A surgical microscope is an important tool in many medical procedures, including procedures performed on the spine and brain. With current advances in optics and digital microscopes, surgeons are able to operate with more visualization power, including higher resolution and higher magnification, allowing surgeons to see much finer details in the surgical field. Surgeons are becoming increasingly accustomed to zooming in to see the details of the anatomy and operating at higher magnifications. It is common for surgeons to switch and select different zoom settings for different steps of a procedure.
There is a tradeoff in any surgical microscope—the higher the magnification and optical resolution that the surgeon utilizes, the smaller the depth of field of the captured image. In procedures, such as spine and brain surgeries, where the surgical field can be quite deep (e.g., in minimal invasive surgeries), this means that the entire surgical field cannot stay in focus at high magnification. When the entire field of interest cannot be in focus, a surgeon may switch to a lower magnification to gain a larger depth of field to focus the entire field of interest. This may be frustrating and time-consuming for the surgeon, if the surgeon repeatedly changes magnification. Alternatively, the surgeon may keep a higher magnification, but repeatedly switch the focus region (e.g., manually or with tracked tools such as tracked pointers or suction tools) to keep the operating region in focus. Manually changing the focus region may be frustrating and time-consuming. Using a tracked tool to change the focus region may require the surgeon to switch between a currently used tool and the tracked tool, which can also be frustrating and time-consuming for the surgeon. Another approach using tracked tools is for all tools used in the procedure to be trackable. This can be expensive and computationally burdensome for the tracking system. Further, adding trackable markers to all tools can sacrifices usability and comfort level of the tools.
It would be useful to provide a solution that can change the magnification and/or focus of the captured image, with consideration of one or more of the above concerns.