Medical tracking system comprising two or more communicating sensor devices

Abstract

A medical tracking system comprising at least two sensor devices which are independently maneuverable and can be positioned in a fixed position relative to targets, each sensor device comprising at least one of an orientation sensor and a position sensor for respectively determining sensor data, the system further comprising a control unit configured to receive and combine the at least two sensor data of the at least two sensor devices in order to determine a relative position between at least two of the at least two sensor devices.

1 . A medical tracking system comprising at least two sensor devices which are independently maneuverable and can be positioned in a fixed position relative to targets, each sensor device comprising a marker device, an orientation sensor for determining sensor data and a camera, the system further comprising a control unit configured to receive and combine the at least two sensor data of the at least two sensor devices in order to determine a relative position between at least two of the at least two sensor devices and configured to identify markers in the output image of the camera in order to determine the position of the markers. 
     
     
         2 . The tracking system of  claim 1 , wherein the sensor data of a single sensor device represent insufficient information for determining the relative position between the at least two sensor devices. 
     
     
         3 . The tracking system of  claim 1 , wherein the at least two sensor data respectively are data describing the relative position between the respective sensor device and a relative position reference. 
     
     
         4 . The tracking system of  claim 1 , wherein the control unit is located in one of the sensor devices, each sensor device comprises a control unit or each sensor device comprises a part of the control unit. 
     
     
         5 . (canceled) 
     
     
         6 . The tracking system of  claim 1 , wherein at least one of the sensor devices comprises an orientation sensor and the control unit is configured to convert orientation data of an orientation sensor into a coordinate system determined by a target to which one of the sensor devices is attached. 
     
     
         7 . The tracking system according to  claim 1 , wherein at least one of the at least two sensor devices comprises an acceleration sensor. 
     
     
         8 . The tracking system according to  claim 1 , wherein a sensor device comprises a distance sensor comprising a laser beam source, wherein the laser beam is angled compared to the optical axis of the camera. 
     
     
         9 . The tracking system of  claim 1 , wherein the control unit is configured to select the function of the sensor device as either acting as a marker device detector or as a marker device in a step of the medical navigation workflow. 
     
     
         10 . A method of determining a relative position between two sensor devices of a medical tracking system in a medical workflow, wherein the sensor devices are independently maneuverable and can be positioned in a fixed position relative to targets, comprising, in one step of the workflow, the steps of
 determining sensor data comprising at least one of orientation data and position data with two or more of the sensor devices   transferring the sensor data to a control unit and   determining the relative position between two sensor devices by the control unit by combining the sensor data;   and comprising, in another step of the workflow, the steps of
 capturing an image using a camera at a sensor device, 
 identifying markers in the output image of the camera and 
 determining the position of the markers. 
   
     
     
         11 . The method of  claim 10 , wherein each sensor device is attached to a target and the relative position of the targets is determined from the relative position of the sensor devices. 
     
     
         12 . The method of  claim 10 , characterized by using a sensor device comprising a marker device and a position sensor being a marker device detector as a marker device detector in one step of the medical navigation workflow for obtaining information for determining the position of a marker device and using the same sensor device as a marker device in another step of the medical navigation workflow. 
     
     
         13 . A method for determining a mechanical property of a joint between two bones, comprising the steps of:
 positioning a first sensor device in a fixed position relative to the first bone,   registering the first bone by sampling a plurality of sample points using a pointer and the first sensor device,   positioning a second sensor device in a fixed position relative to the second bone,   registering the second bone by sampling a plurality of sample points using a pointer and the second sensor device,   optionally re-positioning the first sensor device in its fixed position relative to the first bone if the first sensor device was used as a marker device of the pointer in the previous step,   determining at least one relative position between the first sensor device and the second sensor device for at least one position of the joint as claimed in  claim 10  and   determining the mechanical property of the joint between the first bone and the second bone from the at least one relative position between the first sensor device and the second sensor device.   
     
     
         14 . A method for aiding the adjustment an adjustable cutting block comprising a base and a cutting slot which is adjustable relative to the base, the base being attached to a bone, comprising the steps of:
 positioning a first sensor device in a fixed position relative to the cutting slot,   registering the bone by sampling a plurality of sample points using a pointer and the first sensor device such that the initial alignment of the cutting slot relative to the bone is known,   positioning a second sensor device in a fixed position relative to the base of the cutting block,   determining the relative position between the first sensor device and the second sensor device as claimed in  claim 10  for the initial alignment of the cutting slot,   determining the relative position between the first sensor device and the second sensor device as claimed in  claim 10  while the cutting slot is adjusted and   determining the current alignment of the cutting slot from the initial alignment of the cutting slot and the current relative position between the first sensor device and the second sensor device.   
     
     
         15 . A computer program embodied on a non-transitory computer readable medium which, when running on a computer or when loaded onto the computer, causes the computer to perform
 determining sensor data comprising at least one of orientation data and position data with two or more of the sensor devices   transferring the sensor data to a control unit and   determining the relative position between two sensor devices by the control unit by combining the sensor data;   and comprising, in another step of the workflow, the steps of
 capturing an image using a camera at a sensor device, 
 identifying markers in the output image of the camera and 
 determining the position of the markers.