DE102007023059A1 - Miniaturized device - Google Patents

Abstract

The invention relates to a miniaturized device (1) with a probe (5) and with a first sensor (S1), which determines a first position information, and with a second sensor (S2), which determines a second position information, wherein the first sensor ( S1) and the second sensor (S2) are independent of each other.

Description

The The invention relates to a miniaturized device.

One Such miniaturized device is z. B. as a technical Endoscope (cavity viewing device) executed and allows, for example, the technical examination of hard-to-reach cavities or components in engines, machinery and vehicles as well as aircraft, plants and structures without the need for disassembly or to carry out demolition work.

In the US 2001/0049497 A1 is a miniaturized device is known, which is designed as a medical endoscope. The known endoscope is used to treat internal bleeding or to close open cuts in the body of a living organism and is equipped with a clip. The clip has a pair of pliers which is mounted in a guide associated with the medical endoscope. To clamp the internal bleeding or to close the incision, the clip is moved out of the guide of the medical endoscope, wherein after activation of the clip, the tissue enclosed by the forceps clamped and the bleeding is stopped or the incision wound is closed.

Furthermore, it is off DE 100 12 560 A1 a designed as a robotic endoscope miniaturized device for performing medical endoscopy known. The known robot endoscope has a plurality of segments which are interconnected via a flexible link connections. By means of a plurality of flexible linear propulsion elements obliquely laterally circumferentially around each segment with respect to the longitudinal axis of the robot endoscope and pneumatically or hydraulically pressure driven, the robotic endoscope is moved within a human or animal hollow organ.

From the DE 101 42 253 C1 is a miniaturized medical device known, which is designed as a magnetically navigable endoscopy capsule (Endoroboter). In the housing of the known Endoroboters a bar magnet is arranged, which interacts with defined magnetic fields of an external magnetic coil system, which also includes a magnetic field control system, whereby the Endoroboter is navigable in the cavity of a patient. The magnetic force acting on the endorobot depends on the position of the magnetic dipole to the external magnetic field. Only if this is known, the magnetic force can be optimally dosed.

The from the DE 101 42 253 C1 known Endoroboter can not be held in a predetermined location with the help of magnetic fields levitating. The reason for this is that according to the Earnshaw Theorem (cf. Transactions of the Cambridge Philosophical Society, Vol. 7, 1842, pages 97 to 120 ) any such configuration is unstable in at least one direction. Free-floating is thus never stable, but requires constant stabilization and application of correction forces that can not be applied without knowing the position of the miniaturized medical device (endoscopy capsule, catheter).

The The problem described above arises to a particular extent then, if with the miniaturized medical device interventional procedures, such as biopsies. In such interventional intervention, it is necessary the miniaturized medical device very precisely at one certain position, including fine deflections exactly must be recorded.

In the EP 1 543 766 A1 a system for in vivo positioning of an endoscopy capsule is known, which may also be designed as a magnetically navigable endorobot. In this system, it is possible to associate an image acquisition of an intra-capsule camera with the respective spatial position (location and orientation) of the endoscopy capsule or the endo-robot during this image acquisition

The system according to the EP 1 543 766 A1 comprises a magnetic field generator which is located outside a body and generates a strongly varying alternating magnetic field in the area in which the endoscopy capsule or the endo-robot moves and takes pictures (gradient field, quadrupole field). The frequency of this alternating magnetic field is of the order of a few kHz, so that this alternating field penetrates the human body almost without interference. In order to make the endoscopy capsule or the endorobot nevertheless sensitive to this alternating field, the endoscopy capsule or the endorobot is equipped with a sensor coil which is dimensioned such that the magnetic alternating field is detected by this sensor coil. The sensor coil has five or six degrees of freedom, which are measured as a function of the spatially strongly varying alternating field. The measurement defines the location and orientation of the capsule-internal sensor coil in the alternating field and thus the position of the endoscopy capsule or the endo-robot relative to the body or relative to the surrounding space.

The unique relationship between the position (location and orientation) of the sensor coil and the anatomy of the patient is established by a conventional registration procedure. It will be The user selects anatomical landmarks (bones, organs) on the patient, which can also be identified in the anatomical images of different imaging modalities that support the measurement (eg computer tomography, C-arm, ultrasound, magnetic resonance tomography). An external navigation unit computationally links the signal of the capsule-internal sensor coil with the coordinate system defined by the registration. The registration method on which this system is based is relatively complicated because of the necessary anatomical landmarks in the body of the patient. In addition, the theoretical accuracy of the position determination of about 1 mm in a coordinate system defined by the registry can not be practically achieved. Practically, only an orienting accuracy (depending on the patient and examination area) of a few centimeters is given because there is a time-dependent deviation between the anatomy at the time of registration and the time of the current sensor coil measurement because of the always given organ movement.

• 1. Vorgabe eines Sollwertes für eine Bewegung des Endroboters an das Magnetfeld-Regelsystem,
• 2. Aufnahme eines ersten Bildes von einem Zielgebiet vor der Bewegung des Endroboters,
• 3. Einstellung des Magnetfeldes durch das Magnetfeld-Regelsystem, wodurch die Bewegung des Endroboters entsprechend dem Sollwert ausgeführt wird,
• 4. Aufnahme eines zweiten Bildes von dem Zielgebiet nach der Bewegung des Endroboters,
• 5. Bestimmung eines Istwertes für die Bewegung des Endroboters aus dem ersten und dem zweiten Bild,
• 6. Ermittlung der Abweichung des Istwertes von einem durch das Magnetfeld-Regelsystem vorgebbaren Sollwert,
• 7. Rückmeldung der Abweichung an das Magnetfeld-Regelsystem,
• 8. Berechnung eines optimierten Magnetfeldes aus der Abweichung.

The DE 10 2005 032 577 A1 describes a method for determining the position of an endo-robot that can be navigated in a magnetic field that is generated by an external magnetic system that can be regulated by a magnetic field control system. The known method comprises the following method steps:

• 1. Specification of a desired value for a movement of the end robot to the magnetic field control system,
• 2. taking a first image of a target area before moving the end robot,
• 3. adjustment of the magnetic field by the magnetic field control system, whereby the movement of the end robot is carried out according to the target value,
• 4. taking a second image of the target area after the movement of the end robot,
• 5. determination of an actual value for the movement of the end robot from the first and the second image,
• 6. determination of the deviation of the actual value from a setpoint that can be predetermined by the magnetic field control system,
• 7. feedback of the deviation to the magnetic field control system,
• 8. Calculation of an optimized magnetic field from the deviation.

This Procedure only performs a relative and therefore not particularly exact position determination for the endorobot of two recorded images, namely from a first image from a target area before the movement of the endorobot and from one second picture of this target area after the movement of the endorobot.

By the RU 2 278 356 C1 is an arrangement for determining angular positions in moving objects (submarines, ships, aircraft) known. The known arrangement comprises a 3D magnetometer (magnetic field strength meter) with a magnetic sensor and four 3D accelerometers (accelerometers).

In the US 5,237,753 and the DE 41 06 932 A1 Sensors are known with which each of the current angle (inclination) can be measured relative to the direction of gravity.

From the WO 2005/120345 A2 is a position detection system for capsule endoscopes known. The position sensing system includes a sensor coil that detects the induced magnetic field generated by a magnetic induction coil. The position detection system further comprises a control coil, by which the magnetization is controlled in an induction coil such that the magnetic field in the operating area from at least three different directions acts on the capsule endoscope.

In the WO 2006/064972 A1 discloses a position detection system for a capsule endoscope. The position detecting system includes a magnetic induction coil, a control coil that generates an alternating magnetic field, and magnetic sensors, a frequency detection unit, and a position analysis unit.

From the EP 1 723 898 A1 For example, a position sensing system for a capsular medical device is known. The capsular medical device comprises a main body insertable into a living body. In the main body, a coil (capsule coil) is arranged, which generates a resonant circuit. Arranged around the living body are coils (control coils) which generate an alternating magnetic field and induce a magnetic field in the capsule coil. Further, the position detecting system includes a plurality of coils that detect the magnitude of an induced magnetic field generated in the capsule coil by the control coil.

In the US 2004/0207389 A1 a method for the detection and compensation of eddy currents is known. The method comprises determining an undisturbed phase for at least a first and a second position signal, wherein inter alia a ratio between the amplitude of the first position signal at a first frequency and the amplitude of the second position signal at a second frequency is determined. Furthermore, in this method, the ratio between the eddy current phase of the first position signal and the eddy current phase of the second position signal be Right. By means of this method, magnetic positioning can be improved in image-supported medical applications, since the position determination determines the eddy current generated by the electrically conductive object.

By the US 6,553,326 B1 is a method for detecting errors in a magnetic position (location, orientation) of a probe in an external magnetic field known. The method includes a number of measured values of magnetic field intensity that depend on the location and orientation of a probe inserted in a human body. The position (location, orientation) of the probe is determined from an extremum of an optimization function. The optimization function depends on the differences between the measured magnetic field strength and the magnetic field strength determined from a model. If the determined difference lies in a preselected value range for which a disturbance of the magnetic field is defined, then this disturbance of the magnetic field is eliminated by appropriate measures.

task The present invention is a miniaturized device to create whose probe is accurately determined in their position.

The The object is achieved by a miniaturized Device solved according to claim 1. advantageous Embodiments of the invention are each the subject of further Claims.

The The miniaturized device according to claim 1 comprises a probe and a first sensor that determines a first position information, and a second sensor, which determines a second position information, wherein the first sensor and the second sensor are independent of one another are.

at the miniaturized device according to the invention is from two independent sensors each position information determined. From these two independently determined Position information is then the exact position of the probe determined.

The two independent sensors can be spatially in different places both within the miniaturized device as well as on the outside or in the outside wall be arranged in the miniaturized device, wherein within the miniaturized device arranged sensors the preferred Variant represents.

in the The scope of the invention may be the miniaturized device for example, a technical device, for example technical endoscope, or a medical device, z. As endoscope, endoscopy capsule or Endoroboter act. A Endoscopy capsule becomes passive, ie after taking it alone due peristalsis through the gastrointestinal tract. In contrast, acts an endo robot is a miniaturized medical one Device that uses an internal magnetic element via an external magnetic field is actively navigable. At the present Invention is thus under the term "Endoroboter" a magnetic To understand endoscopy capsule, also called magnetic capsule endoscope referred to as.

at The miniaturized device includes the first position information preferably information about the location of the Son de (information z. In Cartesian coordinates) and the second position information preferably information about the solid angle of the probe (Orientation in 3D space). With the location of the probe and the solid angle the probe at this location has complete information about the position of the probe in front.

in the Under the invention, the first sensor and the second Detect sensor according to the same physical principle. Farther The invention also includes embodiments in which the first sensor and the second sensor according to different physical principles detect.

According to one preferred embodiment of the miniaturized device is the first sensor as a 3D Hall sensor and the second sensor as 3D gravity direction sensor formed.

at this embodiment of the invention miniaturized device measures the 3D Hall sensor (first Sensor) the flux density of a basic magnetic field that uses is to use the known amplitude of the magnetic flux the place the probe (first position information) in a cavity (e.g. in a hollow organ of a mammal or in a cavity a plant). The 3D gravitational direction sensor (second Sensor) measures relative to a fixed with respect to the probe Axis (eg longitudinal, transverse or vertical axis) the direction of gravity, whereby the solid angle of the probe (second position information) can be determined is.

Of the 3D gravitational direction sensor can in this case various configurations exhibit.

So For example, the 3D gravity direction sensor may include at least one hollow sphere with a freely movable and optically detectable liquid and at least one optical detector for detecting the position of comprise optically detectable liquid.

Furthermore, it is possible to 3D Gravitati onsrichtungssensor perform as an acceleration sensor.

According to one In another variant, the 3D gravity direction sensor comprises at least a mechanical element under the influence of gravity a deformation occurs that is detectable.

To In another advantageous embodiment, the 3D gravity direction sensor calculates its required information from data of an analytical model and / or determine its required information from a selective detection of amplitude and flux density of a magnetic field.

According to a further preferred embodiment of the miniaturized device, the first sensor is designed as a 3D Hall sensor and the second sensor as a gyroscope. The arrangement of a gyroscope in a miniaturized medical device, which is preferably designed as an endoscopy capsule or as an endorobot is from the DE 10 2005 031 652 A1 known. With regard to the 3D Hall sensor (first sensor), reference is made to the above statements. Together with the position information provided by the 3D Hall sensor, so that the position can be accurately determined.

The Gyroscope provides information on changes to the miniaturized device the solid angle of the probe (second position information). by virtue of exact positioning can be done with an endoscopy capsule, which is moved solely by peristalsis Movements in the stomach and intestine or lack of movement in the gastrointestinal tract be reliably recognized. For example, diarrhea, Constipation, obstruction or obturation reliably detectable. The information collected by the gyroscope here can z. B. in at least one device-internal storage unit erbespeichert and / or at least one deviceinter ne Sending unit transmitted to a device external evaluation become.

at an endo robot that navigates through an external magnetic field can be detected by the rotations detected by the gyroscope or small translations additionally capturing the absolute position in the gastrointestinal tract, which may cause one required position correction is even more accurate feasible. Especially if the endorobot levitates in the external magnetic field can be kept without "wiggling", the permanent Stabilization, which is the application of corrective forces required to be performed much more accurately.

The Information from the gyroscope are thus used to determine the location of the miniaturized medical device to correct. This can be done either in the miniaturized medical device even if this is about internal possibilities (own drive) for the position correction has. Alternatively can the location of the miniaturized medical device externally, for example via an external magnetic field, the is generated by a navigation magnet can be corrected.

Independently of it, whether the movement of the miniaturized medical device through the peristalsis of the gastrointestinal tract (endoscopy capsule) or by a manual movement (endoscope) or by an internal device Drive or by a device external magnetic field (Endoroboter) takes place, the position change by a suitable visual and / or acoustic signal are displayed. Will the Movement of the miniaturized medical device of causes an operator, then this can correct corrections of the miniaturized medical device.

The preferably three-axis gyroscope, for example, as a gyro gyroscope, as CVG (Coriolis Vibratory Gyroscope) or as optical gyroscope, z. B. laser gyroscope.

at a laser gyroscope becomes a laser beam via a mirror arrangement divided into two sub-beams, both of which go through a ring and be detected by a detector. Change during a rotation of the system the path lengths of the two partial beams to the detector, causing a phase shift of the two partial beams relative comes to each other ("Sagnac Effect"). From this phase shift lets the rotation speed of the gyroscope and this in turn determines the solid angle of the probe.

such Miniaturized gyroscopes can be described, for example, as MEMS (micro-electro-mechanical Systems). This is how the SIGEM project deals with the Production of gyroscopes on the surface of conventional CMOS chips. This may in future be the gyroscope functionality into the already existing electronics (eg for image processing) to get integrated.

According to a likewise preferred embodiment of the miniaturized device, the first sensor and the second sensor are each designed as a 3D Hall sensor, wherein the two independent 3D Hall sensors are arranged spatially at different locations of the miniaturized device. In addition to the 3D magnetic flux (flux density of a magnetic basic field) from which the first position information is determined, the two 3D Hall sensors also detect the 3D dimension gnetflussgradienten, from which the second position information is determined.

following is a schematically illustrated embodiment of a miniaturized device according to the invention explained in detail in the drawing, but without to be limited to it. The only figure shows that miniaturized device that runs as an endo robot is, in a longitudinal section.

In the drawing is with 1 a possible within the scope of the invention embodiment of a magnetically navigable endoscopy capsule (magnetic capsule endoscope Endoroboter) be distinguished. The endorobot 1 has a housing 2 made of biocompatible material resistant to gastrointestinal digestive secretions.

The endorobot 1 further comprises a magnetic element 3 in the illustrated embodiment, as perpendicular to the longitudinal axis of the housing 2 magnetized permanent magnet is executed. This allows the endo robot 1 be navigated from the outside by a magnetic field, by in 1 not shown external navigation magnet is generated. This magnetic field is usually a 6D base and gradient field generated in an examination area.

to Magnetic navigation of an endo robot are typically magnetic Flux densities of up to 100 mT and magnetic field gradients from to to 400 mT / m necessary. The values of the flux density gradients are currently about a factor of 10 above the typical Values for a magnetic resonance imaging system.

The endorobot 1 according to the invention comprises a first sensor S1, which determines a first position information, and a second sensor S2, which determines a second position information. The first sensor S1 and the second sensor S2 are independent of each other.

in the illustrated embodiment, the first sensor S1 formed as a 3D Hall sensor and the second sensor S2 as a 3D gravity direction sensor.

In this embodiment of the endo-robot 1 The 3D Hall sensor S1 measures the flux density of a basic magnetic field used to determine the location of the endorobot with the known amplitude of the magnetic flux 1 To determine (first position information) in a hollow organ of a mammal.

The 3D gravitational direction sensor S2 measures the direction of gravity relative to a probe fixed axis (for example, the longitudinal, transverse or vertical axis), whereby the solid angle of the Endoroboters 1 (second position information) can be determined.

In the illustrated embodiment, the 3D gravity direction sensor S2 comprises at least one mechanical element 4 in which, under the influence of gravity, a deformation occurs which is detectable.

The in 1 illustrated endo robot 1 further comprises a detector device 5 for recording medically relevant data. The detector device 5 includes in the illustrated embodiment, a lens 6 with a CCD chip behind it 7 , Through the lens 6 and the CCD chip 7 Images are taken from the environment, ie from the inner wall of the human or animal hollow organ. The endorobot 1 has this on its front a transparent dome 8th on. In the invention, instead of the CCD chip 7 Also, a CMOS device can be used.

in the Framework of the invention may alternatively or additionally Other sensor devices, such. B. sensor devices that a pH sensor, a pressure sensor or a sensor for detecting the Electrolyte concentration, be present.

The of the sensor device 5 detected medically relevant data are stored in an in-capsule memory unit 9 stored, optionally in an on-chip processor unit 10 processed and if required via an RF transmitter / RF receiver 11 with an antenna 12 given to an external receiver not shown in the drawing.

In the embodiment shown are via the antenna 12 also the first position information of the first sensor S1 and the second position information of the second sensor S2 given to the external receiver via the antenna 12 and the RF transmitter / receiver 11 can also provide external information and control commands to those in the endoscopy capsule 1 arranged processor unit 10 are given.

The data exchange within the endorobot 1 and with external devices (external storage device, external control device) via an I / O interface 13 in the illustrated embodiment of the processor unit 10 assigned.

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

• US 2001/0049497 A1 [0003]
• - DE 10012560 A1 [0004]
• - DE 10142253 C1 [0005, 0006]
• EP 1543766 A1 [0008, 0009]
• - DE 102005032577 A1 [0011]
• - RU 2278356 C1 [0013]
• - US 5237753 [0014]
• - DE 4106932 A1 [0014]
• WO 2005/120345 A2 [0015]
• WO 2006/064972 A1 [0016]
• - EP 1723898 A1 [0017]
• US 2004/0207389 A1 [0018]
• - US 6553326 B1 [0019]
• DE 102005031652 A1 [0035]

Cited non-patent literature

• "Transactions of the Cambridge Philosophical Society", Vol. 7, 1842, pages 97 to 120 [0006]

Claims (14)

Miniaturized device ( 1 ) with a probe ( 5 ) and with a first sensor (S1), which determines a first position information, and with a second sensor (S2), which determines a second position information, wherein the first sensor (S1) and the second sensor (S2) are independent of each other. Miniaturized device ( 1 ) according to claim 1, wherein the first position information contains information about the location of the probe and the second position information contains information about the solid angle of the probe ( 5 ). Miniaturized device ( 1 ) according to claim 1 or 2, wherein the first sensor (S1) and the second sensor (S2) detect according to the same physical principle. Miniaturized device ( 1 ) according to claim 1 or 2, wherein the first sensor ( 1 ) and the second sensor (S2) detect according to different physical principles. Miniaturized device ( 1 ) according to claim 1 or 2, wherein the first sensor (S1) is designed as a 3D Hall sensor and the second sensor (S2) as a 3D gravitational direction sensor. Miniaturized device ( 1 ) according to claim 1 or 2, wherein the first sensor is designed as a 3D Hall sensor and the second sensor as a gyroscope. Miniaturized device ( 1 ) according to claim 1 or 2, wherein the first sensor is designed as a 3D Hall sensor and the second sensor as a 3D Hall sensor. Miniaturized device ( 1 ) according to claim 5, wherein the 3D gravity direction sensor comprises at least one hollow sphere with a freely movable and optically detectable liquid therein and at least one optical detector for detecting the position of the optically detectable liquid. Miniaturized device ( 1 ) according to claim 5, wherein the 3D gravity direction sensor is designed as an acceleration sensor. Miniaturized device ( 1 ) according to claim 5, wherein the 3D gravity direction sensor (S2) comprises at least one mechanical element ( 4 ), which is deformable under the influence of gravity, wherein the deformation occurring is detectable. Miniaturized device ( 1 ) according to claim 5, 6 or 7, wherein the second sensor calculates its required position information at least partially from an analytical model and / or determined from a punctual detection of amplitude and flux density of a magnetic basic field. Miniaturized device ( 1 ) according to claim 1, which is designed as a medical device. Miniaturized device ( 1 ) according to claim 12, which is designed as endoscopy capsule. Miniaturized device ( 1 ) according to claim 12, which is designed as Endoroboter.