by Dowrick, Thomas, Xiao, Guofang, Nikitichev, Daniil, Dursun, Eren, van Berkel, Neils, Allam, Moustafa, Koo, Bongjin, Ramalhinho, Joao, Thompson, Stephen, Gurusamy, Kurinchi, Blandford, Ann, Stoyanov, Danail, Davidson, Brian R. and Clarkson, Matthew J.
Abstract:
Background: Accurate camera and hand-eye calibration are essential to ensure high quality results in image guided surgery applications. The process must also be able to be undertaken by a non-expert user in a surgical setting. Purpose: This work seeks to identify a suitable method for tracked stereo laparoscope calibration within theatre. Methods: A custom calibration rig, to enable rapid calibration in a surgical setting, was designed. The rig was compared against freehand calibration. Stereo reprojection, stereo reconstruction, tracked stereo reprojection and tracked stereo reconstruction error metrics were used to evaluate calibration quality. Results: Use of the calibration rig reduced mean errors: reprojection (1.47mm [SD 0.13] vs 3.14mm [SD 2.11], p-value 1e-8), reconstruction (1.37px [SD 0.10] vs 10.10px [SD 4.54], p-value 6e-7) and tracked reconstruction (1.38mm [SD 0.10] vs 12.64mm [SD 4.34], p-value 1e-6) compared with freehand calibration. The use of a ChArUco pattern yielded slightly lower reprojection errors, while a dot grid produced lower reconstruction errors and was more robust under strong global illumination. Conclusion: The use of the calibration rig results in a statistically significant decrease in calibration error metrics, versus freehand calibration, and represents the preferred approach for use in the operating theatre.
Reference:
T. Dowrick, G. Xiao, D. Nikitichev, E. Dursun, N. van Berkel, M. Allam, B. Koo, J. Ramalhinho, S. Thompson, K. Gurusamy, A. Blandford, D. Stoyanov, B. R. Davidson, M. J. Clarkson, "Evaluation of a calibration rig for stereo laparoscopes", Medical Physics, 2023, to appear.
Bibtex Entry:
@article{Dowrick2023CalibrationRig,
title = {Evaluation of a calibration rig for stereo laparoscopes},
author = {Dowrick, Thomas and Xiao, Guofang and Nikitichev, Daniil and Dursun, Eren and van Berkel, Neils and Allam, Moustafa and Koo, Bongjin and Ramalhinho, Joao and Thompson, Stephen and Gurusamy, Kurinchi and Blandford, Ann and Stoyanov, Danail and Davidson, Brian R. and Clarkson, Matthew J.},
year = 2023,
journal = {Medical Physics},
pages = {to appear},
doi = {10.1002/mp.16310},
url = {https://nielsvanberkel.com/files/publications/medicalphysics2023a.pdf},
abstract = {Background: Accurate camera and hand-eye calibration are essential to ensure high quality results in image guided surgery applications. The process must also be able to be undertaken by a non-expert user in a surgical setting. Purpose: This work seeks to identify a suitable method for tracked stereo laparoscope calibration within theatre. Methods: A custom calibration rig, to enable rapid calibration in a surgical setting, was designed. The rig was compared against freehand calibration. Stereo reprojection, stereo reconstruction, tracked stereo reprojection and tracked stereo reconstruction error metrics were used to evaluate calibration quality. Results: Use of the calibration rig reduced mean errors: reprojection (1.47mm [SD 0.13] vs 3.14mm [SD 2.11], p-value 1e-8), reconstruction (1.37px [SD 0.10] vs 10.10px [SD 4.54], p-value 6e-7) and tracked reconstruction (1.38mm [SD 0.10] vs 12.64mm [SD 4.34], p-value 1e-6) compared with freehand calibration. The use of a ChArUco pattern yielded slightly lower reprojection errors, while a dot grid produced lower reconstruction errors and was more robust under strong global illumination. Conclusion: The use of the calibration rig results in a statistically significant decrease in calibration error metrics, versus freehand calibration, and represents the preferred approach for use in the operating theatre.},
}