Patent application number | Description | Published |
20080249433 | THORACIC IMPEDANCE DETECTION WITH BLOOD RESISTIVITY COMPENSATION - This document discusses, among other things, a cardiac rhythm management device or other implantable medical device that uses thoracic impedance to determine how much fluid is present in the thorax, such as for detecting or predicting congestive heart failure, pulmonary edema, pleural effusion, hypotension, or the like. The thoracic fluid amount determined from the thoracic impedance is compensated for changes in blood resistivity, which may result from changes in hematocrit level or other factors. The blood-resistivity-compensated thoracic fluid amount can be stored in the device or transmitted to an external device for storage or display. The blood-resistivity-compensated thoracic fluid amount can also be used to adjust a cardiac pacing, cardiac resynchronization, or other cardiac rhythm management or other therapy to the patient. This document also discusses applications of the devices and methods for predicting or indicating anemia. | 10-09-2008 |
20090326599 | CALIBRATION OF IMPEDANCE MONITORING OF RESPIRATORY VOLUMES USING THORACIC D.C. IMPEDANCE - A system includes an implantable medical device that includes a trans-thoracic impedance measurement circuit providing a trans-thoracic impedance signal of a subject. A controller is coupled to the trans-thoracic impedance circuit. The controller extracts a respiration signal from the trans-thoracic impedance signal, measures a breathing volume of the subject using the amplitude of the respiration signal and a breathing volume calibration factor, computes an adjusted breathing volume calibration factor using a reference baseline value of the trans-thoracic impedance and a measured baseline value of the trans-thoracic impedance, and computes a calibrated breathing volume using the adjusted breathing volume calibration factor. | 12-31-2009 |
20100076336 | THORACIC IMPEDANCE DETECTION WITH BLOOD RESISTIVITY COMPENSATION - This document discusses, among other things, a cardiac rhythm management device or other implantable medical device that uses thoracic impedance to determine how much fluid is present in the thorax, such as for detecting or predicting congestive heart failure, pulmonary edema, pleural effusion, hypotension, or the like. The thoracic fluid amount determined from the thoracic impedance is compensated for changes in blood resistivity, which may result from changes in hematocrit level or other factors. The blood-resistivity-compensated thoracic fluid amount can be stored in the device or transmitted to an external device for storage or display. The blood-resistivity-compensated thoracic fluid amount can also be used to adjust a cardiac pacing, cardiac resynchronization, or other cardiac rhythm management or other therapy to the patient. This document also discusses applications of the devices and methods for predicting or indicating anemia. | 03-25-2010 |
Patent application number | Description | Published |
20090025483 | Wearable position or motion sensing systems or methods - A wearable system of one or more body position or motion sensors can include a flexible sensing element to be coupled to or worn on a body. When straight, the flexible sensing element defines a longitudinal axis. It includes a lumen carrying a flowable substance, such as a liquid, gas, or gel. A measurable parameter of the flowable substance, such as pressure, volume, or flow, provides an indication of a longitudinal axial bending, twisting, or elongation, such as due to movement of at least one body part to which the sensing element is coupled. The lumen is coupled to a transducer by at least one conduit for the flowable substance. The transducer converts the measurable parameter of the flowable substance into a transducer output signal indicative of the longitudinal axial bending, twisting, or elongation of the sensing element, from which body part position or movement information can be derived. | 01-29-2009 |
20140039916 | SYSTEM TO DYNAMICALLY COLLECT AND SYNCHRONIZE DATA WITH MOBILE DEVICES - The invention enables bi-directional mobile communication by researchers, clinicians or counselors with their patients and study participants. An exemplary application is ecological momentary assessment of psychological and physical status related to weight management. The system may be combined with objective information to trigger a communication and enhance responses assessed on food choices, dietary intake, physical activity, exertion, mood and companions. | 02-06-2014 |
Patent application number | Description | Published |
20080234773 | CLOSED-LOOP RESYNCHRONIZATION THERAPY FOR MECHANICAL DYSSYNCHRONY - An apparatus comprises a first impedance sensing circuit, a second sensing circuit, and an impedance-based cardiac dyssynchrony detector. The impedance sensing circuit senses an intracardiac local impedance signal that is indicative of a cardiac local wall motion of a first cardiac region from an implantable first bipolar pair of impedance sensing electrodes. The second sensing circuit is configured to produce a second sensor signal indicative of cardiovascular activity. The impedance-based cardiac dyssynchrony detector is configured for detecting cardiac dyssynchrony using a relationship between the first intracardiac local impedance signal and the second sensor signal. Other apparatuses and methods are disclosed. | 09-25-2008 |
20090069708 | HISTOGRAM-BASED THORACIC IMPEDANCE MONITORING - Systems and methods for monitoring pulmonary edema or other thoracic fluid status in a subject use thoracic impedance histogram information. An internal or external processor circuit receives the thoracic impedance histogram information and uses it to compute and provide a lung fluid status indication. The thoracic impedance histogram information can include a count, mean or median of a histogram bin or subrange of bins within the histogram range. | 03-12-2009 |
20090118626 | Calculating Respiration Parameters Using Impedance Plethysmography - A method of determining a value for a respiration parameter in a test subject can include capturing—using a fully implanted system that includes a wireless transmitter and at least a first lead wire having a first electrode disposed thereon and a second lead wire having a second electrode disposed thereon—information indicative of an impedance measure between the first and second electrodes and across a thoracic region of the test subject; wirelessly transmitting, from the implanted system and to external equipment, the captured information; and determining a respiration parameter of the test subject based on the captured information. The at least first and second lead wires can be positioned in the test subject subcutaneously and external of any cranial, thoracic, abdominal and pelvic cavities of the test subject | 05-07-2009 |
20090326387 | Electrocardiogram and Respiration Monitoring in Animals - An ambulatory animal monitoring system includes a wearable structure constructed to be worn about a body of a non-human animal to be monitored. The system includes a plurality of electrical signal conduits each associated with the wearable structure and each connectable to a different one of a plurality of surface electrode components. The system includes processing and control device adapted to be worn with the wearable structure, the processing and control device comprising a) an ECG monitoring component and b) an impedance level monitoring component that generates data indicative of electrical impedance levels of the animal over time. | 12-31-2009 |
20090326408 | Providing Impedance Plethysmography Electrodes - A method of measuring lung impedance of a subject can include positioning current-injection electrodes on or within the subject in a configuration such that a current injected between the current-injection electrodes propagates substantially through a first lung of the subject, and not through a heart and a second lung of the subject; positioning voltage-measurement electrodes on or within the subject in a configuration such that voltage measuring fields propagate substantially through the first lung and the second lung of the subject, but not through the heart of the subject; and injecting a current between the current-injection electrodes, as positioned, and measuring a resulting voltage between the voltage-measurement electrodes, as positioned, to obtain an impedance measure across lung tissue. The method can further include injecting current and measuring the resulting voltage multiple times over a time period to monitor respiration of the subject over the time period. | 12-31-2009 |
20090326510 | Drug Delivery Methods and Systems - Drug delivery methods and systems that include a determination of whether a cardiac condition is normal or abnormal, so that a drug may be administered in accordance with that determination. In one implementation, a drug delivery device may be controlled to reduce or stop the drug administration when a normal cardiac condition is detected. In another implementation, a patient monitoring device determines the duration that a cardiac condition is normal and provides an output indicative of the determination so that the patient may alter a therapy accordingly. | 12-31-2009 |
20110218450 | Respiration Measurements and Dosimetry Control in Inhalation Testing Systems - Inhalation measurement systems and methods enable, during inhalant exposure, substantially real-time respiratory measurements of a test subject using techniques that obtain measurements of respiration directly from that test subject, instead of from inhalation chamber parameter measurements. Direct test subject respiratory measurements may be, by way of example only, impedance measurements. These respiratory measurements taken directly from the test subject may be transmitted, wirelessly for example, for processing during the course of the test to a processing system to determine a cumulative volume of inhalant inspired by the test subject. From that, a cumulative amount of inhalant (or dose) inspired by the test subject may be determined during the course of the inhalation compound test. In addition, a calibration procedure may be performed before the inhalant exposure to provide correlation needed to translate chest and/or abdominal wall expansion measurements, made during the test, into lung volume measurements. | 09-08-2011 |
20120029372 | Drug Delivery Methods and Systems - Drug delivery methods and systems that include a determination of whether a cardiac condition is normal or abnormal, so that a drug may be administered in accordance with that determination. In one implementation, a drug delivery device may be controlled to reduce or stop the drug administration when a normal cardiac condition is detected. In another implementation, a patient monitoring device determines the duration that a cardiac condition is normal and provides an output indicative of the determination so that the patient may alter a therapy accordingly. | 02-02-2012 |
20120245475 | Bio-Impedance Sensor and Sensing Method - 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. | 09-27-2012 |
20130138008 | SYSTEM AND METHOD FOR SYSTOLIC INTERVAL ANALYSIS - A system and method provide for systolic interval analysis. In an example, an implantable device measures a cardiac impedance signal. A transformation of the cardiac impedance interval is generated. The device also measures a heart sound signal. A time interval between a point on the transformed signal of the cardiac impedance signal and a point on the heart sound signal is calculated. | 05-30-2013 |
20130303931 | RESPIRATION MEASUREMENTS AND DOSIMETRY CONTROL IN INHALATION TESTING SYSTEMS - Inhalation measurement systems and methods enable, during inhalant exposure, substantially real-time respiratory measurements of a test subject using techniques that obtain measurements of respiration directly from that test subject, instead of from inhalation chamber parameter measurements. Direct test subject respiratory measurements may be, by way of example only, impedance measurements. These respiratory measurements taken directly from the test subject may be transmitted, wirelessly for example, for processing during the course of the test to a processing system to determine a cumulative volume of inhalant inspired by the test subject. From that, a cumulative amount of inhalant (or dose) inspired by the test subject may be determined during the course of the inhalation compound test. In addition, a calibration procedure may be performed before the inhalant exposure to provide correlation needed to translate chest and/or abdominal wall expansion measurements, made during the test, into lung volume measurements. | 11-14-2013 |
20140207206 | SYSTEM AND METHOD FOR SYSTOLIC INTERVAL ANALYSIS - According to a system or method, information indicative of a cardiac depolarization signal can be obtained. Information indicative of an acoustic signal from an implantable acoustic sensor included as a portion of an implantable therapy device can be obtained. A feature indicative of an R wave can be identified from the information indicative of the cardiac depolarization signal, and a feature indicative of an S2 heart sound can be identified from the information indicative of the acoustic signal. A time interval between an instant corresponding to the feature indicative of the R wave and an instant corresponding to the feature indicative of the S2 heart sound can be determined. Using information about the determined time interval, an adjusted pacing therapy parameter can be provided for use in a pacing therapy to be provided by the implantable therapy device. | 07-24-2014 |
20140336521 | INTRACARDIAC IMPEDANCE AND ITS APPLICATIONS - A system to measure intracardiac impedance includes implantable electrodes and a medical device. The electrodes sense electrical signals of a heart of a subject. The medical device includes a cardiac signal sensing circuit coupled to the implantable electrodes, an impedance measurement circuit coupled to the same or different implantable electrodes, and a controller circuit coupled to the cardiac signal sensing circuit and the impedance measurement circuit. The cardiac signal sensing circuit provides a sensed cardiac signal. The impedance measurement circuit senses intracardiac impedance between the electrodes to obtain an intracardiac impedance signal. The controller circuit determines cardiac cycles of the subject using the sensed cardiac signal, and detects tachyarrhythmia using cardiac-cycle to cardiac-cycle changes in a plurality of intracardiac impedance parameters obtained from the intracardiac impedance signal. | 11-13-2014 |
20140378861 | HISTOGRAM-BASED THORACIC IMPEDANCE MONITORING - Systems and methods for monitoring pulmonary edema or other thoracic fluid status in a subject use thoracic impedance histogram information. An internal or external processor circuit receives the thoracic impedance histogram information and uses it to compute and provide a lung fluid status indication. The thoracic impedance histogram information can include a count, mean or median of a histogram bin or subrange of bins within the histogram range. | 12-25-2014 |