TY - JOUR

T1 - Comparative study on surface reconstruction accuracy of stereo imaging devices for microsurgery

AU - Schoob, Andreas

AU - Kundrat, Dennis

AU - Kahrs, Lüder A.

AU - Ortmaier, Tobias

N1 - Funding information: The research leading to the presented results has received funding from the European Union Seventh Framework Programme FP7/2007–2013 Challenge 2 Cognitive Systems, Interaction, Robotics under Grant agreement RALP-No. 288663. We furthermore thank Prof. Giorgio Peretti from the Department of Otorhinolaryngology, University of Genoa, Italy providing in vivo laryngeal image data.

PY - 2016/1

Y1 - 2016/1

N2 - Purpose: Processing stereoscopic image data is an emerging field. Especially in microsurgery that requires sub-millimeter accuracy, application of stereo-based methods on endoscopic and microscopic scenarios is of major interest. In this context, direct comparison of stereo-based surface reconstruction applied to several camera settings is presented. Methods: A method for stereo matching is proposed and validated on in-vitro data. Demonstrating suitability for surgical scenarios, this method is applied to two custom-made stereo cameras, a miniaturized, bendable surgical endoscope and an operating microscope. Reconstruction accuracy is assessed on a custom-made reference sample. Subsequent to its fabrication, a coordinate measuring arm is used to acquire ground truth. Next, the sample is positioned by a robot at varying distances to each camera. Surface estimation is performed, while the specimen is localized based on. markers. Finally, the error between estimated surface and ground truth is computed. Results: Sample measurement with the coordinate measuring arm yields reliable ground truth data with a root-mean-square error of 11.2 μm. Overall surface reconstruction with analyzed cameras is quantified by a root-mean-square error of less than 0.18 mm. Microscope setting with the highest magnification yields the most accurate measurement, while the maximum deviation does not exceed 0.5 mm. Custom-made stereo cameras perform similar but with outliers of increased magnitude. Miniaturized, bendable surgical endoscope produces the maximum error of approximately 1.2mm. Conclusions: Reconstruction results reveal that microscopic imaging outperforms investigated chip-on-the-tip solutions, i.e., at higher magnification. Nonetheless, custom-made cameras are suitable for application in microsurgery. Although reconstruction with the miniaturized endoscope is more inaccurate, it provides a good trade-off between accuracy, outer dimensions and accessibility to hard-to-reach surgical sites.

AB - Purpose: Processing stereoscopic image data is an emerging field. Especially in microsurgery that requires sub-millimeter accuracy, application of stereo-based methods on endoscopic and microscopic scenarios is of major interest. In this context, direct comparison of stereo-based surface reconstruction applied to several camera settings is presented. Methods: A method for stereo matching is proposed and validated on in-vitro data. Demonstrating suitability for surgical scenarios, this method is applied to two custom-made stereo cameras, a miniaturized, bendable surgical endoscope and an operating microscope. Reconstruction accuracy is assessed on a custom-made reference sample. Subsequent to its fabrication, a coordinate measuring arm is used to acquire ground truth. Next, the sample is positioned by a robot at varying distances to each camera. Surface estimation is performed, while the specimen is localized based on. markers. Finally, the error between estimated surface and ground truth is computed. Results: Sample measurement with the coordinate measuring arm yields reliable ground truth data with a root-mean-square error of 11.2 μm. Overall surface reconstruction with analyzed cameras is quantified by a root-mean-square error of less than 0.18 mm. Microscope setting with the highest magnification yields the most accurate measurement, while the maximum deviation does not exceed 0.5 mm. Custom-made stereo cameras perform similar but with outliers of increased magnitude. Miniaturized, bendable surgical endoscope produces the maximum error of approximately 1.2mm. Conclusions: Reconstruction results reveal that microscopic imaging outperforms investigated chip-on-the-tip solutions, i.e., at higher magnification. Nonetheless, custom-made cameras are suitable for application in microsurgery. Although reconstruction with the miniaturized endoscope is more inaccurate, it provides a good trade-off between accuracy, outer dimensions and accessibility to hard-to-reach surgical sites.

KW - Endoscope

KW - Microscope

KW - Stereo matching

KW - Surgical vision

UR - http://www.scopus.com/inward/record.url?scp=84955720636&partnerID=8YFLogxK

U2 - 10.1007/s11548-015-1240-z

DO - 10.1007/s11548-015-1240-z

M3 - Article

C2 - 26100121

AN - SCOPUS:84955720636

VL - 11

SP - 145

EP - 156

JO - International journal of computer assisted radiology and surgery

JF - International journal of computer assisted radiology and surgery

SN - 1861-6410

IS - 1

ER -