DE102007051862A1 - Endoscope capsule for use by medical service personnel i.e. physician, has set of force sensors determining magnetic force exerted on capsule by external magnetic field, and magnetic element with magnetizing device - Google Patents

Abstract

The capsule (1) has a set of force sensors (6) for determining magnetic force exerted on the capsule by an external magnetic field. A cylindrical-shaped magnetic element i.e. permanent magnet (4), with a magnetizing device is elastically supported in a housing (2) of the capsule and mechanically connected with the housing over the force sensors. Cylindrical axis of the element corresponds with a longitudinal axis (L) of the capsule. The force sensors are arranged at a front side (5) of the permanent magnet symmetrically to the cylindrical axis. Independent claims are also included for the following: (1) a capsule endoscope system comprising a guidance magnetic system (2) a method for guiding an endoscope capsule.

Description

The Invention relates to an endoscope capsule for a capsule endoscope, a capsule endoscope with such an endoscope capsule and method for operating the same and capsule endoscope systems.

One previously known magnetically-guided capsule endoscopy device (MGCE device) has an externally applied Magnetic field guided endoscope capsule on. Includes the capsule is a magnetic dipole moment. This is usually done by Installation of a permanent magnet high remanence realized in the capsule.

A control panel for controlling the endoscope capsule is typically operated manually by the desired capsule movements by means of joysticks by the medical operating personnel (a doctor or possibly medical support staff) are given. These manual defaults - such as "drive faster forward / backward" or "swivel left / right" are always made relative to the image captured by the capsule, or relative to a capsule-fixed coordinate system. These manual settings are to be translated into suitable nominal input variables for the capsule-moving guide magnet system. In the case of a magnet system consisting of a rigidly arranged electromagnet, the nominal input variables are typically the nominal coil currents. In the case of a magnetic system consisting of movable permanent magnets, the desired input variables are typically the desired positions (including time derivatives) of the permanent magnets. For the translation of the manual settings in target input quantities for the magnet system, a 5D capsule position measuring system is used according to the prior art. A suitable 5D position measuring system is off WO 2005/120345 A2 known. From the knowledge of the current position and at least the fifth-dimensional position of the capsule, it can be calculated which setpoint forces and torques (in the coordinate system of the magnet system) correspond to the manual settings of the operating personnel. A disadvantage for a position measuring system of the type WO 2005/120345 however, it is comparatively expensive.

It is therefore the object of the present invention, a possibility for comparatively simple and inexpensive magnetically guided To provide capsule endoscopy.

These The object is achieved by means of an endoscope capsule according to claim 1, a A capsule endoscope according to claim 9, a method according to claim 10, a A capsule endoscope system according to claim 11, a method according to claim 12 and a capsule endoscope system according to claim 13.

The Endoscope capsule has at least one force sensor for detecting one by means of an external magnetic field on the endoscope capsule applied force ("magnetic force") on. By the term "magnetic force" should also be magnetically applied to the endoscope capsule Torques are understood.

Instead of So to use a capsule position measuring system that has the absolute Measures capsule position and orientation and uses to guide It is suggested that the capsule is the direction (and possibly also Strength) of the magnetic force acting on the permanent magnet captured in the body-fixed coordinate system of the capsule, and these values are used for capsule management. It can In particular, the magnet system is typically used spatially extended so that the generated by him Magnetic fields and / or magnetic field gradients over a respect of the maneuvering work volume relatively wide (partial) range extend, so a relatively large area with approximately same magnetic properties generated. If the capsule in this (sub) area of the working volume, it can be maneuvered magnetically even when the exact capsule position (i.e. h., the values of the center of gravity coordinates) in the coordinate system of the guide magnet is not known (or are).

Thereby In particular, the actual, external position measuring system can after the prior art with transmit and receive coils, preamplifiers etc. omitted, which saves considerable costs.

Under Force sensor is understood to be any sensor from which get a force measurement - also indirectly leaves, z. B. a pressure sensor, strain gauges etc.

to easy guidance and low-noise force measurement has the endoscope capsule preferably has a magnetic element, in particular permanent magnets, with a magnetization direction known with respect to the capsule on, wherein the magnetic element, at least for small deflections elastic stored in a housing of the endoscope capsule and over at least one force sensor with the housing mechanically connected is.

To the simple construction and easy guidance and evaluation the magnetic element is preferably a permanent magnet with a cylindrical basic shape, its cylinder axis substantially with a longitudinal axis the endoscope capsule coincides or lies parallel to it.

The magnetization direction of the permanent magnet having a cylindrical basic shape preferably coincides with the cylinder axis. If However, the capsule should be rotatable about its longitudinal axis, the permanent magnet is advantageous magnetized diametrically to its cylinder axis.

to simple evaluation are at least three, preferably three or four, force sensors symmetrically at one end face of the permanent magnet arranged to the cylinder axis.

to more precise guidance taking into account lateral forces is at least one other force sensor on a peripheral side of Permanent magnets arranged. At least two more are preferred Force sensors arranged on a peripheral side of the permanent magnet, more preferably at an angle of about 90 ° to each other the cylinder axis is twisted.

In order to the Endoskopkasel elastic, but firmly stored, preferably, it has at least one biasing element for biasing the permanent magnet on. Particularly preferred is an endoscope capsule in which the biasing element having an elastic foam and / or a compression spring.

The Task is also solved by means of a capsule endoscope with such an endoscope capsule.

The The object is also achieved by means of a method for guiding the endoscope capsule, wherein a predetermined by an operator target force on the endoscope capsule with appropriate force measurement data from the Endoscopic capsule compared and based on the comparison Guide magnetic field is adjusted.

The Task is also solved by means of a capsule endoscope system for carrying out the method with a guide magnet system, a receiver for the endoscope capsule (in raw or processed form) an operating unit (manual input device, eg joystick) for presetting a capsule movement and a guide magnet control unit, wherein the guide magnet control unit is arranged is a predetermined by the operating unit target force on the Endoscope capsule with appropriate force measurement data from the endoscope capsule to compare and on the basis of comparison one from the guide magnet system adapted magnetic field.

The The object is also achieved by means of a method for guiding the endoscope capsule in which one of an operator predetermined Target specification (target position, target velocity or nominal force, etc.) the endoscope capsule with a corre sponding, from the force measurement data compared to the endoscope capsule derived position or force and based on the comparison, a guiding magnetic field is adjusted.

specially may be the magnetic force measured in the capsule-fixed coordinate system directly compared with the target force of the manual setting of the operating unit and so the magnet system can be controlled.

The Task is also solved by means of a capsule endoscope system with a guide magnet system for guiding the Endoscope capsule, a receiver for the force measurement data the endoscope capsule according to one of the preceding claims, a Operating unit for specifying a capsule movement and a guide magnet control unit, wherein the guide magnet control unit is set up to a predetermined by the operating unit target position of the endoscope capsule with a corresponding one of the force measurement data from the endoscope capsule to compare the derived position of the endoscope capsule and on the Basis of comparison generated by the guide magnet system Adapt the magnetic field.

specially For example, a controller of the magnet system may be an observation unit for determination of the capsule orientation (and possibly also the capsule center of gravity position) contained in the coordinate system of the magnet system, wherein the observation unit on the capsule orientation (and possibly the capsule center of gravity position) from the time courses of the measured magnetic force (or magnetic force direction) and the desired input variables of the magnet system.

A Determination of the current capsule orientation or position (not the absolute position) in the coordinate system of the guide magnet system, so that in this coordinate system is clear what z. B. "forward driving "or" turning left "means, for example be done so that at some point through the guide magnet system a magnetic field with in place the endoscope capsule defined direction is applied. From the force response The endoscope capsule then allows the position relative to determine applied magnetic field. Preferably, this orientation before use ("initialization"). To be precise Control, it is particularly advantageous if this orientation is repeated at predetermined intervals, for example the influence of a drift or unknown parameters or influencing factors on the capsule movement, such. As friction forces to reduce.

in the The invention is based on an embodiment described in more detail schematically.

1 shows a cross-sectional view in side view of an endoscope capsule;

2 shows the endoscope capsule 1 as a cross-sectional view in front view along a section axis AA 1 ;

3 shows a structure of a system 1 for endoscope control.

1 shows an endoscope capsule 1 with a about a longitudinal axis L substantially rotationally symmetrical housing 2 , The capsule 1 or the housing 2 has, for example, a total diameter of 11 mm and a length of 26 mm and is thus swallowable.

In the case 2 are vertically two solid partitions 3 retracted, which is a space (without reference numeral) for receiving a cylindrical or circular disk-shaped permanent magnet 4 create. The magnetization direction of the permanent magnet 4 is, as indicated by the arrow, parallel to or on the longitudinal axis L. Such a permanent magnet 4 is magnetically not about its cylinder axis - and thus essentially not about the longitudinal axis L - rotatable, but only about the two perpendicular axes.

The permanent magnet 4 is at the front end 5 mechanically with the housing 2 via spatially distributed pressure sensors in the form of pressure / force converters 6 connected. A pressure / force converter 6 has a diameter of 1-2 mm, in particular about 1.5 mm, and a thickness of 0.3 mm. Through the pressure sensors 6 Both the strength of the magnetic force in the magnetization direction (= capsule longitudinal direction L) and the magnetic torques about the two permanent magnet axes can be determined.

On the other sides, namely the rear end 7 and the peripheral side 8th is the permanent magnet 4 from an elastic material, here: foam 9 , surrounded as a biasing element. Due to the (small) mobility of the permanent magnet 4 becomes an actuation of the pressure / force converter 6 allows. In particular by means of biasing the pressure / force transducer 6 With about half the maximum load is achieved that compressive and tensile forces of size up to half of the maximum force can be measured.

Furthermore, two further pressure sensors (not shown) are on the side of the permanent magnet 4 arranged offset by 90 ° to each other, so that also lateral forces on the permanent magnet 4 can be measured in horizontal and vertical image direction.

A front room 10 has a transparent dome 11 on which of a camera recorded there 12 Here sketchy with lens 13 and camera chip 14 , z. B. a CCD chip, is granted a view to the outside. The optical axis of the camera 12 essentially corresponds to the longitudinal axis L of the endoscope capsule 1 ; the two permanent magnet axes thus correspond to the horizontal and the vertical image axis of the capsule camera 14 ,

A back room 15 surrounds, for example, a self-sufficient power supply (battery (s), rechargeable battery (s), etc.) and a high-frequency transmitter for transmitting corresponding signals to the outside (without images). The measuring signals from the miniature pressure transducers 6 are sent either in raw or preprocessed form via the RF transmitter from the capsule. The RF transmitter may be identical to that over which video images are transmitted. The pressure transducer signals (with their low information content compared to video images) can be sent quasi-continuously over the RF transmitter. Alternatively, the readings are attached to each video image and sent out (at a rate of 2 Hz, 4 Hz or more).

Alternatively or additionally, the permanent magnet can be movably mounted in the space by means of one or more springs, e.g. B. by means of a between the rear end 7 and the adjacent partition 3 arranged compression spring. The compression spring may for example be a (slightly) curved leaf spring.

Instead of the pressure / force converters are alternative or additional all other, accessible to the expert force transducer suitable for use, for. B. strain gauges.

2 shows the endoscope capsule 1 as a sectional view in front view along an axis AA 1 , The four pressure / force converters 6 are symmetrical about the longitudinal axis L in front of the permanent magnet 4 arranged.

Of course the present invention is not limited to the embodiment shown limited.

3 shows a structure of a capsule endoscope system 101 for endoscope control with a guide magnet or guide magnet system 102 for magnetic guidance of the endoscope capsule 1 out 1 and 2 , The guide magnet 102 is for operation with power amplifiers 103 and a cooling system 104 connected. The cooling system 104 and the guide magnet 102 are also used for thermal control with a thermal management system 105 connected. With the guiding mag 102 In addition, a force measuring signal receivers are connected ger 108 a position measuring system and an image data receiver 109 and optionally a magnetic field measuring unit 106 and a patient table control unit 107 ,

The central control unit is a guide magnet control unit 110 , The guide magnet control unit 110 is connected to the power amplifiers via digital and / or analog data interfaces 103 , the thermal management system 105 , Magnetic field measuring unit 106 , the patient table control unit 107 , the force measuring signal receiver 108 , the image data receiver 109 as well as the image processing and display unit 118 , the central data storage unit 120 and the graphical user interface 122 , The guide magnet control unit 110 also has an operator input unit or operating unit 124 on or is coupled with this.

By means of the control unit 110 becomes the endoscope system 101 controlled, in particular a current guide through the guide magnet 102 which can also consist of several, in particular independently controllable, individual magnets as a magnet system. For this purpose, force readings of the endoscope capsule by means of the RF receiver 108 received and to the control unit 110 forwarded. The control unit 110 is further adapted from a comparison of associated Kapselkraftmesswerten and Bedieneinheitssollwerte a corresponding adjustment of the current or the currents through the guide magnet 102 implement, for. B. by an adaptation of the control signals to the power amplifier 103 ,

Of course the present invention is not limited to the embodiment shown limited.

Instead of the highly remanent permanent magnet can, for. B. a current-carrying Coil may be used, although this is not usually beneficial is because - apart from energy consumption - that Relationship between magnetic torque and weight worse with an electromagnet.

One Magnetic system of mechanically movable electromagnets, for example also conceivable.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 2005/120345 A2 [0003]
• WO 2005/120345 [0003]

Claims (13)

Endoscope capsule ( 1 ), comprising at least one force sensor ( 6 ) for determining a magnetic force exerted on the endoscope capsule by means of an external magnetic field. Endoscope capsule ( 1 ) according to claim 1, comprising a magnetic element, in particular permanent magnet ( 4 ), with a magnetization direction known with respect to the capsule, wherein the magnetic element ( 4 ) elastically in a housing ( 2 ) of the endoscope capsule ( 1 ) and via the at least one force sensor ( 6 ) with the housing ( 2 ) is mechanically connected. Endoscope capsule ( 1 ) according to claim 1, wherein the magnetic element is a permanent magnet ( 4 ) having a cylindrical basic shape whose cylinder axis substantially coincides with a longitudinal axis (L) of the endoscope capsule ( 1 ) matches. Endoscope capsule ( 1 ) according to claim 3, wherein at least three force sensors ( 6 ) on an end face of the permanent magnet ( 4 ) are arranged symmetrically to the cylinder axis. Endoscope capsule ( 1 ) according to claim 4, in which at least one further force sensor is arranged on a peripheral side ( 8th ) of the permanent magnet ( 4 ) is arranged. Endoscope capsule ( 1 ) according to claim 5, wherein at least two further force sensors on a peripheral side ( 8th ) of the permanent magnet ( 4 ) are arranged, preferably arranged rotated at an angle of 90 ° about the cylinder axis. Endoscope capsule ( 1 ) according to one of claims 2 to 6, comprising at least one biasing element for biasing the permanent magnet ( 4 ). Endoscope capsule ( 1 ) according to claim 7, in which the biasing element comprises an elastic foam ( 9 ) or a compression spring. Capsule endoscope with an endoscope capsule ( 1 ) according to any one of the preceding claims. Method for guiding the endoscope capsule ( 1 ) according to one of claims 1 to 8, in which a prescribable desired force on the endoscope capsule ( 1 ) with corresponding force measurement data from the endoscope capsule ( 1 ) and adjusting a pilot magnetic field based on the comparison. Capsule endoscope system ( 101 ) with a guide magnet system ( 102 ), a recipient ( 108 ) for the force measurement data of the endoscope capsule ( 1 ), a control unit ( 124 ) for specifying a capsule movement and a guide magnet control unit ( 110 ), wherein the guide magnet control unit ( 110 ) is adapted to a predetermined target force on the endoscope capsule ( 1 ) with corresponding force measurement data from the endoscope capsule ( 1 ) and, on the basis of the comparison, one of the guide magnet system ( 102 ) to adjust the magnetic field generated. Method for guiding the endoscope capsule ( 1 ) according to one of claims 1 to 8, in which a predetermined by an operator predetermined force on the endoscope capsule ( 1 ) with a corresponding, from the force measurement data from the endoscope capsule ( 1 ) and a guide magnetic field is adjusted based on the comparison. Capsule endoscope system with a guide magnet system for guiding the endoscope capsule ( 1 ), a receiver for the force measurement data of the endoscope capsule according to one of the preceding claims, an operating unit for specifying a capsule movement and a guide magnet control unit, wherein the guide magnet control unit is adapted to a predefined by the operation unit target position of the endoscope capsule with a corresponding Compare the force measurement data derived from the endoscope capsule position of the endoscope capsule and adapt based on the comparison of a magnetic field generated by the guide magnet system.