shape of the insertion tube as if the source coil were arranged at the virtual point by performing the interpolation processing with respect to the Pi and Pi<SB>+1</SB>including the virtual point. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope shape detecting device for detecting and displaying an insertion shape of an endoscope using a magnetic field generating element and a magnetic field detecting element.

[0002]

2. Description of the Related Art In recent years, there has been used an endoscope shape detecting apparatus which detects the shape of an endoscope inserted into a body or the like by using a magnetic field generating element and a magnetic field detecting element and displays the shape by a display means. Became.

For example, Japanese Unexamined Patent Publication No. 8-107875 discloses an apparatus for detecting an endoscope shape by using a magnetic field and displaying the detected endoscope shape. Then, by driving a plurality of magnetic field generating elements arranged at a predetermined interval in the insertion portion of the endoscope to be inserted into the body to generate a magnetic field around the magnetic field generating elements, the magnetic field detecting elements arranged outside the body A three-dimensional position is detected, a curve that continuously connects the magnetic field generating elements is generated, and a three-dimensional image of the modeled insertion portion is displayed by the display means.

By observing the image, the operator etc.
The position of the distal end of the insertion portion inserted into the body, the shape of the insertion, and the like can be grasped, and the insertion work to the target site can be performed smoothly.

[0005]

However, in the conventional example, when the insertion portion is curved in a loop shape with a small radius of curvature with respect to the distance between the magnetic field generating elements arranged in the insertion portion, However, since the number of magnetic field generating elements existing in the loop-shaped curved portion is small, it may not be possible to display a smooth shape such as an actual loop shape.

(Object of the Invention) The present invention has been made in view of the above points, and an object of the present invention is to provide an endoscope shape detecting apparatus capable of accurately displaying the actual shape of the insertion portion with a simple structure. And

[0007]

One element of a plurality of magnetic field generating elements and a plurality of magnetic field detecting elements is arranged inside an endoscope insertion portion to be inserted into a subject, and the other element is provided outside the subject. And the position of one element placed inside the endoscope insertion section is detected by the detection means using the position data of the other element, thereby estimating the shape of the endoscope insertion section. In the endoscope shape detecting device for displaying the shape of the device by the display means, a virtual element is arranged between the detected one element based on the output of the detecting means, and data between the one element is detected. By providing the data interpolating means for performing the data interpolation by using the position data of the virtual element, the element that is actually arranged as compared with the case where the endoscope insertion portion is bent with a small curvature. That bends like increasing the number of Shape and accurately detected, and to be able to display its shape.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 22 relate to one embodiment of the present invention, FIG. 1 shows a configuration of an endoscope system including the one embodiment, and FIG. 2 shows an example of arrangement of sense coils incorporated in a coil unit. 3 shows the configuration of the endoscope shape detection device in FIG. 1, FIG. 4 shows the configuration of the detection block and host processor of FIG. 3, and the configuration of the connection detection mechanism, and FIG. 5 shows the configuration of the detection block and the like. 6 shows the operation of the 2-port memory or the like in a timing diagram, FIG. 7 shows the configuration of the detection device and the operation panel, and FIG. 8 shows the connection display function when an endoscope or the like is connected to the detection device. FIG. 9 shows a state in which interpolation processing is performed with and without setting virtual points, FIG. 10 shows the shape of the insertion portion displayed in the case of FIG. 9, and FIG. 11 shows virtual point setting processing. 12 is an explanatory diagram of FIG. 12, and FIG. 12 is a process of setting a virtual point. 13 shows the contents, FIG. 13 shows an explanatory diagram of the virtual point setting process of FIG. 12, FIG. 14 shows the contents in which the date display is changed depending on the destination, and FIG. 15 shows the inside of the insertion portion displayed on the monitor. When the source coil portion is within the detection range, its icon is also displayed in green, and FIG. 16 shows a state in which the display color is determined depending on whether the interpolation point of the source coil is inside the detection range. , FIG. 17 shows the processing from the magnetic field measurement to the scope model drawing, FIG. 18 shows the state where the insertion part is divided into three regions, and FIG. 19 shows the buffering of data at shorter intervals as compared with the conventional example. FIG. 20 shows an explanatory diagram that is made, FIG. 20 shows a state of setting a cut surface by a reference plate, etc., FIG. 21 shows detailed setting contents in the case of FIG. 20, and FIG. 22 shows automatic setting even when the scope position is OFF. center A diagram for explaining the effect of performing the ring.

As shown in FIG. 1, an endoscope system 1 having one embodiment includes an endoscope apparatus 2 for performing an endoscopic examination.
And an endoscope shape detecting device 3 used for assisting the endoscopic examination. The endoscope shape detecting device 3 includes an insertion portion of the electronic endoscope 6 in the body cavity of the patient 5 lying on the bed 4. It is used as an insertion assisting means when inserting 7 and performing an endoscopic examination.

In the electronic endoscope 6, an operating portion 8 having a bending operating knob is formed at the rear end of a flexible elongated insertion portion 7, and a universal cord 9 is extended from the operating portion 8. It is connected to a video imaging system (or video processor) 10. The electronic endoscope 6 has a light guide inserted therethrough and transmits illumination light from a light source unit inside the video processor 10 and emits the transmitted illumination light from an illumination window provided at the distal end of the insertion unit 7 to guide a patient or the like. Illuminate. An object such as an illuminated affected part is imaged by an objective lens attached to an observation window provided adjacent to the illumination window on an image pickup device arranged at the image forming position, and the image pickup device photoelectrically converts the image.

The photoelectrically converted signal is a video processor 1
A standard video signal is generated by signal processing by the video signal processing unit in 0, and is displayed on the image observation monitor 11 connected to the video processor 10.

The electronic endoscope 6 includes forceps channels 12
The forceps channel 12 has an insertion opening 12a.
, The probe 15 having, for example, 16 magnetic field generating elements (or source coils) 14a, 14b, ..., 14p (hereinafter represented by reference numeral 14i) is inserted, so that the source coil 14i is installed in the insertion portion 7. To be done.

The source cable 16 extending from the rear end of the probe 15 has a connector 16a at the rear end thereof detachably attached to a detection device (also referred to as a device main body) 21 as a device main body of the endoscope shape detection device 3. Connected. Then, the source coil 14 serving as a magnetic field generating means from the detecting device 21 side via the source cable 16 as a high frequency signal transmitting means.
By applying a high frequency signal (driving signal) to i, the source coil 14i radiates an electromagnetic wave accompanied by a magnetic field to the surroundings.

Further, a (sense) coil unit 23 is provided in the detector 21 arranged near the bed 4 on which the patient 5 lies so as to be vertically movable (elevable).
A plurality of magnetic field detection elements (sense coils) are arranged in the coil unit 23 (more specifically, as shown in FIG. 2, for example, the Z coordinate of the center is the first Z coordinate, for example X. The sense coil 22a-1 oriented toward the axis,
22a-2, 22a-3, 22a-4 and sense coils 22b-1, 22b-2, 22b-3 oriented toward the Y axis, which is a second Z coordinate whose central Z coordinate is different from the first Z coordinate. ,
22b-4, and the sense coil 2 oriented toward the Z axis, which is a third Z coordinate whose center Z coordinate is different from the first and second Z coordinates.
12 of 2c-1, 22c-2, 22c-3, 22c-4
A number of sense coils (hereinafter represented by reference numeral 22j) are arranged).

The sense coil 22j is the coil unit 2
3 is connected to the detection device 21 via a cable (not shown). The detection device 21 is provided with an operation panel 24 for the user to operate the device. Also,
A liquid crystal monitor 25 is arranged above the detection device 21 as a display means for displaying the detected endoscope shape.

As shown in FIG. 3, the endoscope shape detecting apparatus 3 has a drive block 26 for driving the source coil 14i.
And a detection block 27 that detects a signal received by the sense coil 22j in the coil unit 23, and a host processor 2 that processes the signal detected by the detection block 27.
8 and.

As shown in FIG. 4A, the probe 15 installed in the insertion portion 7 of the electronic endoscope 6 has 16 source coils 14i for generating a magnetic field as described above.
Are arranged at predetermined intervals, and these source coils 1
4i is connected to a source coil drive circuit 31 that forms drive signals of 16 different frequencies that form the drive block 26.

The source coil drive circuit section 31 drives each source coil 14i with a sinusoidal drive signal current having a different frequency, and each drive frequency is stored in the drive frequency setting data (not shown) inside the source coil drive circuit section 31. Or drive frequency setting data stored in the drive frequency setting data storage means (also referred to as drive frequency data). This drive frequency data is the drive frequency data in the source coil drive circuit section 31 via the PIO (parallel input / output circuit) 33 by the CPU (central processing unit) 32 that performs endoscope shape calculation processing and the like in the host processor 28. It is stored in storage means (not shown). On the other hand, the twelve sense coils 22j in the coil unit 23 are connected to the sense coil signal amplification circuit section 34 which constitutes the detection block 27.

In the sense coil signal amplifying circuit section 34, as shown in FIG. 5, twelve single-core coils 22k forming the sense coil 22j are connected to the amplifying circuit 35k, respectively, and 12 processing systems are provided. , Each single core coil 2
The minute signal detected by 2k is amplified by the amplifier circuit 35k, and the filter circuit 36k has a band through which a plurality of frequencies generated by the source coil group passes, removes unnecessary components, and is output to the output buffer 37k. analog·
Digital converter) 38k host processor 28
Is converted into a readable digital signal. The detection block 27 includes a sense coil signal amplification circuit section 34 and an ADC 38k, and the sense coil signal amplification circuit section 34 includes an amplification circuit 35k, a filter circuit 36k, and an output buffer 37k.

Returning to FIG. 4A, the 12 systems of outputs of the sense coil signal amplification circuit section 34 are the 12 AD circuits.
It is transmitted to C38k and converted into digital data of a predetermined sampling period by the clock supplied from the control signal generation circuit section 40. This digital data is written in the 2-port memory 42 via the local data bus 41 by the control signal from the control signal generation circuit unit 27.

As shown in FIG. 5, the two-port memory 42 is functionally composed of a local controller 42a, a first RAM 42b, a second RAM 42c and a bus switch 42d, and has a timing as shown in FIG. The ADC 38k starts A / D conversion by the A / D conversion start signal from the local controller 42a, and the bus switch 42d alternately reads the first RAMs 42b and 42c while the bus switch 42d switches the RAMs 42b and 42c by the switching signal from the local controller 42a. It is used as a memory and a write memory, and data is always taken in after the power is turned on by a write signal.

Returning to FIG. 4A again, the CPU 32
The digital data written in the 2-port memory 42 by the control signal from the control signal generation circuit unit 27 is read out via the internal bus 46 including the local data bus 43, the PCI controller 44 and the PCI bus 45 (see FIG. 5), Using the main memory 47, as will be described later, frequency extraction processing (fast Fourier transform:
FFT) to separate and extract the magnetic field detection information of the frequency component corresponding to the drive frequency of each source coil 14i, and the electronic endoscope 6 from each digital data of the separated magnetic field detection information.
The spatial position coordinates of each source coil 14i provided in the insertion section 7 are calculated.

Further, the insertion state of the insertion portion 7 of the electronic endoscope 6 is estimated from the calculated position coordinate data, and the display data for forming the endoscope shape image is generated and output to the video RAM 48. The video signal generation circuit 49 reads out the data written in the video RAM 48, converts it into an analog video signal, and outputs it to the liquid crystal monitor 25. When the liquid crystal monitor 25 receives the analog video signal, the liquid crystal monitor 25 displays the insertion shape of the insertion portion 7 of the electronic endoscope 6 (hereinafter referred to as the scope model) on the display screen.

In the CPU 32, each source coil 14
The magnetic field detection information corresponding to i, that is, the electromotive force (amplitude value of the sine wave signal) and the phase information generated in the single core coil 22k forming each sense coil 22j are calculated. The phase information indicates the polarity of electromotive force ±.

Further, in the present embodiment, as shown in FIG. 1, the detection device 21 has an external body for displaying the position outside the body in order to confirm the position of the insertion portion 7 inserted into the body. The marker 57 and the reference plate 58 used for displaying the scope model always from a specific direction (of the patient 5) even if the patient's position changes by attaching the marker 57 to the abdomen of the patient 5, etc. It can also be used by connecting to 21.

The extracorporeal marker 57 has one source coil housed therein, and the cable 5 of the extracorporeal marker 57 is contained in the extracorporeal marker 57.
The connector 59a at the base end of 9 is detachably connected to the detection device 21.

By connecting the connector 59a, the source coil of the extracorporeal marker 57 is driven as in the case of the source coil in the probe 15, and the position of the source coil of the extracorporeal marker 57 detected by the coil unit 23 is detected. Is also displayed on the monitor 25 similarly to the scope model.

Further, the reference plate 58 has, for example, three source coils arranged on the disc surface inside the disc-shaped portion, and the connector 60a at the base end of the cable 60 connected to these three source coils. Is detachably connected to the detection device 21.

By detecting the positions of these three source coils, the plane on which they are arranged is determined. Then, it is used to draw the scope model so that it becomes the scope model observed when the insertion portion 7 is viewed from the direction perpendicular to the plane.

Further, as shown in FIG. 4 (A), in this embodiment, the connector 16 of the probe 15 is attached to the detection device 21.
a, connector 59a of the extracorporeal marker 57, reference plate 5
The connector receivers 21a, 21b, and 21c to which the eight connectors 60a are respectively connected are provided, and the connector receivers 21a, 21b, and 21c are connected to the source coil drive circuit 31.

Further, as shown in FIG. 4B, for example, the connector receiver 21a is provided with a connection detecting mechanism 80 for detecting whether or not the connector 16a is connected. In the connector 16a, in addition to the connection pins p1 to pn connected to the source coils 14a to 14p, a common pin pc and a connection detection pin pk are provided, and the pin pk is connected to the pin pc.

On the side of the connector receiver 21a are provided pin receivers p1 'to pn', pc 'and pk' which are respectively connected to the connection pins p1 to pn, pc and pk, and the pin receiver pc 'is grounded. It is connected.

The pin receiver pk 'has a pull-up resistor R.
Is connected to the power supply terminal Vc and is also connected to the connection detection port of the CPU 32. And CPU3
2 depends on whether the level of the pin receiving pk 'is "H" level of the power supply terminal Vc or "L" level of the ground.
The probe 15 determines whether the detection device 21 is not connected or is connected.

That is, when the probe 15 is connected as shown in FIG. 4B, the pin receiver pk 'is connected to the ground through the conductive pins pk and pc on the connector 16a side and the pin receiver pc'. Therefore, the level of this pin receiving pk 'becomes the "L" level of the ground,
It is determined that the probe 15 is connected. On the other hand, when the probe 15 is not connected, the pin receiver p
The level of k ′ becomes the “H” level of the level of the power source terminal Vc, and it is determined that no connection is made.

The connector receivers 21b and 21c are also provided with a similar connection detecting mechanism. Then, when the probe 15 (the endoscope provided with it), the extracorporeal marker 57, and the reference plate 58 are connected, the CPU 32 will be described later with reference to FIG.
For example, the endoscope connection icon, the extracorporeal marker connection icon, and the reference plate connection icon connected to the connection state display unit 25a at the lower right corner of the monitor 25 of (A) are displayed.
If not connected, the icon is not displayed.

Further, in the present embodiment, the CPU 32 has the source coil 14i (indicated here by 14i, but in addition to the source coil 14i in the probe 15, an extracorporeal marker 57).
(Including the source coil of the reference plate and the source coil of the reference plate 58) is provided with the function of the determination means 32a for monitoring the abnormality of the position data. The determination means 32a makes the following abnormality determination.

A) It is determined that the position data of each source coil 14i is valid if it is within a predetermined range, and invalid if it is outside the range. b) The electromotive force detected by the sense coil 22j that detects the magnetic field generated by the source coil 14i is compared with a preset reference value. If the electromotive force exceeds the reference value, position detection is possible; To do. c) If the detection result of the source coil disconnection short-circuit detection means (not shown) is disconnection or short circuit, it is judged as abnormal, and otherwise it is judged as normal.

Abnormality of the position data of the source coil is judged based on the results of the above a) b) c). Further determination means 32
The a performs the following abnormality determination on the source coil in the probe. Two source coils 14 for a given distance range
A section where the distance i, 14i + 1 is too short or too long is abnormal, and if it is within the range, it is determined normal.

The judgment result is displayed so that the operator can understand it by changing the display form according to the judgment result when the scope model or the three-dimensional position of the extracorporeal marker 57 is displayed.

For example, when the CPU 32 displays the endoscope connection icon, the extracorporeal marker connection icon, and the reference plate connection icon, the display color selection means 3 is determined according to the determination result.
The control of displaying on the monitor 25 is performed through the function of 2b.
Therefore, the operator operates the connection status display unit 2 at the lower right of FIG.
By the display color of the icon displayed on 5a, it is possible to easily know whether or not the state is detected with a predetermined accuracy or higher.

Further, in the present embodiment, in addition to changing and displaying the display color on the connection status display section 25a, the scope model displayed on the display surface of the monitor 25 and the extracorporeal marker 57 are displayed.
Regarding the display with the marker position of, the display color is changed according to whether it is within the effective detection range.

For example, the probe 15 (that is, the endoscope 6)
In the case of, by detecting the position of each source coil 14i,
In order to display with the scope model after interpolation etc., for example, the scope model part of the part existing within the effective detection range and the part of the scope model part outside the effective detection range should be displayed in different display colors. There is. Therefore, the determination result by the determination means 32a is reflected in the image data stored in the video RAM 48, for example. That is, when the CPU 32 stores image data such as a scope model in the video RAM 48, it stores the image data in the R, G, B planes of the video RAM 48 according to the determination result.

For example, when the entire scope model displayed on the monitor 25 is within the effective detection range, G and R of the video RAM 48 are displayed so as to be displayed in a predetermined color, for example, gray.
The image data is stored in the planes B and B. on the other hand,
If a part of the scope model is out of the effective detection range, that part is displayed in yellow, for example.
The image data of that part is stored in the 48 G and R planes. In the case of the extracorporeal marker 57, the color of the marker displaying the extracorporeal marker is changed in a similar manner depending on whether the extracorporeal marker 57 is within the effective detection range.

As described above, in this embodiment, the monitor 25
It is possible to easily know from the display color of the scope model displayed on the screen or the display color of the extracorporeal marker 57, etc., whether they are within the effective detection range and can be detected with a predetermined accuracy or higher, or a state of less than the predetermined accuracy. The feature is that it is possible to.

Further, even when the probe 15 or the like is connected, or when the source coil side is driven and the detection signal cannot be detected by the sense coil, it is judged as a failure.

FIGS. 7A and 7B show the detection device 21 and the operation panel 24 provided on the detection device 21. As shown in FIG. 7B, the operation panel 24 has
The menu button 51 for displaying the menu bar (of the main menu as shown in FIG. 7C), the reset button 52 for performing the reset operation, and the view angle by rotating the scope model with the up, down, left and right arrows. View angle / select button 53 for changing the display, selecting functions (up / down arrows), and selecting items (left / right arrows)
(In the following, for simplification, it may be explained with ↑ ↓ and → ← buttons etc.)
Zoom button 54 with + and-displays for reduction, date and time, and area change (may be explained with + and-buttons etc.)
A one-screen / two-screen button 55 for instructing display of one screen and two screens, and a scope position button 56 for setting a start position of display of the scope model are provided.
The more detailed functions are as follows.

(A) Function of the menu button 51 The menu bar is displayed / hidden at a specific position on the monitor screen. (When the menu bar 50 is hidden, the state of the set function is stored in the storage device). Selection of items in the date / time and area setting screens. (B) Function of reset button 52 In the situation where the function of each item is set by the menu bar, the setting value of each menu item is returned to the state before the menu bar is displayed. On the date / time and area setting screen,
Returns the function setting values for each item to the status before entering the date / time and area setting screen.

(C) View angle / select button 5
3 function ← ↑ ↓ → button to rotate the scope model. Use the ↑ ↓ buttons to move the focus of the menu bar. ← → button
Display and select submenu. And selection of the function of the item selected by the menu button 51 on the date / time / region setting screen.

(D) Enlargement / reduction of the function scope model of the zoom button 54. Set the function of each item on the date and time and area setting screen. (E) Function of 1-screen / 2-screen button 55 Display of 2 screens with different viewpoint positions / directions.

(F) Function of the scope position button 56 The setting is such that the extracorporeal marker is brought to a position where display of the patient's anus or the like is desired to start and the scope position button 56 is operated to start display from that position.

Next, the function of connection display will be described with reference to FIG. In the present embodiment, as described in FIGS. 1 and 4, the detection device 21 includes the endoscope 6 and the reference plate 5.
7. The extracorporeal marker 58 can be detachably connected. The presence / absence of connection is easily indicated by the connection status display section 25a of the monitor 25 according to the presence / absence of connection.

Further, in the connected state, it is detected whether it is a normal connection state, a decrease in accuracy, an abnormality or a failure,
The display color is changed and displayed so that the user can confirm the display color of the connection state. Extracorporeal marker 5 on the detection device 21
7. When the reference plate 58 and the endoscope 6 are connected,
As shown in FIG. 8 (A), an extracorporeal marker connection icon, a reference plate connection icon, and an endoscope connection icon are displayed on the connection status display unit 25a.

FIG. 8B shows the shapes and contents of the extracorporeal marker connection icon, the reference plate connection icon, and the endoscope connection icon displayed on the connection status display section 25a. Also, the display color of the icon is green when the connection is normal, yellow when the accuracy is low, and red when there is an abnormality or failure so that the user can check the connection status by the display color. I have to.

It should be noted that depending on whether or not the accuracy is within the valid range,
The display color is not limited to the one that is changed and displayed. For example, the icon displayed on the connection status display unit 25a is normally displayed without blinking, and when the accuracy is lowered, the display is displayed with blinking. The display form may be changed to the form.

Further, the display form visually displayed on the monitor 25 is not limited to the one changed, but the notification form for notifying whether the accuracy is within or outside the effective accuracy by sound or voice is changed. You may do it. Further, the presence / absence of connection is not limited to the visual notification form, and the acoustic notification form by sound may be changed. For example, when the accuracy decreases from the effective accuracy, a sound may be notified (for example, when the accuracy is within the effective accuracy, no sound is generated, and when the accuracy decreases, a sound or a voice is output). In other words, it may be displayed or announced by the presence or absence of sound or voice, its change, etc.).

Further, in the present embodiment, the source coil 1
When performing interpolation processing for calculating the shape of the insertion portion 7 by detecting the position of 4i, in addition to the position of the source coil 14i actually arranged in the insertion portion 7, a virtual point is set at an intermediate point between the source coils 14i. Perform the process of arranging various source coils,
Particularly, when it is bent with a small curvature, the shape of the insertion portion can be calculated more accurately. Therefore, the CPU 32 shown in FIG. 4 performs the function of the virtual point setting processing means 32c for adding more virtual elements.

The outline of the operation of the processing means 32c will be described first with reference to FIGS. In the present embodiment, for example, the coil interval L is 100 mm in the insertion portion 7.
A source coil 14i is arranged in each. When the insertion portion 7 is curved in a loop shape with, for example, φ60, the position of the source coil 14i inside the insertion portion 7 is shown in FIG.
In the state as shown by the cross points in FIG. 10, if normal interpolation processing is performed, it cannot be detected as a loop.
It is displayed as an insertion portion shape such as.

When the insertion portion 7 is curved in a loop shape with, for example, φ60, if the internal position is in the state shown by the cross points in FIG. 9A, normal interpolation processing is performed. , Cannot be detected as a loop and is displayed as a shape as shown in FIG.

On the other hand, as shown in FIG. 9B, when a virtual source coil is arranged at the intermediate point of the source coil 14i in the loop portion (that point is Pv1,
(Indicated by Pv2) is approximately equivalent to a state in which many source coils are arranged in the loop portion, and the same interpolation processing as in the case of FIG. When the calculation is performed, the loop shape is identified and the result of FIG.
It can be displayed with a loop-shaped scope model as shown in FIG.

In FIG. 9C, the coil interval is actually set to 5
FIG. 10C shows the coil position when the loop shape is set to 0 mm, and the interpolation process is performed for this case to calculate the shape of the insertion portion.

That is, by performing the virtual point setting process 32c as in this embodiment, the actual source coil 41
It becomes possible to more accurately detect and display the shape of the insertion portion as if the source coil is arranged at the intermediate point of i. Therefore, as the virtual point setting processing means 32c for setting the virtual point, basically the processing for setting the virtual point Q'shown in FIG. 11 is performed by software.

When Pa and Pb in FIG. 11 are the source coil detection points and the arc PaQPb is a normal interpolation shape,
When the length of the arc PaQPb is shorter than the source coil interval L (actually 100 mm) by a predetermined amount or more, the vector OQ is extended to the point Q side to obtain the point Q ′ of the source coil interval L.
Is obtained as a virtual point.

This point Q'is added to the source coil point actually arranged in the insertion portion 7 and interpolation is performed to make it possible to plot even a case where it is bent into a loop shape within a predetermined deviation. As described in FIG. 9 (B) and FIG. 10 (B), the shape of the insertion portion can be displayed with high accuracy.

The processing in this case will be described below with reference to FIG. When the virtual point calculation process starts, the CPU 32
Performs the pre-interpolation processing in step S1 of FIG. 12 and performs the interpolation processing on the position-estimated coil position Pi to obtain the interpolation point dPn. Here, i is for the source coil 41i actually arranged in the insertion portion 7, is 1 to N (for example, 12 or 16), and n is the number of interpolation points between i and i + 1.

The source coil positions decimated by an error are complemented by the midpoints of the arcs interpolated between the source coil positions before and after that (hereinafter simply coil positions). Then, as shown in FIG. 13, for example, an interpolation point indicated by a dotted line is obtained between the coil positions Pi and Pi + 1.

In the next step S2, the distance between the adjacent coils (along the interpolation point dPn) is obtained, and is set as Lri. Then, in the next step S3, the distance Lri between the coils is a larger predetermined value obtained by multiplying the predetermined value Lpi (specifically, the designed coil interval 100 mm) by a predetermined coefficient value (here, 1.5). Determine if: That is, it is determined whether or not Lri ≦ Lpi × 1.5.

According to the determination in step S3, Lri≤Lp
If the condition of i × 1.5 is not satisfied, it is determined that the calculated coil distance Lri is too large, the error process of step S4 is performed, and the process proceeds to step S14. In this error processing, the error level is low, for example, an error code E8 is displayed. In this case, that portion is displayed in yellow, for example.

On the other hand, Lri is determined by the determination in step S3.
When the condition of ≦ Lpi × 1.5 is satisfied, it is further determined in step S5 whether or not it is equal to or larger than the smaller predetermined value, specifically, whether or not Lri ≧ Lpi × 0.8. If this condition is satisfied, it is determined that the coil distance Lri calculated by interpolation is calculated as a normal coil distance, and the process proceeds to step S14.

Further, in this step S5, as shown in FIG. 13, the coil positions Pi-1, Pi, Pi + 1, Pi are set.
Whether or not α + β is 180 ° or more when the angles Pi−1, Pi, Pi + 1 and the angles Pi, Pi + 1, Pi + 2 are respectively α and β at four points of +2 (that is,
α + β ≧ 180 °) is also determined.

When this condition is met, it is judged that at least three coil positions are present on the arc (loop), that is, the actual shape is already approximated only by normal interpolation processing. When it is determined that the calculation can be performed, the process proceeds to step S14. In step S14, the distance Li between the adjacent coils at the correction point dPn obtained by the prior correction
The midpoint is set to the virtual point Pvi and the process proceeds to step S15.

On the other hand, in the determination of step S5, Lr
If i ≧ Lpi × 0.8 does not apply or α + β ≧ 1
If it does not correspond to 80 °, it is determined that the shape cannot be calculated accurately by the interpolation processing, and the interpolation point is corrected to perform the virtual point calculation processing.

For this purpose, first, in step S6, the midpoint of the interpolated arc is obtained and set as dPmi. Specifically, as shown in FIG. 13, the midpoint dPmi of the arc indicated by the dotted line formed by interpolating the section of the coil positions Pi and Pi + 1.
Ask for.

Next, the midpoint of the line segment PiPi + 1 in step S8 is found and set as Pmi. Then, as shown in FIG. 13, it is considered that the actual arc is present by extending the vector obtained by subtracting the midpoint Pmi of the line segment PiPi + 1 from the midpoint dPmi of the arc (in FIG. 13, the origin is O). The unit vector e1 in the case is shown).

Then, in order to obtain the arc midpoint intersecting the arc on the extension of the vector e1, the center of the arc is set to O, the distance to the arc mid point in that case, that is, the radius of the arc is set to ri, and the angle Letting the central angle of PiOPi + 1 be θi, the minimum combination of radii ri and θi that minimizes the difference between the length of the arc PiPi + 1 and the predetermined section distance Lpi is 2.
Calculate by multiplication. Then, as shown in step S8, (r
i, θi) is determined.

Next, as shown in step S9, it is determined whether the calculated radius is twice the radius ri, that is, the calculated diameter of the arc is less than a predetermined minimum diameter φi. The minimum diameter φi is, for example, a value obtained by dividing the minimum radius that can be obtained when the insertion portion 7 is actually looped by a coefficient (for example, 1.5).

Therefore, if the condition of step S9 is satisfied, it is determined that an error has occurred, and after performing the error processing of step S10, the same as in the case of not satisfying the condition of step S10.
Proceed to 11. That is, the calculated radius ri is actually the insertion portion 7
If the radius is less than the minimum radius that can be obtained by looping, and the radius is unreliable, that portion is displayed in yellow. In addition to this, even when the detection range is outside the range of the estimated coordinate system, the display is not performed in that range.

In step S11, the central angle θi is 180
It is determined whether or not it is equal to or less than 0 °, and it is determined whether or not the virtual point Pvi is on the extension of the unit vector e1 shown in FIG. 13 or on the opposite side.

When the central angle θi is 180 ° or less, the imaginary point P is obtained as outlined in step S12.
vi and the central angle θi is 180 ° or more,
The virtual point Pvi is determined as outlined in step S13. After that, it is determined whether or not the coil number i has reached the value N-1 adjacent to the last number N, and if the virtual point processing to be obtained remains, the process returns to step S2 and the same processing is repeated.

After the virtual point setting process is performed by performing such processing, the virtual point is used together with the actual position of the source coil 14i to perform interpolation processing to calculate the shape of the insertion portion. The calculated insertion portion shape is modeled and displayed on the display screen of the monitor 25. By setting the virtual points in this way, data interpolation for the subsequent calculation of the shape of the insertion portion becomes easy.

Even when bent into a loop with a small curvature as shown in FIGS. 9 and 10, the insertion portion shape is accurately calculated and displayed as if a large number of source coils were actually incorporated. be able to.

Further, in the present embodiment, the processing for setting the virtual source coil so as to be arranged so as to satisfy the appropriate condition between the adjacent source coils is performed by software to detect the insertion portion shape and Since it is displayed, it can be applied to existing devices by changing the software. Therefore, by replacing the shape detection processing program of the existing apparatus with that of the present embodiment, it becomes possible to perform shape detection and shape display with high accuracy.

Further, the probe 15 arranged in the insertion portion 7
Since it is not necessary to increase the number of source coils in, there is an advantage that the probe 15 becomes complicated, the number of signal lines does not need to be increased, and the configuration on the drive means side does not need to be changed. That is, the insertion portion 7 has a simple structure.
The shape can be detected with high accuracy and the shape can be displayed.

In the above description, the source coil 14i is arranged on the insertion portion 7 side as a magnetic field generating element for generating a magnetic field, and the coil unit 23 outside the body has a sense coil 22j as a magnetic field detecting element for detecting a magnetic field. However, even if the sense coil is arranged on the side of the insertion section 7 and the source coil is arranged on the side of the coil unit 23, the virtual coil setting process is performed on the sense coil in the same manner (as if inside the insertion section 7). Thus, the shape of the insertion portion can be accurately detected (as if a large number of sense coils are arranged).

In addition to the above, the present embodiment has various functions as described below. As shown in FIG. 14, the endoscope shape detecting device of the present embodiment has five destinations of Japan, the United States, the United Kingdom, France, and Germany, and displays the date according to the destination. The display font and display symbol (display icon) settings are changed. Then, the date display is changed in association with the destination so that a display screen that is easy to see can be provided for each destination.

Further, in the present embodiment, the display color of the icon of the endoscope shown in FIG. 8 is determined by the source coil 14i arranged in the range displayed on the monitor 25 as shown in FIG. I chose In the conventional example, if the source coil 14i in the (endoscope) insertion portion is outside the detection range,
The icon of the endoscope was displayed in yellow, but if the insertion portion shape actually displayed on the monitor 25 is inside the detection range, it is displayed in gray and the displayed insertion portion shape and its correspondence There was a case that the display color was different from that of the icon.

Therefore, in order to eliminate the difference, the display color of the icon is determined depending on whether the portion of the source coil 14i displayed on the monitor 25 is inside the detection range. Therefore, as in the case shown in FIG.
The shape of the insertion part is inside the detection range and is displayed in gray.
Further, the icon is also displayed in green, which makes the display easy to understand. The same display method is used for the extracorporeal marker and the reference plate.

Further, in the conventional example, as a display color for displaying the shape of the insertion portion, when a certain coil position is outside the detection range, the coil position adjacent to the coil (actually within the detection range) is displayed. Also, since the calculation is performed using the coil position information outside the detection range when calculating the position, the coil position near the detection range may actually be displayed in yellow as well.

In the case of such a display, it is possible to display with a highly reliable display color, but it is difficult to grasp the boundary of the detection range as a disadvantage. Therefore, in the present embodiment,
The display color is determined by the interpolation point on the boundary of the detection range.

For example, when the scope model is calculated so as to straddle the boundary of the detection range as shown in FIG. 16, it is in the vicinity of the boundary among a plurality of interpolation points calculated from the coil positions indicated by the cross points. A section sandwiched between two interpolation points indicated by triangles is displayed as yellow out of the range, and an end portion of the triangle interpolation points is displayed as gray within the range. Therefore, it becomes easier to understand the boundary from the display color.

Further, in this embodiment, in order to make the movement of the scope model smooth as described below,
The buffering timing of position data was changed.

FIG. 17 shows the process of drawing the scope model by measuring the magnetic field. That is, after the position detection of step S22 is performed after the magnetic field measurement of step S21, the position-detected data is subjected to the data buffer process of fetching the data in step S23, and the buffered data is subjected to the digital filter process of step S24. ,
The scope drawing process of step S25 is performed.

In this case, as shown in FIG. 18, the coils of the insertion portion 7 are divided into three groups, a tip portion, an intermediate portion and a base end portion, and as shown in FIG. 19 (A), A, B, C, It is driven sequentially at the timing of A, ....

In this case, in order to generate a larger magnetic field in a limited frequency band, the driving is performed in time division. Then, as shown in FIG. 19B, buffering is performed at the timing when the data of one drive group is updated.

On the other hand, in the conventional example, as shown in FIG. 19 (C), buffering is performed at the timing at which all data is updated (that is, the timing rate three times that in FIG. 19 (B)). It was

As described above, in the present embodiment, the data update rate is tripled, and the output data of the digital filter in the subsequent stage is also updated at 1/3 time intervals, so the frame rate of the scope model is tripled. This makes it possible to draw with smooth movement.

Next, when the scope position memory is set when the reference plate 58 is used, it is set so that the positional relationship between the scope model and the apparatus main body can be easily grasped, and a display screen (scope model) that is easy to see can be provided. Explain what you have done.

FIG. 20 shows a state in which the main body device 21 and the bed 4 on which the patient lies are seen from above, and the left side is usually the head side of the patient. The boundary between the outside of the body and the inside of the body (displayed on the monitor 25) is defined by a plane, called a cut surface, and the outside of the cut surface is hidden. The setting of the existing cut surface differs depending on the connection state of the reference plate 58. The -1 plane in FIG. 20 is the unconnected cut plane, and the -1 plane is the cut plane during connection.

The scope position has a function of translating the existing cut plane position (in the left-right direction in FIG. 20) by using the extracorporeal marker 57, and translates to the -2 / -2 plane when ON.

Further, the reference plate 58 and the extracorporeal marker 57
The cut surface is set as shown in the table of FIG. Note that "valid" and "invalid" in the table indicate the states of functions using the detected positions of the reference plate 58 and the extracorporeal marker 57 that are being connected.

Here, the characteristic setting is that when the reference plate 58 is connected, the direction perpendicular to the surface set by the reference plate 58 is the cut surface, and conventionally, the reference is made by turning on the extracorporeal marker 57. The cut plane has a different orientation from the plane of the cut plane-1 set by the plate 58, but in the present embodiment, (when the reference plate 58 is connected, the cut plane The function of the reference plate 58 was made easy to understand by setting it like the cut surface -2 that was translated so as to pass through the extracorporeal marker 57 (without changing the orientation).

In the present embodiment, the grayscale display method of the scope model adopted in the conventional example is changed. In other words, in the conventional example, since the full scale of light and dark is assigned to the range where the scope model is displayed, for example, a part may be extremely bright or dark even in a state close to a plane. there were. Therefore, the following gray scale settings are adopted.

Normal source coil sections that do not correspond to the caution display of the scope model are colored in gray scale. At this time, the gray brightness is set to be dark from the front of the screen in the direction of the screen depth (Z direction of the visual field system coordinates). The following equation is used to calculate the rate of change γ.

Γ = sin θ / 2 × (Cmax−Cmin) + Cmin θ = (Z−Zmin) / (Zmax−Zmin) × π−
π / 2 Cmin: RGB value of the darkest gray (256 gradations) Cmax: RGB value of the brightest gray (256 gradations) Zmin: z on the deepest side of the screen displayed in gray scale
Coordinate Zmax: z on the foremost side of the screen displayed in gray scale
Coordinates The gray scale was determined according to the scope range actually detected in the conventional example, but by changing it to be determined by a fixed value such as the specified detection range, without displaying an extreme gray scale, Made it easier to understand the three-dimensional shape from the gray scale display.

Next, when the scope model to be displayed on the monitor 25 is displayed, the automatic centering function can effectively prevent the scope model from moving off the screen to provide an easy-to-see display screen. In the embodiment, the operation for changing the horizontal direction of the screen is further performed (for example, when the scope position is OFF, the reference plate connection /
At the time of removal), the automatic centering function is always performed so that the scope model can be more effectively prevented from coming off the screen.

The normal centering function is shown in FIG.
As shown in (A), when the tip of the scope model moves to the upper display area side along the horizontal line of the display screen, the tip of the scope model at that time is adjusted to be the center in the horizontal direction of the screen. Display the model.

In FIG. 22A, for example, the tip of the scope model intersects a horizontal line below the screen which is a cut surface on the left side of the horizontal center below the screen, and the position is set to the center position. The display is done.

When the cut surface is moved by the extracorporeal marker 57 in this state, the movement causes the cut surface to move as shown in FIG.
For example, it is assumed that the position is set to a position indicated by a two-dot chain line. When displayed in that state, the upper part of the scope model is displayed from the position of the cut surface, but the scope model position intersecting the cut surface in that case is displaced from the horizontal center position at the bottom of the screen, so automatic centering The scope model position corrected by the function and intersecting the cut surface as shown in FIG. 22B is set and displayed at the horizontal center position at the bottom of the screen.

In this state, when the use of the extracorporeal marker 57 is stopped (the extracorporeal marker 57 is removed or the scope position is turned off), the position of the cut surface of the scope when the extracorporeal marker 57 is not used. Automatic centering is activated so that the bottom of the model screen is in the horizontal center position. That is, the display is as shown by the solid line in FIG.

On the other hand, in the conventional example, as shown by the chain double-dashed line in FIG. 22 (C), the state in FIG. 22 (B) is simply displayed in a state of being shifted to the position before the movement of the cut surface. That is,
In the conventional example, the scope model position intersecting the horizontal line under the screen is displaced from its center position.

In this case also, in this embodiment, the automatic centering function is performed to maintain the state in which the center position is reset as shown by the solid line and the scope model is displayed. Although the case of the extracorporeal marker 57 has been described here, the function of automatic centering is performed even when connecting / withdrawing the reference plate. In this way, it is possible to more effectively prevent the scope model from coming off the screen.

In the above description, the coil unit 23
The number of the sense coils 22j arranged inside is 12, but the number is not limited to this, and it may be set to a plurality other than that, for example, 16 pieces.

[Additional Notes] 1. A plurality of one of the magnetic field generation element and the magnetic field detection element is arranged inside the flexible endoscope insertion portion to be inserted into the subject, and the other element is arranged outside the subject, The shape of the endoscope insertion portion is estimated by detecting the position of each of the one element disposed inside the endoscope insertion portion by the detection means using the position data of the other element. In the endoscope shape detecting device for displaying by means of display means, based on the output of the detecting means, virtual elements are arranged between the detected one element so as to satisfy a predetermined condition, and the one element An endoscope shape detecting apparatus, comprising: a data interpolating means for interpolating data between adjacent virtual elements by using the position data of the virtual element. 2. In Appendix 1, the data interpolation means is formed by software.

[0113]

As described above, according to the endoscope shape detecting apparatus of the present invention, one of the plurality of magnetic field generating elements and the plurality of magnetic field detecting elements is provided inside the endoscope insertion portion to be inserted into the subject. Element is arranged, the other element is arranged outside the subject, and the position of one element arranged inside the endoscope insertion part is detected by the detecting means using the position data of the other element. By doing so, in the endoscope shape detection device that estimates the shape of the endoscope insertion portion and displays the shape on the display means, based on the output of the detection means, a virtual image is generated between the detected one element. Various elements are arranged, and data interpolation means for performing data interpolation between the one element using the position data of the virtual element is provided, so that the endoscope insertion portion is bent with a small curvature. If it is actually placed as if The bent shape in as you increase the number of elements to accurately detect, can display its shape.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an endoscope system equipped with an embodiment of the present invention.

FIG. 2 is a view showing an arrangement example of sense coils incorporated in a coil unit in a reference coordinate system.

FIG. 3 is a block diagram showing the configuration of the endoscope shape detection device in FIG.

FIG. 4 is a diagram showing a configuration of a detection block and a host processor of FIG. 3 and a configuration of a connection detection mechanism.

FIG. 5 is a block diagram showing a configuration of detection blocks and the like.

FIG. 6 is a timing chart of the operation of a 2-port memory or the like.

FIG. 7 is a diagram showing a configuration of a detection device and an operation panel.

FIG. 8 is a diagram showing a connection display function when an endoscope or the like is connected to the detection device.

FIG. 9 is a diagram showing how interpolation processing is performed when a virtual point is not set and when a virtual point is set.

FIG. 10 is a diagram showing the shape of the insertion portion displayed in the case of FIG. 9;

FIG. 11 is a basic explanatory diagram of virtual point setting processing.

FIG. 12 is a flowchart showing the contents of virtual point setting processing.

13 is an explanatory diagram of a virtual point setting process of FIG.

FIG. 14 is a diagram showing the contents in which the date display is changed depending on the destination.

FIG. 15 is an explanatory diagram in which the icon is also displayed in green when the source coil portion in the insertion portion displayed on the monitor is within the detection range.

FIG. 16 is a diagram showing a state in which the display color is determined depending on whether or not the interpolation point of the source coil is inside the detection range.

FIG. 17 is a flowchart showing processing from magnetic field measurement to scope model drawing.

FIG. 18 is a diagram showing a state in which the insertion portion is divided into three regions.

FIG. 19 is an explanatory diagram in which data is buffered at shorter intervals as compared with the conventional example.

FIG. 20 is a diagram showing how a cut surface is set by a reference plate or the like.

FIG. 21 is a diagram showing detailed setting contents in the case of FIG. 20.

FIG. 22 is an explanatory view of the action of performing automatic centering even when the scope position is OFF.

[Explanation of symbols]

1 ... Endoscope system 2 ... Endoscopic device 3 ... Endoscope shape detection device 4 ... bed 5 ... Patient 6 ... Electronic endoscope 7 ... insertion part 8 ... Operation part 10 ... Video processor 12 ... Forceps channel 14i ... Source coil 15 ... probe 16 ... Cable 21 ... Detection device 23 ... Coil unit 22j ... sense coil 24 ... Operation panel 26 ... Drive block 27 ... Detection block 28 ... Host processor 31 ... Source coil drive circuit 32 ... CPU 32a ... Judgment means 32b ... Display color selection means 32c ... Virtual point setting processing means 51 ... Menu button 52 ... Reset button 53 ... View angle / select button 54 ... Zoom button 57 ... Extracorporeal marker 58 ... Reference plate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akira Taniguchi             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. (72) Inventor Fumiyuki Onoda             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. F term (reference) 2F063 AA04 AA41 BC08 CA09 DA01                       DA05 DD06 GA01 LA30 MA05                       NA07 PA10                 4C061 GG22 HH51 NN10

Claims (3)

[Claims] 1. A plurality of one of a magnetic field generating element and a magnetic field detecting element is arranged inside a flexible endoscope insertion portion to be inserted into a subject, and a plurality of other elements are provided outside the subject. The shape of the endoscope insertion part is estimated by detecting the position of each of the one element arranged inside the endoscope insertion part by the detection means using the position data of the other element. Then, in the endoscope shape detection device for displaying the shape on the display means, based on the output of the detection means, a virtual element is arranged between the detected one element, and between the one element. An endoscope shape detecting apparatus, comprising data interpolation means for performing data interpolation by using the position data of the virtual element for data interpolation. 2. The endoscope shape detecting device according to claim 1, wherein the one element disposed inside the endoscope insertion portion is a magnetic field generating element. 3. The endoscope shape according to claim 1, further comprising: an estimating unit that estimates a placement position of the virtual element using a condition such as distance information in which the one element is placed. Detection device.