Abstract: A liquid delivery apparatus for the intrathecal delivery of one or more medications to a patient is disclosed. The liquid delivery apparatus generally includes a liquid reservoir, a liquid metering unit fluidly connected to the liquid reservoir, and a catheter delivery tube fluidly connected to the liquid metering unit. Preferably, the liquid delivery apparatus includes two or more liquid reservoirs. In various embodiments, the liquid reservoir includes a deformable balloon and a compressive sleeve spring as a pressure source, the liquid metering unit is a piezoelectrically actuated microvalve, and/or diagnostic sensors are included in the apparatus. The disclosed apparatus are compact, volume-efficient, energy-efficient, capable of delivering accurate fluid volumes, and address problems associated with multi-medication therapies. Methods of operating the liquid delivery apparatus are also disclosed.

Abstract: A system and method for using an element made of porous ceramic materials such as zeolite to constrain the flow of gas molecules to the free molecular or transitional flow regime. A preferred embodiment of the gas pump may include the zeolite element, a heater, a cooler, passive thermal elements, and encapsulation. The zeolite element may be further comprised of multiple types of porous matrix sub-elements, which may be coated with other materials and may be connected in series or in parallel. The gas pump may further include sensors and a control mechanism that is responsive to the output of the sensors. The control mechanism may further provide the ability to turn on and off certain heaters in order to reverse the flow in the gas pump. In one embodiment, the pump may operate by utilizing waste heat from an external system to induce transpiration driven flow across the zeolite.

Abstract: A stent and a magnetoelastic resonant sensor are provided for sensor a physical characteristic in a bodily vessel or cavity. External coils interact with the sensor to induce a resonance that is responsive to the physical characteristic, such that the device may wirelessly measure physical characteristics such as mass loading effects and viscosity changes due to progression of pathology in implanted stents and stent grafts. The sensor may be fashioned from a magnetoelastic material and may be integrated near the inner sidewall of the stent. The sensor may take on a complex patterned shape to enhance the sensitivity and flexibility of the sensor structure. When the sensor is interrogated with a time-varying magnetic field, the sensor will mechanically vibrate and generate a magnetic flux which is maximum at a resonant characteristic determined by the mass load on the sensor and the viscosity of the fluid surrounding the sensor.

Abstract: This invention addresses a contact mode hybrid scanning system (HSS), which can be used for measuring topography. The system consists of a cantilever or a cantilever array, a scanning stage, a light source, and instrumentation to synchronize and control the individual components. Detection of the cantilever's movement is achieved by directly measuring the change in disposition of the cantilever including its height, rotation at one or more points on the cantilever thereby providing a partial three-dimensional reconstruction without the need for actuating the cantilever. This is achieved by employing a displacement meter such as a triangulation meter or a confocal meter.

Abstract: A sensor is mounted to a needle at a location proximate to a tip of the needle. The sensor senses tissue density of tissue in contact with the tip as the needle passes through the tissue. Further, the sensor detects a change in tissue density as the tip passes from one tissue to a target tissue.

Abstract: A medical device such as a biopsy needle or probe has an integrated piezoelectric transducer. A power source is electrically coupled to the piezoelectric transducer. The power source is configured to generate a signal that causes the piezoelectric transducer to generate heat for cauterizing tissue. A signal analyzer receives a signal from the piezoelectric transducer, or from a sensor integrated into the biopsy needle or probe, to determine the extent of the cauterization.

Abstract: A sensor is mounted to a biopsy needle at a location proximate to a tip of the needle. The sensor senses properties of tissue in contact with the sensor and proximate to the tip.

Abstract: Disclosed herein is an electromagnetic flow sensor device for monitoring flow of fluid in a channel. The sensor device includes a first electrode to be disposed along the channel and in communication with the fluid, a second electrode to be disposed along the channel and in communication with the fluid, and a radially expandable frame to structurally support the first electrode and the second electrode while conforming to the channel to position the first electrode and the second electrode along the channel. The device may also include an antenna coupled to the first and second electrodes to wirelessly provide an indication of a voltage induced between the first and second electrodes. In some embodiments, the radially expandable frame includes an insulating link such that the first and second electrodes are not electrically connected via the radially expandable frame.

Abstract: A liquid delivery apparatus for the intrathecal delivery of one or more medications to a patient is disclosed. The liquid delivery apparatus generally includes a liquid reservoir, a liquid metering unit fluidly connected to the liquid reservoir, and a catheter delivery tube fluidly connected to the liquid metering unit. Preferably, the liquid delivery apparatus includes two or more liquid reservoirs. In various embodiments, the liquid reservoir includes a deformable balloon and a compressive sleeve spring as a pressure source, the liquid metering unit is a piezoelectrically actuated microvalve, and/or diagnostic sensors are included in the apparatus. The disclosed apparatus are compact, volume-efficient, energy-efficient, capable of delivering accurate fluid volumes, and address problems associated with multi-medication therapies. Methods of operating the liquid delivery apparatus are also disclosed.

Abstract: A piezoelectric microvalve employs a valve element formed of hermetically sealed and opposed plates flexed together by a cross axis piezoelectric element. Large flow modulation with small piezoelectric actuator displacement is obtained by perimeter augmentation of the valve seat which dramatically increases the change in valve flow area for small deflections.

Abstract: A stent and a magnetoelastic resonant sensor are provided for sensor a physical characteristic in a bodily vessel or cavity. External coils interact with the sensor to induce a resonance that is responsive to the physical characteristic, such that the device may wirelessly measure physical characteristics such as mass loading effects and viscosity changes due to progression of pathology in implanted stents and stent grafts. The sensor may be fashioned from a magnetoelastic material and may be integrated near the inner sidewall of the stent. The sensor may take on a complex patterned shape to enhance the sensitivity and flexibility of the sensor structure. When the sensor is interrogated with a time-varying magnetic field, the sensor will mechanically vibrate and generate a magnetic flux which is maximum at a resonant characteristic determined by the mass load on the sensor and the viscosity of the fluid surrounding the sensor.

Abstract: A system and method for using an element made of porous ceramic materials such as zeolite to constrain the flow of gas molecules to the free molecular or transitional flow regime. A preferred embodiment of the gas pump may include the zeolite element, a heater, a cooler, passive thermal elements, and encapsulation. The zeolite element may be further comprised of multiple types of porous matrix sub-elements, which may be coated with other materials and may be connected in series or in parallel. The gas pump may further include sensors and a control mechanism that is responsive to the output of the sensors. The control mechanism may further provide the ability to turn on and off certain heaters in order to reverse the flow in the gas pump. In one embodiment, the pump may operate by utilizing waste heat from an external system to induce transpiration driven flow across the zeolite.

Abstract: A piezoelectric microvalve employs a valve element formed of hermetically sealed and opposed plates flexed together by a cross axis piezoelectric element. Large flow modulation with small piezoelectric actuator displacement is obtained by perimeter augmentation of the valve seat which dramatically increases the change in valve flow area for small deflections.

Abstract: A mechanical self-reciprocating oscillator and mechanism and method for establishing and maintaining regular back and forth movement of a micromachined device without the aid of any electronic components are provided. The fully mechanical micromachined oscillator and mechanism are driven using only a DC power source on at least one substrate such as a semiconductor chip. The oscillator and mechanism preferably include an electrothermal actuator, that, when actuated, opens a switch to cut off supply current to the actuator. Two versions of the oscillator and mechanism are provided using distinct hysteresis mechanisms, one structural and the other thermal.

Abstract: Disclosed herein is a stent device useful for maintaining the patency of a lumen while monitoring an intraluminal characteristic. The device includes a structure having a set of extendible bands that are capable of plastic deformation to form a scaffolding having an inductance, and further includes a capacitance coupled to the set of extendible bands and responsive to the intraluminal characteristic. The capacitance and the inductance form a tank circuit after the plastic deformation of the set of extendible bands to enable wireless transmission of an indication of the intraluminal characteristic.

Abstract: The present invention provides a system for determining blood flow rate in a vessel which communicates blood between two locations of a patient, the system comprising: a conduit in fluid communication with the vessel; at least one sensor in communication with the vessel for determining differential blood pressure (? P) between two or more locations within the vessel; and a processor operably connected to the at least one sensor for processing the ? P to obtain blood flow rate within the vessel. A method for determining blood flow rate in a vessel which communicates blood between two locations of a patient, the method comprising: diverting blood from the vessel at a diversion point to obtain a flow of diverted blood in a conduit; determining differential blood pressure (? P) of the diverted blood through the conduit; and processing the ? P to obtain blood flow rate within the vessel.

Abstract: A number of micromachined devices including a micromachined pump for on-chip vacuum is provided. For example, a single-chip micromachined implementation of a Knudsen pump having one or more stages and which uses the principle of thermal transpiration with no moving parts is provided. A six-mask microfabrication process to fabricate the pump using a glass substrate and silicon wafer is shown. The Knudsen pump and two integrated pressure sensors occupy an area of 1.5 mm×2 mm. Measurements show that while operating in standard laboratory conditions, this device can evacuate a cavity to 0.46 atm using 80 mW input power. High thermal isolation is obtained between a polysilicon heater of the pump and the rest of the device.

Abstract: Disclosed herein is a method of collecting suspensions in a liquid film including the steps of developing a variation in surface tension at a gas-liquid interface of the liquid film to generate a circulating flow pattern within the liquid film, and scanning the liquid film with the circulating flow pattern for entrapment of the suspensions in the flow pattern by re-directing the variation in the surface tension across the gas-liquid interface of the liquid film.

Abstract: Disclosed herein is a method of collecting suspensions in a liquid film including the steps of developing a variation in surface tension at a gas-liquid interface of the liquid film to generate a circulating flow pattern within the liquid film, and scanning the liquid film with the circulating flow pattern for entrapment of the suspensions in the flow pattern by re-directing the variation in the surface tension across the gas-liquid interface of the liquid film.

Abstract: Systems and methods are described for identifying characteristics and defects in material such as semiconductors. Methods include scanning a thermal probe in the vicinity of a semiconductor sample, applying stimuli to the thermal probe, and monitoring the interaction of the thermal probe and the semiconductor. The stimulus can be applied by a variety of methods, including Joule heating of a resistor in the proximity of the probe tip, or optically heating a tip of the thermal probe using a laser. Applications of the invention include identification of voids in metallic layers in semiconductors; mapping dopant concentration in semiconductors; measuring thickness of a sample material; mapping thermal hot spots and other characteristics of a sample material.