Abstract: A medical treatment procedure and system that makes use of a bidirectional flow sensor unit to monitor, detect, and control the flow of one or more fluids to and from a patient. The sensor unit measures both flow rate and flow direction of a fluid of a conduit through which a first fluid flows to or from the patient in a first direction, and through which it is possible that the first fluid or a second fluid may flow in a reverse direction through the conduit from or to, respectively, the patient. The sensor unit measures the flow rate of the first fluid as the first fluid flows through the bidirectional flow sensor unit, and senses if the first fluid or the second fluid flows through the bidirectional flow sensor unit in the reverse direction. A signal is relayed to indicate the occurrence of a reverse flow condition.

Abstract: A process for producing a tube suitable for microfluidic devices. The process uses first and second wafers, each having a substantially uniform doping level. The first wafer has a first portion into which a channel is etched partially therethrough between second and third portions of the first wafer. The first wafer is then bonded to the second wafer so that a first portion of the second wafer overlies the first portion of the first wafer and encloses the channel to define a passage. The second wafer is then thinned so that the first portion thereof defines a thinned wall of the passage. Second and third portions of the second wafer and part of the second and third portions of the first wafer are then removed, and the thinned wall defined by the second wafer is bonded to a substrate such that the passage projects over a recess in the substrate surface. The second and third portions of the first wafer are then removed to define a tube with a freestanding portion.

Abstract: A micromachined fluid sensing device and a method for its fabrication. The sensing device incorporates a bypass passage, preferably an integral bypass passage within the device, that enables a volume of fluid to be delivered to the device, with a limited portion of the fluid passing through a passage within the device in which one or more properties of the fluid are sensed, such as but not limited to density, specific gravity, and chemical concentrations. The device is suitable for monitoring the fuel concentration in a fuel mixture for a fuel cell.

Abstract: A method and device for assessing the viscosity of a fluid. The method and device utilize a tube with a vibrating freestanding portion into which the fluid is introduced, and relies on sensing the influence that the fluid has on the vibrational movement of the tube to assess the viscosity of the fluid. For this purpose, the freestanding portion is preferably driven at or near a resonant frequency, movement of the freestanding portion is sensed, and the viscosity of a fluid within the tube is assessed by ascertaining the damping effect the fluid has on movement of the freestanding portion at or near the resonant frequency.

Abstract: A delivery method and system for noninvasively monitoring cardiac physiologic parameters used to evaluate patients with cardiovascular conditions. The system includes an implantable sensing device configured for chronic implantation in a cavity of the cardiovascular system, such as the heart, pulmonary artery (PA), etc. The method involves introducing the sensing device through a cardiovascular cavity that is upstream in the vasculature from the cavity where implantation is intended and has a larger diameter than the intended cavity, and thereafter blood flow through the cardiovascular system delivers the device to the intended cavity. The device is sized and configured so as to secure itself within the intended cavity when the device moves through the cavity to a point where the diameter narrows sufficiently to secure the device and so as to be oriented once secured to sense a pressure either within, upstream (wedge), or downstream (distal) of the cavity.

Abstract: A process for producing a tube suitable for microfluidic devices. The process uses a uniformly-doped first material having a first portion into which a channel is etched partially through the first material between second and third portions of the first material. The first material is then bonded to a second material so that a first portion of the second material overlies the first portion of the first material and encloses the channel to define a passage. The second and third portions of the second material and part of the second and third portions of the first material are then removed, and the first portion of the second material is bonded to a substrate such that the passage projects over a recess in the substrate surface. The second and third portions of the first material are then removed to define a tube with a freestanding portion.

Abstract: A treatment system and method for treating a fluid withdrawn and then returned to a living body. The system includes outgoing and incoming fluid lines connected to the living body for transporting the fluid from the living body, through the treatment system, and back to the living body, a device for altering at least the density of the fluid as it flows through the system, and a sensing unit within the system and comprising a device for sensing the density of the fluid as the fluid flows through the sensing unit. The sensing device may be a micromachined Coriolis-based sensor also capable of sensing mass flow rate.

Abstract: The present invention defines an implantable microfabricated sensor device for measuring a physiologic parameter of interest within a patient. The sensor device includes a substrate and a sensor, integrally formed with the substrate, that is responsive to the physiologic parameter of interest. At least one conductive path is integrally formed with said substrate and coupled to the sensor. Connected to the conductive path is an active circuit. The active circuit is further electrically connected to the sensor.

Abstract: A fluid delivery system and method that combine a fluid source and an inline unit capable of delivering a precise amount of a therapeutic fluid to a patient based on specific data associated with the fluid, such as its identity, density, dosage, and dosage rate, so that the correct fluid is safely delivered in controlled amounts specific to its characteristics, purpose, and intended destination. The inline unit includes a flow controller and a flow sensor that produces a signal corresponding to the flow rate of the fluid flowing therethrough. The system further includes memory containing the data associated with the fluid, and electronic circuitry that causes the controller to regulate flow from the fluid source at the prescribed dosage rate and to deliver the prescribed dosage amount from the fluid source based on the signal from the sensor and the data contained by the memory.

Abstract: Micromachine fluidic apparatus incorporates a free-standing tube section and electrodes to actuate or control the movement of the tube section, or to sense the movement of the tube section, or both. Electronic circuitry, which may be disposed on the same substrate as the fluidic portion of the apparatus, is used in conjunction with the tube and electrodes in conjunction with a variety of different applications, including fluid flow measurement, fluid density measurement, fluid viscosity measurement, fluid transport, separation and/or mixing. According to a particular embodiment, the free-standing section of the tube is resonated for fluid flow and density measurements according to the Coriolis effect. Capacitive/electrostatic actuation techniques are used to control or resonate the free-standing section of the tube, and to detect variations in tube movement.

Abstract: A fluid delivery system capable of delivering a precise amount of fluid and monitor certain properties of the fluid so that the correct fluid is safely delivered to its intended destination. The system makes use of a flow sensor comprising a freestanding tube portion vibrated at a resonant frequency, wherein the resonant frequency corresponds to the density of the fluid flowing through the tube portion and the tube portion exhibits a degree of twist that varies with the mass flow rate of the fluid flowing therethrough. Movement of the tube portion is then sensed to produce a first output signal corresponding to the fluid density and a second output signal corresponding to the mass flow rate. The system is also equipped to measure elapsed time and to stop fluid flow in response to either of the first and second output signals.

Abstract: The present invention relates to an implantable microfabricated sensor device and system for measuring a physiologic parameter of interest within a patient. The implantable device is micro electromechanical system (MEMS) device and includes a substrate having an integrated inductor and at least one sensor formed thereon. A plurality of conductive paths electrically connect the integrated inductor with the sensor. Cooperatively, the integrated inductor, sensor and conductive paths defining an LC tank resonator.

Abstract: A method for preventing contamination, oxidation and gas absorption of reactive materials, and articles formed thereby. The method generally entails depositing a first layer of a reactive material and a second layer of a substantially nonreactive material so that the second layer protects the first layer from a surrounding atmosphere. For example, the first and second layers may be deposited to form a film on a surface within a chamber that is desired to be maintained in a vacuum during use of the article. The second layer is sufficiently thin such that appropriately heating the first and second layers causes the reactive material of the first layer to become interdiffused with the nonreactive material of the second layer, to the extent that at least a portion of the reactive material is able to react and getter gases from the surrounding atmosphere.

Abstract: A system and method for delivering a precise amount of fluid, such as a fluid for medical treatment. The system is a compact, fully-integrated, assembly that includes a sheet configured to be secured to a patient so that a surface of the sheet is held in contact with the patient's skin. The sheet carries a reservoir containing the fluid, a flow sensing device fluidically coupled to the reservoir, a device for initiating and interrupting flow of the fluid from the reservoir to the flow sensing device, a device for introducing the fluid into the patient's body, electronic circuitry for controlling fluid flow based on the output of the flow sensing device, and a power source.

Abstract: A method and device for assessing the viscosity of a fluid. The method and device utilize a tube with a vibrating freestanding portion into which the fluid is introduced, and relies on sensing the influence that the fluid has on the vibrational movement of the tube to assess the viscosity of the fluid. For this purpose, the freestanding portion is preferably driven at or near a resonant frequency, movement of the freestanding portion is sensed, and the viscosity of a fluid within the tube is assessed by ascertaining the damping effect the fluid has on movement of the freestanding portion at or near the resonant frequency.

Abstract: A microminiature sensing module and a sensing catheter system are provided. The module includes a sensor and signal conditioning circuit mounted on a substrate having electrical contacts positioned to facilitate connection of the module to an electrical bus, such as a dual lead electrical bus. The catheter system incorporates a dual lead electrical bus and one or more sensor modules. Methods of fabricating sensing catheter systems are also provided.

Abstract: A fluid delivery system capable of delivering a precise amount of fluid, such as a fluid required for medical treatment. The delivery system makes use of an inline sensing unit that includes a housing comprising an inlet for receiving a fluid from a fluid source, an outlet for discharging the fluid from the housing, and at least one cavity between the inlet and the outlet. A sensing element and electronic circuitry are disposed within the at least one cavity. The electronic circuitry is adapted to produce an electrical output based on at least one response of the sensing element. The sensing unit is further equipped with a communication element for providing communication between the electronic circuitry and an electronic device remote from the housing.

Abstract: A sensing device that comprises a micromachined tube on a substrate for resonant sensing of mass flow and density of a fluid flowing through the tube. The sensing device further incorporates on the same substrate at least a second micromachined tube configured for sensing another property of the fluid, such as pressure, viscosity and/or temperature.

Abstract: A microneedle and a process of forming the microneedle of single-crystal silicon-based material without the need for deposited films. The microneedle comprises a piercing end, an oppositely-disposed second end, and an internal passage having an opening adjacent the piercing end. The cross-section of the microneedle, and therefore the passage within the microneedle, is defined by first and second walls formed of doped single-crystal silicon-based material and separated by the passage, and first and second sidewalls separated by the passage, sandwiched between the first and second walls, and formed of single-crystal silicon-based material that is more lightly doped than the first and second walls.

Abstract: Micromachine fluidic apparatus incorporates a free-standing tube section and electrodes to actuate or control the movement of the tube section, or to sense the movement of the tube section, or both. Electronic circuitry, which may be disposed on the same substrate as the fluidic portion of the apparatus, is used in conjunction with the tube and electrodes in conjunction with a variety of different applications, including fluid flow measurement, fluid density measurement, fluid viscosity measurement, fluid transport, separation and/or mixing. According to a particular embodiment, the free-standing section of the tube is resonated for fluid flow and density measurements according to the Coriolis effect. Capacitive/electrostatic actuation techniques are used to control or resonate the free-standing section of the tube, and to detect variations in tube movement.