Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930306
Yim-Pan Chui, P. Heng
Nowadays, medical diagnosis in critical diseases are seldom executed by only one person. Often, in difficult cases, two or more physicians are involved to reach a diagnosis. The growth of the World Wide Web and the modern trend of cooperative work in scientific research gave rise to a new class of systems, the so-called collaborative visualization systems. We present a new attitude dead reckoning mechanism in a collaborative medical visualization system (CMVS). Using quaterions as the description of attitude, we derive a general trajectory construction scheme of attitude that extrapolates a number of previous packets in order to form the future trajectory of objects. An adaptive prediction and convergence approach is developed based on this cumulative trajectory. The method allows smooth transition between consecutive attitudes obtained from the network.
{"title":"Enhancing view consistency in collaborative medical visualization systems using predictive-based attitude estimation","authors":"Yim-Pan Chui, P. Heng","doi":"10.1109/MIAR.2001.930306","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930306","url":null,"abstract":"Nowadays, medical diagnosis in critical diseases are seldom executed by only one person. Often, in difficult cases, two or more physicians are involved to reach a diagnosis. The growth of the World Wide Web and the modern trend of cooperative work in scientific research gave rise to a new class of systems, the so-called collaborative visualization systems. We present a new attitude dead reckoning mechanism in a collaborative medical visualization system (CMVS). Using quaterions as the description of attitude, we derive a general trajectory construction scheme of attitude that extrapolates a number of previous packets in order to form the future trajectory of objects. An adaptive prediction and convergence approach is developed based on this cumulative trajectory. The method allows smooth transition between consecutive attitudes obtained from the network.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123162849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930304
T. Hayasaka, Hao Liu, R. Himeno, Takami Yamaguchi
Computational biomechanics has been recognized as a powerful tool for cardiovascular research, vascular surgery planning and medical device design. An accurate and efficient construction of anatomic models is a critical element in the application of these computational methods. We developed an interactive modeling system. The novel features of this system were real time volume rendering and multiresolution mesh editing. Using these capabilities, a medical expert can become able to efficiently make accurate models using one's anatomical knowledge and heuristic ability, without requiring a background in intensive computation.
{"title":"A MRI based semi-automatic modeling system for computational biomechanics simulation","authors":"T. Hayasaka, Hao Liu, R. Himeno, Takami Yamaguchi","doi":"10.1109/MIAR.2001.930304","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930304","url":null,"abstract":"Computational biomechanics has been recognized as a powerful tool for cardiovascular research, vascular surgery planning and medical device design. An accurate and efficient construction of anatomic models is a critical element in the application of these computational methods. We developed an interactive modeling system. The novel features of this system were real time volume rendering and multiresolution mesh editing. Using these capabilities, a medical expert can become able to efficiently make accurate models using one's anatomical knowledge and heuristic ability, without requiring a background in intensive computation.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124441895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930274
M. A. Rodrigues, D. Gillies, P. Charters
During the procedure of laryngoscopy, an anaesthetist uses a rigid blade to displace and compress the tongue of the patient, and then inserts a tube into the larynx to allow controlled ventilation of the lungs during an operation. This procedure can sometimes be difficult and even life threatening, and there is therefore a need for regular training. Currently, plastic models are used for this purpose, and these have many disadvantages. Computer simulation is an attractive alternative, however, for proper realism it is necessary to build a model of the upper airway. In particular, we need a deformable model that can realistically simulate the behaviour of the tongue as it is compressed by the blade. We start from medical images, extract the details that characterise the subject and then incorporate these in a finite element model to investigate how the tongue tissue behaves in response to the insertion of the blade, when it is subjected to a variety of loading conditions. The results show that, within a specific set of tongue material parameters, the simulated outcome can be successfully related to the experimental laryngoscopic studies. Further research is underway to apply these results in a virtual reality simulation for laryngoscopic training. One main problem to be solved is computing the deformations in real time.
{"title":"Realistic deformable models for simulating the tongue during laryngoscopy","authors":"M. A. Rodrigues, D. Gillies, P. Charters","doi":"10.1109/MIAR.2001.930274","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930274","url":null,"abstract":"During the procedure of laryngoscopy, an anaesthetist uses a rigid blade to displace and compress the tongue of the patient, and then inserts a tube into the larynx to allow controlled ventilation of the lungs during an operation. This procedure can sometimes be difficult and even life threatening, and there is therefore a need for regular training. Currently, plastic models are used for this purpose, and these have many disadvantages. Computer simulation is an attractive alternative, however, for proper realism it is necessary to build a model of the upper airway. In particular, we need a deformable model that can realistically simulate the behaviour of the tongue as it is compressed by the blade. We start from medical images, extract the details that characterise the subject and then incorporate these in a finite element model to investigate how the tongue tissue behaves in response to the insertion of the blade, when it is subjected to a variety of loading conditions. The results show that, within a specific set of tongue material parameters, the simulated outcome can be successfully related to the experimental laryngoscopic studies. Further research is underway to apply these results in a virtual reality simulation for laryngoscopic training. One main problem to be solved is computing the deformations in real time.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130117276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Auto-segmentation of cells is one of the most interesting segmentation problems due to the complex nature of the cell tissues and to the inherent problems of video microscopic images. Objects, which are variant, narrow range of gray levels, non-random noise, are ubiquitous problems presented in this kind of image. Considering the above characteristics, an adaptive min-distance algorithm is proposed in this paper, which is available to segment the suspected cell and nucleus from the complex background in the microscopic image of cells fallen into peritoneal effusion. 15 features of the cancer cell and calculating formulas are presented respectively. These features are employed to construct a backpropagation neural network classifier which classifies and recognizes the cancer cells fallen into peritoneal effusion. Tests are performed using clinical cases recommended by the pathologists, results show that the proposed algorithm can efficiently segment the cell image and receive higher accuracy of cancer cell diagnosis.
{"title":"The research of microscopic image segmentation and recognition on the cancer cells fallen into peritoneal effusion","authors":"Hongyuan Wang, Shenggen Zeng, Chengang Yu, Xiaogang Wang, Deshen Xia","doi":"10.1109/MIAR.2001.930296","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930296","url":null,"abstract":"Auto-segmentation of cells is one of the most interesting segmentation problems due to the complex nature of the cell tissues and to the inherent problems of video microscopic images. Objects, which are variant, narrow range of gray levels, non-random noise, are ubiquitous problems presented in this kind of image. Considering the above characteristics, an adaptive min-distance algorithm is proposed in this paper, which is available to segment the suspected cell and nucleus from the complex background in the microscopic image of cells fallen into peritoneal effusion. 15 features of the cancer cell and calculating formulas are presented respectively. These features are employed to construct a backpropagation neural network classifier which classifies and recognizes the cancer cells fallen into peritoneal effusion. Tests are performed using clinical cases recommended by the pathologists, results show that the proposed algorithm can efficiently segment the cell image and receive higher accuracy of cancer cell diagnosis.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"84 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122635649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930302
Alan Wee-Chung Liew, Hong Yan
An adaptive fuzzy clustering algorithm is presented for the fuzzy segmentation of medical images. By using a novel dissimilarity index in the cost functional of the fuzzy clustering algorithm our algorithm is capable of utilising contextual information in a 3/spl times/3 neighborhood to impose local spatial homogeneity, as well as the usual feature space homogeneity. This has the effects of smoothing out random noise and resolving classification ambiguities. By introducing a multiplicative bias field into the cost functional, artifacts due to smooth, non-uniform intensity variation can also be corrected. The bias field is regularized by a Laplacian term which forces the bias field to resist bending and to be smooth. To solve for the bias field, the full multigrid algorithm is employed. Experimental results on a synthetic image and a simulated MRI brain image with noise and non-uniform intensity variation have illustrated the effectiveness of the proposed algorithm.
{"title":"An adaptive fuzzy clustering algorithm for medical image segmentation","authors":"Alan Wee-Chung Liew, Hong Yan","doi":"10.1109/MIAR.2001.930302","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930302","url":null,"abstract":"An adaptive fuzzy clustering algorithm is presented for the fuzzy segmentation of medical images. By using a novel dissimilarity index in the cost functional of the fuzzy clustering algorithm our algorithm is capable of utilising contextual information in a 3/spl times/3 neighborhood to impose local spatial homogeneity, as well as the usual feature space homogeneity. This has the effects of smoothing out random noise and resolving classification ambiguities. By introducing a multiplicative bias field into the cost functional, artifacts due to smooth, non-uniform intensity variation can also be corrected. The bias field is regularized by a Laplacian term which forces the bias field to resist bending and to be smooth. To solve for the bias field, the full multigrid algorithm is employed. Experimental results on a synthetic image and a simulated MRI brain image with noise and non-uniform intensity variation have illustrated the effectiveness of the proposed algorithm.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122222490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930266
J. Keegan, P. Gatehouse, Guang-Zhong Yang, D. Firmin
The success of slice-followed magnetic resonance coronary angiography is dependent on how accurately the motion of the arteries can be determined as a function of respiratory position. We have measured the correction factors relating the motion of the heart to that of the diaphragm in 3 orthogonal directions with both breath-holding and free-breathing techniques, showing large variations in all three factors between subjects. We have also shown that there are large variations in the factors calculated from breath-holding and free-breathing studies within the same patient, with breath-holding factors generally being higher. This has important consequences for the quality of slice-followed acquisitions as the majority are acquired during free-breathing, with the correction factor implemented either being assumed to be fixed for all patients or having been determined through breath-holding acquisitions.
{"title":"Subject-specific motion correction factors for magnetic resonance coronary angiography","authors":"J. Keegan, P. Gatehouse, Guang-Zhong Yang, D. Firmin","doi":"10.1109/MIAR.2001.930266","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930266","url":null,"abstract":"The success of slice-followed magnetic resonance coronary angiography is dependent on how accurately the motion of the arteries can be determined as a function of respiratory position. We have measured the correction factors relating the motion of the heart to that of the diaphragm in 3 orthogonal directions with both breath-holding and free-breathing techniques, showing large variations in all three factors between subjects. We have also shown that there are large variations in the factors calculated from breath-holding and free-breathing studies within the same patient, with breath-holding factors generally being higher. This has important consequences for the quality of slice-followed acquisitions as the majority are acquired during free-breathing, with the correction factor implemented either being assumed to be fixed for all patients or having been determined through breath-holding acquisitions.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"89 9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126318266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-10DOI: 10.1109/MIAR.2001.930258
Frederic Devernay, F. Mourgues, È. Coste-Manière
One of the problems tightly linked to endoscopic surgery is the fact that, because of the narrow field of view, it is sometimes quite difficult to locate the objects that can be seen through the endoscope. This is especially true in cardiac surgery, where it is difficult to not confuse two coronary arteries on a beating heart. We propose a methodology to achieve coronary localisation by augmented reality on a robotized stereoscopic endoscope. The method we propose involves five steps: making a time-variant 3D model of the beating heart using coronarography and CT-scan or MRI, calibrating the stereoscopic endoscope, reconstructing the 3D operating field, registering the operating field surface with the 3D heart model, and adding information on the endoscopic images by augmented reality. The da Vinci/sup TM/ surgical system was used for our first experiments with the Cardiac Surgery team at Hopital Europeen Georges Pompidou, Paris, France.
{"title":"Towards endoscopic augmented reality for robotically assisted minimally invasive cardiac surgery","authors":"Frederic Devernay, F. Mourgues, È. Coste-Manière","doi":"10.1109/MIAR.2001.930258","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930258","url":null,"abstract":"One of the problems tightly linked to endoscopic surgery is the fact that, because of the narrow field of view, it is sometimes quite difficult to locate the objects that can be seen through the endoscope. This is especially true in cardiac surgery, where it is difficult to not confuse two coronary arteries on a beating heart. We propose a methodology to achieve coronary localisation by augmented reality on a robotized stereoscopic endoscope. The method we propose involves five steps: making a time-variant 3D model of the beating heart using coronarography and CT-scan or MRI, calibrating the stereoscopic endoscope, reconstructing the 3D operating field, registering the operating field surface with the 3D heart model, and adding information on the endoscopic images by augmented reality. The da Vinci/sup TM/ surgical system was used for our first experiments with the Cardiac Surgery team at Hopital Europeen Georges Pompidou, Paris, France.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129932014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-06-01DOI: 10.1109/MIAR.2001.930267
H. Bogren, M. Buonocore
Cardiac gated three directional time resolved velocity data obtained with MR velocity encoded phase contrast sequences were used. Normal subjects of different ages were studied earlier. Age-matched normal subjects were compared with 15 patients with CAD. Systolic forward velocities were much more rapid in the normal subjects compared to the patients with CAD. Retrograde velocities were more rapid in the patients and particles took longer time to travel from the aortic valve to mid-descending aorta in patients compared with normal subjects. We believe that there is also a factor in the aorta that contributes to cardiac ischemia by allowing less blood flow into the coronary arteries.
{"title":"Four-D blood flow patterns in the thoracic aorta in patients with CAD compared to age-matched normal subjects","authors":"H. Bogren, M. Buonocore","doi":"10.1109/MIAR.2001.930267","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930267","url":null,"abstract":"Cardiac gated three directional time resolved velocity data obtained with MR velocity encoded phase contrast sequences were used. Normal subjects of different ages were studied earlier. Age-matched normal subjects were compared with 15 patients with CAD. Systolic forward velocities were much more rapid in the normal subjects compared to the patients with CAD. Retrograde velocities were more rapid in the patients and particles took longer time to travel from the aortic valve to mid-descending aorta in patients compared with normal subjects. We believe that there is also a factor in the aorta that contributes to cardiac ischemia by allowing less blood flow into the coronary arteries.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115185772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/MIAR.2001.930280
G. de Dietrich
Many algorithms for automatic slice positioning in tubular organs exist but they are generally devoted to one kind of organ (vessel or bronchus) and not usable for the other. We propose a new modular algorithm based on three steps: first a pre-segmentation of the organ; then a skeletonisation step that builds a poly-line skeleton of this organ; finally we are able to position and compute slices from this skeleton and work on them applying more conventional 2D segmentation algorithms.
{"title":"A modular algorithm for automatic slice positioning in tubular organs","authors":"G. de Dietrich","doi":"10.1109/MIAR.2001.930280","DOIUrl":"https://doi.org/10.1109/MIAR.2001.930280","url":null,"abstract":"Many algorithms for automatic slice positioning in tubular organs exist but they are generally devoted to one kind of organ (vessel or bronchus) and not usable for the other. We propose a new modular algorithm based on three steps: first a pre-segmentation of the organ; then a skeletonisation step that builds a poly-line skeleton of this organ; finally we are able to position and compute slices from this skeleton and work on them applying more conventional 2D segmentation algorithms.","PeriodicalId":375408,"journal":{"name":"Proceedings International Workshop on Medical Imaging and Augmented Reality","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126790213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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