3321 results about "Perfusion" patented technology

A treatment tool for performing a treatment for a curative procedure with ultrasonic waves, high frequency current and so on is provided with an identifier formed of a resistor or the like for indicating the type of the treatment tool. A medical instrument such as an ultrasonic wave output apparatus discriminates the type of a treatment tool connected thereto from the identifier to automatically set operating parameters such as an output value suitable for the treatment tool and to associatively operate an ancillary medical instrument such as a perfusion / aspiration apparatus depending on the treatment tool, thereby reducing extra work such as manual setting to allow for a smooth treatment.

One or more implantable system control units (SCU) apply one or more stimulating drugs and / or electrical pulses to one or more predetermined areas affecting circulatory perfusion. The SCU preferably includes a programmable memory for storing data and / or control parameters, and preferably uses a power source / storage device, such as a rechargeable battery. If necessary, periodic recharging of such a power source / storage device is accomplished, for example, by inductive coupling with an external appliance. The SCU provides a means of stimulating a nerve(s) or other tissue with electrical and / or infusion pulses when desired, without the need for external appliances during the stimulation session. When necessary, external appliances are used for the transmission of data to and / or from the SCU(s) and / or for the transmission of power. In a preferred embodiment, the system is capable of open- and closed-loop operation. In closed-loop operation, at least one SCU includes a sensor, and the sensed condition is used to adjust electrical and / or drug stimulation parameters.

A processor provides signal quality based limits to a signal strength operating region of a pulse oximeter. These limits are superimposed on the typical gain dependent signal strength limits. If a sensor signal appears physiologically generated, the pulse oximeter is allowed to operate with minimal signal strength, maximizing low perfusion performance. If a sensor signal is potentially due to a signal induced by a dislodged sensor, signal strength requirements are raised. Thus, signal quality limitations enhance probe off detection without significantly impacting low perfusion performance. One signal quality measure used is pulse rate density, which defines the percentage of time physiologically acceptable pulses are occurring. If the detected signal contains a significant percentage of unacceptable pulses, the minimum required signal strength is raised proportionately. Another signal quality measure used in conjunction with pulse rate density is energy ratio, computed as the percentage of total energy contained in the pulse rate fundamental and associated harmonics.

A method and apparatus for the transcutaneous monitoring of blood gases generally comprises a blood gas data acquisition device, a vacuum source and a blood gas transducer unit. The blood gas transducer unit is adapted for application to a patient's skin and administration of a local vacuum at the area of patient application. It further comprises an electrochemical blood gas transducer, well known to those of ordinary skill in the art, which is disposed entirely within the local vacuum at the area of patient application. The vacuum source is placed in fluid communication with the blood gas transducer unit, through a hydrophobic membrane filter for safety purposes, in order to induce a condition of hyperperfusion in the locality of the electrochemical blood gas transducer. Under the control of a microcontroller, or equivalent means, the blood gas acquisition device is then utilized to capture a measure of skin surface oxygen or carbon dioxide pressure. The microcontroller can then utilize this measure to arrive at an estimate of arterial partial pressure of oxygen or carbon dioxide, accordingly. Because vacuum induced perfusion produces the requisite condition of hyperperfusion without local heating and, therefore, without acceleration of the local metabolic function, the present invention results in more accurate than previously available estimates of partial pressure blood gas pressures and does so while eliminating a significant risk for injury to the patient.

Methods for treating total and partial occlusions employ a perfusion conduit which is penetrated through the occlusive material. Oxygenated blood or other medium is then perfused through the conduit in a controlled manner, preferably at a controlled pressure below the arterial pressure, to maintain oxygenation and relieve ischemia in tissue distal to the occlusion. In another aspect, interventional devices, such as stents or balloon catheters, are passed through the perfusion catheter to remove obstructions. Optionally, the occlusion may be treated while perfusion is maintained, typically by introducing a thrombolytic or other agent into the occlusive material using the perfusion conduit or by employing mechanical means to remove the obstruction. Such methods are particularly suitable for treating acute stroke to prevent damage to the cerebral tissue.

Organs and other tissue structures are isolated and perfused with a therapeutic agent. Isolation is effected by endovascularly positioning catheters having occlusion balloons within the arteries or other blood vessels which supply blood to the organ. Similarly, blood flow from the organ back to the patient's circulatory system is blocked by endovascularly positioning one or more catheters carrying occlusion members within the veins or other blood vessels leading from the organ. The therapeutic agent may then be perfused through the organ in either an antegrade or retrograde fashion using the endovascularly positioned catheters while maintaining isolation.

An ultrasound treatment system in accordance with the present invention comprises an ultrasonic transducer, a handpiece, a probe, a sheath, a clamping member, an operation unit, an operating member, a suction base, and a perfusion base. The ultrasonic transducer generates ultrasonic vibrations. The handpiece has the ultrasonic transducer incorporated therein and serves as an operation unit. The probe is connected to the ultrasonic transducer, and serves as a vibration transmitting member for transmitting ultrasonic vibrations to a distal member realizing a stationary portion that is a treatment portion for treating a living tissue. The sheath serves as a protecting member for shielding the probe. The clamping member is opposed to the distal member at the distal end of the sheath, and realizes a movable portion that is another treatment portion for clamping a living tissue in cooperation with the distal member. The operation unit is manipulated for clamping a living tissue with the clamping member and distal member or freeing the living tissue therefrom.

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.

A surgical instrument includes a handle portion, first and second jaw members operably coupled to the handle portion, and first and second sensors associated with the first or second jaw members. The first sensor is configured to measure local perfusion in tissue grasped between the first and second jaw members, and the second sensor is configured to measure a pressure applied to the tissue by the first and second jaw members.

A method of collecting embryonic-like stem cells from a placenta which has been treated to remove residual cord blood by perfusing the drained placenta with an anticoagulant solution to flush out residual cells, collecting the residual cells and perfusion liquid from the drained placenta, and separating the embryonic-like cells from the residual cells and perfusion liquid. Exogenous cells can be propagated in the placental bioreactor and bioactive molecules collected therefrom.

A combination of a patient core temperature sensor and the dual-wavelength optical sensors in an ear probe or a body surface probe improves performance and allows for accurate computation of various vital signs from the photo-plethysmographic signal, such as arterial blood oxygenation (pulse oximetry), blood pressure, and others. A core body temperature is measured by two sensors, where the first contact sensor positioned on a resilient ear plug and the second sensor is on the external portion of the probe. The ear plug changes it's geometry after being inserted into an ear canal and compress both the first temperature sensor and the optical assembly against ear canal walls. The second temperature sensor provides a reference signal to a heater that is warmed up close to the body core temperature. The heater is connected to a common heat equalizer for the temperature sensor and the pulse oximeter. Temperature of the heat equalizer enhances the tissue perfusion to improve the optical sensors response. A pilot light is conducted to the ear canal via a contact illuminator, while a light transparent ear plug conducts the reflected lights back to the light detector.

A perfusion catheter includes at least one perfusion channel and at least two dilation units disposed at a distance from each other at the distal catheter region in the longitudinal extension of the catheter. Both of the at least two dilation units are projected through by the perfusion catheter and form, in an inflated state, an at least practically fluid-tight occlusion with the aortic wall. At least the dilation unit disposed on the proximal side has at least one passage through which an auxiliary catheter can be introduced in a fluid-tight manner. The perfusion catheter may have a working channel with an outlet opening in the region between the two dilation units and through which at least one auxiliary catheter can be introduced for aortic valve ablation.

The present invention provides a method of extracting and recovering embryonic-like stem cells, including, but not limited to pluripotent or multipotent stem cells, from an exsanguinated human placenta. A placenta is treated to remove residual umbilical cord blood by perfusing an exsanguinated placenta, preferably with an anticoagulant solution, to flush out residual cells. The residual cells and perfusion liquid from the exsanguinated placenta are collected, and the embryonic-like stem cells are separated from the residual cells and perfusion liquid. The invention also provides a method of utilizing the isolated and perfused placenta as a bioreactor in which to propagate endogenous cells, including, but not limited to, embryonic-like stem cells. The invention also provides methods for propagation of exogenous cells in a placental bioreactor and collecting the propagated exogenous cells and bioactive molecules therefrom.

One or more markers or sensors are positioned in the vasculature of a patient to facilitate determining the location, configuration, and / or orientation of a vessel or certain aspects thereof (e.g., a branch vessel), determining the location, configuration and / or orientation of a endovascular devices prior to and during prosthesis deployment as well as the relative position of portions of the vasculature and devices, generating an image of a virtual model of a portion of one or more vessels (e.g., branch vessels) or devices, and / or formation of one or more openings in a tubular prosthesis in situ to allow branch vessel perfusion when the prosthesis is placed over one or more branch vessels in a patient (e.g., when an aortic abdominal artery stent-graft is fixed to the aorta superior to the renal artery ostia).

A system including an implantable neurostimulator device capable of modulating cerebral blood flow to treat epilepsy and other neurological disorders. In one embodiment, the system is capable of modulating cerebral blood flow (also referred to as cerebral perfusion) in response to measurements and other observed conditions. Perfusion may be increased or decreased by systems and methods according to the invention as clinically required.

The invention relates to pulsed oximeters used to measure blood oxygenation. The current trend towards mobile oximeters has brought the problem of how to minimize power consumption without compromising on the performance of the device. To tackle this problem, the present invention provides a method for controlling optical power in a pulse oximeter. The signal-to-noise ratio of the received baseband signal is monitored, and the duty cycle of the driving pulses is controlled in dependence on the monitored signal-to-noise ratio, preferably so that the optical power is minimized within the confines of a predetermined lower threshold set for the signal-to-noise ratio. In this way the optical power is made dependent on the perfusion level of the subject, whereby the power can be controlled to a level which does not exceed that needed for the subject.

A plastically deformable stent for implantation within a body passage includes a plurality of cylindrical segments, and a plurality of connectors extending between adjacent segments. Each segment has an alternating pattern of curvilinear elements extending about its circumference, including first and second sets of curvilinear elements having different resistances to expansion, and preferably defining “U” shapes with alternating lengths that are connected to one another to define a substantially sinusoidal pattern. The connectors define a sinusoidal shape adapted to extend and compress axially substantially evenly when the adjacent segments are subjected to bending. The stent may be delivered on a device including an elongate member with a nose cone, an expandable member, and a proximal shoulder thereon, and an outer sheath for slidably receiving the elongate member therein. The outer sheath and / or nose cone may have perfusion holes for allowing continued perfusion of fluid during stent delivery. The device may be used in a method for implanting a stent within a curved region of a body passage, particularly for creating and / or maintaining a channel connecting a vein to an adjacent artery, preferably in the coronary system.

An enhanced method and device are provided to treat atrial fibrillation or inhibit or reduce restenosis following angioplasty or stent placement. A balloon-tipped catheter is disposed in the area treated or opened through balloon angioplasty immediately following angioplasty. The balloon, which can have a dual balloon structure, may be delivered through a guiding catheter and over a guidewire already in place. A fluid such as a perfluorocarbon flows into the balloon to freeze the tissue adjacent the balloon, this cooling being associated with reduction of restenosis. A similar catheter may be used to reduce atrial fibrillation by inserting and inflating the balloon such that an exterior surface of the balloon contacts at least a partial circumference of the portion of the pulmonary vein adjacent the left atrium. In another embodiment, blood perfusion is performed simultaneously. In another embodiment, tissue contacted by the cryoablation catheter, undesired to be ablated, is protected against damage by a separate heating step.

The present invention describes a catheter suitable for introduction into a tubular tissue for dissolving blockages in such tissue. The catheter is particularly useful for removing thrombi within blood vessels. In accordance with the preferred embodiments, a combination of vibrating motion and injection of a lysing agent is utilized to break up blockages in vessels. The vessels may be veins, arteries, ducts, intestines, or any lumen within the body that may become blocked from the material that flows through it. As a particular example, dissolution of vascular thrombi is facilitated by advancing a catheter through the occluded vessel, the catheter causing a vibrating, stirring action in and around the thrombus usually in combination with the dispensing of a thrombolytic agent such as urokinase into the thrombus. The catheter has an inflatable or expandable member near the distal tip which, when inflated or expanded, prevents the passage of dislodged thrombus around the catheter. The dislodged portions of thrombus are directed through a perfusion channel in the catheter, where they are removed by filtration means housed within the perfusion channel before the blood exits the tip of the catheter. Catheters that allow both frequency (1-1000 Hz) vibratory motion and delivery of such agents to a blockage and a method for using such catheters are disclosed.

A flexible, conformable, sensor assembly is provided, including an electrode array especially adapted for stable, long-term recording of EEG signals from a pre-term or neonatal infant in intensive care. A kit or sterile pack includes guidance for placement of the electrodes over a designated area of the infant's brain, an area likely to be injured. The sensor assembly includes a left-side and a right-side flexible strip bearing at least electrodes and optional temperature, motion, and optical sensors provide for the monitoring of an extended range of parameters including aspects of cerebral perfusion and metabolism. Optional impedance measurements provide an indication of neuronal swelling. Stable performance over from three days to about a week is intended so that progress, effects of treatment, and outcome can be considered.

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.

Methods for treating total and partial occlusions employ a perfusion conduit which is penetrated through the occlusive material. Oxygenated blood or other medium is then perfused through the conduit to maintain oxygenation and relieve ischemia in tissue distal to the occlusion. Optionally, the occlusion may be treated while perfusion is maintained, typically by introducing a thrombolytic or other agent into the occlusive material using the perfusion conduit. Such methods are particularly suitable for treating acute stroke to prevent irreversible damage to the cerebral tissue.

Devices and methods for cooling vessel walls to inhibit restenosis in conjunction with medical procedures such as coronary artery angioplasty. Stenosed vessel walls can be cooled prior to angioplasty, after angioplasty, or both. The invention is believed to inhibit restenosis through cooling to a temperature near freezing, preferably without causing substantial vessel wall cell death. One catheter device includes a distal tube region having coolant delivery holes radially and longitudinally distributed along the distal region. In some devices, holes spray coolant directly onto the vessel walls, with the coolant absorbed into the blood stream. In other embodiments, a balloon or envelope is interposed between the coolant and the vessel walls and the coolant returned out of the catheter through a coolant return lumen. Some direct spray devices include an occlusion device to restrict blood flow past the region being cooled. Pressure, temperature, and ultrasonic probes are included in some cooling catheters. Pressure control valves are included in some devices to regulate balloon interior pressure within acceptable limits. In applications using liquid carbon dioxide as coolant, the balloon interior pressure can be maintained above the triple point of carbon dioxide to inhibit dry ice formation. Some cooling catheters are coiled perfusion catheters supporting longer cooling periods by allowing perfusing blood flow simultaneously with vessel wall cooling. One coiled catheter is biased to assume a coiled shape when unconstrained and can be introduced into the body in a relatively straight shape, having a stiffening wire inserted through the coil strands.

An enhanced method and device are provided to treat atrial fibrillation or inhibit or reduce restenosis following angioplasty or stent placement. A balloon-tipped catheter is disposed in the area treated or opened through balloon angioplasty immediately following angioplasty. The balloon, which can have a dual balloon structure, may be delivered through a guiding catheter and over a guidewire already in place. A fluid such as a perfluorocarbon flows into the balloon to freeze the tissue adjacent the balloon, this cooling being associated with reduction of restenosis. A similar catheter may be used to reduce atrial fibrillation by inserting and inflating the balloon such that an exterior surface of the balloon contacts at least a partial circumference of the portion of the pulmonary vein adjacent the left atrium. In another embodiment, blood perfusion is performed simultaneously. In another embodiment, tissue contacted by the cryoablation catheter, undesired to be ablated, is protected against damage by a separate heating step.

A method and apparatus using photo-stimulation to treat or pretreat a sample site prior to analyte concentration determination is presented. More particularly, photo-stimulation at or near at least one sample site is used to enhance perfusion of the sample site leading to reduced errors associated with sampling. Increased perfusion of the sample site leads to increased volume percentages of the target analyte and / or allows the blood or tissue constituent concentrations to more accurately and / or precisely track corresponding sample constituents in more well perfused body compartments or sites such as arteries, veins, or fingertips. In one embodiment, analysis of the photo-stimulated site is used in conjunction with glucose analyzers to determine the analyte concentration with greater ease, accuracy, or precision and may allow determination of the analyte concentration of another non-sampled body part or compartment.

The present invention relates to a novel non-invasive perfusion / resistance status monitor system and methods of using the same, and more specifically, a vascular perfusion status monitor system receiving and processing signals from at least two pulse oximeter probes, where each of the at least two pulse oximeter probes are situated at advantageously different locations in a patient. Novel pulse oximeter probes are configured to be placed, respectively, across the lip or cheek, across the septum or nares of the nose, and on the tongue. These probes are fabricated to provide signals to estimate arterial oxygen saturation. Conventional oximeter probes also can be configured to function according to the novel methods of determining differences in peripheral blood flow and / or resistance described herein.

A generally spherical vascular remodeling device is permanently positionable at a junction of afferent and efferent vessels of a bifurcation having an aneurysm. After positioning the device at the junction to substantially conform the device to the shape of the junction, the device acts as a scaffolding to inhibit herniation of objects out of the aneurysm and the device permits perfusion to the efferent vessels. Positioning the device may include deployment and mechanical or electrolytic release from a catheter. Embolic material may be inserted in the aneurysm before or after positioning the device. The device may have a first end, a second end substantially opposite to the first end, and a plurality of filaments extending between and coupled at the first end and the second end. Such devices may be football shaped, pumpkin shaped, or twisted. The device may include a plurality of loops forming a generally spherical shape.

A system has been constructed that recapitulate the features of a capillary bed through normal human tissue. The system facilitates perfusion of three-dimensional (3D) cell monocultures and heterotypic cell co-cultures at the length scale of the capillary bed. A major feature is that the system can be utilized within a “multiwell plate” format amenable to high-throughput assays compatible with the type of robotics commonly used in pharmaceutical development. The system provides a means to conduct assays for toxicology and metabolism and as a model for human diseases such as hepatic diseases, including hepatitis, exposure-related pathologies, and cancer. Cancer applications include primary liver cancer as well as metastases. The system can also be used as a means of testing gene therapy approaches for treating disease and inborn genetic defects.

Method for assessing the patency of a patient's blood vessel, advantageously during or after treatment of that vessel by an invasive procedure, comprising administering a fluorescent dye to the patient; obtaining at least one angiographic image of the vessel portion; and evaluating the at least one angiographic image to assess the patency of the vessel portion. Other related methods are contemplated, including methods for assessing perfusion in selected body tissue, methods for evaluating the potential of vessels for use in creation of AV fistulas, methods for determining the diameter of a vessel, and methods for locating a vessel located below the surface of a tissue.