483 results about "Capacitive pressure sensor" patented technology

A device for passively measuring intraocular pressure of a patient including an in vivo sensor and an instrument external to the patient for remotely energizing the sensor, thereby permitting the instrument to determine the intraocular pressure. The device directly and continuously measures the intraocular pressure of a patient. The in vivo sensor in the intraocular pressure monitor includes a capacitive pressure sensor and an inductive component. An instrument, external to the patient, measures the pressure, provides readout of the pressure values and determines the intraocular pressure.

An intelligent insole for generating time sensitive information about the pressure on the foot. The insole includes a custom-made, semi-custom or generically sized orthotic component. The orthotic is laminated with a top cover and an intermediate pressure sensor having an array of capacitive pressure sensors. Signal processing equipment may be embedded in the insole or placed locally with the insole as on the side of a shoe. The processor also can connect to a wireless transmitter for relaying the information to a remote site.

A system and method for the intra corporal, telemetric measuring of blood pressure, particularly within the heart or a great vessel, includes a substantially rigid sensor chip mounted in a holder and an antenna. The holder is anchored within an appropriate location in the cardiovascular system, such as in the cardiac septum, via a catheter or other minimally-invasive procedure to position at least one capacitive pressure sensor on the chip in the blood flow to be sensed. Measured values are transmitted telemetrically from the chip to an extra corporal monitoring device.

A system and method for the intra corporal, measuring of blood pressure includes a substantially rigid sensor structure and an antenna structure, which are separate components. The anchor structure is used to mount the within an appropriate location in the cardiovascular system, such as in the cardiac septum. The substantially rigid sensor structure includes at least one capacitive pressure sensor. Measured values are transmitted telemetrically from the sensor structure to an extra corporal monitoring device.

Embodiments of the invention provide systems and methods for an implantable capacitive pressure sensor. Some embodiments of the invention include a capacitive pressure sensor capsule comprising a substrate, a conductive plate functionally coupled to the substrate, a conductive diaphragm spaced from the conductive plate and functionally coupled to the substrate, a lid hermetically sealed against the substrate, and pressure sensing circuitry disposed within a volume generally defined by the lid and the substrate. Embodiments of the invention also include a lead provided with an implantable pressure sensor capsule and a method of manufacturing a capacitive pressure sensor capsule.

By sealing a diaphragm with less processes and lower cost and reducing deformation due to remaining stress, a stable and highly reliable pressure sensor construction is proposed. The pressure sensor is low in measurement error and small in floating capacitance and leakage current and good in characteristic. As a means to attain the above object, a polycrystalline silicon diaphragm is sealed with a silicon oxide film deposited through a LPCVD method and then completely covered. The diaphragm is placed on a surface of a semiconductor substrate with a nearly constant gap of 0.15 to 1.3 μm, and has difference-in-grade constructions of a deformation reducing means due to remaining stress.

A pressure sensor (30) for harsh environments such as vehicle tires, formed from a chamber (58) partially defined by a flexible membrane (50), the chamber (58) containing a fluid at a reference pressure. In use, the flexible membrane (50) deflects due to pressure differentials between the reference pressure and the fluid pressure, the membrane being at least partially formed from conductive material. A conductive layer (36) is deposited within the chamber (58) spaced from the flexible membrane (50) such that they form opposing electrodes of a capacitor. Associated circuitry (34) is also deposited for converting the deflection of the flexible membrane (50) into an output signal indicative of the fluid pressure. The conductive layer (36) is less than 50 microns from the membrane in its undeflected state because capacitative sensors with closely spaced electrodes can have small surface area electrodes while maintaining enough capacitance for the required operating range. Furthermore, small electrodes reduce the power consumption of the sensor which in turn reduces the battery size needed for the operational life of the sensor.

The disclosed transducer includes a housing, a diaphragm, an inner conductor, an outer conductor, and a first baffle. The housing defines an interior volume. The diaphragm is disposed in the housing and divides the interior volume into a first chamber and a second chamber. The diaphragm flexes in response to pressure differentials in the first and second chambers. The inner conductor is disposed in the first chamber. The outer conductor is disposed in the first chamber around the inner conductor. The first baffle is disposed in the second chamber and defines an inner region, a middle region, and an outer region. The inner region underlies the inner conductor. The middle region underlies the outer conductor. The outer region underlies neither the inner conductor nor the outer conductor. The first baffle defines apertures in at least two of the inner, middle, and outer regions.

A capacitive pressure sensor and method for its fabrication. The sensor is fabricated from first and second wafers to have a mechanical capacitor comprising a fixed electrode and a moving electrode defined by a conductive plate. The sensor further has a diaphragm on a surface of the first wafer that is mechanically coupled but electrically insulated from the conductive plate. A conductive layer on the surface of the first wafer is spaced apart from the conductive plate to define the fixed electrode. The second wafer is bonded to the first wafer and carries interface circuitry for the sensor, including the conductive plate and the fixed electrode which are between the first and second wafers and electrically connected to the interface circuitry. At least an opening is present in the first wafer and its first conductive layer by which the diaphragm is released and exposed to an environment surrounding the sensor.

A MEMS pressure sensor wherein at least one of the electrode arrangements comprises an inner electrode and an outer electrode arranged around the inner electrode. The capacitances associated with the inner electrode and the outer electrode are independently measured and can be differentially measured. This arrangement enables various different read out schemes to be implemented and also enables improved compensation for variations between devices or changes in device characteristics over time.

A capacitive pressure sensor includes a electrically conductive, generally piston shaped diaphragm with a flexible base wall configured to deflect under pressure. The diaphragm is generally U-shaped in cross section. The base wall includes an upper, flat sensing surface which acts as a capacitive electrode. The diaphragm further includes a step around a radially-outermost perimeter which is elevated from the flat sensing surface. A sensing electrode body is located on top of the step and creates a capacitive sensing cavity between the sensing surface and the bottom surface of the electrode body. On the bottom surface of the electrode body is formed a center, circular electrode and a ring electrode that surrounds the center electrode. The center electrode and the sensing surface form a variable capacitor which changes with pressure and the ring electrode and the sensing surface form a reference capacitor. A circuit determines a differential capacitance between the variable capacitor and the reference capacitor and generates a pressure signal indicative of the fluid pressure applied to the diaphragm. A spring ring holds the sensing electrode body against the diaphragm when assembled. The diaphragm can be a machined metal part or a sheet metal cup. The sensing electrodes and signal generating circuit can take the form of a hybrid circuit.

The invention discloses a multiphase dielectric layer capacitive pressure sensor with a microstructure and a preparation method thereof. The pressure sensor comprises the components of two flexible electrodes which are oppositely arranged, wherein at least one in two opposed surfaces of the two flexible electrodes has the microstructure which is formed by a plurality of projections and/or recessed parts; and a multiphase dielectric layer which is arranged between the two flexible electrodes, wherein the multiphase dielectric layer comprises a micro-ball dielectric layer which is formed by a plurality of micro-balls that can freely move and air and/or flexible polymer that are filled in the micro-ball dielectric layer. The multiphase dielectric layer capacitive pressure sensor with the microstructure has advantages of small thickness, high softness, etc. The multiphase dielectric layer capacitive pressure sensor can be machined to various shapes and has advantages of wearability and adhesiveness. The multiphase material is used as the dielectric layer, thereby improving device sensitivity and reducing least measurement pressure.

A capacitive measurement device including first measurement device designed to carry out a first measurement function in relation to a nearby object, the first measurement device including a body and, a capacity electrode, both of a substantially conductive material, and a guard electrode placed between the body and the capacitive electrode and insulated from the body on the one hand and from the capacitive electrode on the other hand by dielectric elements; an excitation apparatus which maintains the capacitive electrode and the guard electrode to a desired AC electrical potential; a first electronic apparatus, connected to the capacitive and guard electrodes, for measuring the capacitance between the capacitive electrode and the object; and a second measurement device designed to carry out a second measurement function, which are located in the vicinity of either the capacitive or guard electrode, and maintained by the excitation apparatus to a desired AC electrical potential.

An electronic circuit (10) for controlling a capacitive pressure sensor (1), which capacitive pressure sensor (1) comprises a plate electrode capacitor (C) with a capacity that varies in dependence on pressure changes exerted on a deflectable diaphragm (2) forming one plate electrode of the capacitor (C), wherein the electronic circuit (10) comprises a DC voltage source (12) being adapted to generate a DC bias-voltage (UDC) to be applied across the electrodes of the capacitor (C), an AC voltage source (13) being adapted to generate an AC voltage signal (UAC) to be applied across the electrodes of the capacitor (C) and a controller (18) being adapted to receive an output signal (OUT) of the capacitor (C) and to control the DC voltage source (12) such that the DC bias-voltage (UDC) applied to the capacitor (C) adopts a value that maintains the capacity of the capacitor (C) at a desired value.

PCT No. PCT/SE95/00426 Sec. 371 Date Apr. 8, 1997 Sec. 102(e) Date Apr. 8, 1997 PCT Filed Apr. 18, 1995 PCT Pub. No. WO95/28623 PCT Pub. Date Oct. 26, 1995A capacitive pressure sensor for measurement of the pressure of a fluid comprises a sensor element (1) which is made of a ceramic, in particular glass ceramic, material and in the conventional way has interior capacitor plates. The sensor element (1) is plate-shaped and joined to a surrounding support ring (5''). The support ring (5'') is made of metal and is connected to the sensor elemnt (1) by means of a joint (3') made of ceramics, in particular glass ceramics, at an annular region around an edge line of the sensor element (1). The support ring (5'') can have a shoulder formed by a protrusion (15) in the interior surface thereof, against which shoulder then a region of the sensor element (1) rests and at which the joint (3') is made.

The invention provides an intelligent insole system based on capacitive pressure sensors. The intelligent insole system comprises an insole and the flexible capacitive pressure sensosr and a signal collecting circuit system which are distributed in the insole; the signal collecting system comprises a sensor signal collecting module, a main control chip, a data storage module and a power source and wireless transmission module; the flexible capacitive pressure sensors transmit measured pressure signals of all the sole portions to the sensor signal collecting module, the sensor signal collecting module converts the pressure signals of multiple channels into digital signals and inputs the digital signals to the main control chip, the main control chip stores acquired pressure data into the data storage module or transmits the pressure data to the power source and wireless transmission module and analyzes and calculates human body state data including the heart rate, the weight, the walking postures, the walking numbers, the walking frequency and the walking speed, and the power source and wireless transmission module sends the pressure data to a mobile terminal. The intelligent insole system is reasonable in structure, wide in detection range, high in precision, short in responding time and capable of analyzing the human body states according to insole pressure distribution.

Disclosed is an implant and method of making an implant. The implant having a housing that defines a cavity. The housing includes a sensor comprising a base attached to a diaphragm wherein said base may be positioned within said cavity. The sensor may be a capacitive pressure sensor. The diaphragm may be connected to the housing to hermetically seal said housing. The sensor may include electrical contacts positioned on the diaphragm. The base may define a capacitive gap and a vent wherein the electrodes may be positioned within said capacitive gap such that at least a portion of the electrical contacts extend through the vent. The implant may include a coil in electric communication with the sensor, said coil may be positioned within said housing. A printed circuit board having at least one component may be attached to the floating base.

Methods and apparatus for measurement of IOP following glaucoma surgery comprise an implant device having a pressure sensitive capacitor and coil sized for placement along the tissue drainage path, to monitor the success of the surgery and measure IOP directly. The implantable sensor device may comprise a MEMS based capacitive pressure sensor and coil. A complaint material is disposed over the pressure sensitive capacitor and coil to conform with tissue to further decrease invasiveness and such that the implant can measure pressure from at least a first side and a second side when positioned along the drainage path. The implant can work well with trabeculectomies and trabeculotomies, and can be positioned on the sclera at a location corresponding to the bleb, such that the effectiveness of the surgery and medication can be determined postoperatively to detect pressure changes and elevations.

The invention relates to a capacitive pressure sensor and a method for fabricating thereof. The capacitive pressure sensor comprises a cover, a plurality of first electrode, a substrate and a plurality of second electrode. The cover owns an upper wall and a plurality of side walls. The plurality of first electrode is disposed on the inside of the upper wall of the cover. The side walls of the cover are connected to the substrate to form a space. The plurality of second electrode is disposed on the substrate. The plurality of first electrode and the plurality of second electrode are both in the space. In the invention, the material for cover, the plurality of first electrodes and the substrate are all flexible polymeric material.

A capacitance-type pressure sensor for measuring a change in a physical volume of a medium to be measured, by measuring two capacitances wherein the capacitances vary differently from each other in accordance with a change in the physical volume of the medium to be measured, provided with a function for measuring independent values for each capacitance and determining that there is an disconnect failure when at least one of these capacitance values falls below a capacitance value that indicates the normal operating range of the capacitance-type pressure sensor, to thereby provide a pressure sensor with higher reliability through performing the disconnect detection robustly.