ABSTRACT As Image Analysis resorts to increasingly powerful algorithms, the processing time is co... more ABSTRACT As Image Analysis resorts to increasingly powerful algorithms, the processing time is correspondingly extended. Consequently, system designers are constantly looking for new technologies and new architectures capable of improving processing speed without increasing the complexity and the cost of the machines.
Proceedings 10th International Conference on Image Analysis and Processing, 1999
In the framework of object-based video coding morphological filtering has became an important tec... more In the framework of object-based video coding morphological filtering has became an important technique for image simplification. Morphological filters are used in a pre-processing step to improve the chances of obtaining meaningful segmentation results. However the computation cost of these filters limits their practical use. An improvement of the processing time is then required for their use in real-time applications. In this paper the implementation issue is addressed. Improvement of the processing time is achieved by exploiting the local parallelism of these filters and by reducing the number of clock cycles used to access a specific data structure called the hierarchical queue. As various morphological filters can be used, an architecture based on hardware software partitioning is proposed. Performance results showing the benefits of the proposed architecture are provided
Maintenance hemodialysis and renal transplantation are increasingly used for treating diabetic pa... more Maintenance hemodialysis and renal transplantation are increasingly used for treating diabetic patients with end-stage renal failure. The use of the artificial pancreas is able to prevent large blood glucose fluctuations in these patients with atherosclerosis, advanced retinopathy or neuropathy in which hyper- and hypoglycemia are potentially deleterious. For this purpose, we have developed and are utilizing an artificial pancreas easily utilizable without special training by the staff of a dialysis unit. This artificial pancreas uses a polarographic glucose electrode with a fast response time (45 to 90 seconds), a terminal display for operator communication, and a continuous digital and analogyl display for control of the running operation. There is also a printer to display in tabular and graphical form the values at any time during the operation. In this preliminary study, 7 patients have been studied: five under repetitive hemodialysis for four hours, 3 times a week; one treated by peritoneal dialysis for 12 hours, twice a week and one controlled during, and 48 hours after, renal transplantation. The macroscopic pancreas normalizes blood glucose under these circumstances, helps in a better understanding of blood glucose homeostasis in uremic patients under dialysis, leads to a more precise evaluation of insulin needs, may help to improve the nutritional status of the patients, and has an educational value for the patient and the medical staff.
ABSTRACT As Image Analysis resorts to increasingly powerful algorithms, the processing time is co... more ABSTRACT As Image Analysis resorts to increasingly powerful algorithms, the processing time is correspondingly extended. Consequently, system designers are constantly looking for new technologies and new architectures capable of improving processing speed without increasing the complexity and the cost of the machines.
The changes in plasma glucose concentration and in interstitial glucose concentration, determined... more The changes in plasma glucose concentration and in interstitial glucose concentration, determined with a miniaturized subcutaneous glucose sensor, were investigated in anesthetized nondiabetic rats. Interstitial glucose was estimated through two different calibration procedures. First, after a glucose load, the magnitude of the increase in interstitial glucose, estimated through a one-point calibration procedure, was 70% of that in plasma glucose. We propose that this is due to the effect of endogenous insulin on peripheral glucose uptake. Second, during the spontaneous secondary decrease in plasma glucose after the glucose load, interstitial glucose decreased faster than plasma glucose, which may also be due to the effect of insulin on peripheral glucose uptake. Third, during insulin-induced hypoglycemia, the decrease in interstitial glucose was less marked than that of plasma glucose, suggesting that hypoglycemia suppressed transfer of glucose into the interstitial tissue; subsequently, interstitial glucose remained lower than plasma glucose during its return to basal value, suggesting that the stimulatory effect of insulin on peripheral glucose uptake was protracted. If these observations obtained in rats are relevant to human physiology, such discrepancies between plasma and interstitial glucose concentration may have major implications for the use of a subcutaneous glucose sensor in continuous blood glucose monitoring in diabetic patients.
ABSTRACT A complete prototype for the automatic detection of normal examinations on a teleophthal... more ABSTRACT A complete prototype for the automatic detection of normal examinations on a teleophthalmology network for diabetic retinopathy screening is presented. The system combines pathological pattern mining methods, with specific lesion detection methods, to extract information from the images. This information, plus patient and other contextual data, is used by a classifier to compute an abnormality risk. Such a system should reduce the burden on readers on teleophthalmology networks.
Graefe's Archive for Clinical and Experimental Ophthalmology, 2007
The present work aims to demonstrate the role of redistribution of the neurosensory retina (RNR)-... more The present work aims to demonstrate the role of redistribution of the neurosensory retina (RNR)-that is, retinal tissue stretching and compression-in inferior limited macular translocation (LMT), to perform displacement mapping all over the area centralis, and to try and improve displacement evaluation precision. Using piecewise linear image registration (through Matlab) on indocyanine green angiographic frames, we have evaluated the deformation (on both the retinal and choroido-scleral layer) of a pre-operative grid superimposed on the area centralis, plotted displacement vectors all over the area centralis, and calculated a scale ratio between pre- and post-operative frames. The scale ratio tests whether or not the same physical distance is represented by the same distance on these frames. The choroido-scleral layer is not deformed following surgery. The retinal layer shows areas of stretching and compression, demonstrating the RNR. Displacement vectors feature a rotating pattern around the optic disk (except if a macular fold exists) and a positive naso-temporal gradient. The median scale ratio is 3.8% (2.5% to 5.8%). LMT involves RNR accounting for inferior retinal displacement, despite the supposedly limited internal scleral shortening. Our study confirms that the optic disk temporal edge is the displacement axis (except if a macular fold exists). Our method, unaffected by a non-zero scale ratio, provides more precision than previously published.
ABSTRACT As Image Analysis resorts to increasingly powerful algorithms, the processing time is co... more ABSTRACT As Image Analysis resorts to increasingly powerful algorithms, the processing time is correspondingly extended. Consequently, system designers are constantly looking for new technologies and new architectures capable of improving processing speed without increasing the complexity and the cost of the machines.
Proceedings 10th International Conference on Image Analysis and Processing, 1999
In the framework of object-based video coding morphological filtering has became an important tec... more In the framework of object-based video coding morphological filtering has became an important technique for image simplification. Morphological filters are used in a pre-processing step to improve the chances of obtaining meaningful segmentation results. However the computation cost of these filters limits their practical use. An improvement of the processing time is then required for their use in real-time applications. In this paper the implementation issue is addressed. Improvement of the processing time is achieved by exploiting the local parallelism of these filters and by reducing the number of clock cycles used to access a specific data structure called the hierarchical queue. As various morphological filters can be used, an architecture based on hardware software partitioning is proposed. Performance results showing the benefits of the proposed architecture are provided
Maintenance hemodialysis and renal transplantation are increasingly used for treating diabetic pa... more Maintenance hemodialysis and renal transplantation are increasingly used for treating diabetic patients with end-stage renal failure. The use of the artificial pancreas is able to prevent large blood glucose fluctuations in these patients with atherosclerosis, advanced retinopathy or neuropathy in which hyper- and hypoglycemia are potentially deleterious. For this purpose, we have developed and are utilizing an artificial pancreas easily utilizable without special training by the staff of a dialysis unit. This artificial pancreas uses a polarographic glucose electrode with a fast response time (45 to 90 seconds), a terminal display for operator communication, and a continuous digital and analogyl display for control of the running operation. There is also a printer to display in tabular and graphical form the values at any time during the operation. In this preliminary study, 7 patients have been studied: five under repetitive hemodialysis for four hours, 3 times a week; one treated by peritoneal dialysis for 12 hours, twice a week and one controlled during, and 48 hours after, renal transplantation. The macroscopic pancreas normalizes blood glucose under these circumstances, helps in a better understanding of blood glucose homeostasis in uremic patients under dialysis, leads to a more precise evaluation of insulin needs, may help to improve the nutritional status of the patients, and has an educational value for the patient and the medical staff.
ABSTRACT As Image Analysis resorts to increasingly powerful algorithms, the processing time is co... more ABSTRACT As Image Analysis resorts to increasingly powerful algorithms, the processing time is correspondingly extended. Consequently, system designers are constantly looking for new technologies and new architectures capable of improving processing speed without increasing the complexity and the cost of the machines.
The changes in plasma glucose concentration and in interstitial glucose concentration, determined... more The changes in plasma glucose concentration and in interstitial glucose concentration, determined with a miniaturized subcutaneous glucose sensor, were investigated in anesthetized nondiabetic rats. Interstitial glucose was estimated through two different calibration procedures. First, after a glucose load, the magnitude of the increase in interstitial glucose, estimated through a one-point calibration procedure, was 70% of that in plasma glucose. We propose that this is due to the effect of endogenous insulin on peripheral glucose uptake. Second, during the spontaneous secondary decrease in plasma glucose after the glucose load, interstitial glucose decreased faster than plasma glucose, which may also be due to the effect of insulin on peripheral glucose uptake. Third, during insulin-induced hypoglycemia, the decrease in interstitial glucose was less marked than that of plasma glucose, suggesting that hypoglycemia suppressed transfer of glucose into the interstitial tissue; subsequently, interstitial glucose remained lower than plasma glucose during its return to basal value, suggesting that the stimulatory effect of insulin on peripheral glucose uptake was protracted. If these observations obtained in rats are relevant to human physiology, such discrepancies between plasma and interstitial glucose concentration may have major implications for the use of a subcutaneous glucose sensor in continuous blood glucose monitoring in diabetic patients.
ABSTRACT A complete prototype for the automatic detection of normal examinations on a teleophthal... more ABSTRACT A complete prototype for the automatic detection of normal examinations on a teleophthalmology network for diabetic retinopathy screening is presented. The system combines pathological pattern mining methods, with specific lesion detection methods, to extract information from the images. This information, plus patient and other contextual data, is used by a classifier to compute an abnormality risk. Such a system should reduce the burden on readers on teleophthalmology networks.
Graefe's Archive for Clinical and Experimental Ophthalmology, 2007
The present work aims to demonstrate the role of redistribution of the neurosensory retina (RNR)-... more The present work aims to demonstrate the role of redistribution of the neurosensory retina (RNR)-that is, retinal tissue stretching and compression-in inferior limited macular translocation (LMT), to perform displacement mapping all over the area centralis, and to try and improve displacement evaluation precision. Using piecewise linear image registration (through Matlab) on indocyanine green angiographic frames, we have evaluated the deformation (on both the retinal and choroido-scleral layer) of a pre-operative grid superimposed on the area centralis, plotted displacement vectors all over the area centralis, and calculated a scale ratio between pre- and post-operative frames. The scale ratio tests whether or not the same physical distance is represented by the same distance on these frames. The choroido-scleral layer is not deformed following surgery. The retinal layer shows areas of stretching and compression, demonstrating the RNR. Displacement vectors feature a rotating pattern around the optic disk (except if a macular fold exists) and a positive naso-temporal gradient. The median scale ratio is 3.8% (2.5% to 5.8%). LMT involves RNR accounting for inferior retinal displacement, despite the supposedly limited internal scleral shortening. Our study confirms that the optic disk temporal edge is the displacement axis (except if a macular fold exists). Our method, unaffected by a non-zero scale ratio, provides more precision than previously published.
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Papers by Jean-claude Klein