Abstract: A system for measurements and calculations of a microcirculatory high-velocity blood flow includes a data acquisition module configured to select and acquire microcirculatory blood vessel image data; a storage module configured to store the acquired microcirculatory blood vessel image data; a velocity measurement module configured to measure a traveling distance and a traveling time of red blood cell (RBC), white blood cell (WBC), or plasma particles in a blood vessel sample and calculate a ratio of the traveling distance to the traveling time to obtain a blood flow velocity; and a high-velocity blood flow index module configured to determine an index level for the microcirculatory high-velocity blood flow. Specifically, an initial threshold, i.e. 1000 ?m/s, for the microcirculatory high-velocity blood flow of sepsis is proposed, which facilitates early diagnosis on sepsis. The changing process of the high-velocity blood flow shows development of the early-stage, intermediate-stage and end-stage sepsis.

Abstract: Described herein is a neuroaspiration catheter for removing a blood clot in a blood vessel. The neuroaspiration catheter includes a first tube, a second tube and a wire for guiding the navigation of the catheter. The wire can be navigated to the site of the blood clot, aid the navigation of the catheter, and left in the blood vessel during and after the aspiration. If the aspiration fails, the catheter can be quickly navigated back to the site of the blood clot using the wire as a guide. Also described herein is a method of removing a blood clot using the neuroaspiration catheter.

Abstract: The disclosed invention provides a bridge voltage inversion circuit for vacuum gauge and a pressure gauge sensor that includes the bridge voltage inversion circuit. The bridge voltage inversion circuit for a pressure gauge includes a reference capacitance, a sensor capacitance, and a transformer including a primary winding and a secondary winding that outputs a bridge voltage. The reference capacitor is connected to a first side of the secondary winding of the transformer, and the sensor capacitor is connected to a second side of the secondary winding of the transformer. The sensor capacitor senses and responds to a pressure, and a capacitance of the sensor capacitor is at a minimum when the pressure is at vacuum. The capacitance of the sensor capacitor at vacuum is less than a capacitance of the reference capacitor.

Abstract: An infusion and blood collection device allows clean blood collections into a collection tube via a previously installed angiocatheter without interrupting the administration of intravenous therapies after initial installation. The device optionally includes passive control of the blood collection flow rate to prevent contamination of the collected blood draw with the IV therapy fluid being simultaneously infused through the angiocatheter. A blood collection method uses an infusion and blood collection device to draw a clean blood sample from a patient and into a collection tube via a previously installed angiocatheter without interrupting the administration of intravenous therapies.

Abstract: Apparatus and methods are described including placing, into a subject's body, a blood-pump tube, with a blood pump disposed within the blood-pump tube. At least one blood-pressure-measurement tube, which defines an opening at a distal end thereof, extends to at least an outer surface of the blood-pump tube, such that the opening at the distal end of the blood-pressure-measurement tube is in direct fluid communication with a bloodstream of the subject outside the blood-pump tube. Blood is pumped through the blood-pump tube, using the blood pump. Pressure of the bloodstream of the subject outside the blood-pump tube is measured by measuring pressure of blood within the blood-pressure-measurement tube. Other applications are also described.

Abstract: A pressure-measuring system, including a tube system having at least first and second pressure measuring devices, each including a pressure transducer membrane and a measuring chamber. A first flow regulation device with a perfusion tube section is positioned between the first pressure measuring device and a supply of fluid, and has a first tube clamp that acts on a tube section by squeezing. The system further includes at least one non-perfusion regulation device.

Abstract: A catheter includes a distal distension balloon and circumferentially arranged motility measurement balloons proximal of the distension balloon. A manifold includes balloon ports each configured to fluidly couple to a motility measurement balloon, pressure transducer ports, and a priming port. A port selector is coupled to the manifold and movable between different positions. Each port selector position causes the manifold to establish different fluidic couplings between the respective motility balloon, pressure transducer, and priming ports. A pressure sensing device includes pressure transducers each fluidly coupled to one of the pressure transducer ports. The pressure sensing device is configured to coordinate calibration of the pressure transducers at atmospheric pressure with the port selector in a first position and motility balloon pressure measurements with the port selector in a third position.

Abstract: Aspects of the invention relates to systems and methods for monitoring an intravenous (IV) line functionality of an IV device. In one embodiment, the system includes an IV catheter to be inserted into the vein of the living subject, at least one pressure sensor in fluid communication with the IV catheter to acquire peripheral venous signals; and a processing device. The processing device receives the peripheral venous signals from the pressure sensor, performs a spectral analysis on the peripheral venous signals to obtain a peripheral venous pressure frequency spectrum, and then performs a statistical analysis on amplitudes of peaks of the peripheral venous pressure frequency spectrum to determine an IV line functionality of the IV catheter in real time. When the IV line functionality indicates IV infiltration, the processing device may control the fluid controlling device to stop the fluid flow from the fluid source to the IV catheter.

Abstract: In particular embodiments, a method for determining a heart-rate variability (HRV) measurement of a user may include receiving, from a sensor of an electronic device of the user, heart sensor data, determining a noise level of the heart sensor data, and then adjusting the HRV measurement by an amount calculated based on the determined noise level. The sensor data may include data on a photoplethysmograph (PPG) signal over a noise-calculation time period.

Abstract: A device for non-invasively measuring at least one parameter of a cardiac blood vessel in a patient comprises at least one light source that directs light at a tissue site on the patient; at least one photodetector adapted to receive light emitted by the light source and generate an output based on the received light, the output of said photodetector being correlated with a parameter of the blood vessel; and at least one probe for facilitating delivery of light from the light source to the tissue site, and receipt of light by the photodetector. The device may include a height sensor to adapt it for use to determine central venous pressure, or the configuration of light source(s) and photodetector(s) may be adapted to permit the device to provide attenuation correction in the determination of venous blood oxygenation.

Abstract: Disclosed herein is a framework for facilitating adaptive control of monitoring devices. In accordance with one aspect, a position detector detects a chest elevation level and provides chest elevation level data. A processor uses the chest elevation level data to determine a heart elevation level with respect to a reference level. A comparator compares the determined heart elevation level with an elevation level of a monitoring device with respect to the reference level. In response to the comparison, a movement system adjusts the elevation level of the monitoring device.

Abstract: Catheters for infusion of cardiovascular fluids into blood are disclosed. The cardiovascular fluid may, for example, comprise water highly supersaturated with a gas such as oxygen. Each catheter comprises one or more capillary tubings (or capillaries) through which a cardiovascular fluid flows. The distal end of each capillary is mounted (e.g., potted) preferably flush with an external surface of a catheter sidewall, while the proximal end of each capillary is in fluid communication with a cardiovascular fluid flowing through the lumen of the catheter. The combination of the catheter shape and the orientation of the distal end of each capillary relative to the longitudinal axis of the catheter provides control over the mixing pattern of the cardiovascular fluid with blood flowing within a vascular space such as an aorta.

Abstract: The invention relates to a liquid nitrogen cooling sensor device container and liquid nitrogen cooling sensor equipment, and effectively reduces low-frequency noise while maintaining the ease with which a probe can be inserted in and removed from liquid nitrogen. Said invention comprises: a liquid nitrogen containing insulating container that contains liquid nitrogen; a sensor fixing member which has a distal end portion to which a sensor operating at a temperature of the liquid nitrogen is attached; and a fixing buffer member which is for fixing the sensor fixing member to the liquid nitrogen containing insulating container, wherein the fixing buffer member exerts a buffering effect in the liquid nitrogen.

Abstract: A balloon catheter including a dedicated contrast fluid lumen is disclosed. The contrast fluid lumen extends through the catheter shaft to a contrast fluid delivery port located proximate the inflatable balloon and is configured to deliver contrast fluid to a target location. The catheter shaft includes a joint located proximate the contrast fluid port formed between a distal end of a proximal outer tubular member, a distal end of an inner tubular member and a proximal end of a distal outer tubular member. A guidewire tube, defining a guidewire lumen, may extend through the lumen of the proximal and distal outer tubular members.

Abstract: A non-invasive venous pressure measurement apparatus is provided, including: a first cuff attached to a portion including a vein and an artery in a living body; a pressure control unit that changes a first applied pressure applied by the cuff to the portion; a pulse wave detection unit that detects a pulse wave from a pressure received by the cuff from the portion; another pulse wave detection unit that detects another pulse wave including at least an arterial pulse wave in another portion of the living body; an analyzing unit that analyzes a correlation between the two pulse waves, which are changed as the applied pressure is changed by the pressure control unit changes; and a venous pressure calculation unit that calculates a venous pressure based on the applied pressure and a result of analysis by the analyzing unit.

Abstract: An irrigated catheter includes a catheter body having both proximal and distal irrigation passageways. A first fluid delivery tube feeds the proximal irrigation passageway and is fluidly isolated from the distal irrigation passageway, while a second fluid delivery tube feeds the distal irrigation passageway and is fluidly isolated from the proximal irrigation passageway. Typically, the first and second fluid delivery tubes will be unitary, at least through the catheter body. The overall shape of the first and second fluid delivery tubes, as well as their respective lumens, may vary as necessary for a particular application of the irrigated catheter. The system also includes an irrigation fluid source and at least one pump to deliver the irrigation fluid through the irrigation passageways. Typically, the pump will be a volume-driven pump, such as a rolling pump.

Abstract: A method is disclosed for continuously monitoring a blood pressure measurement using a sensor connected by a hydraulic link to an arterial catheter, the method includes determining the dynamic parameters of the link, analyzing the frequency content of the incident signal, detecting one of the following situations: (a) ability of the link to transmit the incident signal with a distortion below a threshold, (b) ability of the link to transmit the incident signal with a distortion above the threshold and possibility of correcting the measured signal, (c) inability of the link to transmit the incident signal with a distortion below the threshold and impossibility of correcting the measured signal, periodic application of a mechanical action to the tubing providing the hydraulic link.

Abstract: A medical blood pressure transducer that provides an identifier to a monitor that conveys characteristics of the transducer. The monitor can use the information to decide whether to function, or in calibration of the system. The transducer may be part of a disposable blood pressure monitoring system, and may include two transducers closely-spaced to provide two separate but identical outputs. In this way, the transducer may be connected to both a patient monitor and a cardiac output monitor at the same time measurements from a single line can be simultaneously supplied to two separate monitoring devices (for example a patient monitor and a cardiac output monitor). The identifier for the transducer may be circuitry, specifically a resistance/capacitance (RC) combination that possesses a characteristic time constant.

Abstract: An apparatus for measuring distensibility of a vessel, lumen or sphincter includes a balloon catheter having a balloon located adjacent a distal end of a catheter for inserting in, for example, the sphincter, the distensibility of which is to be determined. The balloon is inflated to respective first and second pressures to distend the sphincter to respective first and second transverse cross-sectional areas which are measured. The first and second pressures are selected so that the relationship between the pressure and the cross-sectional area of the sphincter is linear. The distensibility of the sphincter is determined as a distensibility index, which is the value of c from the equation of a line y=mx+c containing the values of the first and second pressures and areas, where x represents pressure and y represents area.

Abstract: An implantable medical device system and method provide physiological variable monitoring for use in patient management. A target value for a physiological variable and formulations for computing metrics of the physiological variable are stored. Values of the physiological variable are determined from a sensed physiological signal and are used to compute a selected metric. The metric is compared to the stored target value.

Abstract: The present invention discloses a heat exchanging assembly with a body adaptable to a catheter for measuring blood flow rate with a supply system for providing the heat exchanging medium to the heat exchanging assembly at a constant temperature and constant flow rate. The heat exchanging assembly comprises a heat exchanging element, a plurality of temperature sensors, a sensor lumen and an inflation lumen.

Abstract: A pressure sensor, for example, employed by a medical injection system for monitoring blood pressure, is isolated from relatively high pressures by a volume of a compressible medium, preferably air, or other suitable gas. The volume fills an entirety of a cavity of a pressure transducer assembly, and is enclosed between a pressure transmission interface of the assembly and the pressure sensor. The pressure transducer assembly is integrated into a fluid circuit such that the pressure transmission interface is exposed to flow through the fluid circuit. The cavity of the assembly has a configuration that allows transmission of a patient's blood pressure from the fluid circuit, via the interface and gas volume, to the pressure sensor, yet prevents transmission of the relatively high pressures, for example, injection pressures. The pressure transducer assembly may be part of a disposable fluid circuit subassembly, for example, packaged as a kit.

Abstract: Methods and apparatus for determining a cardiac parameter from cardiovascular pressure signals including arterial blood pressure (ABP) and the photoplethysmographic signal to quantify the degree of amplitude modulation due to respiration and predict fluid responsiveness are disclosed. Disclosed embodiments include a method for assessing fluid responsiveness implemented in a digital computer with one or more processors comprising: (a) measuring a cardiovascular signal, and (b) computing a dynamic index predictive of fluid responsiveness from said cardiovascular signal using a nonlinear state space estimator. According to one particular embodiment, and without limitation, the nonlinear state space estimator is based on a model for cardiovascular signals such as arterial blood pressure or plethysmogram signals, and employs a marginalized particle filter to estimate a dynamic index predictive of fluid responsiveness that is substantially equivalent to a variation in pulse pressure of said cardiovascular signal.

Abstract: A disposable manometer includes a chamber connectable to a source of respiratory gases via a patient breathing valve and a passageway. A pointer is rotatably disposed with respect to a dial to indicate pressure within the chamber. The pointer has an actuator stem with a spiral-shaped protrusion coupled to a groove within an opening of a stem coupling attached at the center of a diaphragm forming one wall of the chamber. Responsive to pressure entering the chamber, the diaphragm reciprocates against the force of a biasing non-magnetic resilient member moving the stem coupling with respect to the actuator stem of the pointer so that the interaction between the spiral-shaped protrusion and the groove causes rotation of the pointer to indicate the pressure within the chamber. The disposable manometer is useful with any source of respiratory gasses and in the vicinity of any strong magnetic field.

Abstract: A device is configured to monitor a cardiovascular property of a subject. The device obtains measurement data from a primary pressure wave sensor arranged to detect pressure waves in an extracorporeal fluid circuit in fluid communication with the cardiovascular system of the subject. The device has a signal processor configured to generate a time-dependent monitoring signal based on the measurement data, such that the monitoring signal comprises a sequence of heart pulses, wherein each heart pulse represents a pressure wave originating from a heart beat in the subject; determine beat classification data for each heart pulse in the monitoring signal; and calculate, based at least partly on the beat classification data, a parameter value indicative of the cardiovascular property. The beat classification data may distinguish between heart pulses originating from normal heart beats and heart pulses originating from ectopic heart beats.

Abstract: A liquid dispensing circuit is provided with: a multi-way cock; a first line; a second line; a third line; a fourth line; a fifth line; and a casing which houses some of the above. When a cock in the multi-way cock is situated in a priming position, a distal opening in a second part of a first flow channel communicates with a first port, and a distal opening in a third part communicates with a second port; thus, the first port and the second port are in an open state wherein the ports are connected to each other via the first flow channel, whereas a third port, a fourth port, and a sixth port are in an open state wherein the ports are connected to one another via a second flow channel.

Abstract: The fluid delivery system includes a pressurizing device for delivering a pressurized injection fluid, a low pressure fluid delivery system, and a pressure isolation mechanism adapted for fluid communication with the pressurizing device and low pressure fluid delivery system. The pressure isolation mechanism includes a housing defining an inlet port, an isolation port, and an internal cavity. The housing defines a seal seat in the internal cavity between the inlet port and isolation port. A valve member is disposed in the internal cavity. The valve member is free floating in the internal cavity and is adapted to engage the seal seat. The valve member has an open position permitting fluid communication between the inlet port and isolation port, and is fluid flow responsive to fluid flow in the inlet port to engage the seal seat and attain a closed position preventing fluid flow between the inlet port and isolation port.

Abstract: A guidewire is disclosed that is constructed using tubular members that create a hollow lumen that runs from the proximal end of the guidewire to a window towards the distal end of the wire. This internal lumen is filled with a fluid that allows pressure exerted at the window to exert pressure at the proximal end of the guide wire proportional to the pressure exerted at the window. This pressure exerted at the proximal end of the guidewire is measured using a pressure transducer external of the guidewire. The pressure transducer converts the measured pressure into an electrical signal that is proportional to the pressure at the window. The electrical signal is manipulated to correct for errors that are due to the pressure signal traveling though the inner lumen of the guidewire to ensure the electrical signal matches the pressure exerted at the window.

Abstract: Many people do not have a physical feeling for what normal and abnormal blood pressure levels mean in relation to the forces exerted on the heart and blood vessels. A blood pressure simulation apparatus provides human subjects a means to physically feel simulated blood pressure levels through tactile feedback. Both normal and abnormal blood pressure cycles are simulated. Interfacing of the apparatus to an electronic blood pressure monitor is provided.

Abstract: Methods and devices for detecting positioning of a probe in a tissue of a patient. A method can include providing a detection device; advancing a device coupled probe through the tissue of the patient and toward the patient's target tissue; detecting a change in pressure about the distal portion of the coupled probe during advancing, where the detected pressure change indicates probe positioning in a vein or artery of the patient; outputting the detected pressure change or indication of probe positioning to a visual display.

Abstract: A blood pressure measuring apparatus includes a plurality of mechanisms compressing a cuff, and the mechanisms are separately controlled. Therefore, a stable measurement attitude is maintained irrespective of a circumference or a shape of an upper arm. Compression degrees are separately controlled, whereby a pressure can evenly be applied to the cuff to improve a compression force acting on an artery.

Abstract: An indicator device for visually indicating a pressure of blood inside a blood vessel includes: a body, the body comprising a duct extending in the body and having a sealed proximal end; a distal end portion adapted to be positioned inside the blood vessel and including a liquid inlet opening in fluid communication with the duct; and a window including an at least semi-transparent section configured to enable visual observation of blood entering into the duct via the inlet opening when the inlet opening is located inside the blood vessel.

Abstract: A venous-arterial detector is disclosed. The detector includes a first chamber in fluid communication with a needle, and an indicator chamber in selective fluid communication with the first chamber through a valve. The indicator chamber is pre-pressurized to a defined pressure that preferably exceeds typical venous pressure, and the valve retains that pressure within the indicator chamber. When the needle is inserted into a vessel, if the pressure in the vessel is greater than the defined pressure in the indicator chamber, blood will flow into the indicator chamber, indicating that the vessel is most likely to be an artery.

Abstract: An ultrasonic transducer device comprising: an ultrasonic transducer array micromachined on a substrate; flexible electrical connections connected to the transducer array; and a body of acoustically attenuative material that supports the substrate and the flexible electrical connections. The acoustic backing material may contain additional features, such as tabs or notches, for use in positioning the transducer on fixtures during manufacturing or positioning the transducer within a housing during final assembly. Tabs or other features that are used only during manufacturing may be subsequently removed from the device. The MUT device itself may also be thinned so as to provide flexibility as desired. The backing material is preferably matched in acoustic impedance to the silicon wafer so as to prevent reflection at the interface of any acoustic energy propagating rearward, i.e., in the direction away from the device front surface.

Abstract: A sphygmomanometer with an air reservoir connected above a tube for a mercury column and a selectively openable and closeable valve to the air reservoir. With the valve open, first blood pressure measurements can be made by pressure rising in the mercury reservoir. With the valve closed, the air above the mercury column resists rise in the mercury column but also permits higher pressure measurements using the same mercury column. One scale at the mercury tube measures the pressure with the valve open and another scale at the tube measures the pressure with the valve closed. The measurements with the valve closed are calibrated by appropriately altering the volume of the air reservoir depending upon altitude at barometric pressure. The sphygmomanometer can be used to perform a mercury drop test for determining the altitude at which the sphygmomanometer is located.

Abstract: An apparatus for monitoring fluid pressure includes a reusable base section, and a disposable dome section detachably connected to the base section. The disposable dome section defines a fluid pathway and includes a dome viewing segment in fluid communication with a flush segment and a stopcock segment. A pressure transducer sensor is disposed in the reusable base section and is adapted to produce electrical signals proportional to fluid pressures sensed in the fluid pathway. A usage indicator can be disposed in the base section to provide a visual indication of usage of the apparatus within a predetermined number of uses. A calibration port can be provided in the base section to allow for simple calibration by the user without violating the sterility of the apparatus. The ability to reuse the base section with the sensor component reduces the cost of the apparatus, while the disposability of the dome section with the fluid pathway ensures sterility for each use.

Abstract: The present invention is directed toward determining a Coronary Flow Reserve (CFR) value for a stenosed blood vessel by way of pressure measurements acquisitioned proximal a stenosis in a stenosed blood vessel and distal thereto both at rest and at hyperemia in accordance with the relationship CFR &agr; (&Dgr;Phyper, &Dgr;Prest) where &Dgr;Phyper and &Dgr;Prest are the pressure gradients across the stenosis at rest and at hyperemia, respectively.

Abstract: The invention concerns a one-person-operable, sterilisable, medical pressure measuring apparatus (1: 6: 8: 11: 12: 23: 31), in particular for blood pressure measurement, wherein the pressure measuring apparatus (1: 8: 11: 12: 23: 31) has least one cannula connection (26), a measuring duct (4) and an entry (27). The measuring duct (4) opens into a closed container (2) with rigid walls (7), a compressible medium (3) being disposed in the container (2). The pressure measuring apparatus (1: 6: 3: 11: 12: 23: 31), besides the measurement of the pressure in a vessel, permits contamination-free insertion of a catheter, preferably for monitoring the position of a cannula (24). Unnecessary injury to vessels can be avoided thereby and complications upon the insertion of catheters can be considerably reduced.

Abstract: The invention relates to a method for the correction of measured value falsifications in invasive pressure measurements with a fluid-filled system, in which the measured pressure is passed via the fluid-filled system to an external pressure transducer, which converts the pressure signal into an electrical signal. To provide a method and a device for invasive pressure measurement with fluid-filled systems which are improved with respect to the correction of measured value falsifications, are cost-effective and versatile in their use, the electrical signal is passed through an analog/digital converter and the digitized signal is fed to a signal analyzing and processing unit, which operates on the basis of a digital Fourier analysis. Furthermore, a heartbeat-related or segmental analysis is carried out and the signal is combined with empirically determined correction data on the basis of the analysis.

Abstract: A sensor device (20) comprises a sensor package (22) having a cavity (24) formed therein, a sensor die (26) mounted on a bottom surface (28) of the cavity (24) and a protective coating (30) formed over the sensor die in the cavity. The protective coating (30) is formed from a material, preferably a polymer material, which is arranged to have a graduated cross-linking density such that the material at the top of the cavity (24) has a high density of cross-linking and the material at the bottom of the cavity (24), which material is in contact with the sensor die, has a low density of cross-linking.

Abstract: A non-invasive venous pressure measurement apparatus is provided, including: a first cuff attached to a portion including a vein and an artery in a living body; a pressure control unit that changes a first applied pressure applied by the cuff to the portion; a pulse wave detection unit that detects a pulse wave from a pressure received by the cuff from the portion; another pulse wave detection unit that detects another pulse wave including at least an arterial pulse wave in another portion of the living body; an analyzing unit that analyzes a correlation between the two pulse waves, which are changed as the applied pressure is changed by the pressure control unit changes; and a venous pressure calculation unit that calculates a venous pressure based on the applied pressure and a result of analysis by the analyzing unit.