Surgical navigation is critical in assisting surgeons in confirming the spatial positions of surgical instruments and patients in minimally invasive surgery. Traditional tracking systems in surgical navigation have different types, from marker-based optical tracking to magnetic tracking systems. As a promising one, marker-based visible optical tracking systems can provide both surgical tools’ information and environmental information without magnetic interference. However, to ensure positional measurement accuracy and the spatial degrees of freedom in tracking, markers of the tracking tool should be dedicated non-collinearly. Thus, it is difficult to apply current marker-based optical tracking systems conveniently in narrow or limited spaces due to the large spatial volumes of the tracking tools. To provide a tracking tool with compact volume and high accurate positional measurement accuracy, we propose a spatial position measurement system for surgical navigation, especially in limited surgical environment in MIS.
We generate 3-D image markers with spatial information encoded to 2-D images, design tracking tools with the 3-D image markers, and analyze the tracking tools’ theoretical spatial errors, which are primarily limited by the spatial distribution of reconstructed fiducial 3-D markers. A pattern analysis-based positional measurement algorithm is developed to calculate the tool’s spatial information using its spatial configuration. Evaluation experiments and further surgical navigation feasibility studies were conducted to demonstrate the accuracy and effectiveness of the proposed system. Results demonstrate that the proposed tracking tools are of potential use to assist surgeons intuitively and accurately in minimally invasive surgery in a limited space.
The novel spatial position measurement system using 3-D image marker can be utilized in limited space in MIS and other commercial fields for flexible spatial position measurement with further research.