摘要:
A vascular access port system including means for detecting and indicating the presence or absence of a needle. The detecting and indicating means may be carried in whole or in part by one of or both of the needle and/or the vascular access port. The detecting and indicating means may utilize a conductive needle, a mechanical switch, a magnetic switch, a Hall effect sensor, an electric field, a magnetic field, or an inductor, for example, for detection purposes. The vascular access port system permits the practitioner to confirm that the needle has been correctly inserted into the VAP, and notifies the patient and/or practitioner if the needle has been accidentally withdrawn.
摘要:
The disclosed embodiments present improved catheters with physiological sensors. In one embodiment, the catheter includes, generally, a pressure transducer/electronics assembly connected to a pressure transmission catheter. The pressure transmission catheter includes a hollow tube made from a low compliance material. The distal end of the hollow tube is filled with a gel-like material or plug which acts as a barrier between the catheter liquid and the target fluid. The hollow tube is partially filled with a low viscosity liquid and is in fluid communication with the gel-like material and the pressure transducer. The pressure of the target fluid is transmitted to the liquid in the hollow tube through the gel-like material and/or the wall of the distal tip and is fluidically transmitted to the pressure transducer. The pressure transmission catheter is capable of being inserted into a vessel lumen or inserted into a lumen of a therapeutic or diagnostic catheter for biomedical applications. This provides the ability to directly measure the pressure effects of the treatment catheter. In another embodiment, the distal end of the pressure transmission catheter may be electrically conductive so as to detect and transmit an electric signal. Thus, in this embodiment, the catheter can be used to detect a physiological signal.
摘要:
A device capable of sensing pressure allows the sensor and amplifying electronics to be packaged in a very small size and implanted within the body. The sensor consists of a small catheter, the tip of which is placed at the point at which pressure is to be measured, attached to a solid-state pressure sensor. The catheter is filled with a fluid and is connected to an implantable infusion pump which dispenses through the lumen of the catheter, heparin or other drug which inhibits thrombogenisis.
摘要:
A sensing circuit for a cardiac stimulator which can adapt to the use therewith of either bipolar leads or unipolar leads without the need for telemetric programming of a switch internal to the implanted pacemaker. If a unipolar lead is plugged into the terminal receptacle of the pacer at the time of implant, the pacer will sense R-wave activity and other artifacts between a distal tip electrode and the metal body of the pacemaker, but if a bipolar lead is plugged into that same receptacle at the time of implant, the pacer will sense such artifacts between a tip electrode and a ring electrode spaced a predetermined short distance proximally of the tip electrode along the surface of the lead body.
摘要:
An electrical pacer device which responds to cardiac demand so as to alter the cardiac output in a fashion to satisfy that demand. Changes in the fundamental period of the atrial electrical cycle are detected and averaged over a predetermined time interval and the resulting control signal is used to raise and lower the ventricular heart rate to increase and decrease the aforesaid cardiac output. At the same time, means are provided for continuously driving the ventricular rate toward a predetermined lower rate (the at rest rate) on a time cycle which is significantly longer than the above-mentioned predetermined time interval.
摘要:
An implantable monitoring device includes a flexible lead body that includes at least one sensing element. The device also includes a rigid main body connected to the flexible lead body at an attachment point. The rigid main body is generally centered about a longitudinal axis defined by the flexible lead body when the lead body is unflexed. The device further includes a measurement circuit, which is housed within the rigid main body and electrically coupled to the at least one sensing element of the flexible lead body and at least another sensing element on an outside surface of the rigid main body. The measurement circuit is configured to measure a potential difference between the at least one sensing element of the flexible lead body and the at least another sensing element of the main body.
摘要:
An ambulatory monitoring device includes a sensor to monitor a physiological signal and a battery power source. The device also includes a wireless receiver adapted to monitor a first frequency band having frequencies below 1 MHz and configured to detect and receive, using less than 10 micro-amps of current from the battery power source when operating, wireless communications within the first frequency band from a remote device at least one meter away. The device further includes a wireless transmitter adapted to transmit—after receipt from the remote device of a first wireless communication within the first frequency band that includes an invitation for further communication—a second wireless communication in a second frequency band having frequencies above 10 MHz, the second wireless communication comprising data indicative of the physiological signal as sensed by the sensor.
摘要:
A programmable cardiac pacemaker that is selectively programmable via a radio frequency communications link into one of a plurality of a single and dual chamber pacing modes. Depending upon the mode selected, an associated plurality of pacing parameters may be programmed, each within a predetermined range of possible magnitudes.The pacemaker includes a rate smoothing function for preventing the rate interval from changing by more than a predetermined percentage on a cycle-to-cycle basis; and a graceful degradation function for causing the ventricular pacing rate to decay when the atrial rate exceeds a programmed upper rate limit for a predetermined length of time. A graceful degration onset time and rate of decay are also programmable. Additionally, the pacemaker contains a set of pre-programmed alternative pacing parameters for at least one mode and which can be independently reverted to.The pacemaker control circuitry is organized about a central bus into an I/O controller and a pacing controller. Pacing control is continuous and its I/O communications operate on a prioritized basis. I/O control permits the programming of any register and the interrogation of a variety of analog parameters associated therewith.
摘要:
An implantable monitoring device includes a flexible lead body that includes at least one sensing element. The device also includes a rigid main body connected to the flexible lead body at an attachment point. The rigid main body is generally centered about a longitudinal axis defined by the flexible lead body when the lead body is unflexed. The device further includes a measurement circuit, which is housed within the rigid main body and electrically coupled to the at least one sensing element of the flexible lead body and at least another sensing element on an outside surface of the rigid main body. The measurement circuit is configured to measure a potential difference between the at least one sensing element of the flexible lead body and the at least another sensing element of the main body.
摘要:
An ambulatory monitoring device includes a sensor to monitor a physiological signal and a battery power source. The device also includes a wireless receiver adapted to monitor a first frequency band having frequencies below 1 MHz and configured to detect and receive, using less than 10 micro-amps of current from the battery power source when operating, wireless communications within the first frequency band from a remote device at least one meter away. The device further includes a wireless transmitter adapted to transmit—after receipt from the remote device of a first wireless communication within the first frequency band that includes an invitation for further communication—a second wireless communication in a second frequency band having frequencies above 10 MHz, the second wireless communication comprising data indicative of the physiological signal as sensed by the sensor.