摘要:
A sensor is located within the body of a subject, such as for capturing pacing pulses transmitted as part of cardiac therapy from an implanted cardiac function management device. Counted pulses may be used to derive the onset of pulmonary edema within the body through pulse characteristics such as frequency and amplitude. The sensor may be anchored within mediastinal pleura or the airway of the body with the ability to communicate wirelessly to one or more other medical devices, such as an implanted cardiac function management device. It may also adjust transmission of the communication to discriminate among multiple sensors. Methods of use are also described.
摘要:
Changes in an amount of fluid in a region of a subject, such as the lung(s), may be detected by internally injecting a current through the region, detecting a resulting voltage at an upper and lower body portion, and calculating an impedance value using knowledge of the injected current and resulting voltage. Alternatively, the amount of fluid in the region may be found by internally applying a voltage of known or controllable value (thereby, injecting a current), detecting a resulting voltage at the upper and lower body portions, and calculating a fluid indicative signal using the resulting voltage or using a product of the resulting voltage and the injected current (i.e., power). A method for performing such measurements includes, among other things, injecting a current between first and second internal electrodes and measuring a resulting voltage between first and second external electrodes contacting the subject's upper and lower body portions.
摘要:
An implantable medical device includes a voltage measurement circuit to measure a potential difference between implanted electrodes in a thorax of a living being, the potential difference resulting from an electrical P-wave cardiac signal. The implantable medical device also includes a processing unit to calculate a vector corresponding to the P-wave cardiac signal, the vector comprising a magnitude and a direction, and derived from measured potential differences and orientations defined by locations of the implanted electrodes. The implantable medical device further includes a monitoring unit to track a rotation of the vector corresponding to the P-wave cardiac signal. In various implementations, the monitoring unit may use the rotation to detect an inter-atrial block condition.
摘要:
A method and apparatus for measuring impedance for pathology assessment in a living being using convergent bioelectric lead fields is disclosed, including injecting a current between first and second electrodes implanted in a body of a living being, where the first and second electrodes define a first electric lead field oriented between the first and second electrodes. A potential difference is measured between third and fourth electrodes implanted in the body, where the potential difference results from the current injected between the first and second electrodes. The third and fourth electrodes define a second electric lead field oriented between the third and fourth electrodes. The first and second electric lead fields converge near an assessment site within the body, but are substantially separated otherwise. An impedance value is calculated based on the potential difference and the current injection, and is used to assess a pathology near the assessment site.
摘要:
A method and device to enable a medical or surgical procedure using electro-cautery on a patient with an implantable device in a cautery-safe mode of operation. In one embodiment, the invention provides an electronic implantable device programmer having a computer processor, and a display screen configured to display information based on signals from the computer processor. The programmer also includes an input device, and a wireless transmitter controlled by the computer processor. The programmer display and input give the operator the option of programming an implanted electronic device in a cautery-safe mode. With this input, from the operator, instructions are provided in the programmer to transmit a signal from the wireless transmission device to the implanted electronic device to program the electronic device to be in a dedicated bipolar mode where electrical noise produced when operating an electro-cautery device during and medical/surgical procedure does not interfere with operation of the electronic device.
摘要:
An implantable pacing device for delivering ventricular pacing may be configured to intermittently reduce the AVD interval for beneficial effect in patients with compromised ventricular function (e.g., HF patients and post-MI patients). The AVD interval may be reduced in an AVD reduction mode, by shortening the AVD in an atrial triggered ventricular pacing mode or by switching to a non-atrial triggered ventricular pacing mode (e.g., VVI) and delivering paces at a rate above the intrinsic rate. The physiological effects of AVD reduction may be either positive or negative on cardiac output, depending upon the individual patient.
摘要:
A system and method to sense heart sounds with one or more implantable medical devices according to one or more parameters. The system alters one or more of the parameters as a function of one or more triggering events. The system then senses heart sounds with the one or more implantable medical devices according to at least the one or more altered parameters.
摘要:
An implantable medical device includes a voltage measurement circuit to measure a potential difference between implanted electrodes in a thorax of a living being, the potential difference resulting from an electrical P-wave cardiac signal. The implantable medical device also includes a processing unit to calculate a vector corresponding to the P-wave cardiac signal, the vector comprising a magnitude and a direction, and derived from measured potential differences and orientations defined by locations of the implanted electrodes. The implantable medical device further includes a monitoring unit to track a rotation of the vector corresponding to the P-wave cardiac signal. In various implementations, the monitoring unit may use the rotation to detect an inter-atrial block condition.
摘要:
An implantable pacing device for delivering ventricular pacing may be configured to intermittently reduce the AVD interval for beneficial effect in patients with compromised ventricular function (e.g., HF patients and post-MI patients). The AVD interval may be reduced in an AVD reduction mode, by shortening the AVD in an atrial triggered ventricular pacing mode or by switching to a non-atrial triggered ventricular pacing mode (e.g., VVI) and delivering paces at a rate above the intrinsic rate. The physiological effects of AVD reduction may be either positive or negative on cardiac output, depending upon the individual patient.
摘要:
A sensor is located within the body of a subject, such as for capturing pacing pulses transmitted as part of cardiac therapy from an implanted cardiac function management device. Counted pulses may be used to derive the onset of pulmonary edema within the body through pulse characteristics such as frequency and amplitude. The sensor may be anchored within mediastinal pleura or the airway of the body with the ability to communicate wirelessly to one or more other medical devices, such as an implanted cardiac function management device. It may also adjust transmission of the communication to discriminate among multiple sensors. Methods of use are also described.