High-Accuracy Head Tracking for Cranial Radiation Therapy

Project Description

Thermoplastic mask
Thermoplastic mask

Compensating for patient motion constitutes a challenging as well as important problem for high precision cranial radiotherapy. Common approaches rely on patient immobilization using stereotactic frames, masks or bite bars, or employ X-ray based monitoring and motion compensation such as the 6D skull tracking used by the CyberKnife®. These techniques entail several drawbacks: First, the mask systems are rather inconvenient and also not tolerated by all patients. They further provide no motion monitoring during the treatment - the patient is assumed to be fixed. This is indeed only true up to errors in millimeter range. Second, X-ray based imaging exposes the subject to an unnecessary amount of additional radiation. This exposure also limits the head-tracking speed to about 1 Hz.

Therefore, marker-less optical head-tracking provides a promising alternative, where a laser constantly scans the patient's forehead. This approach requires only light patient fixation  and  provides a basis for fast real-time monitoring. While promising results have already been achieved using commercial systems such as the Microsoft Kinect®, the accuracy still lags behind the desirable standard of sub-millimeter accuracy. One major drawback of marker-less tracking is given by the lack of point-to-point correspondences. Finding these, for objects which are not strictly rigid, is challenging and prone to registration errors. Point cloud matching algorithms are used which rely, if at all, on a few spatial landmarks. The surface geometry very often introduces further ambiguities which lead to a convergence into local error minima and hence poor robustness.

Figure (1) Laser scanning optics, (2) Laser scan of the forehead, (3) MRI segmented tissue ground truth.

By combining expertise from the fields of computer science, electronics, applied mathematics, machine learning and biomedical optics our research group works on laser triangulation, dedicated electronic and optical hardware, as well as enhanced tracking approaches. Specifically the feasibility of optically detecting subcutaneous as well as cutaneous structures is evaluated. The structures serve as supportive landmarks and can be used to localize rigid cranial bone. To uncover these landmarks the developed system extracts optical  backscatter features. These are obtained from near-infrared (NIR) laser scans of the forehead. Finally, machine learning algorithms such as Gaussian Processes or Support Vector regression are used to obtain the tissue thickness. In cooperation with Varian Medical, Inc., the world-leading manufacturer for LINACs, we develop a novel prototype for high-accuracy head-tracking  in radiotherapy.

Figure (1) Triangulated 3D surface point cloud, (2) feature-labeled point cloud, (3) reconstructed tissue-labeled point cloud.

Publications

2019

Jirapong Manit, Luise Preusse, Achim Schweikard, and Floris Ernst,
Human Forehead Recognition: A Novel Biometric Modality based on NIR Laser Backscattering Feature Image using Deep Transfer Learning, IET Biometrics , vol. online first, 2019. Institution of Engineering and Technology.
DOI:10.1049/iet-bmt.2019.0015
File: iet-bmt.2019.0015

2018

Jirapong Manit, Floris Ernst, and Achim Schweikard,
Relationship between NIR laser power and the human forehead tissue backscattering image features: Photonic Solutions for Better Health Care VI, Popp, Jürgen and Tuchin, Valery V. and Pavone, Francesco S., Eds. Strasbourg (France): SPIE, 2018. pp. 136.
DOI:10.1117/12.2306827
ISBN:9781510618961
File: 12.2306827

2017

Jirapong Manit, Achim Schweikard, and Floris Ernst,
Deep Convolutional Neural Network Approach for Forehead Tissue Thickness Estimation from NIR Laser Backscattering Images, Dresden, Germany; Dresden , 2017. pp. submitted.
File:
Jirapong Manit, Christina Bremer, Achim Schweikard, and Floris Ernst,
Patient identification using a near-infrared laser scanner: Image-Guided Procedures, Robotic Interventions, and Modeling, Orlando, FL: SPIE, 2017. pp. 101352L.
DOI:10.1117/12.2254963
File: 12.2254963

2016

Tobias Wissel, Patrick Stüber, Benjamin Wagner, Ralf Bruder, Christian Erdmann, Christin-Sophie Deutz, Benjamin Sack, Jirapong Manit, Achim Schweikard, and Floris Ernst,
Enhanced Optical Head Tracking for Cranial Radiotherapy: Supporting Surface Registration by Cutaneous Structures, International Journal of Radiation Oncology, Biology, Physics , vol. 95, no. 2, pp. 810-817, 2016.
DOI:10.1016/j.ijrobp.2016.01.041
File: j.ijrobp.2016.01.041

2015

Tobias Wissel, Patrick Stüber, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Enhanced Tissue Thickness Computation by Exploiting Local Neighborhoods, Barcelona, Spain , 2015.
Tobias Wissel, Patrick Stüber, Benjamin Wagner, Achim Schweikard, and Floris Ernst,
Tissue Segmentation from Head MRI: A Ground Truth Validation for Feature-Enhanced Tracking, Lübeck, Germany , 2015. pp. S184.
DOI:10.1515/bmt-2015-5008
File: bmt-2015-5008
Benjamin Wagner, Patrick Stüber, Tobias Wissel, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Ray Interpolation for Generic Triangulation Based on a Galvanometric Laser Scanning System, New York: IEEE, 2015. pp. 1419-1422.
DOI:10.1109/ISBI.2015.7164142
File: ISBI.2015.7164142
Floris Ernst, Tobias Wissel, Patrick Stüber, Benjamin Wagner, Ralf Bruder, and Achim Schweikard,
Optical localization of the human skull for cranial radiation therapy, Atlanta, GA, USA , 2015.
Tobias Wissel, Patrick Stüber, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Enriching 3D optical surface scans with prior knowledge: tissue thickness computation by exploiting local neighborhoods, International Journal of Computer Assisted Radiology and Surgery , vol. 11, no. 4, pp. 569-579, 2015. Springer Berlin Heidelberg.
DOI:10.1007/s11548-015-1246-6
File: s11548-015-1246-6
Tobias Wissel, Benjamin Wagner, Patrick Stüber, Achim Schweikard, and Floris Ernst,
Data-driven Learning for Calibrating Galvanometric Laser Scanners, IEEE Sensors Journal , vol. 15, no. 10, pp. 5709-5717, 2015.
DOI:10.1109/jsen.2015.2447835
File: jsen.2015.2447835
Tobias Wissel, Patrick Stüber, Benjamin Wagner, Achim Schweikard, and Floris Ernst,
Efficient Estimation of Tissue Thicknesses using Sparse Approximation for Gaussian Processes, Milano, Italy: IEEE, 2015. pp. 7015-7018.
DOI:10.1109/EMBC.2015.7320007
File: EMBC.2015.7320007
S. Lüdtke, Benjamin Wagner, Ralf Bruder, Patrick Stüber, Floris Ernst, Achim Schweikard, and Tobias Wissel,
Calibration of galvanometric laser scanners using statistical learning methods, Berlin, Heidelberg, New York; Lübeck, Germany: Springer, 2015. pp. 467-472.
DOI:10.1007/978-3-662-46224-9_80
File: 978-3-662-46224-9_80
Floris Ernst, Achim Schweikard, Patrick Stüber, Ralf Bruder, Benjamin Wagner, and Tobias Wissel,
Analysis of feature stability for laser-based determination of tissue thickness, San Francisco, CA , 2015. pp. 93130Q.
DOI:10.1117/12.2078722
File: 12.2078722
Patrick Stüber, Benjamin Wagner, Tobias Wissel, Ralf Bruder, Achim Schweikard, and Floris Ernst,
An Approach to Improve Accuracy of Optical Tracking Systems in Cranial Radiation Therapy, Cureus , vol. 7, no. 1, pp. e239, 2015.
Jirapong Manit, Tobias Wissel, Patrick Stüber, Achim Schweikard, and Floris Ernst,
A Study of Gaussian Noise Effects on Skin Thickness Measurement, Lübeck, Germany , 2015. pp. S190.
DOI:10.1515/bmt-2015-5008
File: bmt-2015-5008

2014

Floris Ernst, Ralf Bruder, Tobias Wissel, Patrick Stüber, Benjamin Wagner, and Achim Schweikard,
Measuring cranial soft tissue thickness with MRI or pressure-compensated tracked ultrasound, British Journal of Medicine and Medical Research , vol. 4, no. 4, pp. 937-948, 2014.
Tobias Wissel, Patrick Stüber, Benjamin Wagner, Robert Dürichen, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Tissue Thickness Estimation for High Precision Head-Tracking using a Galvanometric Laser Scanner - A Case Study, Chicago, IL: IEEE, 2014. pp. 3106-3109.
Patrick Stüber, Tobias Wissel, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
A comparison of different hardware design approaches for feature-supported optical tracking with respect to angular dependencies, 2014. pp. 204.
DOI:10.1118/1.4888259
File: 1.4888259
Jan Graßhoff, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Kalman Filter based Head Tracking for Cranial Radiation Therapy with low-cost Range-Imaging Cameras, Deserno, Thomas M. and Handels, Heinz and Tolxdorff, Thomas and Meinzer, Hans-Peter and Ehrhardt, Jan, Eds. Aachen, Germany; Berlin, Heidelberg: Springer, 2014. pp. 324-329.
DOI:10.1007/978-3-642-54111-7_60
File: 978-3-642-54111-7_60
Tobias Wissel, Patrick Stüber, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Angle influence and compensation for marker-less head tracking based on laser scanners, Fukuoka, Japan , 2014. pp. 62-63.
File:
Benjamin Wagner, Patrick Stüber, Tobias Wissel, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Accuracy analysis for triangulation and tracking based on time-multiplexed structured light, Medical Physics , vol. 41, no. 8, pp. 082701, 2014.
DOI:10.1118/1.4890093
File: 1.4890093

2013

Benjamin Wagner, Patrick Stüber, Tobias Wissel, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Accuracy of object tracking based on time-multiplexed structured light, Innsbruck, Austria , 2013. pp. 139-142.
Patrick Stüber, Tobias Wissel, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
An improvement for the scanning process in high accuracy head tracking, Innsbruck, Austria , 2013. pp. 179-182.
Patrick Stüber, Tobias Wissel, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Design and evaluation of a highly accurate optical setup for backscatter analysis, Treuer, Harald, Eds. Cologne, Germany , 2013. pp. 181-186.

Veröffentlichungen

2019

Jirapong Manit, Luise Preusse, Achim Schweikard, and Floris Ernst,
Human Forehead Recognition: A Novel Biometric Modality based on NIR Laser Backscattering Feature Image using Deep Transfer Learning, IET Biometrics , vol. online first, 2019. Institution of Engineering and Technology.
DOI:10.1049/iet-bmt.2019.0015
File: iet-bmt.2019.0015

2018

Jirapong Manit, Floris Ernst, and Achim Schweikard,
Relationship between NIR laser power and the human forehead tissue backscattering image features: Photonic Solutions for Better Health Care VI, Popp, Jürgen and Tuchin, Valery V. and Pavone, Francesco S., Eds. Strasbourg (France): SPIE, 2018. pp. 136.
DOI:10.1117/12.2306827
ISBN:9781510618961
File: 12.2306827

2017

Jirapong Manit, Achim Schweikard, and Floris Ernst,
Deep Convolutional Neural Network Approach for Forehead Tissue Thickness Estimation from NIR Laser Backscattering Images, Dresden, Germany; Dresden , 2017. pp. submitted.
File:
Jirapong Manit, Christina Bremer, Achim Schweikard, and Floris Ernst,
Patient identification using a near-infrared laser scanner: Image-Guided Procedures, Robotic Interventions, and Modeling, Orlando, FL: SPIE, 2017. pp. 101352L.
DOI:10.1117/12.2254963
File: 12.2254963

2016

Tobias Wissel, Patrick Stüber, Benjamin Wagner, Ralf Bruder, Christian Erdmann, Christin-Sophie Deutz, Benjamin Sack, Jirapong Manit, Achim Schweikard, and Floris Ernst,
Enhanced Optical Head Tracking for Cranial Radiotherapy: Supporting Surface Registration by Cutaneous Structures, International Journal of Radiation Oncology, Biology, Physics , vol. 95, no. 2, pp. 810-817, 2016.
DOI:10.1016/j.ijrobp.2016.01.041
File: j.ijrobp.2016.01.041

2015

Tobias Wissel, Patrick Stüber, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Enhanced Tissue Thickness Computation by Exploiting Local Neighborhoods, Barcelona, Spain , 2015.
Tobias Wissel, Patrick Stüber, Benjamin Wagner, Achim Schweikard, and Floris Ernst,
Tissue Segmentation from Head MRI: A Ground Truth Validation for Feature-Enhanced Tracking, Lübeck, Germany , 2015. pp. S184.
DOI:10.1515/bmt-2015-5008
File: bmt-2015-5008
Benjamin Wagner, Patrick Stüber, Tobias Wissel, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Ray Interpolation for Generic Triangulation Based on a Galvanometric Laser Scanning System, New York: IEEE, 2015. pp. 1419-1422.
DOI:10.1109/ISBI.2015.7164142
File: ISBI.2015.7164142
Floris Ernst, Tobias Wissel, Patrick Stüber, Benjamin Wagner, Ralf Bruder, and Achim Schweikard,
Optical localization of the human skull for cranial radiation therapy, Atlanta, GA, USA , 2015.
Tobias Wissel, Patrick Stüber, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Enriching 3D optical surface scans with prior knowledge: tissue thickness computation by exploiting local neighborhoods, International Journal of Computer Assisted Radiology and Surgery , vol. 11, no. 4, pp. 569-579, 2015. Springer Berlin Heidelberg.
DOI:10.1007/s11548-015-1246-6
File: s11548-015-1246-6
Tobias Wissel, Benjamin Wagner, Patrick Stüber, Achim Schweikard, and Floris Ernst,
Data-driven Learning for Calibrating Galvanometric Laser Scanners, IEEE Sensors Journal , vol. 15, no. 10, pp. 5709-5717, 2015.
DOI:10.1109/jsen.2015.2447835
File: jsen.2015.2447835
Tobias Wissel, Patrick Stüber, Benjamin Wagner, Achim Schweikard, and Floris Ernst,
Efficient Estimation of Tissue Thicknesses using Sparse Approximation for Gaussian Processes, Milano, Italy: IEEE, 2015. pp. 7015-7018.
DOI:10.1109/EMBC.2015.7320007
File: EMBC.2015.7320007
S. Lüdtke, Benjamin Wagner, Ralf Bruder, Patrick Stüber, Floris Ernst, Achim Schweikard, and Tobias Wissel,
Calibration of galvanometric laser scanners using statistical learning methods, Berlin, Heidelberg, New York; Lübeck, Germany: Springer, 2015. pp. 467-472.
DOI:10.1007/978-3-662-46224-9_80
File: 978-3-662-46224-9_80
Floris Ernst, Achim Schweikard, Patrick Stüber, Ralf Bruder, Benjamin Wagner, and Tobias Wissel,
Analysis of feature stability for laser-based determination of tissue thickness, San Francisco, CA , 2015. pp. 93130Q.
DOI:10.1117/12.2078722
File: 12.2078722
Patrick Stüber, Benjamin Wagner, Tobias Wissel, Ralf Bruder, Achim Schweikard, and Floris Ernst,
An Approach to Improve Accuracy of Optical Tracking Systems in Cranial Radiation Therapy, Cureus , vol. 7, no. 1, pp. e239, 2015.
Jirapong Manit, Tobias Wissel, Patrick Stüber, Achim Schweikard, and Floris Ernst,
A Study of Gaussian Noise Effects on Skin Thickness Measurement, Lübeck, Germany , 2015. pp. S190.
DOI:10.1515/bmt-2015-5008
File: bmt-2015-5008

2014

Floris Ernst, Ralf Bruder, Tobias Wissel, Patrick Stüber, Benjamin Wagner, and Achim Schweikard,
Measuring cranial soft tissue thickness with MRI or pressure-compensated tracked ultrasound, British Journal of Medicine and Medical Research , vol. 4, no. 4, pp. 937-948, 2014.
Tobias Wissel, Patrick Stüber, Benjamin Wagner, Robert Dürichen, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Tissue Thickness Estimation for High Precision Head-Tracking using a Galvanometric Laser Scanner - A Case Study, Chicago, IL: IEEE, 2014. pp. 3106-3109.
Patrick Stüber, Tobias Wissel, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
A comparison of different hardware design approaches for feature-supported optical tracking with respect to angular dependencies, 2014. pp. 204.
DOI:10.1118/1.4888259
File: 1.4888259
Jan Graßhoff, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Kalman Filter based Head Tracking for Cranial Radiation Therapy with low-cost Range-Imaging Cameras, Deserno, Thomas M. and Handels, Heinz and Tolxdorff, Thomas and Meinzer, Hans-Peter and Ehrhardt, Jan, Eds. Aachen, Germany; Berlin, Heidelberg: Springer, 2014. pp. 324-329.
DOI:10.1007/978-3-642-54111-7_60
File: 978-3-642-54111-7_60
Tobias Wissel, Patrick Stüber, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Angle influence and compensation for marker-less head tracking based on laser scanners, Fukuoka, Japan , 2014. pp. 62-63.
File:
Benjamin Wagner, Patrick Stüber, Tobias Wissel, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Accuracy analysis for triangulation and tracking based on time-multiplexed structured light, Medical Physics , vol. 41, no. 8, pp. 082701, 2014.
DOI:10.1118/1.4890093
File: 1.4890093

2013

Benjamin Wagner, Patrick Stüber, Tobias Wissel, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Accuracy of object tracking based on time-multiplexed structured light, Innsbruck, Austria , 2013. pp. 139-142.
Patrick Stüber, Tobias Wissel, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
An improvement for the scanning process in high accuracy head tracking, Innsbruck, Austria , 2013. pp. 179-182.
Patrick Stüber, Tobias Wissel, Benjamin Wagner, Ralf Bruder, Achim Schweikard, and Floris Ernst,
Design and evaluation of a highly accurate optical setup for backscatter analysis, Treuer, Harald, Eds. Cologne, Germany , 2013. pp. 181-186.