Patents by Inventor Stefan Hjelm
Stefan Hjelm has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9436801Abstract: A patient-specific hemodyanmic status model is determined from impedance data collected during periods of normal and abnormal hemodynamic status by deriving parameter values of a set of multiple impedance-derivable parameters from impedance signals collected during periods of normal hemodynamic status and in connection with periods of abnormal hemodynamic status. The parameter values are employed to estimate coefficients of a linear parametric status model. These coefficients can then be used together with parameter values determined from impedance signals determined during status assessment periods in order to determine a current hemdoynamic status of the patient.Type: GrantFiled: March 18, 2011Date of Patent: September 6, 2016Assignee: St. Jude Medical ABInventors: Karin Jarverud, Anders Bjorling, Malin Hollmark, Kjell Noren, Tomas Svensson, Stefan Hjelm
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Patent number: 9119545Abstract: An implantable medical device, is designed to collect a signal representative of the electric activity of the heart and determine a cardiogenic impedance signal for at least a portion of the heart. An R-wave detector of the IMD detects the timing of an R-wave during a cardiac cycle based on the signal representative of the electric activity. A minimum detector detects the timing of a cardiogenic impedance minimum in the cardiogenic impedance signal and within a systolic time window of the cardiac cycle. A detected arrhythmia is then classified by the IMD based on the timing of the R-wave detected by the R-wave detector and the timing of the cardiogenic impedance minimum detected by the minimum detector.Type: GrantFiled: March 31, 2011Date of Patent: September 1, 2015Assignee: St. Jude Medical, ABInventors: Anders Bjorling, Malin Hollmark, Tomas Svensson, Stefan Hjelm, Kjell Noren, Karin Jarverud
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Patent number: 8781580Abstract: An implantable medical device is connected to a multipolar LV lead and an implantable sensor. The sensor signal from the sensor is used to identify a time point of mitral valve closure for a cardiac cycle when a ventricular pulse generator generates pacing pulses that are applied to the electrodes of the multipolar LV lead according to a pacing sequence. A time interval processor determines the time interval from onset of LV activation to the time point of mitral valve closure. This procedure is repeated for multiple different pacing sequences of a sequence set. The pacing sequence that resulted in shortest time interval is then selected by a selector as the currently optimal pacing sequence for the patient.Type: GrantFiled: October 10, 2012Date of Patent: July 15, 2014Assignee: St. Jude Medical ABInventors: Sven-Erik Hedberg, Malin Hollmark, Stefan Hjelm, Michael Broome
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Patent number: 8738120Abstract: An implantable medical device (100) is configured for generating a cardiogenic impedance signal representative of the cardiogenic impedance of at least a portion of a heart (10) of a subject (20) during at least a portion of cardiac cycle. A moment processor (132) calculates a moment parameter value based on the cardiogenic impedance signal. The moment parameter is representative of a weighted sum of impedance amplitudes within a time window centered at defined time instance within the cardiac cycle. The weights of the impedance amplitudes are further dependent on the length in time between the defined time instance and the point of time of the associated impedance amplitude. The moment parameter is of high diagnostic value and is employed by an arrhythmia classifier (132) in order to classify a detected arrhythmia of the heart (10), such as discriminate between hemodynamically stable or unstable arrhythmias and/or supraventricular or ventricular tachycardia.Type: GrantFiled: May 12, 2010Date of Patent: May 27, 2014Assignee: St. Jude Medical ABInventors: Anders Björling, Malin Hollmark, Tomas Svensson, Stefan Hjelm, Kjell Norén, Karin Järverud
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Publication number: 20130325359Abstract: A patient-specific hemodyanmic status model is determined from impedance data collected during periods of normal and abnormal hemodynamic status by deriving parameter values of a set of multiple impedance-derivable parameters from impedance signals collected during periods of normal hemodynamic status and in connection with periods of abnormal hemodynamic status. The parameter values are employed to estimate coefficients of a linear parametric status model. These coefficients can then be used together with parameter values determined from impedance signals determined during status assessment periods in order to determine a current hemdoynamic status of the patient.Type: ApplicationFiled: March 18, 2011Publication date: December 5, 2013Applicant: St. Jude Medical ABInventors: Karin Jarverud, Anders Bjorling, Malin Hollmark, Kjell Noren, Tomas Svensson, Stefan Hjelm
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Publication number: 20130289642Abstract: An implantable medical device is connected to a multipolar LV lead and an implantable sensor. The sensor signal from the sensor is used to identify a time point of mitral valve closure for a cardiac cycle when a ventricular pulse generator generates pacing pulses that are applied to the electrodes of the multipolar LV lead according to a pacing sequence. A time interval processor determines the time interval from onset of LV activation to the time point of mitral valve closure. This procedure is repeated for multiple different pacing sequences of a sequence set. The pacing sequence that resulted in shortest time interval is then selected by a selector as the currently optimal pacing sequence for the patient.Type: ApplicationFiled: October 10, 2012Publication date: October 31, 2013Inventors: Sven-Erik Hedberg, Malin Hollmark, Stefan Hjelm, Michael Broome
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Publication number: 20130060118Abstract: An implantable medical device (100) is configured for generating a cardiogenic impedance signal representative of the cardiogenic impedance of at least a portion of a heart (10) of a subject (20) during at least a portion of cardiac cycle. A moment processor (132) calculates a moment parameter value based on the cardiogenic impedance signal. The moment parameter is representative of a weighted sum of impedance amplitudes within a time window centered at defined time instance within the cardiac cycle. The weights of the impedance amplitudes are further dependent on the length in time between the defined time instance and the point of time of the associated impedance amplitude. The moment parameter is of high diagnostic value and is employed by an arrhythmia classifier (132) in order to classify a detected arrhythmia of the heart (10), such as discriminate between hemodynamically stable or unstable arrhythmias and/or supraventricular or ventricular tachycardia.Type: ApplicationFiled: May 12, 2010Publication date: March 7, 2013Applicant: ST. JUDE MEDICAL ABInventors: Anders Björling, Malin Hollmark, Tomas Svensson, Stefan Hjelm, Kjell Norén, Karin Järverud
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Publication number: 20130046194Abstract: An implantable medical device (100) is configured for generating a cardiogenic impedance signal representative of the cardiogenic impedance of at least a portion of a heart (10) of a subject (20) during multiple cardiac cycles. A transform processor (132) generates a spectrum signal by applying a time-to-frequency transform to the cardiogenic impedance signal. The spectrum signal is processed by a distribution processor (133) configured to calculate a distribution parameter indicative of a distribution in at least a portion of the spectrum signal. The calculated distribution parameter is of high diagnostic value and is employed by an arrhythmia classifier (134) in order to classify a detected arrhythmia of the heart (10), such as discriminate between hemodynamically stable or unstable arrhythmias and/or supraventricular or ventricular tachycardia.Type: ApplicationFiled: April 27, 2010Publication date: February 21, 2013Applicant: ST. JUDE MEDICAL ABInventors: Anders Bjolring, Malin Hollmark, Tomas Svensson, Stefan Hjelm, Kjell Noren, Karin Jarverud
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Patent number: 8126556Abstract: In a medical implantable device having a hermetically sealed, radio shielded encapsulations containing an RF circuit therein and having an antenna located outside of the encapsulation, and in a method for connecting the RF circuit to the antenna, at least one hermetical feedthrough connection is provided in the form of at least one conductor passing through a wall portion of the encapsulation in a liquid-tight and gas-tight manner, with the feedthrough being electrically insulated from the encapsulation. At least one connector pin is provided on an RF circuit board, which is resiliently mounted on the RF circuit board. The RF circuit is mounted in the encapsulation so as to cause the connector pin to resiliently engage the conductor and to electrically connect the conductor with the RF circuit board.Type: GrantFiled: October 27, 2005Date of Patent: February 28, 2012Assignee: St. Jude Medical ABInventors: Stefan Hjelm, Tomas Snitting, Wisit Lim, Kavous Sahabi
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Publication number: 20110319769Abstract: An ischemia monitoring system has detectors for detecting the onset of an ischemic event of a tissue in subject, the end of the ischemic event and the end of a following recovery from the ischemic event, respectively. A time processor determines the duration of the ischemic event and the recovery period based on the detected onset and end times. A status processor co-processes the two determined time durations for the purpose of monitoring the ischemic status of the subject and detecting any deterioration in ischemic status for the latest ischemic event as compared to previous ischemic events that have occurred in the subject's tissue.Type: ApplicationFiled: March 13, 2009Publication date: December 29, 2011Inventors: Sven-Erik Hedberg, Tomas Svensson, Michael Broomé, Karin Järverud, Stefan Hjelm
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Publication number: 20110245701Abstract: An implantable medical device, is designed to collect a signal representative of the electric activity of the heart and determine a cardiogenic impedance signal for at least a portion of the heart. An R-wave detector of the IMD detects the timing of an R-wave during a cardiac cycle based on the signal representative of the electric activity. A minimum detector detects the timing of a cardiogenic impedance minimum in the cardiogenic impedance signal and within a systolic time window of the cardiac cycle. A detected arrhythmia is then classified by the IMD based on the timing of the R-wave detected by the R-wave detector and the timing of the cardiogenic impedance minimum detected by the minimum detector.Type: ApplicationFiled: March 31, 2011Publication date: October 6, 2011Inventors: Anders Bjorling, Malin Hollmark, Tomas Svensson, Stefan Hjelm, Kjell Noren, Karin Jarverud
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Publication number: 20090163979Abstract: In a medical implantable device having a hermetically sealed, radio shielded encapsulations containing an RF circuit therein and having an antenna located outside of the encapsulation, and in a method for connecting the RF circuit to the antenna, at least one hermetical feedthrough connection is provided in the form of at least one conductor passing through a wall portion of the encapsulation in a liquid-tight and gas-tight manner, with the feedthrough being electrically insulated from the encapsulation. At least one connector pin is provided on an RF circuit board, which is resiliently mounted on the RF circuit board. The RF circuit is mounted in the encapsulation so as to cause the connector pin to resiliently engage the conductor and to electrically connect the conductor with the RF circuit board.Type: ApplicationFiled: October 27, 2005Publication date: June 25, 2009Inventors: Stefan Hjelm, Tomas Snitting, Wisit Lim, Kavous Sahabi
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Publication number: 20080039898Abstract: An implantable medical device has a conductive housing containing circuitry for operation of the device and radio frequency circuitry for transmitting and/or receiving radio frequency signals. An insulating header is arranged adjacent to the conductive housing. A conductive structure is provided on a surface of, and/or within, the insulating header. An antenna feed is operatively interconnected between the radio frequency circuitry and the conductive structure. The conductive structure is galvanically connected to the conductive housing, and the conductive structure and the conductive housing, in combination, operate as a transmitting and/or receiving antenna for the radio frequency signals.Type: ApplicationFiled: May 28, 2004Publication date: February 14, 2008Applicant: ST. JUDE MEDICAL ABInventors: Wisit Lim, Kavous Sahabi, Niklas Skoldengen, Tomas Snitting, Stefan Hjelm