摘要:
An implantable sensor includes electronic circuitry for automatically performing on a periodic basis, e.g., every 1 to 24 hours, specified integrity tests which verify proper operation of the sensor.
摘要:
An implantable substrate sensor has electronic circuitry and electrodes formed on opposite sides of a substrate. A protective coating covers the substrate, effectively hermetically sealing the electronic circuitry under the coating. Exposed areas of the electrodes are selectively left uncovered by the protective coating, thereby allowing such electrodes to be exposed to body tissue and fluids when the sensor is implanted in living tissue. The substrate on which the electronic circuitry and electrodes are formed is the same substrate or “chip” on which an integrated circuit (IC) is formed, which integrated circuit contains the desired electronic circuitry. Such approach eliminates the need for an hermetically sealed lid or cover to cover hybrid electronic circuitry, and allows the sensor to be made much thinner than would otherwise be possible. In one embodiment, two such substrate sensor may be placed back-to-back, with the electrodes facing outward. As required, capacitors that form part of the sensor's electronic circuits are formed on the substrate by placing metalization layers and a dielectric in vacant areas of the substrate surface.
摘要:
An implantable substrate sensor has electronic circuitry and electrodes formed on opposite sides of a substrate. A protective coating covers the substrate, effectively hermetically sealing the electronic circuitry under the coating. Exposed areas of the electrodes are selectively left uncovered by the protective coating, thereby allowing such electrodes to be exposed to body tissue and fluids when the sensor is implanted in living tissue. The substrate on which the electronic circuitry and electrodes are formed is the same substrate or “chip” on which an integrated circuit (IC) is formed, which integrated circuit contains the desired electronic circuitry. Such approach eliminates the need for an hermetically sealed lid or cover to cover hybrid electronic circuitry, and allows the sensor to be made much thinner than would otherwise be possible. In one embodiment, two such substrate sensors may be placed back-to-back, with the electrodes facing outward. As required, capacitors that form part of the sensor's electronic circuits are formed on the substrate by placing metalization layers and a dielectric in vacant areas of the substrate surface.
摘要:
An implantable substrate sensor has electronic circuitry and electrodes formed on opposite sides of a substrate. A protective coating covers the substrate, effectively hermetically sealing the electronic circuitry under the coating. Exposed areas of the electrodes are selectively left uncovered by the protective coating, thereby allowing such electrodes to be exposed to body tissue and fluids when the sensor is implanted in living tissue. The substrate on which the electronic circuitry and electrodes are formed is the same substrate or “chip” on which an integrated circuit (IC) is formed, which integrated circuit contains the desired electronic circuitry. Such approach eliminates the need for an hermetically sealed lid or cover to cover hybrid electronic circuitry, and allows the sensor to be made much thinner than would otherwise be possible. In one embodiment, two such substrate sensors may be placed back-to-back, with the electrodes facing outward. As required, capacitors that form part of the sensor's electronic circuits are formed on the substrate by placing metalization layers and a dielectric in vacant areas of the substrate surface.
摘要:
An implantable substrate sensor has electronic circuitry and electrodes formed on opposite sides of a substrate. A protective coating covers the substrate, effectively hermetically sealing the electronic circuitry under the coating. Exposed areas of the electrodes are selectively left uncovered by the protective coating, thereby allowing such electrodes to be exposed to body tissue and fluids when the sensor is implanted in living tissue. The substrate on which the electronic circuitry and electrodes are formed is the same substrate or “chip” on which an integrated circuit (IC) is formed, which integrated circuit contains the desired electronic circuitry. Such approach eliminates the need for an hermetically sealed lid or cover to cover hybrid electronic circuitry, and allows the sensor to be made much thinner than would otherwise be possible. In one embodiment, two such substrate sensors may be placed back-to-back, with the electrodes facing outward. As required, capacitors that form part of the sensor's electronic circuits are formed on the substrate by placing metalization layers and a dielectric in vacant areas of the substrate surface.
摘要:
A protective, biocompatible coating or encapsulation material protects and insulates a component or device intended to be implanted in living tissue. The coating or encapsulation material comprises a thin layer or layers of alumina, zirconia or other ceramic, less than 25 microns thick, e.g., 5-10 microns thick. The alumina layer(s) may be applied at a relatively low temperature. Once applied, the layer provides excellent hermeticity, and prevents electrical leakage. Even though very thin, the alumina layer retains excellent insulating characteristics. In one embodiment, an alumina layer less than about 6 microns thick provides an insulative coating that exhibits less than 10 pA of leakage current over an area 75 mils by 25 mils area while soaking in a saline solution at temperatures up to 80° C. over a three month period.
摘要:
Improved implantable monitoring systems suitable for long-term in vivo use to measure the concentration of one or more prescribed substances, such as glucose, are described herein. In particular, an implantable enzyme-based glucose monitoring system is described that includes at least one of the following: means for replenishing the enzyme solution as it is consumed by the enzymatic reaction; means for replenishing the electrolyte solution bathing the electrode assembly; and microprocessing means proximal the electrode assembly. In preferred embodiments, a microprocessor assembly is hermetically associated with the substrate to which the electrode assembly is affixed. Further, the monitoring systems employ one or more reservoir systems in fluid communication with enzyme and electrolyte chambers wherein the enzyme and electrolyte solutions are used. In a further embodiment, the monitoring systems use enzyme and electrolyte reservoir bulbs in fluid communication with the enzyme and electrolyte reservoirs, respectively, and positioned near the skin surface, thereby providing ready access to the enzyme and electrolyte solutions without the need for explantation of the device. Further provided herein is an enzyme solution comprising microspheres in association with the enzyme; whereby the enzyme is immobilized by the microspheres and the microspheres are in a fluid, flowable solution. Also provided herein is a method of extending the useful life of an implantable enzyme-based monitoring system, which method comprises providing means, within the system, to replenish the enzyme and/or electrolyte solution.
摘要:
An electronic circuit for sensing an output of a sensor having at least one electrode pair and circuitry for obtaining and processing the sensor output. The electrode pair may be laid out such that one electrode is wrapped around the other electrode in a U-shaped fashion. The electronic circuitry may include, among other things, a line interface for interfacing with input/output lines, a rectifier in parallel with the line interface, a counter connected to the line interface and a data converter connected to the counter and the electrode pair. The data converter may be a current-to-frequency converter. In addition, the rectifier may derive power for the electronic circuit from communication pulses received on the input/output lines.
摘要:
An electrochemical sensor includes electronic circuitry for automatically performing on a periodic basis, e.g., every 1 to 24 hours, specified integrity tests which verify proper operation of the sensor.
摘要:
A protective, biocompatible coating or encapsulation material protects and insulates a component or device intended to be implanted in living tissue. The coating or encapsulation material includes a thin layer or layers of alumina, zirconia, or other ceramic, less than 25 microns thick, e.g., 5-10 microns thick. The alumina layer(s) may be applied at relatively low temperature. Once applied, the layer provides excellent hermeticity, and prevents electrical leakage. Even though very thin, the alumina layer retains excellent insulating characteristics. In one embodiment, an alumina layer less than about 6 microns thick provides an insulative coating that exhibits less than 10 pA of leakage current over an area 75 mils by 25 mils while soaking in a saline solution at temperatures up to 80.degree. C. over a three month period.