Navigation of medical instrument
The subject invention pertains to a device for inserting medical instruments into the human body. In a specific embodiment, the subject device can be made from a material which is invisible under Magnetic Resonance Imaging (MRI). The subject device can incorporate three or more MRI compatible marks. The imaging of these three or more markers can allow the determination of the orientation of the device. A virtual image of the device can then be shown in an MRI image.
This application is a divisional of U.S. patent application Ser. No. 10/632,685; filed Aug. 1, 2003, which is a continuation of U.S. Ser. No. 09/954,725; filed Sep. 14, 2001, now abandoned.
BACKGROUND OF THE INVENTION With the German patent specification DE 198 44 767 A1, a method attaching markers to a medical instrument that are detectable under MRI is already known. The orientation of the instrument within the MRI device can be determined with these points. However, the respective allocation of the measured markers to the instrument markers is impeded due to the similarity of the signal-emitting substance to the instrument material. The non-availability of an instrument fixation to the patient proves to be a further disadvantage. Such fixation could be achieved by use of trocars.
The adjustment of a navigation system adapting the devices to MRI imaging to such a neuro trocar is difficult.
The neuro trocar is manufactured of titanium alloy, so that it is depicted as a homogenous formation with indistinct rim demarcation in the MR image. A three-dimensional orientation is difficult to assess. This, however, is highly essential, with the neuro trocar, unlike a stereotactic system, having no own reference point as it is fixed to the patient.
The invention presented herein aims to solve these and other problems.
BRIEF SUMMARY OF THE INVENTIONThe subject invention pertains to a device for inserting medical instruments into the human body. In a specific embodiment, the subject device can be made from a material which is invisible under Magnetic Resonance Imaging (MRI). The subject device can incorporate three or more MRI compatible markers. The imaging of these three or more markers can allow the determination of the orientation of the device. A virtual image of the device can then be shown in an MRI image.
DETAILED DESCRIPTION OF THE FIGURES
The problem of the conventional neuro trocar being not sufficiently identifiably with regard to its orientation within the MRI, as described in patent DE 197 26 141, can be solved by designing a device of a material that is totally invisible under MRI. If then a minimum of three MRI compatible points are marked on it, an exact orientation can be determined by these three points; its position in the MRI procedure can be precisely assessed, and a virtual image of the trocar can be shown in the MRI picture.
Various systems for the technical realization of these points are described below.
The problem is shown in
Both the adjustment of the instrument insertion channel 10 and the adjustment of the device 3, which essentially corresponds to the devices 1 and 2, can be correlated to each other by an angle adjustment (see
The fixation of the instrument insertion channel 10 in a certain position can be achieved by tightening a fixing screw 22 as shown in
Through the instrument insertion channel 10, a tube can be inserted deep into the operation site, which will then serve as a channel for inserting further instruments as shown in
The orientation of the instrument insertion channel can be achieved by tilting. To allow this, two movable laminas 7 and 8, relative to the device 2 and shifting to each other (as shown in
A further possibility of adjustment of the instrument insertion channel 10, as shown in
The orientation of the instrument is directly readable by the scaling at the positioning unit. It could also be monitored via the above-mentioned markers in the MR image.
In order to adapt the device to the imaging of the MRI device, a navigation system is to be integrated into the device itself.
A so-called TrackPointer, as described in patent specification 298 21 944.1, can also be connected to the device by implanting it in the instrument insertion channel 10.
The orientation of the instrument with regard to the operation system, or, in other words, the adaptation of the image to the device presented herein via the MRI device, can also be realized with the markers 20, according to the principle stated herein, not only attached to the device 3 itself, but also to the instrument 24, being inserted into the minimally-invasive channel 2 for a certain procedure, and to the angle measuring system 25 (
Such a device can be used to insert probes, for mechanical and mechanical-surgical instruments or endoscopes. The instrument insertion channel 10 could also be designed in form of several lumens, resulting in several channels instead of only one. The device can also be used to insert larger instruments in open OP's. Such a device could be designed as either reusable or disposable instrument.
A system as presented herein can be used not only for surgical interventions and procedures, but also for the insertion of electrodes to fight Parkinson's disease. It could also be applied as a shunt.
REFERENCE NUMBERS
- 1. Device
- 2. Device, general for adaptation to a navigation system
- 3. Device
- 4. Plastic Device
- 5. Double-walled top filled with contrast medium
- 6. Mounting
- 7. Movable lamina
- 8. Movable lamina
- 9. Opening
- 10. Instrument insertion channel
- 11. Worm wheel
- 12. Reflector/optically emitting elements
- 13. Reflector fitting
- 14. Angle adjustment azimuth angle
- 15. Angle adjustment zenith angle
- 16. Operation site
- 17. Titanium screw
- 18. Hollow space filled with gadolinium-containing liquid
- 19. Self-cutting thread
- 20. MRI markers according to one principle presented herein
- 21. Top with angle adjustment
- 22. Fixing screw
- 23. Stabilization channel
- 24. Instrument
- 25. Angle measuring system
Claims
1. An apparatus for inserting an instrument into a human body, comprising:
- an element configured to be fixedly positioned relative to a part of the human body, wherein at least a portion of the element is invisible under magnetic resonance imaging;
- an instrument insertion channel movably connected to the element, wherein at least a portion of the instrument insertion channel is invisible under magnetic resonance imaging;
- a means for determining the relative position of the instrument insertion channel with respect to the element such that once the position of the element is known, the position of the instrument insertion channel is known, or that once the position of the instrument insertion channel is known, the position of the element is known; and
- at least three positioning markers, wherein the at least three positioning markers are each fixedly positioned relative to the element, fixedly positioned relative to the instrument insertion channel, or fixedly positioned relative to an instrument.
2. The apparatus according to claim 1, wherein the element is configured to be fixedly positioned relative to a human head.
3. The apparatus according to claim 1, wherein the at least three positioning markers are visible under magnetic resonance imaging.
4. The apparatus according to claim 3, wherein under magnetic resonance imaging, the at least three positioning markers allow determination of the orientation of the element and determination of the orientation of the instrument insertion channel.
5. The apparatus according to claim 3, wherein the at least three positioning markers can be distinguished from one another by magnetic resonance imaging.
6. The apparatus according to claim 5, wherein the at least three positioning markers comprise coils.
7. The apparatus according to claim 5, wherein at least one of the at least three positioning markers comprises a volume filled with a material positively or negatively identifiable under magnetic resonance imaging.
8. The apparatus according to claim 3, further comprising a means for showing a virtual image of the instrument insertion channel in a magnetic resonance image.
9. The apparatus according to claim 1, wherein the at least three positioning markers comprise optically active or optically reflecting positioning markers.
10. The apparatus according to claim 1, wherein the at least three positioning markers are fixedly positioned relative to the element, wherein the position of the element can be determined by monitoring the at least three positioning markers fixedly positioned with respect to the element such that the position of the instrument insertion channel can be determined via the means for determining the relative position of the instrument insertion channel with respect to the element.
11. The apparatus according to claim 10, wherein one of the at least three positioning markers comprises a titanium screw.
12. The apparatus according to claim 10, wherein at least one of the at least three positioning markers are within the element.
13. The apparatus according to claim 1, wherein the at least three positioning markers are fixedly positioned relative to the instrument insertion channel,
- wherein the position of the instrument insertion channel can be determined by monitoring the at least three positioning markers such that the position of the element can be determined via the means for determining the relative position of the instrument insertion channel with respect to the element.
14. The apparatus according to claim 1, wherein the at least three positioning markers comprise six positioning markers, wherein three of the six positioning markers are fixedly positioned relative to the element and three of the six positioning markers are fixedly positioned relative to the instrument insertion channel.
15. The apparatus according to claim 14, wherein the three of the six positioning markers fixedly positioned relative to the element are distinguishable from the three of the six positioning markers fixedly positioned relative to the instrument insertion channel.
16. The apparatus according to claim 15, wherein the three of the six positioning markers fixedly positioned relative to the element and the three of the six positioning markers fixedly positioned relative to the instrument insertion channel correspond to different wavelengths.
17. The apparatus according to claim 15, wherein the three of the six positioning markers fixedly positioned relative to the element and the three of the six positioning markers fixedly positioned relative to the instrument insertion channel correspond to a different codification.
18. The apparatus according to claim 15, wherein the three of the six positioning markers fixedly positioned relative to the element and the three of the six positioning markers fixedly positioned relative to the instrument insertion channel correspond to different geometrically designed reflectors.
19. The apparatus according to claim 1, wherein two of the at least three positioning markers are fixedly positioned relative to the element, and
- wherein one of the at least three positioning markers is fixedly positioned relative to the instrument insertion channel.
20. The apparatus according to claim 19, wherein at least one of the two of the at least three positioning markers fixedly positioned relative to the element comprises a titanium screw.
21. The apparatus according to claim 1, wherein the at least three positioning markers comprise:
- a first positioning marker fixedly positioned relative to the instrument insertion channel,
- a second positioning marker fixedly positioned relative to the element, and
- a third positioning marker fixedly positioned relative to a distal end of the instrument.
22. The apparatus according to claim 1, wherein the means for determining the relative position of the instrument insertion channel with respect to the element comprises:
- a means for measuring an azimuth angle that the instrument insertion channel makes with respect to an axis parallel to a plane of the element, and
- a means for measuring a zenith angle that the instrument insertion channel makes with respect to the plane of the element.
23. The apparatus according to claim 22, wherein the means for measuring the azimuth angle comprises a scaling on a top piece attached to the element, and
- wherein the means for measuring the zenith angle comprises a scaling on the element.
24. The apparatus according to claim 1, further comprising:
- a means for positioning the instrument insertion channel with respect to the element configured to be fixedly positioned relative to a part of the human body.
25. The apparatus according to claim 24, wherein the means for positioning the instrument insertion channel with respect to the element configured to be fixedly positioned relative to a part of the human body comprises:
- a tilting means, wherein the tilting means comprises: a first movable lamina having a first opening, and a second movable lamina having a second opening,
- wherein the first movable lamina is positioned relative to the element configured to be fixedly positioned relative to a human skull and the second movable lamina is positioned relative to the first movable lamina such that the instrument insertion channel extends through the first opening of the first movable lamina and the second opening of the second movable lamina,
- wherein the first opening is shaped such that the first movable lamina allows the instrument insertion channel to tilt in a first plane, wherein the second opening is shaped such that the second movable lamina allows the instrument insertion channel to tilt in a second plane orthogonal to the first plane.
26. The apparatus according to claim 25, further comprising a means for actuating a tilting motion.
27. The apparatus according to claim 24, wherein the means for positioning the instrument insertion channel with respect to the element configured to be fixedly positioned relative to a part of the human body comprises:
- a worm wheel movable attached to the instrument insertion channel, wherein the worm wheel provides a tilting motion and a rotating motion.
28. The apparatus according to claim 27, further comprising a means for actuating the tilting motion and the rotating motion.
29. The apparatus according to claim 1, further comprising:
- a stabilization channel removably positioned within the instrument insertion channel such that upon inserting an instrument into the instrument insertion channel, the instrument is inserted through the stabilization channel.
30. The apparatus according to claim 29, further comprising:
- a mounting for shifting in an axial direction with respect to the instrument insertion channel, wherein the stabilization channel extends through the mounting.
31. The apparatus according to claim 30, further comprising a means for actuating movement of the mounting in the axial direction.
32. A method for inserting an instrument into a human body, comprising:
- positioning an apparatus at a location relative to a part of a human body, wherein the apparatus comprises: i) an element configured to be fixedly positioned relative to the part of a human body, ii) an instrument insertion channel, and iii) at least three positioning markers at a location relative to the part of a human body, wherein the at least three positioning markers are each fixedly positioned relative to the element, fixedly positioned relative to the instrument insertion channel, or fixedly positioned relative to an instrument,
- wherein positioning the apparatus at a location relative to a part of a human body comprises: positioning the element with relative to the part of a human body, and positioning the instrument insertion channel with respect to the element; and
- determining the orientation of the apparatus with respect to the part of a human body, wherein determining the orientation of the apparatus with respect to the part of a human body comprises: monitoring the at least three positioning markers, and determining the relative position of the instrument insertion channel with respect to the element.
33. The method according to claim 32, wherein the element comprises a self-cutting thread, wherein fixedly attaching the element to the part of a human body comprises screwing the element into a human skull.
34. The method according to claim 32, wherein monitoring the at least three positioning markers comprises imaging the at least three positioning markers with a magnetic resonance imaging system.
35. The method according to claim 32, wherein monitoring the at least three positioning markers comprises imaging the at least three positioning markers with a respective camera system.
36. The method according to claim 32, wherein determining the relative position of the instrument insertion channel with respect to the element comprises:
- monitoring a means for measuring an azimuth angle that the instrument insertion channel makes with respect to an axis parallel to a plane of the element, and
- monitoring a means for measuring a zenith angle that the instrument insertion channel makes with respect to the plane of the element.
37. The method according to claim 36, further comprising indicating the azimuth angle and the zenith angle in an MR image.
38. The method according to claim 37, further comprising adjusting the orientation of the MR image to the orientation of the apparatus with respect to the part of a human body.
39. The method according to claim 37, further comprising adjusting the position of the instrument insertion channel with respect to the orientation of the MR image.
40. The method according to claim 32, further comprising creating a virtual image of the apparatus in a MR image.
41. The method according to claim 32, wherein determining the orientation of the apparatus with respect to the part of a human body determines the orientation of an instrument inserted through the instrument insertion channel.
Type: Application
Filed: Jan 23, 2006
Publication Date: Jun 8, 2006
Inventors: Wolfgang Daum (Groton, MA), Axel Winkel (Zapel-Hof)
Application Number: 11/338,044
International Classification: A61B 19/00 (20060101);