摘要:
An implantable living tissue stimulator avoids the use of conventional coupling capacitors in its output stage, yet still prevents an average dc current flow from flowing through living tissue in electrical contact with the stimulator. The output stage generates and applies a biphasic stimulating current pulse to selected paired output terminals. The terminals, in turn, are electrically connected to respective electrodes which are positioned so as to contact the living tissue to be stimulated. In one embodiment, special circuitry is employed within the output stage to block dc current flow through the living tissue and to balance the electrical charge that is delivered to the living tissue. In another embodiment, the electrodes themselves are made from a material that allows them to function as a capacitor. In yet an additional embodiment, the coupling capacitors are integrated into the leads that connect the output terminals of the output stage with the electrodes.
摘要:
A glucose monitoring system continuously measures the glucose concentration in a patient's blood, provides an indication of the rate of change of such concentration, and determines whether the measured concentration and rate of change are within certain preset limits. If not, an audible and/or visual alarm signal is generated. The glucose monitoring system includes a glucose sensor adapted to be inserted into the venous system of the patient, where it responds to blood glucose and produces sensor signals related to the glucose concentration. The sensor signals are delivered through a suitable interconnect cable to a glucose monitor. In one embodiment, the interconnect cable includes a contactless connector that electrically isolates the glucose sensor from the monitor, and reduces the number of conductors required to interface with a plurality of sensors. The glucose monitor interprets the sensor signals by applying a previously determined calibration to quantitatively determine the blood glucose value. The blood glucose value thus determined is then processed in order to determine the rate of change, is stored (to create a history or record), and may also be displayed in large, easy-to-read numerals. Rate of change information (trend) may also be numerically or graphically displayed.
摘要:
A disposable cassette for use with a main infusion pump unit is disclosed which contains both a disposable pump and a battery, thereby requiring the simultaneous replacement of both the pump and the battery. The controller contained in the main pump unit includes a timer which prevents the cassette from being used for longer than a predetermined time, which is substantially less than the life of the battery. An interlock prevents a cassette from being reinstalled following a single use.
摘要:
A transcutaneous coupling device having an implanted unit and an external unit uses VELCRO for attaching the external unit to the skin in a proper location for optimal electromagnetic coupling between the units. The VELCRO has two surfaces, which adhere to one another, one surface being affixed to the external unit, and the other surface being adhesively attached to the skin. In one embodiment, the VELCRO is a patch coextensive with the surface area of the side of the external unit. In another embodiment, where the thickness of the VELCRO interferes with the coupling, the VELCRO takes the form of a ring or set of smaller patches permitting projecting portions of the side of the external unit to directly contact the skin for better coupling.
摘要:
A glucose monitoring system continuously measures the glucose concentration in a patient's blood, provides an indication of the rate of change of such concentration, and determines whether the measured concentration and rate of change are within certain preset limits. If not, an audible and/or visual alarm signal is generated. The glucose monitoring system includes a glucose sensor adapted to be inserted into the venous system of the patient, where it responds to blood glucose and produces sensor signals related to the glucose concentration. The sensor signals are delivered through a suitable interconnect cable to a glucose monitor. In one embodiment, the interconnect cable includes a contactless connector that electrically isolates the glucose sensor from the monitor, and reduces the number of conductors required to interface with a plurality of sensors. The glucose monitor interprets the sensor signals by applying a previously determined calibration to quantitatively determine the blood glucose value. The blood glucose value thus determined is then processed in order to determine the rate of change, is stored (to create a history or record), and may also be displayed in large, easy-to-read numerals. Rate of change information (trend) may also be numerically or graphically displayed.
摘要:
A replaceable catheter system provides a way to replace an implantable sensor, electrode system, and/or fluid delivery/receiving system. The replaceable catheter includes an elongated tubular catheter holder for surgical implantation in a patient. The catheter holder has an open neck at a proximal end thereof just under the patient's skin. A distal end of the catheter holder extends into a body cavity in the patient. A manually replaceable catheter is inserted through a self-sealing barrier over the open end of the catheter holder. A distal end of the replaceable catheter extends longitudinally through the catheter holder and beyond the distal end thereof to expose one or more physiological/chemical sensors, tissues stimulating electrodes, and/or a fluid delivery/receiving tube carried by or formed within the replaceable catheter. The sensors and/or electrodes are electrically connected to an electronic package including a signal coupler adjacent a signal coupler carried by the catheter holder. The signal coupler is connected to an implanted control device whereby electrical signals are transmitted to and/or from the sensor and/or electrode from the control device. The control device may include, or be connected to, an implantable fluid dispenser/analyzer for dispensing or analyzing fluid via a conduit connected through the catheter holder to an opening in the replaceable catheter.
摘要:
A patient monitoring system measures the concentration of a particular substance in a patient's tissue, blood, or other bodily fluids, provides an indication of the rate of change of such concentration, and determines whether the measured concentration and rate of change are within certain preset limits. If not, an audible and/or visual alarm signal is generated. The patient monitoring system includes at least one enzymatic sensor adapted to be inserted into the patient, where it produces sensor signals related to the concentration of the substance being measured. The sensor signals are delivered through a suitable interconnect cable to a monitor. In one embodiment, the interconnect cable includes a contactless connector that electrically isolates the enzymatic sensor from the monitor, and reduces the number of conductors required to interface with a plurality of sensors. The monitor interprets the sensor signals by applying a previously determined calibration to quantitatively determine the substance concentration value. The substance concentration value thus determined is then processed in order to determine the rate of change, is stored (to create a history or record), and may also be displayed in large, easy-to-read numerals. Rate of change information (trend) may also be numerically or graphically displayed.
摘要:
An implantable system, such as a neural stimulator or a cochlear implant system, includes a rechargeable battery configuration having improved recharging and lifetime characteristics. The battery is housed within the implant's case and has first and second electrode plates. Each electrode plate has a plurality of slits that extend across a substantial portion of the plate's surface area. The slits in the electrode plates reduce the magnitude of eddy currents induced in the plates by external ac magnetic fields allowing faster battery recharging times. Alternatively, the electrode plates are wrapped in a spiral configuration such that, in the plane of the spiral, the electrode plates have a small cross-sectional area and no closed current loops. Additionally, the implant device may be housed in a case formed of a high-resistivity material and a circuit included in the implant device is configured to avoid large current loops that would result in eddy current heating. As a backup option, the circuitry of the implant device may optionally be powered from an external battery that inductively couples energy to the same coil that is used to charge the internal battery. In one embodiment, the implantable system is partitioned into first and second implantable cases, each having electrical circuitry therein, and only one having a rechargeable power source therein, facilitating its subsequent replacement for repair or upgrading purposes. The two cases are coupled together when the system is in use. Coupling is achieved either magnetically and/or with a detachable electrical cable. In one embodiment, power is transferred from one implant case to the other using a 3-phase transmission scheme.
摘要:
A replaceable catheter system provides a way to replace an implantable sensor, electrode system, and/or fluid delivery/receiving system. The replaceable catheter system includes an implantable shunt, such as an arteriovenous shunt, attached to an implantable introducer. The introducer and implantable shunt are adapted for surgical implantation within a patient such that it extends from immediately below the patient's skin to the implantable shunt site. The replaceable catheter system further includes a replaceable catheter that is adapted to be contained within the introducer and properly aligned such that an implantable sensor, electrode system, and/or fluid delivery system that is carried by the replaceable catheter is placed in operative association with the implantable shunt and exposed to any fluids passing through the implantable shunt.
摘要:
A system is disclosed for controlling the charging of a rechargeable battery in an implanted human tissue stimulator by means of an external power source. Included in the stimulator are battery protection devices designed to sense the state of charge of the battery and limit the charging currrent amplitude so as not to exceed a selected maximum based on different criteria including battery state of charge signals from the implanted stimulator which are indicative of the current amplitude and battery state of charge from one of the protection devices are transmited to an external unit. Based on these signals the external unit is operated in one of a plurality of modes to cause the battery to be charged by a current with an optimum safe amplitude irrespective of determined failure of one or more of the battery protection devices.