Gregory Hager - Academia.edu (original) (raw)
Papers by Gregory Hager
The ability to accurately recognize elementary surgical gestures is a step- ping stone to automat... more The ability to accurately recognize elementary surgical gestures is a step- ping stone to automated surgical assessment and surgical training. However, as the pool of subjects increases, variation in surgical techniqu es and unanticipated mo- tion increases the challenge of creating robust statistica l models of gestures. This paper examines the applicability of advanced modeling techniques from automated speech recognition
Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006., 2006
We present a system architecture for robust target following with a mobile robot. The system is b... more We present a system architecture for robust target following with a mobile robot. The system is based on tracking multiple cues in binocular stereo images using the XVision toolkit. Fusion of complementary information in the images, including texture, color and depth, combined with a fast optimized processing reduces the possibility of loosing the tracked object in a dynamic scene with
Abstract, We present a platform for human-machine in-terfaces that provides functionality for rob... more Abstract, We present a platform for human-machine in-terfaces that provides functionality for robust, unencumbered interaction: the 4D Touchpad (4DT). The goal is direct in-teraction with interface components through intuitive actions and gestures. The 4DT is based on the 3D-2D Projection-based mode of the VICs framework. The fundamental idea behind VICs is that expensive global image processing with user modeling and
Medical Image Computing and Computer-Assisted Intervention, 2001
Medical Image Computing and Computer-Assisted Intervention, 2001
We report on applications of an augmentation system for cooperative fine manipulation using the s... more We report on applications of an augmentation system for cooperative fine manipulation using the steady hand manipulation paradigm. Using the "steady hand" robot as the experimental platform we investigate using such a system for creating composite retinal images using a GRIN lens endoscope and for puncturing small blood vessels in the retina.
2008 2nd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, 2008
2009 IEEE International Conference on Robotics and Automation, 2009
2007 IEEE Conference on Computer Vision and Pattern Recognition, 2007
Proceedings 2007 IEEE International Conference on Robotics and Automation, 2007
Lecture Notes in Computer Science, 2011
In retinal surgery, surgeons face difficulties such as indirect visualization of surgical targets... more In retinal surgery, surgeons face difficulties such as indirect visualization of surgical targets, physiological tremor and lack of tactile feedback. Such difficulties increase the risks of incorrect surgical gestures which may cause retinal damage. In this context, robotic assistance has the potential to overcome current technical limitations and increase surgical safety. In this paper we present a method for robustly
We present the design and implementation of a vi- sion-based system for cooperative manipulation ... more We present the design and implementation of a vi- sion-based system for cooperative manipulation at millimeter to micrometer scales. The system is based on an admittance control algorithm that implements a broad class of guidance modes called virtual fixtures. A virtual fixture, like a real fixture, limits the mo- tion of a tool to a prescribed class or range of
IFMBE Proceedings, 2009
In this paper, we describe current progress on the development of a Computer Assisted Diagnosis S... more In this paper, we describe current progress on the development of a Computer Assisted Diagnosis System (CAD) for the classification of Barrett’s esophagus and associated neoplasia. Barrett’s esophagus is a condition in which normal squamous mucosa is replaced by columnar epithelium, which is similar to the lining of the intestine. Barrett’s esophagus as a known precancerous condition leading to esophageal
Intelligent Robots and Systems, 1995
Recent advances in visual servoing theory and practice now make it possible to accurately and rob... more Recent advances in visual servoing theory and practice now make it possible to accurately and robustly position a robot manipulator relative to a target, Both the vision and con-trol algorithms are extremely simple, however they must be initialized on task-relevant features in order ...
Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171), 1998
Lecture Notes in Computer Science, 2013
Automatic surgical gesture segmentation and recognition can provide useful feedback for surgical ... more Automatic surgical gesture segmentation and recognition can provide useful feedback for surgical training in robotic surgery. Most prior work in this field relies on the robot's kinematic data. Although recent work [1,2] shows that the robot's video data can be equally effective for surgical gesture recognition, the segmentation of the video into gestures is assumed to be known. In this paper, we propose a framework for joint segmentation and recognition of surgical gestures from kinematic and video data. Unlike prior work that relies on either frame-level kinematic cues, or segment-level kinematic or video cues, our approach exploits both cues by using a combined Markov/semi-Markov conditional random field (MsM-CRF) model. Our experiments show that the proposed model improves over a Markov or semi-Markov CRF when using video data alone, gives results that are comparable to state-of-the-art methods on kinematic data alone, and improves over state-of-the-art methods when combining kinematic and video data.
Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171), 1998
Page 1. FM02 11:30 Proceedings of the 37th IEEE Conference on Decision & Control Tampa, F... more Page 1. FM02 11:30 Proceedings of the 37th IEEE Conference on Decision & Control Tampa, Florida USA December 1998 Decidability of Robot Positioning Tasks Using Stereo Vision Systems* JP Hespanha Z. Dodds G. D. Hager A. S. Morse ...
Proceedings. 1998 IEEE International Conference on Robotics and Automation (Cat. No.98CH36146), 1998
The ability to accurately recognize elementary surgical gestures is a step- ping stone to automat... more The ability to accurately recognize elementary surgical gestures is a step- ping stone to automated surgical assessment and surgical training. However, as the pool of subjects increases, variation in surgical techniqu es and unanticipated mo- tion increases the challenge of creating robust statistica l models of gestures. This paper examines the applicability of advanced modeling techniques from automated speech recognition
Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006., 2006
We present a system architecture for robust target following with a mobile robot. The system is b... more We present a system architecture for robust target following with a mobile robot. The system is based on tracking multiple cues in binocular stereo images using the XVision toolkit. Fusion of complementary information in the images, including texture, color and depth, combined with a fast optimized processing reduces the possibility of loosing the tracked object in a dynamic scene with
Abstract, We present a platform for human-machine in-terfaces that provides functionality for rob... more Abstract, We present a platform for human-machine in-terfaces that provides functionality for robust, unencumbered interaction: the 4D Touchpad (4DT). The goal is direct in-teraction with interface components through intuitive actions and gestures. The 4DT is based on the 3D-2D Projection-based mode of the VICs framework. The fundamental idea behind VICs is that expensive global image processing with user modeling and
Medical Image Computing and Computer-Assisted Intervention, 2001
Medical Image Computing and Computer-Assisted Intervention, 2001
We report on applications of an augmentation system for cooperative fine manipulation using the s... more We report on applications of an augmentation system for cooperative fine manipulation using the steady hand manipulation paradigm. Using the "steady hand" robot as the experimental platform we investigate using such a system for creating composite retinal images using a GRIN lens endoscope and for puncturing small blood vessels in the retina.
2008 2nd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, 2008
2009 IEEE International Conference on Robotics and Automation, 2009
2007 IEEE Conference on Computer Vision and Pattern Recognition, 2007
Proceedings 2007 IEEE International Conference on Robotics and Automation, 2007
Lecture Notes in Computer Science, 2011
In retinal surgery, surgeons face difficulties such as indirect visualization of surgical targets... more In retinal surgery, surgeons face difficulties such as indirect visualization of surgical targets, physiological tremor and lack of tactile feedback. Such difficulties increase the risks of incorrect surgical gestures which may cause retinal damage. In this context, robotic assistance has the potential to overcome current technical limitations and increase surgical safety. In this paper we present a method for robustly
We present the design and implementation of a vi- sion-based system for cooperative manipulation ... more We present the design and implementation of a vi- sion-based system for cooperative manipulation at millimeter to micrometer scales. The system is based on an admittance control algorithm that implements a broad class of guidance modes called virtual fixtures. A virtual fixture, like a real fixture, limits the mo- tion of a tool to a prescribed class or range of
IFMBE Proceedings, 2009
In this paper, we describe current progress on the development of a Computer Assisted Diagnosis S... more In this paper, we describe current progress on the development of a Computer Assisted Diagnosis System (CAD) for the classification of Barrett’s esophagus and associated neoplasia. Barrett’s esophagus is a condition in which normal squamous mucosa is replaced by columnar epithelium, which is similar to the lining of the intestine. Barrett’s esophagus as a known precancerous condition leading to esophageal
Intelligent Robots and Systems, 1995
Recent advances in visual servoing theory and practice now make it possible to accurately and rob... more Recent advances in visual servoing theory and practice now make it possible to accurately and robustly position a robot manipulator relative to a target, Both the vision and con-trol algorithms are extremely simple, however they must be initialized on task-relevant features in order ...
Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171), 1998
Lecture Notes in Computer Science, 2013
Automatic surgical gesture segmentation and recognition can provide useful feedback for surgical ... more Automatic surgical gesture segmentation and recognition can provide useful feedback for surgical training in robotic surgery. Most prior work in this field relies on the robot's kinematic data. Although recent work [1,2] shows that the robot's video data can be equally effective for surgical gesture recognition, the segmentation of the video into gestures is assumed to be known. In this paper, we propose a framework for joint segmentation and recognition of surgical gestures from kinematic and video data. Unlike prior work that relies on either frame-level kinematic cues, or segment-level kinematic or video cues, our approach exploits both cues by using a combined Markov/semi-Markov conditional random field (MsM-CRF) model. Our experiments show that the proposed model improves over a Markov or semi-Markov CRF when using video data alone, gives results that are comparable to state-of-the-art methods on kinematic data alone, and improves over state-of-the-art methods when combining kinematic and video data.
Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171), 1998
Page 1. FM02 11:30 Proceedings of the 37th IEEE Conference on Decision & Control Tampa, F... more Page 1. FM02 11:30 Proceedings of the 37th IEEE Conference on Decision & Control Tampa, Florida USA December 1998 Decidability of Robot Positioning Tasks Using Stereo Vision Systems* JP Hespanha Z. Dodds G. D. Hager A. S. Morse ...
Proceedings. 1998 IEEE International Conference on Robotics and Automation (Cat. No.98CH36146), 1998