Positioning system for an applicator and positioning method for an applicator

A positioning system for an applicator includes a glove for being used for a diagnosis of the affected part, a mark body provided on the glove, an applicator for being inserted into a living body, and an energy emitter provided on the applicator for supplying energy to the living body. The positioning system further includes a sensor provided on the applicator which is capable of detecting the distance to the mark body, a control apparatus for discriminating an optimum position of the applicator based on the distance between the sensor and the mark body while the mark body is disposed in the proximity of the affected part based on a diagnosis performed using the glove, and a display apparatus for displaying a result of the discrimination by the control apparatus.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a positioning system and a positioning method for an applicator which can present an optimum position of an applicator inserted in a living body to an operator in order to treat an affected part of the patient.

2. Description of the Prior Art

As one of treating methods for a disease in a living body such as a tumor or a hypertrophy, a method is known wherein energy is applied to the affected part to cause coagulation or sphacelation of the cells at the affected part. One of measures for applying energy is an applicator for heating the affected part, for example, by laser heating.

In the treatment, if some other sound part of the living body than the affected part is laser heated, then even the sound part is damaged. On the other hand, if the affected part is not laser heated appropriately, then a sufficient treatment effect may not be achieved. Accordingly, the positioning of the applicator is very significant in the treatment and must be conducted carefully.

Various techniques have conventionally been proposed for the positioning of an applicator.

Prior Art (1)

A technique is available wherein a probe having an ultrasonic transmission/reception section provided thereon together with an applicator is inserted into a body cavity. The probe can form an intracorporeal sectional image by transmitting and receiving an ultrasonic wave in the body cavity. Accordingly, a user such as a doctor can position the applicator while observing the intracorporeal sectional image (refer to, for example, Japanese Patent Laid-Open No. 2000-271235).

Prior Art (2)

Another technique is available wherein a probe having an endoscope built therein together with an applicator is inserted into a body cavity. A user can position the applicator while observing the internal surface of a living body by means of the endoscope via an opening provided in the probe (refer to Japanese Patent Laid-Open No. Hei 11-318928 or U.S. Pat. No. 6,383,183).

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a positioning system and a positioning method for an applicator which can simplify a treatment system without the necessity for an image production apparatus, can reduce the burden on the patient and can make it possible to position the applicator readily at an optimum position.

(1) According to an aspect of the present invention, there is provided a positioning system for an applicator, comprising a diagnosing implement to diagnose of a living body including an affected part, a mark body provided on said diagnosing implement, an applicator, an energy emitter provided in said applicator and emitting energy to the living body, at least one sensor provided on said applicator for outputting a signal corresponding to a distance between the sensor and said mark body, and an indicator which indicate a preferable position of said applicator based on the output of said sensor while said mark body is disposed in the proximity of the affected part through a diagnosis performed using said diagnosing implement.

With the positioning system for an applicator, since the mark body is provided on the diagnosing implement, while a doctor or the like diagnoses the affected part of a patient using the diagnosing implement, it can dispose the mark body using the same as a mark representative of the position of the affected part. Since the distance to the mark body can be detected by means of the sensor, the optimum position of the applicator can be discriminated based on the detected distance. Since the information detected by the sensor is presented by means of the presentation means, the user can position the applicator readily at the affected part in accordance with the presentation.

(2) According to another aspect of the present invention, there is provided a positioning system for an applicator, comprising an applicator, an energy emitter provided in said applicator and emitting energy to a living body, a mark body provided on said applicator, a diagnosing implement to diagnose of a living body including an affected part, a sensor provided on said diagnosing implement and capable of detecting a distance between the sensor and said mark body, and an indicator which indicates a preferable position of said applicator based on an output of said sensor while said sensor is disposed in the proximity of the affected part through the diagnosis performed using said diagnosing implement.

With the positioning system for an applicator, since the sensor is provided on the diagnosing implement, while a doctor or the like diagnoses the affected part of a patient using the diagnosing implement, it can dispose the sensor at the position of the affected part. Since the sensor can detect the distance to the mark body provided on the applicator, the optimum position of the applicator can be discriminated based on the detected distance. Since the information detected by the sensor is presented by means of the presentation means, the user can position the applicator readily at the affected part in accordance with the presentation.

(3) According to a further aspect of the present invention, there is provided a positioning method for an applicator, comprising the steps of diagnosing a living body including an affected part with a diagnosing implement which has a mark body, specifying the position of the affected part and disposing the mark body in the proximity of the affected part, inserting an applicator having a sensor capable of detecting the distance between the sensor and said mark body into the living body, and positioning said applicator in response to information indicated corresponding to an output of said sensor.

With the positioning method for an applicator, since the mark body is provided on the diagnosing implement, while a doctor or the like diagnoses the affected part of a patient using the diagnosing implement, it can dispose the mark body using the same as a mark representative of the position of the affected part. Since the distance to the mark body can be detected by means of the sensor, the optimum position of the applicator can be discriminated based on the detected distance. Since the information detected by the sensor is presented by means of presentation means, the user can position the applicator readily at the affected part in accordance with the presentation.

(4) According to a still further aspect of the present invention, there is provided a positioning method for an applicator, comprising the steps of diagnosing a living body including an affected part with a diagnosing implement which has a sensor specifying the position of the affected part and disposing the sensor in the proximity of the affected part, inserting an applicator having a mark body into a living body, detecting the distance between of said sensor and the mark body, and positioning said applicator in response to information detected by said sensor.

With the positioning system for an applicator, since the sensor is provided on the diagnosing implement, while a doctor or the like diagnoses the affected part of a patient using the diagnosing implement, it can dispose the sensor at the position of the affected part. Since the sensor can detect the distance to the mark body provided on the applicator, the optimum position of the applicator can be discriminated based on the detected distance. Since the information detected by the sensor is presented by means of presentation means, the user can position the applicator readily at the affected part in accordance with the presentation.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a schematic view showing a positioning system for an applicator. It is to be noted that various components shown inFIG. 1are represented individually in a simplified shape and in a suitable size so as to facilitate understanding of the applicator positioning system.

Referring toFIG. 1, the positioning system1for an applicator (hereinafter referred to simply as system1) includes a glove2(diagnosing implement) for being used for a diagnosis of an affected part of a patient, a mark body3provided on the glove2, an applicator4for being inserted into a living body to treat the living body, and an energy emitter5provided on the applicator4for emitting energy to the living body. The system1further includes two sensors6provided on the applicator4in a substantially neighboring relationship to the energy emitter5for detecting the distance to the mark body3, a control apparatus70(processor) for discriminating an optimum position of the applicator4based on the distance between the sensor6and the mark body3while the mark body3is disposed in the proximity of the affected part based on a diagnosis performed using the glove2, and a display apparatus8for displaying a result of the discrimination by the control apparatus70. The control apparatus70and the display apparatus8may be referred to generally as indicator7.

The glove2is formed so thin that it may not degrade a delicate feeling of a finger and formed so tough that it may not be broken during treatment. For example, natural rubber latex is used as the material for the glove2. The glove2is in a sterilized state in order to prevent an otherwise possible infectious disease.

Also the mark body3is in a sterilized state similarly. The mark body3may be in any form only if it can be detected by the sensor6. For example, where the sensor6is an elastic wave sensor preferably an ultrasonic wave sensor6, the mark body3is formed from an ultrasonic wave reflecting element such as a metal piece. The ultrasonic wave reflecting member is a body having an acoustic impedance different from that of a living body and may otherwise be the air or the like other than a metal piece. Where the air is used as the mark body3, the air is filled in and attached together with a balloon to the glove2.

The attached position of the mark body3preferably corresponds to the tip of a finger of the glove2. Where the mark body3is provided at the top of a finger, while the user keeps a posture in which it has confirmed the affected part through palpation, it can dispose the mark body3substantially at the middle of the affected part. The mark body3is formed small in size and in thickness so that it may not degrade the feeling of a finger of the user upon palpation. The mark body3is preferably formed in a substantially disk-like shape free from any angle.

The applicator4has an insertion portion43formed long in a tapering fashion toward the distal end thereof and has a holding portion44provided on a proximal end side thereof and having a shape with which the holding portion44can be held readily. The insertion portion43has the energy emitter5built therein and has a window41provided therein for radiating energy toward the living body therethrough. The energy emitter5is connected to an energy generator9through an energy route42extending along the inside of the insertion portion43. The energy generator9generates energy in accordance with an instruction by the user to start a diagnosis. Here, the energy generated by the energy generator9is an electromagnetic wave such as a laser beam, a microwave or a radio frequency wave and is supplied from the energy emitter5to the affected part to heat and treat the affected part.

Two sensors6are provided in the proximity of the energy emitter5. The sensors6are disposed at positions spaced equally from the center of the energy emitter5and the window41in a juxtaposed relationship on a straight line parallel to the lengthwise direction of the insertion portion43. The sensors6are preferably provided on an outer face of the insertion portion43in order to detect the mark body3provided on the glove2. The sensors6are connected to the control apparatus70through signal lines not shown which extend through the inside of the insertion portion43. Also the display apparatus8is connected to the control apparatus70. The control apparatus70includes a storage section71for storing predetermined information.

Now, description is given of how the system1is used for treatment by the user with reference toFIGS. 2 to 4. The following description relates to a case wherein treatment of prostatic hypertrophy is conducted.

FIG. 2is a flow chart illustrating a flow of operation of the user when it specifies an affected part of a patient;FIG. 3is a flow chart illustrating a flow of operation of the user when it confirms the optimum position of the applicator4; andFIG. 4is a schematic view illustrating a manner in which the user treats the affected part.

First, the user would wear the glove2on which the mark body3is provided in preparation for the treatment (step S11). Then, the user would fill the rectum with physiological saline or sterilized water, insert the finger on which the mark body3is provided (for example, the middle finger) into the rectum and start the palpation of the affected part (step S12). Here, in the case of the prostatic hypertrophy, the most swollen portion of the spherical prostate is the center of the affected part.

The user would specify the most swollen portion of the prostate as the affected part through the palpation (step S13) and dispose the mark body3at the position of the specified affected part (step S14). Here, the user would closely contact the mark body3with the wall of the rectum on the affected part side. This is intended to facilitate propagation of the ultrasonic wave. Since the palpation of the user is used, the most swollen portion of the prostate can be specified readily.

While the user keeps the state wherein it inserts the middle finger in the rectum and disposes the mark body3at the affected part, it would insert the insertion portion43of the applicator4into the living body (step S21). Here, since the treatment of the prostatic hypertrophy is to be performed, the applicator4is inserted into the urethra.

The user would operate the applicator4in accordance with a display of the display apparatus8to position the applicator4(step S22). The user would discriminate whether or not a display of an optimum position is given on the display apparatus8(step S23). If a display of an optimum position is not given (step S23: NO), then the positioning is continued. If a display of an optimum position is given (step S23: YES), then the user would fix the applicator4at the position and start treatment of the affected part (step S24). Here, to start treatment particularly signifies to turn the switch of the energy generator9ON to instruct the system1to supply the energy. The prostate surrounds the urethra as seen inFIG. 4. In order to treat the prostatic hypertrophy part, the applicator4is rotated successively by an arbitrary angle to supply the energy to the prostatic hypertrophy part.

Now, action of the system1is described with reference toFIGS. 5 to 9.

FIG. 5is a flow chart illustrating a flow of operation when the system1discriminates the optimum position of the applicator;FIG. 6is a flow chart illustrating a flow of operation when the system1detects a positional displacement;FIG. 7is a view illustrating a manner wherein the mark body3is detected by two sensors6;FIG. 8is a similar view but illustrating a manner wherein it is discriminated whether or not the applicator is at the optimum position; andFIG. 9is a view showing a screen displayed on the display apparatus8. The procedure illustrated inFIG. 5indicates operation after the processes at steps S11to S21illustrated inFIGS. 2 and 3are completed. Further, in the following description, the sensor6is an ultrasonic wave sensor6, and the mark body3is a metal piece.

The system1starts oscillation of an ultrasonic wave having directivity by means of the sensors6as seen inFIG. 7(step S31). If the mark body3is present at a position at which the ultrasonic wave hits on the same, then since the ultrasonic wave is reflected by the mark body3, the sensors6receive the reflected ultrasonic wave and output reception signals to the control apparatus70(step S32). The control apparatus70measures the periods of time required to receive the ultrasonic wave after oscillated and calculates the distances to the mark body3based on the measured periods of time (step S33).

The control apparatus70discriminates whether or not the distances to the mark body3calculated with regard to the two sensors6are substantially equal to each other (step S34). If they are not equal to each other (step S34: NO), then the processes at the steps beginning with step S31are repeated. If the distances (Da, Db) are substantially equal to each other (step S34: YES) as seen inFIG. 8, then the control apparatus70discriminates that the applicator4is now at its optimum position and controls the display apparatus8to display that the applicator4is at the optimum position (step S35). The control apparatus70stores the distances between the sensors6and the mark body3when it is discriminated that the applicator4is at its optimum position into the built-in storage section71(step S36). Then, the processing advances to the procedure illustrated inFIG. 6.

The control apparatus70discriminates whether or not an energy supplying instruction is inputted by the user (step S41). The control apparatus70waits until an energy supplying instruction is inputted (step S41: NO). If such an instruction is inputted (step S41: YES), then the control apparatus70starts counting of the period of time for the energy supply (step S42). Simultaneously, the energy emitter5starts supply of energy to the affected part (step S43).

Further, the system1periodically oscillates ultrasonic waves by means of the two sensors6(step S44) and receives the ultrasonic waves reflected by and returned from the mark body3(step S45). The control apparatus70measures the periods of time before the reception after the oscillation of the ultrasonic wave is started and then calculates the distances to the mark body3(step S46). Further, the control apparatus70calculates, based on the calculated distances, a positional displacement from the position then to the optimum position of the applicator4stored in the storage section71(step S47).

The control apparatus70discriminates whether or not the positional displacement is within an allowable range (step S48). If the positional displacement is within the allowable range (step S48: YES), then the control apparatus70refers to the count value of the period of time of the energy supply started at step S42to discriminate whether or not a period of time for supply set as a period of time necessary for the intended treatment elapses (step S49). If the preset time period does not elapse (step S49: NO), then the processing returns to step S44while the control apparatus70continues the supply of energy. However, if the preset time period elapses based on the count value of the supply time period (step S49: YES), then the control apparatus70stops the energy supply (step S50) and controls the display apparatus8to display that the treatment is completed (step S51), thereby ending the treatment process for the affected part.

On the other hand, if the positional displacement of the applicator4from the optimum position is outside the allowable range (step S48: NO), then the display apparatus8issues alarming sound and displays a warning display on the screen thereof as seen inFIG. 9(step S52). In response to the warning, the user can correct the positional displacement. The control apparatus70discriminates whether or not 3 seconds or more elapse after the positional displacement occurs (step S53). Thus, the control apparatus70repeats the detection of the positional displacement at steps S44to48for the period of time of 3 seconds (step S53: NO). If the positional displacement is corrected within the period, then the processing advances from step S48to step S49.

However, if 3 seconds or more elapse after the occurrence of the positional displacement (step S53: YES)), then the energy emitter5interrupts the supply of energy (step S54) and the treatment is interrupted (step S55). Here, it is assumed that the period of time after the positional displacement occurs is measured after the control apparatus70discriminates at step S48that the positional displacement is outside the allowable range. Then, the display apparatus8displays that the treatment is interrupted (step S56) to notify the user of the interruption and then waits until the applicator4is returned to the appropriate position and the treatment is resumed.

Now, the foundation on which it is discriminated at step S34that the applicator4is at its optimum position when the distances to the mark body3detected by the two sensors6are equal to each other is described with reference toFIG. 8.

InFIG. 8, an imaginary chain line V is indicated at a position at which the mark body3is disposed. As described hereinabove, the two sensors6are disposed at distances equal to each other from the center of the energy emitter5. In other words, the center of the energy emitter5is positioned at the center between the two sensors6.

The sensor6on the left side inFIG. 8is represented as sensor6awhile the sensor6on the right side is represented as sensor6b. The distances to the mark body3calculated based on transmission and reception of ultrasonic waves by the sensors6aand6bare represented as distance Da and distance Db, respectively. Further, a point at which a straight line interconnecting the sensors6aand6band the imaginary chain line V intersect with each other is represented as intersecting point I.

When the distance Da and the distance Db are not equal to each other, the triangle including the three points of the sensor6a, sensor6band mark body3do not make an isosceles triangle. Accordingly, since the distance from the sensor6ato the intersecting point I and the distance from the sensor6bto the intersecting point I are not equal to each other, the center of the energy emitter5and the mark body3are displaced in position from each other.

On the other hand, where the distance Da and the distance Db are equal to each other, the triangle including the three points of the sensor6a, sensor6band mark body3is an isosceles triangle. Accordingly, since the distance from the sensor6ato the intersecting point I and the distance from the sensor6bto the intersecting point I are equal to each other, the center of the energy emitter5and the mark body3coincide in position with each other. In other words, the positions of the center of the energy emitter5and the center of the affected part coincide with each other. In this instance, the energy emitter5can irradiate energy radially from the center of the affected part. Consequently, energy can be supplied sufficiently to the affected part.

From the reason described, it can be determined that the applicator4is at its optimum position where the distance Da and the distance Db are equal to each other.

It is to be noted that the allowable range for the discrimination of the positional displacement at step S48is determined in advance from the point of view of whether or not the supply of energy in the state of the positional displacement has a seriously bad influence on the living body.

As described above, according to the system1of the present embodiment, since the mark body3is provided on the glove2, the user can dispose the mark body3as a mark indicative of the position of the affected part while the user performs palpation using the glove2. Since the distances to the mark body3can be detected by means of the sensors6, the optimum position of the applicator4can be discriminated based on the detected distances. Since a result of the discrimination is displayed by the display apparatus8, the user can position the applicator4at the affected part readily in accordance with the display.

Further, since the sensor6oscillates an ultrasonic wave and besides receives it, the configuration of the applicator4is simplified and the diameter of the applicator4can be reduced. Consequently, the burden on the patient can be reduced. Furthermore, since the mark body3has an acoustic impedance different from that of a living body, it is detected with certainty by means of the sensors6.

Further, since the two sensors6are provided, if the distances from the sensors6to the mark body3are calculated, then when the distances coincide with each other, the position of the applicator4then can be discriminated decisively as the optimum position.

Since the display apparatus8displays it by sound and an image that the applicator4is positioned at its optimum position, the user can confirm the optimum position of the applicator4using the auditory sense and the visual sense thereof, respectively. It is to be noted that the presentation to the user may be based on either one of an image and sound.

Further, since the display apparatus8displays a warning by sound and an image also when the position of the applicator4is displaced from the optimum position, the user can confirm the warning using the auditory sense and the visual sense thereof, respectively. Although a technique that an expansion portion which can be expanded by an extracorporeal operation is provided and hooked intracorporeally in order to fix the position of the applicator4is conventionally available, a defect of the technique can be overcome. In particular, since a patient has some individual difference, the applicator4cannot necessarily be fixed by the expansion portion of the conventional technique, and even if some positional displacement occurs with the applicator4, this cannot be detected and there is the possibility that the normal living body may be damaged. However, according to the present embodiment, although the applicator4is not fixed by a special mechanism, since a positional displacement can be detected, a sufficient treatment effect can be achieved without damaging the normal living body. It is to be noted that the presentation of the warning may be performed by one of an image and sound.

Further, since the mark body3can be sterilized, it does not give rise to an infectious disease and can be introduced into the living body in safety. Since the mark body3is thin and small and is formed in a substantially round shape free from an angle so that it may not have an influence on the palpation, the user can perform the palpation without degradation of the delicate feeling of the fingertip.

Furthermore, the embodiment described above is suitable for treatment of the prostatic hypertrophy because the applicator4is inserted in the urethra and the sensor6is disposed in the rectum.

Now, particular operations or different operations of and modifications to the components described above in connection with the embodiment are described.

(Modification to the Indicator7)

The indicator7may be modified such that it uses only sound as the presentation method thereof and calculates a difference between the distances between the two sensors6and the mark body3from outputs of the two sensors6and then performs presentation by high/low and/or strong/weak of sound based on the difference. Where the modified configuration is adopted, since the sound changes (for example, the sound volume decreases) upon insertion of the applicator4and the direction of the change of the sound reverses (for example, the sound volume increases) when the applicator4passes its optimum position, the user can discriminate the position upon the change as the optimum position. Thus, the user can move back the excessively inserted applicator4and position the applicator4at the optimum position.

At step S52described above, the system1performs such warning display as seen inFIG. 9. According to the warning display, also the error from the optimum position of the applicator4stored at step S36can be displayed. For example, where there is an error of +3 mm in the insertion direction of the applicator4, that there is a displacement of +3 mm can be displayed together with a display of displacement as seen inFIG. 9. Here, the error is calculated based on the distance to the mark body3determined from the times required for back and forth travel of ultrasonic waves between the two sensors6and the mark body3.

Details are described with reference toFIG. 8. If the position of the applicator4is displaced from the optimum position, then the distance Da from the sensor6ato the mark body3and the distance Db from the sensor6bto the mark body3become different from each other. The distances from the sensors6aand6bto the intersecting point I can be calculated based on the values of the distances Da and Db at this time, respectively. The error can be calculated by comparing the distance values then with the distance from the sensor6ato the intersecting point I when the applicator4is at the optimum position.

Here, upon warning display, it is discriminated which one of the distances from the sensor6aon the distal end side and the sensor6bon the proximal end side is greater to discriminate whether the applicator4is displaced to the distal end side or the proximal end side, and a result of the discrimination is displayed. More particularly, when the distance between the mark body3and the sensor6aon the distal end side is greater than the distance between the mark body3and the sensor6bon the proximal end side, it is discriminated that the applicator4is displaced to the distal end side, and a display for urging the user to draw the applicator4to the proximal end side is displayed. On the contrary, when the distance between the mark body3and the sensor6aon the distal end side is smaller, it is discriminated that the applicator4is displaced to the proximal end side, and a display for urging the user to push the applicator4to the distal end side is displayed.

(Modifications to the Sensors)

The embodiment described above involves two sensors6. However, the number of sensors6may be greater than two or otherwise be one. The accuracy can be raised as the number of sensors6increases. Also where the number of sensors6is greater than two, the optimum position of the applicator4can be determined by calculating the distance to the mark body3similarly as in the case where the number of sensors6is two. Therefore, overlapping description of the determination of an optimum position of the applicator4is omitted herein to avoid redundancy.

A technique for discriminating an optimum position of the applicator4where the number of sensors6is one is described. The sensor6is attached to the applicator4at a position corresponding to the center of the energy emitter5. In particular, the sensor6and the center of the energy emitter5are juxtaposed on a straight line in a radial direction of the applicator4. Here, it is assumed that the mark body3is disposed at the center of the affected part by the user in accordance with the processes up to step S14described hereinabove.

As described above, the sensor6oscillates an ultrasonic wave to the mark body3and measures the period of time before it receives the ultrasonic wave reflected from the mark body3to calculate the distance to the mark body3. This is also possible where the number of sensors6is one, that is, only one sensor6is involved. However, different from the case wherein two sensors6are involved, it is impossible to discriminate an optimum position from the fact that the distances to the mark body3are equal to each other.

Here, the control apparatus70successively detects the distance to the mark body3using the single sensor6and stores the thus detected distance values into the storage section71so that they can be compared with each other. As the insertion of the applicator4proceeds, initially the distance to the mark body3detected exhibits a decrease, but after the mark body3is passed, the detected distance now exhibits an increase. Accordingly, the position of the applicator4at which the distance begins to increase is the optimum position of the applicator4. Based on this, the control apparatus70can successively measure the distance between the mark body3and the sensor6and compare the measured distance values, and can discriminate the position at which the sensor6is positioned nearest to the mark body3as the optimum position of the applicator4.

<Voltage Detection by the Sensor>

Also it is possible for each of the sensors6to detect the intensity of an ultrasonic wave upon reception of the ultrasonic wave as a voltage. In this instance, even if the back and forth travel time of the ultrasonic wave between the sensor6and the mark body3is not measured as described above, the optimum position of the applicator4can be discriminated. A capacity of the sensor6for detecting a voltage of an ultrasonic wave is described under the following particular conditions.

(1) A PZT (lead zirconate titanate) oscillator having a high gain at 15 MHz is used as the sensor6.

(2) A metal chip (flat plate of stainless steel) having a diameter of 5 mm is used as the mark body3.

(3) The mark body3of (2) is adhered to the glove2and water is infused into between the inside of the glove2and the hand.

(4) The glove2is disposed so that the mark body3may be positioned at a distance of 22 mm from the sensor6. The position of the glove2is fixed. It is to be noted that the distance of 22 mm is an average distance from the rectum to the urethra among patients of the prostatic hypertrophy.

Under the conditions, the sensor6was moved parallelly with respect to the mark body3. The parallel movement was performed in a certain one direction (X direction: for example, the direction of the longitudinal axis of the insertion portion43) and a perpendicular direction (Y direction). At this time, a result illustrated inFIG. 10was obtained.FIG. 10is a view illustrating a relationship between the relative distance between the sensor6and the mark body3and the voltage detected by the sensor6. The axis of abscissa indicates the relative distance between the sensor6and the mark body3, and the axis of ordinate indicates the voltage. InFIG. 10, the relationship when the sensor6was moved in the X direction is indicated by a solid line, and the relationship when the sensor6was moved in the Y direction is indicated by a broken line.

As seen fromFIG. 10, as the relative distance between the sensor6and the mark body3decreases, the voltage detected exhibits a sudden increase. Particularly where the sensor6is moved in the Y direction, the voltage variation is significant and can be discriminated on the order of 1 mm in the distance of movement. On the other hand, it is considered that the reason why such a significant voltage variation is not obtained where the sensor6is moved in the X direction depends upon the posture of the sensor6or unevenness of the wave front of the ultrasonic wave transmitted.

In this manner, also where the sensor6which can detect an ultrasonic wave as a voltage is used, it is considered based on the variation of the output voltage of the sensor6that the position at which the voltage value exhibits its peak value is the optimum position of the applicator4.

Accordingly, the sensor6can be applied to the system1for the applicator4.

A magnetic sensor can be used in place of the ultrasonic wave sensor6. As the magnetic sensor, a magnetic sensor which can measure a magnetic field with a high degree of accuracy such as an MI sensor or an MR sensor is preferably used. Where a magnetic sensor is used, a magnetic material such as a magnet or an induction coil is used as the mark body3. The magnetic sensor can measure the distance to the mark body3based on a magnetic field generated by the magnetic material or the induction coil.

<Form of the Sensor>

FIG. 11is a view showing a modified form of the sensor6.

In the embodiment described hereinabove, the sensors6are disposed at one point on a circumference of the applicator4. However, the ultrasonic sensors can be provided along an outer periphery of the applicator4of a cylindrical shape as shown inFIG. 11. Where a PZT oscillator is used, a plurality of ultrasonic wave sensors60are disposed in an array on the applicator4. The ultrasonic wave sensors60can be formed in an elongated shape using a piezoelectric polymer such as PVDF as a material therefor and disposed around the applicator4.

Where the ultrasonic wave sensors are provided along the outer periphery of the applicator4in this manner, even if the applicator4is rotated around its axis for treatment of the affected part, ultrasonic waves reflected from the mark body3can be received by the ultrasonic wave sensors60, and consequently, the optimum position of the applicator4can be discriminated. This is particularly effective when the prostate is treated from the urethra over the range of 360° around the urethra as in the treatment of the prostatic hypertrophy.

(Discrimination Time Before Interruption of Treatment)

The period of time, at step S53of the embodiment described above, before interruption of the treatment is discriminated after a positional displacement occurs is set to 3 seconds. However, the period of time may be set to any period only if no damage to the living body occurs even if energy is supplied in response to a positional displacement.

The energy emitter5may supply energy not only in the form of a magnetic waveform but also in the form of an acoustic wave or electric current to the affected part. This makes it possible to treat the affected part using the energy in the form of an acoustic wave or electric current.

In the embodiment described above, the positioning system1for the applicator4is used for the treatment of the prostatic hypertrophy. However, it can be applied not only to the treatment of the prostatic hypertrophy but also to the treatment of any other part. For example, in the treatment of the esophagi, it is possible to use the glove2to palpate the affected part extracorporeally from the throat, the breast or the belly to dispose the mark body3at the position of the affected part and then insert the applicator4from the mouth and present the optimum position of the applicator4to the user in such a manner as described hereinabove.

(Replacement of the Mark Body and the Sensors)

In the embodiment described above, the mark body3is provided on the glove2while the sensors6are provided on the applicator4. However, it is otherwise possible to replace the mark body3and the sensor6with each other such that the sensors6are provided on the glove2and the mark body3is provided on the applicator4. The arrangement in this instance is different from the embodiment described hereinabove in addition to the replacement of the positions at which the mark body3and the sensors6are provided only in that the control apparatus70and the display apparatus8are connected to the glove2side. Therefore, detailed description of the arrangement is omitted herein to avoid redundancy.

The user would use the glove2with the sensors6to palpate the affected part of the patient to dispose the sensors6in the proximity of the affected part. Consequently, the positioning system for the applicator4detects the mark body3provided on the applicator4by means of the sensors6, discriminates the optimum position of the applicator4based on the detected distances and displays the optimum position on the display apparatus8.

Accordingly, also with the present modified system, the user can position the applicator4readily at the affected part in accordance with the display of the display apparatus8.

(Effects of the Invention)

Since the mark body is provided on the diagnosing implement, while a doctor or the like palpates the affected part of a patient using the diagnosing implement, it can dispose the mark body using the same as a mark representative of the position of the affected part. Since the distance to the mark body can be detected by means of the sensor, the optimum position of the applicator can be discriminated based on the detected distance. Since a result of the discrimination is presented by means of the presentation means, the user can position the applicator readily at the affected part in accordance with the presentation.

The mark body can be detected readily by means of the elastic wave sensor or the magnetic sensor.

Since the ultrasonic wave sensor oscillates an ultrasonic wave and besides receives the ultrasonic wave, the applicator is simplified in configuration and the diameter thereof can be reduced. Consequently, the burden on the patient can be reduced. Further, since the mark body has an acoustic impedance different from that of the living body, it can be detected with certainty by the ultrasonic wave sensor.

Also where the applicator is rotated to perform treatment of the affected part, the mark body can be detected by means of the ultrasonic wave sensor, and the optimum position of the applicator can be discriminated.

The single sensor can be used to successively measure the distance between the mark body and the sensor and compare the measured distance values, and when the sensor is positioned nearest to the mark body, the optimum position of the applicator can be discriminated readily.

Where two sensors are provided, when the distances between the sensors and the mark body coincide with each other, the position of the applicator then can be determined decisively as the optimum position of the applicator.

The optimum position of the applicator can be confirmed using at least one of the visual sense and the auditory sense.

When the position of the applicator is displaced from the optimum position, since a warning is presented by an image or by sound, the warning can be confirmed using at least one of the visual sense and the auditory sense.

Energy of any one of an acoustic wave, an electromagnetic wave and electric current can be supplied to the living body to treat the affected part.

Since the mark body can be sterilized, it can be inserted into the living body without the possibility of an infectious disease.

The prostatic hypertrophy can be treated.

Since the mark body is formed in a shape and a size which have no influence on the palpation, the user can perform palpation and so forth without suffering from any degradation of the feeling of the fingertip.

Since the sensor is provided on the diagnosing implement, while a doctor or the like palpates the affected part of a patient using the diagnosing implement, it can dispose the sensor at the position of the affected part. Since the sensor can detect the distance to the mark body provided on the applicator, the optimum position of the applicator can be discriminated based on the detected distance. Since a result of the discrimination is presented by means of the presentation means, the user can position the applicator readily at the affected part in accordance with the presentation.

The entire disclosure of Japanese Patent Application No. 2003-087932 filed on Mar. 27, 2003 including specification, claims, drawings, and summary are incorporated herein by reference in its entirety.