摘要:
An implanted medical device (IMD) conserves power by discriminating received radio frequency (RF) signals between noise and data based on frequency. Data is processed while noise is attenuated. The IMD operates in a first, relatively low, power mode while not receiving the RF signals, in a second, higher, power mode responsive to receiving RF signals, and operates in still higher power mode when the RF signals' average frequency over a selected period is within a predetermined range. A receiver circuit receives RF signals and discriminates a data signal from noise based on average frequency of the RF signals over selected time periods. The receiver circuit operates in a power-conserving mode unless it receives RF signals, or otherwise operates in a relatively higher-power mode. The receiver transfers signals to a telemetry circuit that operates in a power-conserving mode until it receives a valid data signal to operate in higher power mode.
摘要:
An implantable medical device having an optical sensor selects the function of modular opto-electronic assemblies included in the optical sensor. Each assembly is provided with at least one light emitting device and at least one light detecting device. A device controller coupled to the optical sensor controls the function of each the assemblies. The controller executes a sensor performance test and selects at least one of the plurality of assemblies to operate as a light emitting assembly in response to a result of the performance test. The controller selects at least one other of the plurality of optical sensor assemblies to operate as a light detecting assembly in response to a result of the performance test.
摘要:
A reflectance-type optical sensor includes one or more photodiodes formed in a semiconductor substrate. A well having sidewalls and a bottom is formed in the top surface of the substrate, and a reflective layer is formed on the sidewalls and bottom. A light-emitting diode (LED) is mounted in the well, so that light emitted laterally and rearwardly from the LED strikes the sidewalls or bottom and is redirected in a direction generally perpendicular to the top surface of the substrate. The optical sensor can be fabricated using microelectromechanical systems (MEMS) fabrication techniques.
摘要:
An implantable medical device having an optical sensor selects the function of modular opto-electronic assemblies included in the optical sensor. Each assembly is provided with at least one light emitting device and at least one light detecting device. A device controller coupled to the optical sensor controls the function of each the assemblies. The controller executes a sensor performance test and selects at least one of the plurality of assemblies to operate as a light emitting assembly in response to a result of the performance test. The controller selects at least one other of the plurality of optical sensor assemblies to operate as a light detecting assembly in response to a result of the performance test
摘要:
A reflectance-type optical sensor includes one or more photodiodes formed in a semiconductor substrate. A well having sidewalls and a bottom is formed in the top surface of the substrate, and a reflective layer is formed on the sidewalls and bottom. A light-emitting diode (LED) is mounted in the well, so that light emitted laterally and rearwardly from the LED strikes the sidewalls or bottom and is redirected in a direction generally perpendicular to the top surface of the substrate. The optical sensor can be fabricated using microelectromechanical systems (MEMS) fabrication techniques.
摘要:
In a pacemaker, a method and apparatus for providing rate response in proportion to the patient's metabolic demand for cardiac output as determined in response to the patient's breathing rate or respiratory minute ventilation or contraction strength, optionally augmented by the patient's activity level. An implantable pulse generator (IPG) has one or more pacing leads having a proximal end coupled to the IPG and a distal end in contact with a patient's heart. A pressure wave transducer mounted in the IPG in relation to the proximal end of the pacing lead senses pressure waves transmitted from the distal end of the pacing lead to the proximal end thereof. The pressure waves originate from disturbances imparted to the lead by heart contractions and breathing. A further isolated, reference sensor is also incorporated into the IPG in a similar fashion. An activity signal processor is coupled to the pressure wave or reference sensor for providing a patient activity physiologic signal. A respiration signal processor is coupled to said pressure wave and reference transducers for nulling out common mode noise and providing physiologic respiration rate and/or respiratory minute ventilation signals. A contraction strength signal processor is coupled to said pressure wave and reference transducers for nulling out common mode noise and providing physiologic contraction strength signals. Pacing rate control circuitry is responsive to one or more of the physiologic signals for setting the pacing rate to meed the metabolic demand.
摘要:
In an implanted medical device, a method and apparatus for detecting pressure waves caused by movement of a body organ, muscle group, limb or the like and transmitted through a catheter or lead body to the implanted medical device employing a pressure wave transducer mounted in relation to the proximal end of the catheter or lead to detect the transmitted pressure waves. The system may also include a reference transducer having the same pressure wave response characteristics as the pressure wave transducer but isolated from the proximal connector end for providing a reference signal including common mode pressure wave noise that both transducers are simultaneously subjected to. The pressure wave signal and the reference signal are preferably amplified, bandpass filtered to the body pressure wave of interest and stored, telemetered out or used to trigger a device operation. The pressure and reference wave transducers preferably are piezoelectric crystal transducers or accelerometers in direct or indirect mechanical contact with the proximal connector end of the catheter and is encapsulated from the body within a device connector assembly. Preferably, the catheter is a lead extending into direct or indirect contact with the patient's heart. Cardiac pressure waves and respiration pressure waves are both transmitted proximally through the lead body to the pressure wave transducer. Pressure wave signals may be derived in parallel to detect particular characteristics of the cardiac and/or respiratory cycle to provide timing signal(s) for controlling the device operations.
摘要:
A capture verification system for a cardiac pacemaker comprising an implantable pulse generator (IPG) and one or more pacing leads having a proximal end coupled to the IPG and a distal end in contact with a patient's heart. The capture verification system employs a pressure wave sensor mounted in the IPG in relation to the proximal end of the pacing lead for sensing pressure waves transmitted from the distal end of the pacing lead to the proximal end thereof. The pressure waves include characteristic sounds of heart contraction and/or distal end lead motion caused by the contraction motion of the patient's heart that are transmitted along the lead body to the active sensor. A further isolated, reference sensor is also incorporated into the IPG in a similar fashion. Signal processors are coupled to the pressure wave and reference sensors for nulling out common mode noise.
摘要:
An implantable medical lead includes a device, such as a physiological sensor, that is coupled to one or more stimulation/sensing sensing conductors within the lead. When the implantable medical lead is coupled to an implantable medical device, the device carried by the lead both receives power from, and communicates with the implantable medical device via the one or more stimulation/sensing sensing conductors. Each of the one or more stimulation/sensing sensing conductors is also coupled to an electrode that is exposed to body tissue.
摘要:
An implantable medical device communication system communicates information between an implantable medical device and at least one slave device by way of a two-wire bus. Slave devices may include remote sensors and other implantable medical devices. The implantable medical device includes a communication unit to combine data and power for transmission over the two wire bus. The transmitted signal is selectively changeable between a first and second voltage. The slave device includes a recovery unit to recover data and power from the received signal. An extendable command set includes long commands to set up the system and shorter commands to conserve power. Selectively addressable multicast commands, and shortened quick trigger commands conserve power by lowering system current and increasing data throughput.