Image marker-based navigation using a tracking frame

Abstract

Disclosed is a computer-implemented method for navigating an anatomical body part, a corresponding computer program, a non-transitory program storage medium storing such a program and a computer for executing the program, as well as a system for navigating the anatomical body part, the system comprising an electronic data storage device and the aforementioned computer, and to a system for conducting medical navigation.

1 . A method for navigating an anatomical body part using a data processing computer comprising a memory device storing code and a processor operable to execute the code stored in the memory device to perform the method for navigating comprising:
 acquiring planning image data, the planning image data depicting the anatomical body part supported by a patient support device, and the planning image data depicting at least three image markers provided in or on a registration frame attached with the patient support device,
 wherein the planning image data describes a frame-patient transformation (M R ) defining a relative position between the at least three image markers and the anatomical body part, 
 wherein the planning image data further describes a tracking-registration transformation (M TR ) defining a relative position between the image markers provided in or on the registration frame and an image marker provided in or on a tracking frame connector connected with the registration frame, 
 wherein the tracking frame connector is defined by a portion of a tracking frame, the tracking frame comprising a tracking marker array comprising at least three optical markers, 
 wherein the tracking frame connector is connected with both the tracking marker array and the registration frame, 
 wherein the tracking frame is attached with the registration frame at a predetermined position on the registration frame, and 
 wherein a location of the predetermined position on the registration frame at which the tracking frame is attached is determined based on the tracking-registration transformation M TR , and 
 wherein the tracking marker array and the tracking frame connector are provided as separate connected pieces; 
   acquiring construction data, the construction data describing a predetermined tracking frame transformation (M T ) defining a relative position between the at least three optical markers and the image marker provided in or on the tracking frame connector,
 wherein a relative position between the image markers provided in or on the registration frame and the image marker provided in or on the tracking frame connector is determined based on the location of the predetermined position on the registration frame at which the tracking frame is attached and the construction data; 
   determining a registration (REG) of the anatomical body part as a relative position between the optical markers and the depiction of the anatomical body part by the planning image data,
 wherein determining the registration REG comprises determining the registration REG based on the frame-patient transformation M R  and by determining the relative position between the image markers provided in or on the registration frame and the optical markers based on the tracking-registration-transformation M TR  and the tracking frame-transformation M T . 
   
     
     
         2 . The method according to  claim 1 , wherein the frame-patient transformation M R  is defined in a planning reference system, the method further comprising:
 acquiring marker navigation data, the marker navigation data describing a position of the optical markers in a navigation reference system; and   transforming the position of the anatomical body part between a planning reference system in which positions in the planning image data are defined and the navigation reference system using a reference system transformation.   
     
     
         3 . The method according to  claim 2 , comprising transforming the position of the anatomical body part from the planning reference system into the navigation reference system using the reference system transformation. 
     
     
         4 . The method according to  claim 1 , wherein
 he acquiring the planning image data depicting the at least three image markers provided in or on a registration frame attached with the patient support device comprises acquiring the planning image data depicting at least three image markers are arranged in or on the registration frame in an un-symmetric pattern, for example three-dimensionally un-symmetric three-dimensional pattern.   
     
     
         5 . The method according to  claim 1 , further comprising determining the relative position between the image markers provided in or on the registration frame and the at least three optical markers of the tracking marker array of the tracking frame based on the tracking frame-transformation M T . 
     
     
         6 . The method according to  claim 1 , wherein the registration frame is provided with at least two attachment parts for attaching with the tracking frame, and wherein the tracking frame is attached with the registration frame at the predetermined position on the registration frame at a selected one of the at least two attachment parts. 
     
     
         7 . The method according to  claim 1  wherein acquiring the planning image data comprises:
 acquiring planning image data depicting at least part of the head of an associated patent supported by a headrest of the patient support device. 
 
     
     
         8 . A non-transitory computer-readable medium including instructions stored thereon for supporting navigating an anatomical body part in data processing computer having a microprocessor and memory, which instructions, when executed cause data processing computer to perform steps comprising:
 acquiring planning image data, the planning image data depicting the anatomical body part supported by a patient support device, and the planning image data depicting at least three image markers provided in or on a registration frame  4  attached with the patient support device,
 wherein the planning image data describes a frame-patient transformation (M R ) defining a relative position between the at least three image markers and the anatomical body part, 
 wherein the planning image data further describes a tracking-registration transformation (M TR ) defining a relative position between the image markers provided in or on the registration frame and an image marker provided in or on a tracking frame connector connected with the registration frame, 
 wherein the tracking frame connector is defined by a portion of a tracking frame, the tracking frame comprising a tracking marker array comprising the at least three optical markers, 
 wherein the tracking frame connector is connected with both the tracking marker array and the registration frame, 
 wherein the tracking frame is attached with the registration frame at a predetermined position on the registration frame, 
 wherein a location of the predetermined position on the registration frame at which the tracking frame is attached is determined based on the tracking-registration transformation M TR , and 
 wherein the tracking marker array and the tracking frame connector are provided as separate connected pieces; 
   acquiring construction data, the construction data describing a predetermined tracking frame transformation (M T ) defining a relative position between the at least three optical markers and the image marker provided in or on the tracking frame connector,
 wherein a relative position between the image markers provided in or on the registration frame and the image marker provided in or on the tracking frame connector is determined based on the location of the predetermined position on the registration frame at which the tracking frame is attached and the construction data; 
   determining a registration (REG) of the anatomical body part as a relative position between the optical markers and the depiction of the anatomical body part by the planning image data,
 wherein determining the registration REG comprises determining the registration REG based on the frame-patient transformation M R  and by determining the relative position between the image markers provided in or on the registration frame and the optical markers based on the tracking-registration-transformation M TR  and the tracking frame-transformation M T . 
   
     
     
         9 . The computer-readable medium according to  claim 8 , wherein the frame-patient transformation M R  is defined in a planning reference system, the method further comprising:
 acquiring marker navigation data, the marker navigation data describing a position of the optical markers in a navigation reference system; and   transforming the position of the anatomical body part between a planning reference system in which positions in the planning image data are defined and the navigation reference system using a reference system transformation.   
     
     
         10 . The computer-readable medium according to  claim 9 , comprising transforming the position of the anatomical body part from the planning reference system into the navigation reference system using the reference system transformation. 
     
     
         11 . The computer-readable medium according to  claim 8 , wherein
 he acquiring the planning image data depicting the at least three image markers provided in or on a registration frame attached with the patient support device comprises acquiring the planning image data depicting at least three image markers are arranged in or on the registration frame in an un-symmetric pattern, for example three-dimensionally un-symmetric three-dimensional pattern.   
     
     
         12 . The computer-readable medium according to  claim 8 , further comprising determining the relative position between the image markers provided in or on the registration frame and the at least three optical markers of the tracking marker array of the tracking frame based on the tracking frame-transformation M T . 
     
     
         13 . The computer-readable medium according to  claim 8 , wherein the registration frame is provided with at least two attachment parts for attaching with the tracking frame, and wherein the tracking frame is attached with the registration frame at the predetermined position on the registration frame at a selected one of the at least two attachment parts. 
     
     
         14 . The computer-readable medium according to  claim 8 , wherein acquiring the planning image data comprises:
 acquiring planning image data depicting at least part of the head of an associated patent supported by a headrest of the patient support device.   
     
     
         15 . A system for navigating an associated anatomical body part, the system comprising:
 a computer comprising at least one processor, a memory, and a non-transitory program storage medium storing a program thereon that, when executed by the processor performs a method comprising:
 acquiring planning image data, the planning image data depicting the anatomical body part supported by a patient support device, and the planning image data depicting at least three image markers provided in or on a registration frame attached with the patient support device,
 wherein the planning image data describes a frame-patient transformation (M R ) defining a relative position between the at least three image markers and the anatomical body part, 
 wherein the planning image data further describes a tracking-registration transformation (M TR ) defining a relative position between the image markers provided in or on the registration frame and an image marker provided in or on a tracking frame connector connected with the registration frame, 
 wherein the tracking frame connector is defined by a portion of a tracking frame, the tracking frame comprising a tracking marker array comprising the at least three optical markers, 
 
 wherein the tracking frame connector is connected with both the tracking marker array and the registration frame,
 wherein the tracking frame is attached with the registration frame at a predetermined position on the registration frame, 
 wherein a location of the predetermined position on the registration frame at which the tracking frame is attached is determined based on the tracking-registration transformation MTR, and 
 wherein the tracking marker array and the tracking frame connector are provided as separate connected pieces; 
 
 acquiring construction data, the construction data describing a predetermined tracking frame transformation (M T ) defining a relative position between the at least three optical markers and the image marker provided in or on the tracking frame connector,
 wherein a relative position between the image markers provided in or on the registration frame and the image marker provided in or on the tracking frame connector is determined based on the location of the predetermined position on the registration frame at which the tracking frame is attached and the construction data; 
 
 determining a registration (REG) of the anatomical body part as a relative position between the optical markers and the depiction of the anatomical body part by the planning image data,
 wherein determining the registration REG comprises determining the registration REG based on the frame-patient transformation M R  and by determining the relative position between the image markers provided in or on the registration frame and the optical markers based on the tracking-registration-transformation M TR  and the tracking frame-transformation M T;    
 
   at least one electronic data storage device storing at least planning image data and construction data;   a system for conducting medical navigation, the system comprising:
 a tracking frame comprising a tracking marker array comprising at least three optical markers; 
 a registration frame, comprising:
 a patient support unit attachment part for attaching the registration frame with a patient support unit; 
 at least three image markers arranged in or on the registration frame; and 
 a plurality of attachment parts for selectively attaching the tracking frame directly or indirectly with the registration frame; and 
 
 a tracking frame connector comprising an image marker provided in or on the tracking frame connector, the tracking frame connector being operable to selectively connect the tracking frame with the registration frame, wherein the tracking marker array and the tracking frame connector are provided as separate connected pieces; and 
   a tracking device for tracking the position of the optical markers,
 wherein the computer is operably coupled with the at least one electronic data storage device for acquiring, from the at least one data storage device, at least the planning image data and the construction data, 
 wherein the computer is operably coupled with the tracking device for acquiring, from the tracking device, signals corresponding to information about the positions of the optical markers.