DEVICE AND METHOD FOR CONNECTING A MEDICAL INSTRUMENT TO A POSITION-DETECTING SYSTEM

Abstract

The invention relates to a device for connecting a medical instrument to a position-detecting system, the device having a localization element. The medical instrument has an instrument shaft, an instrument tip and an operating point. At least one localization element for determining position information for the device within a coordinate system of the position-detecting system can be provided on the device, the device having at least one retaining means for attaching the localization element to the medical instrument.

Claims

1. A device having a localization element for connecting a medical instrument to a location-detecting system, the medical instrument having an instrument shaft, an instrument tip and a working point, wherein at least one localization element for determining location information of the device within a coordinate system of the location-detecting system can be arranged on the device, wherein the device has at least one holding means for fastening to the medical instrument, and the localization element has a sensor coil for use in position-detecting systems with an alternating electromagnetic field generated by a field generator, and the device can be connected by a cable to a control unit of the location-detecting system in order to transmit signals from the localization element to the control unit of the location-detecting system.

2. The device as claimed in claim 1, characterized in that the holding means has an instrument holder, at least a subsection of the medical instrument being engageable with the instrument holder and being fastenable to the instrument holder by at least one fixing means.

3. The device as claimed in claim 2, characterized in that the fixing means comprises a screw, which can be screwed into the device so that, as a result, its preferably flattened screw tip presses against an instrument shaft section which the instrument holder comprises, so as to hold the medical instrument in the instrument holder.

4. The device as claimed in claim 2 or 3, characterized in that the fixing means has a clamping device.

5. The device as claimed in one of the preceding claims, characterized in that the device has a sensor holder for holding the localization element.

6. The device as claimed in one of claims 1 to 4, characterized in that the localization element is arranged irreleasably on the holding means.

7. The device as claimed in one of the preceding claims, characterized in that the device has an essentially cylindrical outer surface.

8. The device as claimed in one of the preceding claims, characterized in that the holding means has a channel extending in the longitudinal direction, the channel being open at both end sides of the holding means, it being possible to pass at least the instrument tip of the medical instrument through the channel.

9. The device as claimed in claim 8, characterized in that the channel essentially has an oval cross section.

10. The device as claimed in one of the preceding claims, characterized in that the device has a reference point with which an instrument tip of a further medical instrument can be automatically calibrated in the location-detecting system by bringing the instrument tip into contact with the reference point.

11. The device as claimed in claim 10, characterized in that the reference point has a depression or an elevation, the reference point being arranged on a midpoint of the depression or elevation.

12. A method with which a localization element held on the medical instrument by the device can be calibrated to the working point of the medical instrument, wherein during the method a reference point is approached with the working point of the instrument tip, and at the same time the location and orientation of the localization element held on the instrument are detected.

13. The method as claimed in claim 12, wherein, at the moment when the working point of the instrument tip reaches the reference point, the working point is automatically calibrated, or automatic calibration is carried out when the working point remains at the reference point for a predetermined time.

14. The method as claimed in claim 12 or 13, wherein the automatic calibration is made possible by a pressure sensor at the reference point, or an electrical circuit which is closed by contact of the working point of the instrument tip with the reference point.

15. The method as claimed in one of claims 12 to 14, wherein as a starting condition for calibration of the localization element to the instrument tip, a check is made whether the reference point to be approached lies within a search sector which relates to the localization element held/to be held on the medical instrument.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The invention will now be explained in more detail with the aid of an exemplary embodiment with reference to the figures. In the figures:

[0035] FIG. 1 shows a schematic side view of a medical instrument with localization element fitted thereon;

[0036] FIG. 2 shows the view of the medical instrument of FIG. 1, a further localization element being arranged on the instrument tip; and

[0037] FIG. 3 shows a front view of a control unit with localization element is coupled thereto, a localization element being arranged on a medical instrument.

DETAILED DESCRIPTION

[0038] The medical instrument 10 represented in FIG. 1 has an instrument shaft 12 and an instrument tip 14. The instrument shaft 12 has a distal shaft region 12a and a handle region 12b, a proximal tip region 14b of the instrument tip 14 being arranged on the distal shaft region 12a. The instrument shaft 12 may be configured in one piece or in several pieces, separately, with the instrument tip 14.

[0039] The instrument tip 14 has a distal tip region 14a, on the end of which facing away from the proximal tip region 14b a working point 16 is arranged. The instrument tip 14 furthermore has a curved region 15, which is next to the distal tip region 14a. In alternative embodiments, the instrument tip 14 may also have curvatures stronger (smaller radius) than represented, or further curvatures. The instrument shaft 12 and the instrument tip 14 have an essentially round cross section.

[0040] A localization element 20 is arranged next to the distal shaft region 12a on the proximal tip region 14b of the instrument tip 14. According to the embodiment shown, the distal shaft region 12a has a conical taper extending in the direction of the instrument tip 14, which can be engaged at least partially with the localization element 20. The localization element 20 is secured against displacement along a longitudinal axis of the instrument tip 14 by means of a clamping screw 22 on the proximal tip region of the instrument tip. Furthermore, the localization element 20 has a cable 18 for connection to a control unit 26 shown in FIG. 3.

[0041] By means of reference point 24, the localization element 20 can be calibrated to the working point 16 of the medical instrument 10 for calibration. The calibration process may be carried out essentially automatically by the operator bringing the working point 16 of the medical instrument 10 into contact with the reference point 24 and, for example, maintaining this state for a predetermined time—for example from 1 to 2 seconds. As an alternative, for example, the reference point 24 may have a sensor (not represented here) which detects the moment of contact of the working point 16 with the reference point 24 and forwarding a corresponding signal to the control unit 26, so that the control unit 26 can record the location data of the localization element 20 at the time of contact of the working point 16 with the working point 24 and therefore complete the calibration measurement. After calibration has been carried out, the location information of the working point 16 of the medical instrument in an operation region can be determined by means of the sensor signals transmitted from the localization element 20 to the location-detecting system.

[0042] As shown by FIG. 2, a plurality of localization elements 20 may be arranged according to the invention on a medical instrument 10. One localization element 20 is already arranged in this view on the proximal tip region 14b of the instrument tip 14 as previously in FIG. 1, while a further localization element 20 is furthermore held on the distal tip region 14a and can be displaced toward the proximal tip region 14b along the tip longitudinal axis. The advantage of using a plurality of localization elements 20 on a medical instrument 10 is that the localization elements 20 provide mutually complementary and partially redundant location information, and measurement variations or measurement errors can therefore be detected by the control unit 26 of the location-detecting system.

[0043] Likewise shown in FIG. 2 is a wedge-shaped search sector 27. The search sector 27 relates to the localization element 20 held on the medical instrument 10 in the proximal tip region 14b. The wedge axis z lies coaxially with the longitudinal axis of the instrument tip 14. The wedge tip of the wedge-shaped search sector 27 points toward and lies at the center of the localization element 20 which is held in the proximal tip region 14b. The wedge-shaped search sector 27 therefore starts from the localization element 20 and extends and widens in the distal direction. Preferably, it ends at a defined distance from the localization element 20 and therefore defines a search space delimited on all sides. The search sector 27 is in the present case specified in such a way that an instrument tip 14 lies inside the search sector 27 when the localization element 20 is held on the medical instrument 10. The search sector 27 may also have a different shape, and need not be wedge-shaped. The purpose of the search sector 27 is to trigger automatic calibration only when it is found that the position data of the reference point 24, detected by the location-detecting system, lie inside the position data space (set of position data falling within the search sector) spanned by the search sector 27. In embodiments of the medical instrument 10 with an instrument shaft 12 and instrument tip 14 which can be separated from one another, the localization element 20 may be configured in order to be fitted directly onto the proximal tip region 14b when the instrument shaft 12 and the instrument tip 14 are separated from one another. After the fitting of the localization element 20, the instrument shaft 12 and the instrument tip 14 may be reconnected to one another.

[0044] As an alternative, embodiments are provided in which the localization element 20 can be fitted onto the instrument shaft 12. To this end, in principle, the same holding means as for fastening to the instrument tip 14 are suitable, the dimensions of the instrument shaft 12 needing to be taken into account.

[0045] According to the invention, a control unit 26 (as represented in FIG. 3) may be connected to a plurality of localization elements 20, preferably in each case by a cable 18. In this case, one or more localization elements 20 may respectively be arranged on a medical instrument 10. Furthermore, the localization elements 20 may be arranged on different medical instruments 10, only one medical instrument 10 being shown in FIG. 3. The control unit 26 may have a filter in order to block out inactive instruments 10, which are arranged for example on an instrument rack (not represented). In this way, the stability of the signals of the active instruments 10 is increased.

LIST OF REFERENCES

[0046] 10 medical instrument [0047] 12 instrument shaft [0048] 12a distal shaft region [0049] 12b handle region [0050] 14 instrument tip [0051] 14a distal tip region [0052] 14b proximal tip region [0053] 15 curved region [0054] 16 working point [0055] 18 cable [0056] 20 localization element [0057] 22 clamping screw [0058] 24 reference point [0059] 26 control unit [0060] 27 search sector [0061] Z cone axis