摘要:
In general, the invention is directed to methods and devices for determining an ion concentration in the extracellular fluid of a patient. As examples, the ion may be one or more of potassium, sodium, chloride, or calcium. A system includes an electrode deployed in or near a tissue, such as a skeletal muscle, of the patient. A pulse generator supplies one or more stimulations to the tissue, and a sensor, such as an accelerometer, detects the response of the tissue to the stimulations. A processor determines a concentration of ions in the extracellular fluid as a function of the response. The system may detect an ion imbalance based upon the determined concentration of ions.
摘要:
A medical device system and associated method are used for monitoring a heart failure patient. A medical device for monitoring delivery of a therapy includes a sensor sensing an optical sensor signal corresponding to light attenuation by a volume of body tissue of a patient, a therapy delivery module to deliver a therapy, and a processor configured to compute a first tissue oxygenation measurement from the optical sensor signal prior to initiating delivery of the therapy, compute a second tissue oxygenation measurement from the optical sensor signal subsequent to initiating delivery of the therapy, compare the first and the second tissue oxygenation measurements, and determine whether the delivered therapy was successful in response to the first tissue oxygenation measurement and the second tissue oxygenation measurement.
摘要:
A medical system that includes an identification patch having a memory that stores identification information associated with the patch. A monitoring device to be used with the identification patch interrogates the patch to obtain the identification information stored within the memory of the patch. The monitoring device determines whether the identification information is valid and, if so, measures values representing one or more parameters of the patient. If the identification information is not valid, monitoring device does not measure values representing the one or more parameters of the patient.
摘要:
A medical system that includes an identification patch having a memory that stores identification information associated with the patch. A monitoring device to be used with the identification patch interrogates the patch to obtain the identification information stored within the memory of the patch. The monitoring device determines whether the identification information is valid and, if so, measures values representing one or more parameters of the patient. If the identification information is not valid, monitoring device does not measure values representing the one or more parameters of the patient.
摘要:
A medical device for monitoring delivery of a therapy that includes a therapy delivery module to deliver a therapy, a controller to set a therapy delivery control parameter, an optical sensor to produce a signal corresponding to tissue light attenuation, and a processor configured to compute a tissue oxygenation measurement from the optical sensor signal, wherein the controller, the optical sensor, and the processor operate cooperatively to determine a setting of the therapy delivery control parameter corresponding to a maximum tissue oxygenation.
摘要:
A medical device system and associated method are used for monitoring a heart failure patient. A medical device for monitoring delivery of a therapy includes a sensor sensing an optical sensor signal corresponding to light attenuation by a volume of body tissue of a patient, a therapy delivery module to deliver a therapy, and a processor configured to compute a first tissue oxygenation measurement from the optical sensor signal prior to initiating delivery of the therapy, compute a second tissue oxygenation measurement from the optical sensor signal subsequent to initiating delivery of the therapy, compare the first and the second tissue oxygenation measurements, and determine whether the delivered therapy was successful in response to the first tissue oxygenation measurement and the second tissue oxygenation measurement.
摘要:
A method and medical device for detecting signals that detects emitted light scattered by a volume of tissue delivered along a first pathway and a second pathway different from the first pathway, detects emitted light scattered by a volume of tissue delivered along a third pathway and a fourth pathway different from the third pathway, determines a first uniformity corresponding to the emitted light detected along the first pathway and the second pathway, determines a second uniformity corresponding to the emitted light detected along third pathway and the fourth pathway, determines a total uniformity in response to the determined first uniformity and the determined second uniformity, and alters sensing by the device in response to the determined total uniformity.
摘要:
A medical device for implantation within a patient comprising a lead body including a conductor within the lead body and a transducer supported by the lead body. The conductor is electrically coupled to the transducer by a conductive fluid, paste or gel. The conductive fluid, paste or gel may be contained within a well in the lead body. The transducer may be a MEMS chip and/or an integrated circuit and may perform any of a variety of functions such as sensing physiological data.
摘要:
A method for estimating pulmonary artery diastolic pressure, for a single heart beat, includes establishing a time window for sampling and storing pressure data points from a right ventricular pressure transducer. The time window may be established according to predetermined parameters and/or according to one or more triggering events. An approximate time at which the pulmonary artery valve opens is determined, either via the sampled pressure data points, or via another form of more direct monitoring, during the time window, in order to estimate the pulmonary artery diastolic pressure. A plurality of sets of N pressure data points may be collected, from the sampled data, and, for each collected set, a weighted sum is calculated. Each weighted sum may be employed to evaluate a quality of the sampled data and/or to estimate the pulmonary artery diastolic pressure, if the more direct monitoring of the pulmonary artery valve is not employed.
摘要:
An integrated activation system for an implantable medical device (IMD) sharing a power source, the activation system having a switching circuit and a sensing element coupled to the switching circuit. The switching circuit is configured to gate power from the power source to the IMD. The sensing element is configured to draw current from the power source of less than or equal to about 1 nA during inactivation, enable an operation interval of the switching circuit, and trigger a first state change in the switching circuit. The switching circuit further is configured to gate power to the IMD upon receipt of a pre-determined number of signals from the sensing element.