44 results about "Pulsatile blood flow" patented technology

An active-pulse blood analysis system has an optical sensor that illuminates a tissue site with multiple wavelengths of optical radiation and outputs sensor signals responsive to the optical radiation after attenuation by pulsatile blood flow within the tissue site. A monitor communicates with the sensor signals and is responsive to arterial pulses within a first bandwidth and active pulses within a second bandwidth so as to generate arterial pulse ratios and active pulse ratios according to the wavelengths. An arterial calibration curve relates the arterial pulse ratios to a first arterial oxygen saturation value and an active pulse calibration curve relates the active pulse ratios to a second arterial oxygen saturation value. Decision logic outputs one of the first and second arterial oxygen saturation values based upon perfusion and signal quality.

An ear sensor provides a sensor body having a base, legs extending from the base and an optical housing disposed at ends of the legs opposite the base. An optical assembly is disposed in the housing. The sensor body is flexed so as to position the housing over a concha site. The sensor body is unflexed so as to attach the housing to the concha site and position the optical assembly to illuminate the concha site. The optical assembly is configured to transmit optical radiation into concha site tissue and receive the optical radiation after attenuation by pulsatile blood flow within the tissue.

A pulse oximetry sensor comprises emitters configured to transmit light having a plurality of wavelengths into a fleshy medium. A detector is responsive to the emitted light after absorption by constituents of pulsatile blood flowing within the medium so as to generate intensity signals. A sensor head has a light absorbing surface adapted to be disposed proximate the medium. The emitters and the detector are disposed proximate the sensor head. A detector window is defined by the sensor head and configured so as to limit the field-of-view of the detector.

PCT No. PCT/CA95/00144 Sec. 371 Date Jan. 6, 1997 Sec. 102(e) Date Jan. 6, 1997 PCT Filed Mar. 15, 1995 PCT Pub. No. WO95/24936 PCT Pub. Date Sep. 21, 1995The flow of a biological fluid to an organ is computer controlled so that natural variation of such flow is simulated. Specifically described are control of a blood pump flow output during CPB to mimic normal pulsatile blood flow from the heart and control of a ventilator output To mimic normal breathing of healthy lungs. A pattern of variation over Time of instantaneous flow of a biological fluid to an organ of a mammalian species is established, a variable control parameter for regulation of flow of the biological fluid to the organ is generated in accordance with the pattern, and the flow of biological fluid is to the organ is controlled in accordance with the variable control parameter.

A congenital heart disease monitor utilizes a sensor capable of emitting multiple wavelengths of optical radiation into a tissue site and detecting the optical radiation after attenuation by pulsatile blood flowing within the tissue site. A patient monitor is capable of receiving a sensor signal corresponding to the detected optical radiation and calculating at least one physiological parameter in response. The physiological parameter is measured at a baseline site and a comparison site and a difference in these measurements is calculated. A potential congenital heart disease condition in indicated according to the measured physiological parameter at each of the sites or the calculated difference in the measured physiological parameter between the sites or both.

Method and apparatus to non-invasively measure fetal blood oxygen saturation levels. Optical sensors capable of producing and detecting multiple wavelengths of tissue penetrating light are placed on the surface of the maternal abdomen, and the light beams directed to pass through at least a portion of the uterus containing the fetus. The fetal heart rate is monitored by Doppler ultrasound, and pure maternal optical signal related to maternal arterial blood flow are also measured. The optical sensors collect composite signals containing both maternal and fetal hemoglobin absorption spectral data and modulated by their respective pulsatile blood flows. The composite signals processed in the time domain and frequency domain, the pure maternal pulsatile optical signal used to extract the maternal contribution to the composite signal, and the fetal pulsatile signal is used to lock onto and extract the fetal contribution to the composite signal, and a fetal blood oxygen level deduced.

The invention discloses a biomechanical experiment simulation device for implantation of intravascular stent, which consists of an artificial cardiovascular system, an artificial blood and pulsatile blood flow field control system and a mechanical experiment observation device. The upper part of a liquid storage box of the artificial cardiovascular system is soaked in a silica gel ventriculus sinister model geometrically similar to the ventriculus sinister; the inlet end of the silica gel ventriculus sinister model is connected with the open liquid storage box through a silica gel hollow round ball simulating the right atrium; the outlet end of the silica gel ventriculus sinister model is connected with an aortic arch model; a microcomputer of the artificial blood and pulsatile blood flow field control system is connected with a power amplifier, a linear step motor and a piston in turn; and artificial blood with similar blood viscosity and specific gravity and containing simulated thrombus particles polystyrene microspheres is arranged in a closed-loop blood flow field model. Through the device, a simulated operation for stent implantation can be effectively and visually preformed between the clinical experiments and animal experiments on the intravascular stent, and effective biochemical evaluation on the flexibility, strength and stability of the stent can be realized.

A biometric identification apparatus includes a control module, a fingerprint identification module including a fingerprint scan controller and a fingerprint receiver, a pulsatile blood flow detection module including one or multiple light sources and a photo detector, and a holder body defining a fingerprint identification zone and a pulsatile blood flow identification zone. In application, the user simply needs to press the fingertip of one single finger on the fingerprint identification zone and pulsatile blood flow identification zone of the holder body so that the biometric identification apparatus can detect user's fingerprint and pulsatile blood flow signals, fetch and convert characteristic data of detected signals, and then match fetched fingerprint and pulsatile blood flow characteristic data with respective reference data for security access control. The application of this dual-biometric identification technology greatly increases the cracking difficulty, achieving better anti-theft function.

The invention discloses a liver normal temperature perfusion restoration system. The system comprises a liver container. The liver container comprises a main body and an upper cover. The main body and the upper cover are fastened tightly. A silica gel flexible net is fixed to the main body of the liver container. The lower end of the main body of the liver container is provided with a blood return channel. The blood return channel is connected to a centrifugal pump by a blood storage tank. The front end of the blood storage tank is provided with a filter film. An outlet end of the centrifugal pump is connected to an oxygenator. The oxygenator is connected to an oxygen control device. A blood pipe of the oxygenator is divided into two paths by a heat exchanger, one path is used for hepatic artery perfusion by a roller pump and the other path is used for direct portal vein perfusion. Liver artery forms a pulsatile blood flow under the action of the roller pump so that physiological liver artery perfusion is simulated and bile duct cell protection is realized in perfusion. The system can keep hepatocyte aerobic metabolism at a normal temperature, realizes short-time restoration treatment on the liver and widens a liver source.

A reflection-detector sensor position indicator comprises emitters that transmit light having a plurality of wavelengths. A detector outputs a sensor signal. At least one reflection detector outputs at least one sensor position signal. An attachment assembly attaches the emitters, the detector and the reflection detector onto a tissue site. A sensor-on condition indicates that the attachment assembly has positioned the emitters generally centered over a fingernail, the detector on a fingertip opposite the fingernail and the reflection detector over the fingernail. The sensor signal, in the sensor-on condition, is at least substantially responsive to the emitter transmitted light after attenuation by pulsatile blood flow perfused within a fingernail bed underneath the fingernail. The sensor position signal, in the sensor-on condition, is at least substantially responsive to the emitter transmitted light after reflection off of the fingernail.

A pulse blood pump for external circulation of blood is composed of a blood storage chamber with hard shell and two single-flap check valves, blood inlet tube, blood outlet tube, and a pulse driver arranged in said blood storage chamber and consisting of blood valve, air inlet tube and ball.

The invention is about a next-generation blood pump that provides pulsatile blood flow, and has been developed for cardiopulmonary by-pass devices used for maintaining extracorporeal blood circulation during heart surgeries and the supportive devices of circulation system. This device is technically a sort of synchronous power-assisted motor employing direct driver technology. The mentioned blood pump contains a rotor rotating on a magnetic bearing without a shaft and through the helical wings placed into the rotor it provides pulsatile blood supply adequate for the body requirement synchronous with the ECG signals received from the patients. It provides a patient safer and controlled pulsatile blood flow while running at high efficiency.

The invention discloses an apparatus (2), a system (1) and a method (100) for characterization of vessels and for vessel modeling. The cross sectional area (A₁) of the vessel is derived from pressure measurements (p₁, p₂) obtained by an instrument (3) from within the vessel. When multiple cross sectional areas (A₁, A₂) are derived for multiple reference positions (r₁, r₂) based on pressure measurements (p₁, p₂, p₃) along the vessel, a representation (20, 30) of the vessel can be rendered, without requiring any imaging modality. Furthermore, the effect of the pulsatile blood flow on the elasticity of the vessel walls can be visualized, supporting assessment of a stenosis or an aneurysm formation along the vessel.

A secondary-emitter sensor position indicator has primary emitters that transmit light having primary wavelengths and at least one secondary emitter that transmits light having at least one secondary wavelength. A detector outputs a sensor signal in response to received light. An attachment assembly, in a sensor-on condition, positions the emitters and detector relative to a tissue site so that the sensor signal is substantially responsive to the primary wavelength light after attenuation by pulsatile blood flow within the tissue site and is negligibly responsive to the secondary wavelength light. The attachment assembly, in a sensor out-of-position condition, positions the secondary emitter relative to the tissue site so that the sensor signal is at least partially responsive to the secondary wavelength.

A disposable active pulse sensor has an emitter that generates optical radiation having a plurality of wavelengths, a detector that is responsive to the optical radiation and an unbalanced electrical motor that vibrates when energized. A tape assembly removably attaches the emitter, the detector and the unbalanced electrical motor to a tissue site. The tape assembly also physically mounts the emitter, the detector and the unbalanced electrical motor in a spatial arrangement so that vibration from the unbalanced electrical motor induces pulsatile blood flow within the tissue site, the emitter transmits the optical radiation into the tissue site and the detector generates a sensor signal responsive to the intensity of the optical radiation after attenuation by the pulsatile blood flow within the tissue site.