Method for enabling medical navigation with minimised invasiveness

A non-transitory computer readable medium storing a computer program that, when running on an associated computer or loaded onto the associated computer for execution by a processor of the associated computer, causes the associated computer to perform a method for determining a position of a bone comprising:

• receiving bone registration data into the associated computer, the bone registration data being representative of spatial locations of a first set of points which lie on a surface of a bone relative to an associated marker device carried by an associated adjustable cutting block affixed to the bone, wherein the associated adjustable cutting block defines a cutting slot and wherein the associated marker device is rigidly coupled with the cutting block by a plate of the marker device received in the cutting slot of the associated adjustable cutting block thereby establishing a fixed relative position between the associated marker device and the cutting slot of the associated adjustable cutting block;
• processing the bone registration data by the associated computer to calculate, based on the bone registration data and the fixed relative position between the associated marker device and the cutting slot of the cutting block, a current relative position between the bone and the cutting slot of the associated adjustable cutting block;
• determining, by the associated computer, an offset between:
• the current relative position between the cutting slot and the bone, and
• a desired relative position between the cutting slot and the bone;
• outputting indication information by the associated computer, wherein the indication information is provided for indicating an adjustment to be made to the associated adjustable cutting block based on the determined offset such that a relative movement between the cutting slot carrying the associated market device and the bone is caused;
• receiving degree of freedom data into the associated computer, the degree of freedom data being representative of a number of degrees of freedom of movement of the bone;
• receiving, following the adjustment to the associated adjustable cutting block such that the relative movement between the cutting slot carrying the associated marker device and the bone is caused, bone re-registration data into the associated computer, the bone re-registration data being representative of spatial locations of one or more points forming a second set of points which lie on the surface of the bone, wherein a quantity of the one or more points forming the second set of points is based on the received number of degrees of freedom of movement of the bone and wherein the second set of points comprises fewer points than the first set of points;
• and
• tracking a position of the bone using a determined position of the associated marker device and the bone re-registration data.

A system for determining a position of a bone, the system comprising:

• a memory device storing a computer program;
• a computer comprising a processor operable to execute the computer program stored in the memory device to:
• receive bone registration data into the system, the bone registration data being representative of spatial locations of a first set of points which lie on a surface of a bone relative to an associated marker device carried by an associated adjustable cutting block affixed to the bone, wherein the associated adjustable cutting block defines a cutting slot and wherein the associated marker device is rigidly coupled with the cutting block by a plate of the marker device received in the cutting slot of the associated adjustable cutting block thereby establishing a fixed relative position between the associated marker device and the cutting slot of the associated adjustable cutting block;
• process the bone registration data to calculate, based on the bone registration data and the fixed relative position between the associated marker device and the cutting slot of the cutting block, a current relative position between the bone and the cutting slot of the associated adjustable cutting block;
• determine an offset between:
• the current relative position between the cutting slot and the bone, and
• a desired relative position between the cutting slot and the bone;
• output indication information, wherein the indication information is provided for indicating an adjustment to be made to the associated adjustable cutting block based on the determined offset such that a relative movement between the cutting slot carrying the associated marker device and the bone is caused;
• receive degree of freedom data into the system, the degree of freedom data being representative of a number of degrees of freedom of movement of the bone;
• receive, following the adjustment to the associated adjustable cutting block such that the relative movement between the cutting slot carrying the associated marker device and the bone is caused, bone re-registration data into the system, the bone re-registration data being representative of spatial locations of one or more points forming a second set of points which lie on the surface of the bone, wherein a quantity of the one or more points forming the second set of points is based on the received number of degrees of freedom of movement of the bone and wherein the second set of points comprises fewer points than the first set of points;
• and
• track a position of the bone using a determined position of the associated marker device and the bone re-registration data.