Jan Madsen - Academia.edu (original) (raw)
Papers by Jan Madsen
American Heart Journal, 2003
Journal of the American College of Cardiology, 2009
Acta Radiologica, May 1, 1998
X-ray film processing is associated with pollution from photo chemicals and from the water used t... more X-ray film processing is associated with pollution from photo chemicals and from the water used to rinse the film. We tested a new processing system that was aimed at reducing both environmental pollution and costs through the use of solid photo chemicals and recirculation of the rinsing water. Before and after the installation of new mixers for the solid chemicals and a system for recirculating the rinsing water, we measured: water consumption, processor function quality, image quality, archivability, and the waste-silver content in the rinsing water. After the installation of a simple system for recirculating the rinsing water, there was an 88% reduction in water and film consumption as shown in the amount of water/m2 film that was used. At the same time, the release of silver-contaminated rinsing water directly into the sewers was stopped. Image quality remained unchanged. Archivability was assessed at more than 100 years. The solid photo chemicals and specially designed mixers proved efficient and provided a stable image quality of high standard. It was thus possible to reduce the risk of pollution from the transportation, storage and handling of liquid chemicals. A simple recirculation system for the rinsing water would significantly reduce water consumption and eliminate contamination of the environment by silver. The on-site preparation of photo chemicals proved viable and reduced the costs of film processing.
Proceedings of the Fifth Symposium on Virtual Reality Modeling Language, Feb 21, 2000
... in Netscape Navigator or Microsoft Internet Explorer would not allow the flexibility needed, ... more ... in Netscape Navigator or Microsoft Internet Explorer would not allow the flexibility needed, such as writing to the local disc and allocating large memory blocks. ... We are currently in progress of designing and building a parallel hard-ware prototype implementation of the ...
The Lancet, 2016
Despite successful treatment of the culprit artery lesion by primary percutaneous coronary interv... more Despite successful treatment of the culprit artery lesion by primary percutaneous coronary intervention (PCI) with stent implantation, thrombotic embolisation occurs in some cases, which impairs the prognosis of patients with ST-segment elevation myocardial infarction (STEMI). We aimed to assess the clinical outcomes of deferred stent implantation versus standard PCI in patients with STEMI. We did this open-label, randomised controlled trial at four primary PCI centres in Denmark. Eligible patients (aged >18 years) had acute onset symptoms lasting 12 h or less, and ST-segment elevation of 0·1 mV or more in at least two or more contiguous electrocardiographic leads or newly developed left bundle branch block. Patients were randomly assigned (1:1), via an electronic web-based system with permuted block sizes of two to six, to receive either standard primary PCI with immediate stent implantation or deferred stent implantation 48 h after the index procedure if a stabilised flow could be obtained in the infarct-related artery. The primary endpoint was a composite of all-cause mortality, hospital admission for heart failure, recurrent infarction, and any unplanned revascularisation of the target vessel within 2 years' follow-up. Patients, investigators, and treating clinicians were not masked to treatment allocation. We did analysis by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01435408. Between March 1, 2011, and Feb 28, 2014, we randomly assigned 1215 patients to receive either standard PCI (n=612) or deferred stent implantation (n=603). Median follow-up time was 42 months (IQR 33-49). Events comprising the primary endpoint occurred in 109 (18%) patients who had standard PCI and in 105 (17%) patients who had deferred stent implantation (hazard ratio 0·99, 95% CI 0·76-1·29; p=0·92). Procedure-related myocardial infarction, bleeding requiring transfusion or surgery, contrast-induced nephopathy, or stroke occurred in 28 (5%) patients in the conventional PCI group versus 27 (4%) patients in the deferred stent implantation group, with no significant differences between groups. In patients with STEMI, routine deferred stent implantation did not reduce the occurrence of death, heart failure, myocardial infarction, or repeat revascularisation compared with conventional PCI. Results from ongoing randomised trials might shed further light on the concept of deferred stenting in this patient population. Danish Agency for Science, Technology and Innovation, and Danish Council for Strategic Research.
Ugeskrift for laeger
This study prospectively evaluates the long-term prognosis of patients admitted with chest pain u... more This study prospectively evaluates the long-term prognosis of patients admitted with chest pain under suspicion of acute myocardial infarction (AMI) with and without confirmed diagnosis. Altogether 275 patients with and 257 patients without confirmed AMI (non-AMI) were consecutively included. During seven years of follow-up 122 cardiac events occurred in the AMI patients (i.e. 96 cardiac deaths and 26 nonfatal-AMI), and 69, occurred in the non-AMI patients (44 cardiac deaths and 25 non-fatal AMI). In multivariate Cox-analysis the following risk factors contained independent prognostic information for non-AMI patients: 1) a history of angina pectoris and 2) ST or T changes in the ECG on admission. In patients with AMI the risk factors were 1) previous AMI and 2) clinical heart failure. We conclude that a subset of non-AMI patients who have an increased long-term risk of cardiac events, can be identified from the medical history and the ECG at admission. These patients should be carefully evaluated prior to discharge.
Ugeskrift for laeger
In order to perform risk stratification 158 patients with acute chest pain, but without myocardia... more In order to perform risk stratification 158 patients with acute chest pain, but without myocardial infarction (non-AMI) underwent exercise 201-thallium scintigraphy at the time of discharge. The patients, of whom 38 (24%) were women, were followed for seven years. The diagnostic sensitivity, specificity and predictive values of the outcome of the examination for identification of patients, who had a cardiac event (cardiac death or later non-fatal AMI) during follow-up, was calculated. Forty-one had a cardiac event during follow-up. The highest sensitivity (85%) was achieved by the combination of transient defect and/or persistent defect and/or abnormal ST-segment response. The highest specificity was provided by a transient defect (90%) and the predictive value of a positive test was 60%-17 of 29 patients with a transient defect had a cardiac event during follow-up. Patients with a normal test had an excellent prognosis, 94% of 82 patients were free of cardiac events during follow-up. Exercise 201-thallium scintigraphy is suitable for long-term risk stratification in patients with chest pain and suspicion of but unconfirmed myocardial infarction, because high and very low risk subsets can be identified at the time of discharge.
International Journal of Angiology, 1995
Ugeskrift for laeger, Jan 4, 2002
Coronary arteriography (CAG) is an expensive investigation that provides potentially valuable inf... more Coronary arteriography (CAG) is an expensive investigation that provides potentially valuable information, but also carries a risk of severe complications. It is therefore natural to examine the usefulness of an existing database on CAG. The analysis covers all registrations of CAG entered into the database at the Heart Centre at Rigshospitalet, Copenhagen, from April 1999 to September 2000. Altogether, 5536 CAGs were registered. The indication was stable coronary artery disease in 52.0% and acute ischaemic heart disease in 25.5%. As an example of the medical information available from the data base, it is notable that left main coronary stenosis or three-vessel disease, conditions in which coronary bypass surgery increases long-term survival, was found in 42.4% of patients with angina pectoris in Canadian Cardiovascular Society (CCS) class 4, but also in 24.4% of patients in CCS class 1. Clinical databases, such as the one presented, can ensure that all relevant information is stor...
Ugeskrift for laeger, Jan 29, 1993
This study prospectively evaluates the long-term prognosis of patients admitted with chest pain u... more This study prospectively evaluates the long-term prognosis of patients admitted with chest pain under suspicion of acute myocardial infarction (AMI) with and without confirmed diagnosis. Altogether 275 patients with and 257 patients without confirmed AMI (non-AMI) were consecutively included. During seven years of follow-up 122 cardiac events occurred in the AMI patients (i.e. 96 cardiac deaths and 26 nonfatal-AMI), and 69, occurred in the non-AMI patients (44 cardiac deaths and 25 non-fatal AMI). In multivariate Cox-analysis the following risk factors contained independent prognostic information for non-AMI patients: 1) a history of angina pectoris and 2) ST or T changes in the ECG on admission. In patients with AMI the risk factors were 1) previous AMI and 2) clinical heart failure. We conclude that a subset of non-AMI patients who have an increased long-term risk of cardiac events, can be identified from the medical history and the ECG at admission. These patients should be caref...
2010 IEEE International Symposium on "A World of Wireless, Mobile and Multimedia Networks" (WoWMoM), 2010
... Sensor Networks Mikkel Koefoed Jakobsen, Jan Madsen, and Michael R. Hansen Embedded System En... more ... Sensor Networks Mikkel Koefoed Jakobsen, Jan Madsen, and Michael R. Hansen Embedded System Engineering Informatics and Mathematical Modelling Technical University of Denmark, DK-2800 Lyngby, Denmark {mkoe|jan|mrh}@imm.dtu.dk ...
Proceedings of the eighth international workshop on Hardware/software codesign - CODES '00, 2000
Lecture Notes in Computer Science, 2014
ABSTRACT Although energy consumption of wireless sensor network has been studied extensively, we ... more ABSTRACT Although energy consumption of wireless sensor network has been studied extensively, we are far behind in understanding the dynamics of the power consumption along with energy production using harvesters. We introduce Energy Harvesting Routing Analysis (EHRA) as a formal modelling framework to study wireless sensor networks (WSN) with energy-harvesting capabilities. The purpose of the framework is to analyze WSNs at a high level of abstraction, that is, before the protocols are implemented and before the WSN is deployed. The conceptual basis of EHRA comprises the environment, the medium, computational and physical components, and it captures a broad range of energy-harvestingaware routing protocols. The generic concepts of protocols are captured by a many-sorted signature, and concrete routing protocols are specified by corresponding many-sorted algebras. A first analysis tool for EHRA is developed as a simulator implemented using the functional programming language F#. This simulator is used to analyze global properties of WSNs such as network fragmentation, routing trends, and energy profiles for the nodes. Three routing protocols, with a progression in the energy-harvesting awareness, are analyzed on a network that is placed in a heterogeneous environment
Lecture Notes in Computer Science, 2007
ABSTRACT In this paper we consider a high-level hardware description language Gezel, from which h... more ABSTRACT In this paper we consider a high-level hardware description language Gezel, from which hardware can be synthesized through a translation to VHDL. The language is equipped with a simulator and supports exploration of hardware designs. The language has no semantics and it is difficult to get a deep understanding of many of the constructions. We therefore give a semantic domain for Gezel. Aiming at automated verification we relate this domain to the timed-automata model and we have experimented with verification of Gezel-specifications using the Uppaal system. In particular, we have proven the correctness of a hardware specification of the Simplified DES algorithm. We have also used Uppaal for small experiments of verifying resource usage.
Computational Analysis, Synthesis, & Design Dynamic Systems, 2009
2009 International Conference on Microelectronics - ICM, 2009
ABSTRACT The MoVES framework is being developed to assist in the early phases of embedded systems... more ABSTRACT The MoVES framework is being developed to assist in the early phases of embedded systems design. A system is modelled as an application running on an execution platform. The application is modelled through the individual tasks, and the execution platform is modelled through the processing elements, including the operating systems, and their interconnections. The tasks and processing elements are characterized by their real-time properties. The framework can be used to conduct schedulability analysis and has the potential to reason about different types of resource usage such as memory usage and power consumption. A simple specification language for embedded systems and a verification backend are presented. The framework has a modular, parameterized structure supporting easy extension and adaptation of the specification language as well as of the verification backend. We show, using a number of small examples, how MoVES can be used to model and analyze embedded systems.
American Heart Journal, 2003
Journal of the American College of Cardiology, 2009
Acta Radiologica, May 1, 1998
X-ray film processing is associated with pollution from photo chemicals and from the water used t... more X-ray film processing is associated with pollution from photo chemicals and from the water used to rinse the film. We tested a new processing system that was aimed at reducing both environmental pollution and costs through the use of solid photo chemicals and recirculation of the rinsing water. Before and after the installation of new mixers for the solid chemicals and a system for recirculating the rinsing water, we measured: water consumption, processor function quality, image quality, archivability, and the waste-silver content in the rinsing water. After the installation of a simple system for recirculating the rinsing water, there was an 88% reduction in water and film consumption as shown in the amount of water/m2 film that was used. At the same time, the release of silver-contaminated rinsing water directly into the sewers was stopped. Image quality remained unchanged. Archivability was assessed at more than 100 years. The solid photo chemicals and specially designed mixers proved efficient and provided a stable image quality of high standard. It was thus possible to reduce the risk of pollution from the transportation, storage and handling of liquid chemicals. A simple recirculation system for the rinsing water would significantly reduce water consumption and eliminate contamination of the environment by silver. The on-site preparation of photo chemicals proved viable and reduced the costs of film processing.
Proceedings of the Fifth Symposium on Virtual Reality Modeling Language, Feb 21, 2000
... in Netscape Navigator or Microsoft Internet Explorer would not allow the flexibility needed, ... more ... in Netscape Navigator or Microsoft Internet Explorer would not allow the flexibility needed, such as writing to the local disc and allocating large memory blocks. ... We are currently in progress of designing and building a parallel hard-ware prototype implementation of the ...
The Lancet, 2016
Despite successful treatment of the culprit artery lesion by primary percutaneous coronary interv... more Despite successful treatment of the culprit artery lesion by primary percutaneous coronary intervention (PCI) with stent implantation, thrombotic embolisation occurs in some cases, which impairs the prognosis of patients with ST-segment elevation myocardial infarction (STEMI). We aimed to assess the clinical outcomes of deferred stent implantation versus standard PCI in patients with STEMI. We did this open-label, randomised controlled trial at four primary PCI centres in Denmark. Eligible patients (aged >18 years) had acute onset symptoms lasting 12 h or less, and ST-segment elevation of 0·1 mV or more in at least two or more contiguous electrocardiographic leads or newly developed left bundle branch block. Patients were randomly assigned (1:1), via an electronic web-based system with permuted block sizes of two to six, to receive either standard primary PCI with immediate stent implantation or deferred stent implantation 48 h after the index procedure if a stabilised flow could be obtained in the infarct-related artery. The primary endpoint was a composite of all-cause mortality, hospital admission for heart failure, recurrent infarction, and any unplanned revascularisation of the target vessel within 2 years' follow-up. Patients, investigators, and treating clinicians were not masked to treatment allocation. We did analysis by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01435408. Between March 1, 2011, and Feb 28, 2014, we randomly assigned 1215 patients to receive either standard PCI (n=612) or deferred stent implantation (n=603). Median follow-up time was 42 months (IQR 33-49). Events comprising the primary endpoint occurred in 109 (18%) patients who had standard PCI and in 105 (17%) patients who had deferred stent implantation (hazard ratio 0·99, 95% CI 0·76-1·29; p=0·92). Procedure-related myocardial infarction, bleeding requiring transfusion or surgery, contrast-induced nephopathy, or stroke occurred in 28 (5%) patients in the conventional PCI group versus 27 (4%) patients in the deferred stent implantation group, with no significant differences between groups. In patients with STEMI, routine deferred stent implantation did not reduce the occurrence of death, heart failure, myocardial infarction, or repeat revascularisation compared with conventional PCI. Results from ongoing randomised trials might shed further light on the concept of deferred stenting in this patient population. Danish Agency for Science, Technology and Innovation, and Danish Council for Strategic Research.
Ugeskrift for laeger
This study prospectively evaluates the long-term prognosis of patients admitted with chest pain u... more This study prospectively evaluates the long-term prognosis of patients admitted with chest pain under suspicion of acute myocardial infarction (AMI) with and without confirmed diagnosis. Altogether 275 patients with and 257 patients without confirmed AMI (non-AMI) were consecutively included. During seven years of follow-up 122 cardiac events occurred in the AMI patients (i.e. 96 cardiac deaths and 26 nonfatal-AMI), and 69, occurred in the non-AMI patients (44 cardiac deaths and 25 non-fatal AMI). In multivariate Cox-analysis the following risk factors contained independent prognostic information for non-AMI patients: 1) a history of angina pectoris and 2) ST or T changes in the ECG on admission. In patients with AMI the risk factors were 1) previous AMI and 2) clinical heart failure. We conclude that a subset of non-AMI patients who have an increased long-term risk of cardiac events, can be identified from the medical history and the ECG at admission. These patients should be carefully evaluated prior to discharge.
Ugeskrift for laeger
In order to perform risk stratification 158 patients with acute chest pain, but without myocardia... more In order to perform risk stratification 158 patients with acute chest pain, but without myocardial infarction (non-AMI) underwent exercise 201-thallium scintigraphy at the time of discharge. The patients, of whom 38 (24%) were women, were followed for seven years. The diagnostic sensitivity, specificity and predictive values of the outcome of the examination for identification of patients, who had a cardiac event (cardiac death or later non-fatal AMI) during follow-up, was calculated. Forty-one had a cardiac event during follow-up. The highest sensitivity (85%) was achieved by the combination of transient defect and/or persistent defect and/or abnormal ST-segment response. The highest specificity was provided by a transient defect (90%) and the predictive value of a positive test was 60%-17 of 29 patients with a transient defect had a cardiac event during follow-up. Patients with a normal test had an excellent prognosis, 94% of 82 patients were free of cardiac events during follow-up. Exercise 201-thallium scintigraphy is suitable for long-term risk stratification in patients with chest pain and suspicion of but unconfirmed myocardial infarction, because high and very low risk subsets can be identified at the time of discharge.
International Journal of Angiology, 1995
Ugeskrift for laeger, Jan 4, 2002
Coronary arteriography (CAG) is an expensive investigation that provides potentially valuable inf... more Coronary arteriography (CAG) is an expensive investigation that provides potentially valuable information, but also carries a risk of severe complications. It is therefore natural to examine the usefulness of an existing database on CAG. The analysis covers all registrations of CAG entered into the database at the Heart Centre at Rigshospitalet, Copenhagen, from April 1999 to September 2000. Altogether, 5536 CAGs were registered. The indication was stable coronary artery disease in 52.0% and acute ischaemic heart disease in 25.5%. As an example of the medical information available from the data base, it is notable that left main coronary stenosis or three-vessel disease, conditions in which coronary bypass surgery increases long-term survival, was found in 42.4% of patients with angina pectoris in Canadian Cardiovascular Society (CCS) class 4, but also in 24.4% of patients in CCS class 1. Clinical databases, such as the one presented, can ensure that all relevant information is stor...
Ugeskrift for laeger, Jan 29, 1993
This study prospectively evaluates the long-term prognosis of patients admitted with chest pain u... more This study prospectively evaluates the long-term prognosis of patients admitted with chest pain under suspicion of acute myocardial infarction (AMI) with and without confirmed diagnosis. Altogether 275 patients with and 257 patients without confirmed AMI (non-AMI) were consecutively included. During seven years of follow-up 122 cardiac events occurred in the AMI patients (i.e. 96 cardiac deaths and 26 nonfatal-AMI), and 69, occurred in the non-AMI patients (44 cardiac deaths and 25 non-fatal AMI). In multivariate Cox-analysis the following risk factors contained independent prognostic information for non-AMI patients: 1) a history of angina pectoris and 2) ST or T changes in the ECG on admission. In patients with AMI the risk factors were 1) previous AMI and 2) clinical heart failure. We conclude that a subset of non-AMI patients who have an increased long-term risk of cardiac events, can be identified from the medical history and the ECG at admission. These patients should be caref...
2010 IEEE International Symposium on "A World of Wireless, Mobile and Multimedia Networks" (WoWMoM), 2010
... Sensor Networks Mikkel Koefoed Jakobsen, Jan Madsen, and Michael R. Hansen Embedded System En... more ... Sensor Networks Mikkel Koefoed Jakobsen, Jan Madsen, and Michael R. Hansen Embedded System Engineering Informatics and Mathematical Modelling Technical University of Denmark, DK-2800 Lyngby, Denmark {mkoe|jan|mrh}@imm.dtu.dk ...
Proceedings of the eighth international workshop on Hardware/software codesign - CODES '00, 2000
Lecture Notes in Computer Science, 2014
ABSTRACT Although energy consumption of wireless sensor network has been studied extensively, we ... more ABSTRACT Although energy consumption of wireless sensor network has been studied extensively, we are far behind in understanding the dynamics of the power consumption along with energy production using harvesters. We introduce Energy Harvesting Routing Analysis (EHRA) as a formal modelling framework to study wireless sensor networks (WSN) with energy-harvesting capabilities. The purpose of the framework is to analyze WSNs at a high level of abstraction, that is, before the protocols are implemented and before the WSN is deployed. The conceptual basis of EHRA comprises the environment, the medium, computational and physical components, and it captures a broad range of energy-harvestingaware routing protocols. The generic concepts of protocols are captured by a many-sorted signature, and concrete routing protocols are specified by corresponding many-sorted algebras. A first analysis tool for EHRA is developed as a simulator implemented using the functional programming language F#. This simulator is used to analyze global properties of WSNs such as network fragmentation, routing trends, and energy profiles for the nodes. Three routing protocols, with a progression in the energy-harvesting awareness, are analyzed on a network that is placed in a heterogeneous environment
Lecture Notes in Computer Science, 2007
ABSTRACT In this paper we consider a high-level hardware description language Gezel, from which h... more ABSTRACT In this paper we consider a high-level hardware description language Gezel, from which hardware can be synthesized through a translation to VHDL. The language is equipped with a simulator and supports exploration of hardware designs. The language has no semantics and it is difficult to get a deep understanding of many of the constructions. We therefore give a semantic domain for Gezel. Aiming at automated verification we relate this domain to the timed-automata model and we have experimented with verification of Gezel-specifications using the Uppaal system. In particular, we have proven the correctness of a hardware specification of the Simplified DES algorithm. We have also used Uppaal for small experiments of verifying resource usage.
Computational Analysis, Synthesis, & Design Dynamic Systems, 2009
2009 International Conference on Microelectronics - ICM, 2009
ABSTRACT The MoVES framework is being developed to assist in the early phases of embedded systems... more ABSTRACT The MoVES framework is being developed to assist in the early phases of embedded systems design. A system is modelled as an application running on an execution platform. The application is modelled through the individual tasks, and the execution platform is modelled through the processing elements, including the operating systems, and their interconnections. The tasks and processing elements are characterized by their real-time properties. The framework can be used to conduct schedulability analysis and has the potential to reason about different types of resource usage such as memory usage and power consumption. A simple specification language for embedded systems and a verification backend are presented. The framework has a modular, parameterized structure supporting easy extension and adaptation of the specification language as well as of the verification backend. We show, using a number of small examples, how MoVES can be used to model and analyze embedded systems.