EP-4739245-A1 - CALIBRATION DEVICE, SYSTEM AND METHOD

EP4739245A1EP 4739245 A1EP4739245 A1EP 4739245A1EP-4739245-A1

Abstract

A calibration device (1) for a surgical instrument (4) having an adapter (41) for receiving a tool and an imaging unit (42) directed towards the adapter (41) for imaging the tool in operation comprises a stud member (2) and a marker carrier (3). The stud member (2) is configured to be received by the adapter (41) of the surgical instrument (4). The marker carrier (3) has a first face and a second face. The marker carrier (3) is connected to the stud member (2). The stud member (2) has an axis (23). The first face of the marker carrier (3) is provided with a first marker structure (33). The first marker structure (33) is positioned in line with the axis (23) of the stud member (2). The second face of the marker carrier (3) is provided with a second marker structure (34) and a third marker structure (35), wherein the second marker structure (34) and the third marker structure (35) are positioned offset the axis (23) of the stud member (2). The calibration device (1) is configured to selectively expose either the first face of the marker carrier (3) or the second face of the marker carrier (3) towards the imaging unit (42) of the surgical instrument (4), when the stud member (2) is received by the adapter (41) of the surgical instrument (4).

Inventors

Böhringer, Stephan
Müller, Sven
RUDIN, Adrian

Assignees

Institut Straumann AG

Dates

Publication Date: 20260513
Application Date: 20240703

Claims (1)

CLAIMS 1. A calibration device (1 ) for a surgical instrument (4) having an adapter (41 ) for receiving a tool and an imaging unit (42) directed towards the adapter (41 ) for imaging the tool in operation, comprising a stud member (2) configured to be received by the adapter (41 ) of the surgical instrument (4); and a marker carrier (3) having a first face and a second face, wherein the marker carrier (3) is connected to the stud member (2), and wherein the stud member (2) has an axis (23), characterized in that the first face of the marker carrier (3) is provided with a first marker structure (33), wherein the first marker structure (33) is positioned in line with the axis (23) of the stud member (2), the second face of the marker carrier (3) is provided with a second marker structure (34) and a third marker structure (35), wherein the second marker structure (34) and the third marker structure (35) are positioned offset the axis (23) of the stud member (2), and the calibration device (1 ) is configured to selectively expose either the first face of the marker carrier (3) or the second face of the marker carrier (3) towards the imaging unit (42) of the surgical instrument (4), when the stud member (2) is received by the adapter (41 ) of the surgical instrument (4). 2. The calibration device (1 ) of claim 1 , wherein the marker carrier (3) is configured to rotate about the axis (23) of the stud member (2) such that the calibration device (1 ) is configured to selectively expose either the first face of the marker carrier (3) or the second face of the marker carrier (3) towards the imaging unit (42) of the surgical instrument (4). 3. The calibration device (1 ) of claim 1 or 2, being configured to be held in one hand of an operator. 4. The calibration device (1 ) of any one of the preceding claims, comprising a cover configuration (31 , 312, 314) arranged to selectively cover either the second marker structure (34) of the marker carrier (3) or the third marker structure (35) of the marker carrier (3). 5. The calibration device (1 ) of any one of the preceding claims, wherein the marker carrier (3) has a body (32) and a housing (31 ), wherein the body (32) is arranged in the housing (31 ) and wherein the first marker structure (33), the second marker structure (34) and the third marker structure (35) are arranged on the body (32). 6. The calibration device (1 ) of claim 5, wherein the housing (31 ) is made of an obscure material and has a window (312). 7. The calibration device (1 ) of claim 6, wherein the body (32) of the marker carrier (3) and the housing (31 ) of the marker carrier (3) are movable relative to each other such that in a second state of the housing (31 ) relative to the body (32) the second marker structure (34) is visible through the window (312) and in a third state of the housing (31 ) relative to the body (32) the third marker structure (35) is visible through the window (312). 8. The calibration device (1 ) of claim 7 or 8, wherein the housing (31 ) of the marker carrier (3) is laterally movable relative to the body (32) of the marker carrier (3) in a direction essentially perpendicular to the axis (23) of the stud member (2). 9. The calibration device (1 ) of claim 8, wherein the body (32) of the marker carrier (3) and the stud member (2) are laterally and axially fixed to each other. 10. The calibration device (1 ) of claim 8 or 9, wherein the housing (31 ) of the marker carrier (3) is laterally movable relative to the body (32) of the marker carrier (3) between the second state and the third state. 11. The calibration device (1 ) of claim 10, wherein the marker carrier (3) comprises a movement delimiter stopping lateral movement of the housing (31 ) of the marker carrier (3) relative to the body (32) of the marker carrier (3) on one side at the second state and on the other side at the third state. 12. The calibration device (1 ) of any one of claims 7 to 11 , wherein the housing (31 ) has a further window (314) and, in a first state of the housing (31 ) relative to the body (32), the first marker structure (33) is visible through the further window (314). 13. The calibration device (1 ) of claim 12, wherein the marker carrier (3) has a spring arrangement forcing the housing (31 ) into the first state. 14. A method of calibrating a surgical instrument (4) having an adapter (41 ) for receiving a tool and an imaging unit (42) directed towards the adapter (41 ) for imaging the tool in operation, comprising: obtaining a calibration device (1 ) according to any one of the preceding claims; receiving the stud member (2) of the calibration device (1 ) in the adapter (41 ) of the surgical instrument (4); orienting the first face of the marker carrier (3) towards the imaging unit (42); determining an alignment of the imaging unit (42) relative to the adapter (41 ) by the imaging unit (42) imaging the first marker structure (33); orienting the second face of the marker carrier (3) towards the imaging unit (42); and measuring a clearance of the surgical instrument (4) by the imaging unit (42) selectively imaging the second marker structure (34) and the third marker structure (35). 15. The method of claim 14, wherein imaging the first marker structure (33) is stereo-imaging the first marker structure (33) and wherein selectively imaging the second marker structure (34) and the third marker structure (35) is selectively stereo-imaging the second marker structure (34) and the third marker structure 16. The method of claim 14 or 15, wherein for determining an alignment of the imaging unit (42) relative to the adapter (41 ) by the imaging unit (42) imaging the first marker structure (33) while the first face of the marker carrier (3) is oriented towards the imaging unit (42), the surgical instrument (4) is rotated. 17. The method of claim 16, wherein the imaging unit (42) is rotated about an axis extending essentially perpendicular to the first face of the marker carrier (3). 18. The method of claim 16 or 17, wherein the imaging unit (42) is rotated clockwise by about 90° and counter-clockwise by about 90°. 19. A calibration system, comprising a surgical instrument (4) and a calibration device (1 ) according to any one of the preceding claims, wherein the surgical instrument (4) has an adapter (41 ) for receiving a tool and an imaging unit (42) directed towards the adapter (41 ) for imaging the tool in operation. 20. The calibration system of claim 19, wherein the surgical instrument (4) comprises a handheld motor (43), a coupling piece (45) and a support member (44), wherein the imaging unit (42) is fixed to the support member (44), the support member (44) is mounted to the handheld motor (43), the coupling piece (45) is releasably coupled to the handheld motor (43) and the coupling piece (45) is equipped with the adapter (41 ). 21. The calibration system of claim 19 or 20, comprising a processing unit configured to determine an alignment of the imaging unit (42) of the calibration device (1 ) relative to the adapter (41 ) of the calibration device (1 ) by evaluating alignment data collected by the imaging unit (42) of the calibration device (1 ) when imaging the first marker structure (33) of the calibration device (1 ) while the adapter (41 ) of the surgical instrument (4) receives the stud member (2) of the calibration device (1 ). 22. The calibration system of claim 21 , wherein the processing unit is configured to measure a clearance of the surgical instrument (4) by evaluating clearance data collected by the imaging unit (42) of the calibration device (1 ) when selectively imaging the second marker structure (34) of the calibration device (1 ) and the third marker structure (35) of the calibration device (1 ) while the adapter (41 ) of the surgical instrument (4) receives the stud member (2) of the calibration device (1 ).

Description

DESCRIPTION Title CALIBRATION DEVICE, SYSTEM AND METHOD Technical Field [0001] The present invention relates to a calibration device according to the preamble of independent claim 1 and, more particularly, to a calibration system and a method of calibrating a surgical instrument. Such calibration devices comprising a stud member configured to be received by an adapter of a surgical instrument and a marker carrier having a first face and a second face, wherein the marker carrier is connected to the stud member and the stud member has an axis, can be used for calibrating the surgical instrument including the adapter for receiving a tool and an imaging unit directed towards the adapter for imaging the tool in operation. Background Art [0002] In dental and/or cranio-maxillofacial surgery it is known to use instruments for bone surgery having an intervention tool such as a drill, a round burr, a saw, a cutter, an osteotome, a scissel or the like together with a camera for observing the intervention tool and its operation. Moreover, in order to assist an operator during dental and/or cranio-maxillofacial surgery, navigation systems have been developed for controlling and/or monitoring the position and orientation of the intervention tool relative to a body part of a patient. [0003] For example, surgical devices are known involving an image output on which the intervention tool and the body part are shown in the correct position and orientation relative to each other. An image processor generates a representation of the body part on the basis of image data captured by means of a medical imaging method such as computer tomography or the like, and on the basis of actual images captured during operation. The devices may further comprise an image display control which shows a virtual image of an actual situation on a display, wherein the virtual image is superimposed with information about the operation such as a tool axis or the like (augmented reality). The actual situation is provided by a video image capture unit which is fixedly arranged on the surgery device. The position and orientation of the intervention tool with respect to the body part is ascertained by a stationary tracking system having two or more cameras and two reference assemblies, one assembly being placed on the part of the patient’s body and the other assembly being placed on the instrument. In order to allow proper operation, the two reference assemblies always have to be within a field of view (FoV) of the tracking system. [0004] More compact and handy systems are also known, which comprise a surgical handpiece, an imaging unit which is movably attached to the surgical handpiece, and a marker member which is attachable to a cranial bone, a facial bone, a tooth or teeth of a patient. The marker member comprises a plurality of marker elements which are detectable by the imaging unit. [0005] In order to allow precise surgical navigation during dental and/or cranio- maxillofacial surgery, it is necessary to provide the known systems with precise and reliable information about the geometrical characteristics of the surgical instrument, in particular about the surgical instrument and its intervention tool, as well as the relative position and orientation of the surgical tool to the remainder of the surgical instrument. Hence, it is necessary to measure the geometrical characteristics of the intervention tool and the relative position and orientation of the intervention tool in the surgical instrument every time the intervention tool is changed or adapted. Moreover, as during the dental and/or cranio-maxillofacial surgery procedure the intervention tool might move inside a tool holder of the surgical instrument, it typically is also necessary to acquire or update before-mentioned information during the dental and/or cranio-maxillofacial surgery procedure. [0006] For accurate registration and identification of a dental and/or cranio- maxillofacial surgical instrument in a comparably simple and reliable manner, WO 2018/171862 A1 describes a registration and identification tool (RIT). The RIT comprises a body, a marker member which is optically detectable and provided on the body, and a recess in the body which extends from an outer surface of the body into the inside of the body, thereby defining an extension direction of the recess. The recess has a shape such as a tapered shape such that a lateral extension of the recess decreases in a direction from the outer surface of the body towards the inside of the body. [0007] Even though the RIT of the prior art allows for efficient registration and identification of the surgical instrument and tool, there is still a need for a preferably more conveniently applicable device allowing to calibrate a surgical instrument and intervention tool as to clearance as well as position and orientation relative to each other. Disclosure of the Invention [0008] According to the invention this need is settled by a calibr