Abstract:
The health state of a subject is automatically evaluated or predicted using at least one implantable device. In varying examples, the health state is determined by sensing or receiving information about at least one physiological process having a circadian rhythm whose presence, absence, or baseline change is associated with impending disease, and comparing such rhythm to baseline circadian rhythm prediction criteria. Other chronobiological rhythms beside circadian may also be used. The baseline prediction criteria may be derived using one or more past physiological process observation of the subject or population of subjects in a non-disease health state. The prediction processing may be performed by the at least one implantable device or by an external device in communication with the implantable device. Systems and methods for invoking a therapy in response to the health state, such as to prevent or minimize the consequences of predicted impending heart failure, are also discussed.
Abstract:
Devices and methods for detecting disordered breathing involve determining that the patient is asleep and sensing one or more signals associated with disordered breathing indicative of sleep-disordered breathing while the patient is asleep. Sleep-disordered breathing is detected using the sensed signals associated with disordered breathing. The sensed signals associated with disordered breathing may also be used to acquire a respiration pattern of one or more respiration cycles. Characteristics of the respiration pattern are determined. The respiration pattern is classified as a disordered breathing episode based on the characteristics of the respiration pattern. One or more processes involved in the detection of disordered breathing are performed using an implantable device.
Abstract:
An apparatus comprises a physiologic sensing circuit and a control circuit. The physiologic sensing circuit is configured to sense an electrical respiration signal representative of respiration of a subject. The control circuit includes a respiration monitor circuit and a therapy circuit. The respiration monitor circuit is configured to extract a respiration parameter from the respiration signal and detect that a value of the respiration parameter is outside of a target value range for the respiration parameter. The therapy circuit is configured to deliver neural stimulation to the carotid sinus of the subject to stimulate respiration and to adjust respiration to maintain the value of the respiration parameter within the target value range.
Abstract:
Implantable medical devices and techniques are implemented that use bio-impedance to measure aspects of patient physiology. A signal separation method is performed at least in part in an implantable device. The method involves detecting a plurality of impedance signals using a plurality of implantable electrodes coupled to the implantable device. The method further involves separating one or more signals from the plurality of impedance signals using a signal separation technique, such as an algorithm-based separation technique.
Abstract:
A device can include a multi-dimensional posture sensor that provides an electrical sensor output representative of alignment of first, second, and third non-parallel axes of the device with the gravitational field of the earth, and a processor that includes a calibration circuit and a posture circuit. The calibration circuit measures a first sensor output for the first device axis and a second sensor output for one of a second device axis while the subject is in a first specified posture, measures sensor outputs for the first, second, and third device axes while the subject is in a second specified posture, calculates one or more coordinate transformations, generates transformed sensor outputs using the coordinate transformations, and calibrates the posture sensor by calculating a calibration transformation using the first and second sensor outputs and the transformed sensor outputs. The posture circuit determines a subsequent posture of the subject using the posture sensor.
Abstract:
Systems and methods involve use of a medical device comprising sensing circuitry. One or more respiratory parameters are detected using the device. Patient baseline weight is provided, and an output signal indicative of a patient's congestive heart failure status is generated based on a change in the one or more respiratory parameters and a change in the patient's measured weight or predicted weight relative to the patient baseline weight. The respiratory parameters may include one or more of respiration rate, relative tidal volume, an index indicative of rapid shallow breathing by the patient, an index derived by computing a respiration rate and a tidal volume for each patient breath, and an index indicative of dyspnea, for example.
Abstract:
The health state of a subject is automatically evaluated or predicted using at least one implantable device. In varying examples, the health state is determined by sensing or receiving information about at least one physiological process having a circadian rhythm whose presence, absence, or baseline change is associated with impending disease, and comparing such rhythm to baseline circadian rhythm prediction criteria. Other chronobiological rhythms beside circadian may also be used. The baseline prediction criteria may be derived using one or more past physiological process observation of the subject or population of subjects in a non-disease health state. The prediction processing may be performed by the at least one implantable device or by an external device in communication with the implantable device. Systems and methods for invoking a therapy in response to the health state, such as to prevent or minimize the consequences of predicted impending heart failure, are also discussed.
Abstract:
Devices and methods for detecting disordered breathing involve determining that the patient is asleep and sensing one or more signals associated with disordered breathing indicative of sleep-disordered breathing while the patient is asleep. Sleep-disordered breathing is detected using the sensed signals associated with disordered breathing. The sensed signals associated with disordered breathing may also be used to acquire a respiration pattern of one or more respiration cycles. Characteristics of the respiration pattern are determined. The respiration pattern is classified as a disordered breathing episode based on the characteristics of the respiration pattern. One or more processes involved in the detection of disordered breathing are performed using an implantable device.
Abstract:
A physiological sensor is located within the airway of the subject's body, such as for measuring barometric pressure and communicating this value to a blood pressure or other monitoring device, which can derive gauge pressure using the barometric pressure and a measured absolute pressure within the body. The physiological sensor may also detect one or more other physiological parameters such as air flow, sound, or a chemical property. It may be anchored within the airway with the ability to communicate wirelessly to one or more other medical devices, such as an implanted cardiac function management device. Methods of use are also described.
Abstract:
An implantable system for ambulatory monitoring of a high-risk heart failure patient includes a first pressure sensor implantable within an abdomen of the patient for sensing and generating an output representative of a baseline intra-abdominal pressure value of the patient and for chronically sensing and generating an output representative of an intra-abdominal pressure value of the patient at periodic intervals. At least one second implantable sensor is provided for sensing and generating an output representative of a second physiological parameter of the patient. Additionally, the system includes a processor for correlating the output of the first pressure sensor and the second physiologic sensor, and for comparing differences between the baseline intra-abdominal pressure value and subsequent intra-abdominal pressure values. The processor can reside in another implantable device or in an external device/system.