Intra-operative determination of a focal length of a camera for medical applications

A program logic stored in a memory device of a computer that when executed on the computer or when loaded onto the computer, causes the computer to perform a method comprising:

• providing uncalibrated camera data of a camera, wherein the uncalibrated camera data comprise an image of at least a part of a tracking system;
• specifying an initial value of a focal length of the camera;
• specifying a working distance value of a distance between the camera and the at least part of the tracking system;
• calculating a distance value of the distance between the camera and the at least part of the tracking system based on the uncalibrated camera data and based on the specified initial value of the focal length of the camera;
• calculating a change factor based on the specified working distance value and the calculated distance value, the calculating comprising calculating a ratio of the specified working distance value and the calculated distance value, and/or wherein the change factor correlates with and/or is indicative of a ratio of the specified working distance value and the calculated distance value;
• and
• calculating an adapted value of the focal length of the camera based on the initial value of the focal length and based on the change factor.

A medical system, comprising:

• a) at least one computer configured to perform a method including:
• providing uncalibrated camera data of a camera, wherein the uncalibrated camera data comprise an image of at least a part of a tracking system;
• specifying an initial value of a focal length of the camera;
• specifying a working distance value of a distance between the camera and the at least part of the tracking system;
• calculating a distance value of the distance between the camera and the at least part of the tracking system based on the uncalibrated camera data and based on the specified initial value of the focal length of the camera;
• calculating a change factor based on the specified working distance value and the calculated distance value, the calculating comprising calculating a ratio of the specified working distance value and the calculated distance value, and/or wherein the change factor correlates with and/or is indicative of a ratio of the specified working distance value and the calculated distance value;
• and
• calculating an adapted value of the focal length of the camera based on the initial value of the focal length and based on the change factor;
• b) at least one electronic data storage device storing at least the uncalibrated camera data;
• and
• c) a medical device for carrying out a medical procedure on the patient,
• wherein the at least one 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 uncalibrated camera data, and
• the medical device for issuing a control signal to the medical device for controlling an operation of the medical device.