Abstract:
The present invention relates to a method for creating hemodynamic sensor signal templates using an implantable medical device being connectable to a patient. A heart activity of a patient is sensed in order to identify a paced or sensed sequence of events of a heart cycle; hemodynamic sensor signals for consecutive heart cycles is sensed; and the sensed hemodynamic sensor signals for consecutive heart cycles is stored. Furthermore, sensed sensor signals are classified on basis of at least one predetermined heart event sequence condition and, for example, a template may be created using said classified sensor signals. The invention also relates to an implantable medical device for creating hemodynamic sensor signal templates, a computer program product, and a computer readable medium comprising instructions for bringing a computer to perform the method.
Abstract:
The present invention relates to a method for determining the posture of a patient. The method comprises the steps of: initiating (50, 52) a patient posture determining session by performing an electrical bio-impedance measurement session in at least one of a number of different electrode configurations in order to measure an impedance value for the at least one configuration; obtaining reference impedance values (54) stored in advance for the at least one configuration and for at least one potential posture of the patient; comparing (54) the measured impedance value for the at least one configuration with corresponding stored reference impedance values for at least one potential posture of the patient; and determining (56) the present posture of the patient by using results from the comparison between measured impedance values and the stored reference impedance values. Furthermore, the invention relates to a medical device for determining the posture of a patient and a computer readable medium comprising instructions for bringing a computer to perform the inventive method.
Abstract:
The present invention relates to a method for evaluating the prevalence of different postures of a patient. The method includes the steps of: sensing (60) signals indicating the posture of the patient during a monitoring period having a predetermined length; determining (60) specific body postures of the patient during the monitoring period using the signals; measuring (62) the amount of time the patient spends in each of the specific postures; storing (62) information regarding each specific posture and the amount of time spent in each posture; and evaluating (64) the prevalence of the different postures of the patient by classifying the stored information with respect of specific postures and the amount of time spent in corresponding postures. Furthermore, the invention relates to a medical device (20) for evaluating the prevalence of different postures of a patient and a computer readable medium comprising instructions for bringing a computer to perform the inventive method.
Abstract:
Implantable heart stimulator connectable to an electrode arrangement comprising a pulse generator adapted to deliver stimulation pulses to a heart of a subject; an impedance measurement unit adapted monitor at least one heart chamber of the heart of the subject to measure the impedance in the at least one monitored heart chamber for generating an impedance signal corresponding to the measured impedance. The impedance signal is applied to a processing means where the signal is processed, according to specified criteria, and a fractionation index value is determined represented by the curve length of the impedance signal during a predetermined measurement period. The fractionation index value being a measure of different degrees of mechanical dyssynchrony of the heart.
Abstract:
The invention concerns an implantable heart monitoring device (10) comprising, inter alia, a control circuit (14) configured to be able to measure an impedance across at least part of an atrium, such that the variation of the impedance is related to the volume change of the atrium. The control circuit (14) is configured to carry out certain steps, and to store values at different occasions that indicate the rate of change of the meas¬ ured impedance. The stored values have been determined such that, when the device (10) is used in a living being, the variation of the stored values will be related to the variation of the speed with which the atrium is filled with blood during the atrial dias¬ tole. The invention also concerns a corresponding system and method.
Abstract:
A device and method of a medical implant for monitoring progression of heart failure in a human heart. An activity sensor provides information related to the activity level of a patient and an oxygen sensor provides information related to the level of oxygen content in venous blood. A determined level of venous oxygen content at a determined activity level is obtained, and that level of venous oxygen content is compared to stored values at a corresponding activity level. The result of the comparison is used as a basis for determining a degree of heart failure.
Abstract:
An implantable cardiac device comprises a heart stimulator (10, 12) for electricly stimulating the heart of a patient, detecting means (2, 4) for measuring a physiologic parameter which is affected by the status of a cardiovascular disease associated with sympathetic activation, signal processing means (6) for determining at least one of a low frequency, LF, and a very low frequency, VLF, Mayer wave component in the measured parameter, and an analysor for analyzing the determined Mayer wave component in relation to a predetermined reference value to determine the status of the cardiovascular disease. The detecting means comprise measuring means (2) arranged to measure, as said physiologic parameter, a mechanical change in at least one of the four chambers of the heart. In a corresponding method for monitoring the status of a cardiovascular disease associated with sympathetic activation of a patient having an implantable electric heart stimulator (10, 12) a physiologic parameter affected by the cardiac disease is measured. At least one of a low frequency, LF, and a very low frequency, VLF, Mayer wave component in the parameter is determined, and the wave component is analysed in relation to a predetermined reference value to determine the status of the cardiovascular disease. A mechanical change in at least one of the four chambers of the heart is measured as the physiologic parameter.
Abstract:
The present invention generally relates to cardiac pacing systems and, in particular, to a method and an implantable medical device (2; 20) for monitoring physiological parameters such as hematocrit and SvO2 levels of a patient to determine a patient status. The implantable medical device (2; 20) comprises a blood constituent determining device (30) adapted to determine a present hematocrit level and a SvO2 level and a patient status determining device (31) adapted to determine a patient status based on an evaluation of a present hematocrit level and a present SvO2 level, wherein a change of a condition of the patient can be derived.
Abstract:
An implantable medical apparatus for detecting diastolic heart failure, DHF, comprises a DHF determining device for determining at least one DHF parameter for detecting a DHF state of the heart of a patient. The DHF determining device comprises a means for determining, as said DHF parameter, the time length (DT,IVRT) of a predetermined phase of diastole. A pacemaker comprises such an apparatus and control means for optimising pacing therapy and pacemaker settings depending on the determined time length. A corresponding method of detecting diastolic heart failure, DHF, comprises the step of determining at least one DHF parameter for detecting a DHF state of the heart of a patient. This step comprises determining, as said DHF parameter, the time length (DT,IVRT) of a predetermined phase of diastole.
Abstract:
An implantable medical device (100) comprises an impedance determiner (120) for determining a cardiogenic impedance signal (20, 30) based on electric signals sensed by connected electrodes. A parameter calculator (130) processes the impedance signal (20, 30) to calculate an impedance parameter representative of the cardiogenic impedance in connection with the diastolic phase of a heart cycle. This parameter is then employed by the device (100) for monitoring acute decompensated heart failure status of a subject (1).