Abstract: A catheter is designed with a virtual electrode structure for creating a linear lesion. The catheter includes a sensor array that measures temperatures of adjacent tissue along the length of the virtual electrode section. The sensors in the sensor array include a conductive material that is substantially coated with an electrically and thermally insulating material. An aperture is formed in the insulating coating to expose an area of the conductive material. Leads are coupled with each sensor and are connected at their opposite, proximal ends with a discrimination circuit. The circuit processes the signals induced in the sensors to output a single temperature measurement, for example, the highest temperature, the lowest temperature, or the average temperature. The sensors also measure cardiac electrical activity and the leads are further connected to an electrocardiograph monitor to determine the efficacy of treatment.

Abstract: A catheter is designed with a virtual electrode structure for creating a linear lesion. The catheter includes a sensor array that measures temperatures of adjacent tissue along the length of the virtual electrode section. The sensors in the sensor array include a conductive material that is substantially coated with an electrically and thermally insulating material. An aperture is formed in the insulating coating to expose an area of the conductive material. Leads are coupled with each sensor and are connected at their opposite, proximal ends with a discrimination circuit. The circuit processes the signals induced in the sensors to output a single temperature measurement, for example, the highest temperature, the lowest temperature, or the average temperature. The sensors also measure cardiac electrical activity and the leads are further connected to an electrocardiograph monitor to determine the efficacy of treatment.

Abstract: The present invention is a method for calculating blood pressure of an artery having a pulse. The method includes applying a varying pressure to the artery. Pressure waveforms are sensed to produce pressure waveform data. Waveform parameters are derived from the sensed pressure waveform data. Blood pressure is then determined using the derived parameters.

Abstract: The present invention is a method for calculating blood pressure of an artery having a pulse. The method includes applying a varying pressure to the artery. Pressure waveforms are sensed to produce pressure waveform data. Waveform parameters are derived from the sensed pressure waveform data. Blood pressure is then determined using the derived parameters.

Abstract: A hand-held non-invasive blood pressure measurement device allows a varying pressure to be applied to an artery while pressure waveforms are sensed to produce pressure waveform data. Waveform parameters are derived from the sensed pressure waveform data. Blood pressure is then determined using the derived parameters. The user is guided or prompted to apply the varying pressure through audible and visual feedback.

Abstract: A non-invasive blood pressure sensor includes a first fluid filled sensing chamber having a diaphragm. A first transducer is fluidly coupled to the first sensing chamber to sense fluid pressure within the first chamber. A flexible body conformable wall surrounds the sensing chamber. The wall applies force to the artery while preventing pressure in a direction generally parallel to the artery from being applied to the sensing chamber. The flexible body conformable wall includes a second fluid filled chamber. A second transducer fluidly coupled to the second chamber senses fluid pressure within the second chamber. As varying pressure is applied to the artery pressure waveforms are sensed by the first transducer. Using output signals of the first and second transducers, the sensed pressure waveform data is analyzed to derive waveform parameters from which blood pressure values are derived. The effects of motion artifacts are reduced by the use of signals from both the first and second transducers.

Abstract: The present invention is an improvement to a non-invasive blood pressure sensing device and method. The present invention is an improvement that includes a transducer with an associated memory or memories for storing data such as sensor characteristics and history information. In a preferred embodiment, the stored information includes transducer offsets and gains, date code, serial number, model type, usage counter, time stamp of the last test of the device, motor characteristics and one or more checksums. The stored data is used by the device for several purposes including calibration, generation of indications such as component expiration indications and test needed indications, automatic identification of appropriate algorithms for control and data manipulation, service and billing.

Abstract: A non-invasive blood pressure sensor includes a first fluid filled sensing chamber having a diaphragm. A first transducer is fluidly coupled to the first sensing chamber to sense fluid pressure within the first chamber. A flexible body conformable wall surrounds the sensing chamber. The wall applies force to the artery while preventing pressure in a direction generally parallel to the artery from being applied to the sensing chamber. The flexible body conformable wall includes a second fluid filled chamber. A second transducer fluidly coupled to the second chamber sensing fluid pressure within the second chamber. As varying pressure is applied to the artery pressure waveforms are sensed by the first transducer. Using output signals of the first and second transducers, the sensed pressure waveform data is analyzed to derive waveform parameters from which blood pressure values are derived. The effects of motion artifacts are reduced by the use of signals from both the first and second transducers.

Abstract: The present invention is a method for calculating blood pressure of an artery having a pulse. The method includes applying a varying pressure to the artery. Pressure waveforms are sensed to produce pressure waveform data. Waveform parameters are derived from the sensed pressure waveform data. Blood pressure is then determined using the derived parameters.

Abstract: A hand-held non-invasive blood pressure measurement device allows a varying pressure to be applied to an artery while pressure waveforms are sensed to produce pressure waveform data. Waveform parameters are derived from the sensed pressure waveform data. Blood pressure is then determined using the derived parameters. The user is guided or prompted to apply the varying pressure through audible and visual feedback.

Abstract: The present invention is a method for locating a sensor over an underlying artery having a blood pulse. The sensor is positioned at a plurality of locations above a known appoximate location of the artery while applying a constant hold down pressure to the artery. The sensor is finally positioned at the location which exhibits the largest maximum pressure ampltiude.

Abstract: The present invention is a method for locating a sensor over an underlying artery having a blood pulse. The sensor is positioned at a plurality of locations above a known approximate location of the artery while applying a constant hold down pressure to the artery. The sensor is finally positioned at the location which exhibits the largest maximum pressure ampltiude.

Abstract: The present invention is a method and apparatus for calculating blood pressure of an artery having a pulse. The method includes applying a varying pressure to the artery. Pressure waveforms are sensed to produce pressure waveform data. Waveform parameters are derived from the sensed pressure waveform data. Blood pressure is then determined using the derived parameters. The apparatus is a blood pressure monitoring device which includes pressure means for applying a varying pressure to the artery so that the artery exhibits pressure data, sensing means for sensing the pressure data, signal producing means connected to the sensing means for producing output signals corresponding to the sensed pressure data and processing means for receiving the output signals from the signal producing means, for deriving a plurality of parameters using sensed pressures and for determining a blood pressure value using the derived parameters.

Abstract: A sensor having a sensing surface for sensing blood pressure within an underlying artery of a patient includes a transducer, a sidewall, a flexible diaphragm and a fluid coupling medium. The sidewall is distinct from transducer and supports the transducer above the underlying artery. The fluid coupling medium is coupled between the sensing surface of transducer and the flexible diaphragm and transmits blood pressure pulses within the underlying artery from the flexible diaphragm to the sensing surface of transducer. In one embodiment, the fluid coupling medium is isolated from sidewall.

Abstract: A sensor for sensing blood pressure within an underlying artery as the underlying artery is compressed includes a transducer and a compressible sidewall. The transducer senses blood pressure of blood pressure pulses as the pulses travel beneath the sensor. As each blood pressure pulses crosses an edge of the sensor, each pulse exerts a force on the sensor in a direction parallel to the underlying artery. Tissue surrounding the underlying artery also exerts a force. The compressible sidewall is distant from the transducer and engages tissue surrounding the underlying artery. The compressible side wall neutralizes the force exerted by the tissue surrounding the underlying artery and dampens the force parallel to the underlying artery so that a substantially zero pressure gradient exists across the transducer.

Abstract: A device for supporting a sensing surface above an underlying artery of a patient includes a hold down assembly and a sensor interface pivotally coupled to the hold down assembly. The hold down assembly is secured at a spaced position relative to the underlying artery of the patient. The sensor interface includes a flexible diaphragm, a compressible side wall and a mount. The flexible diaphragm has an active portion for transmitting blood pressure pulses of the underlying artery. The compressible side wall encircles the active portion and has a top end and a bottom end. The bottom end is secured to the flexible diaphragm. The mount is coupled to the top end of the compressible side wall. The mount has a connection located below the top end of the compressible side wall for receiving a movable member of the hold down assembly so that the movable member may be pivotally coupled to the sensor below the top end of the compressible side wall.

Abstract: A transducer having a sensing surface for sensing blood pressure within an underlying artery of a patient includes a transducer, a sidewall, a flexible diaphragm and a fluid coupling medium. The sidewall supports the transducer above the underlying artery. The flexible diaphragm is spaced from the sensing surface of the transducer. The fluid coupling medium is coupled between the sensing surface of the transducer and the flexible diaphragm and transmits blood pressure pulses within the underlying artery from the flexible diaphragm to the sensing surface of the transducer. The fluid coupling medium is isolated from the sidewall so that forces are not transmitted from the sidewall through the fluid coupling medium to the transducer.

Abstract: A free flow prevention system for preventing undesired free flow of fluid through IV tubing of the type used in an infusion pump. The system comprises a spring clip having a base and a spring arm defining a channel adapted to receive the IV tubing. The spring arm is resiliently biased to a closed position in which the IV tubing is squeezed by the spring clip to close the lumen to prevent fluid flow, and the spring arm is movable against the bias to an open position wherein the lumen of the IV tubing is allowed to open to allow flow. The system also includes a clip-opening pin in the infusion pump for moving the spring arm of the clip from its closed position to the open position.

Abstract: The present invention comprises an audio alarm for providing a back-up acoustic output in response to a sensed parameter including a first audio alarm circuit having a first transducer for providing a first acoustic output in response to the sensed parameter, a second audio alarm circuit having a second transducer which provides the back-up acoustic output in response to a predetermined fault condition, and which is acoustically coupled to the first transducer. The second audio alarm circuit provides an electrical signal by converting the first acoustic output of the first transducer into an electrical signal. A detector circuit is connected to the first and second audio alarm circuits and responds to the sensed parameter and to the electrical signal from the second audio alarm circuit to provide the predetermined fault condition by interpreting the electrical signal from the second audio alarm circuit.