Abstract: A method and assembly is provided which allows measurement of intracranial fluid charateristics at the intracranial region of the brain. The invention contemplates a method of implanting a ventricular catheter having one end residing in the ventricular region and the other end exiting the cranial region at a distal location. A grooved needle allows placement of a transducer tipped catheter and rerouting of both the ventricular, in-dwelling catheter and the transducer tipped catheter placed within the in-dwelling catheter. Intracranial fluid characteristics are monitored by an electrically coupled distal monitor. Further, access to the intracranial fluid is also provided to allow either short-term or long-term withdrawal or injection of intracranial fluid.

Abstract: A method and assembly is provided which allows measurement of intracranial fluid characteristics at the intracranial region of the brain. The invention contemplates a method of implanting a ventricular catheter having one end residing in the ventricular region and the other end exiting the cranial region at a distal location. A grooved needle allows placement of a transducer tipped catheter and rerouting of both the ventricular, in-dwelling catheter and the transducer tipped catheter placed within the in-dwelling catheter. Intracranial fluid characteristics are monitored by an electrically coupled distal monitor. Further, access to the intracranial fluid is also provided to allow either short-term or long-term withdrawal or injection of intracranial fluid.

Abstract: A method and system for introducing one or more devices into a biological fluid vessel. The system includes a device having a coupling structure comprising a pair of spaced-apart fingers adapted for receiving a guidewire therebetween. Preferably, the system includes a guidewire having a constricted fitting region at its proximal end where the coupling structure may be easily connected to the guidewire. In one use, the method is used in coronary angioplasty to diagnose and treat stenosis across a coronary valve or other vessel in the coronary arterial tree. In this method, a guiding catheter is percutaneously inserted with its distal end proximate the ostium. A guidewire is inserted through the guiding catheter and subselectively positioned in a region of interest in the coronary arterial tree. Multiple devices may be coupled to the guidewire in accordance with the present invention and then threaded down the guidewire and positioned in the region of interest.

Abstract: A method and assembly for inserting one or more diagnostic sensors into a biological fluid vessel for diagnosing the condition of the vessel or fluid. Different types of diagnostic sensors, such as pressure, velocity, pH, temperature, or infusion catheter, are particularly adapted for use with a steerable guidewire for selective positioning in the vessel. In one application, the method is used in coronary diagnosis, to determine the pressure gradient or other fluid characteristics across a coronary valve or stenosis in the coronary arterial tree. In this method, a guiding catheter is percutaneously inserted with its distal end proximate the ostium. A guidewire is inserted through the guiding catheter and subselective positioned in a region of interest in the coronary arterial tree. Multiple diagnostic sensors are then threaded down the guidewire and positioned in the region of interest.

Abstract: An apparatus and method for sensing in vivo the fluid pressure differential between spaced locations in a biological fluid vessel using a single pressure transducer. The transducer has a deformable member mounted to a housing; a conduit extends within the housing with one end opening at a location spaced from the transducer and the other end opening adjoining the inner surface of the member. With the housing inserted in the biological fluid vessel, the outer surface of the deformable member is exposed to the fluid pressure adjacent the member, while the inner surface is exposed to the fluid pressure within the conduit. The deformable member flexes in response to the fluid pressure differential across the member, which is a direct measure of the fluid pressure differential between spaced-apart locations in the fluid-filled vessel.

Abstract: A method and assembly for inserting a plurality of sensors into a biological fluid vessel for diagnosing the condition of the vessel or fluid. A pressure sensor is described which is particularly adapted for use with a steerable guidewire for selective positioning in the vessel. In one application, the method is used in coronary diagnosis, to determine the pressure gradient across a coronary valve or stenosis in the coronary arterial tree. In this method, a guiding catheter is percutaneously inserted with its distal end proximate the ostium. A guidewire is inserted through the guiding catheter and subselectively positioned in a region of interest in the coronary arterial tree. Multiple pressure sensors are then threaded down the guidewire and positioned in the region of interest. Advantageously, such pressure sensors are approximately 3 French in diameter, allowing multiple sensors to be threaded through the guiding catheter and positioned in the small arteries of the coronary arterial tree.

Abstract: A method and assembly for inserting a plurality of sensors into a biological fluid vessel for diagnosing the condition of the vessel or fluid. A pressure sensor is described which is particularly adapted for use with a steerable guidewire for selective positioning in the vessel. In one use, the method is used in coronary diagnosis, to determine the pressure gradient across a coronary valve or stenosis in the coronary arterial tree. In this method, a guiding catheter is percutaneously inserted with its distal end proximate the ostium. A guidewire is inserted through the guiding catheter and subselectively positioned in a region of interest in the coronary arterial tree. Multiple pressure sensors are then threaded down the guidewire and positioned in the region of interest. Advantageously, such pressure sensors are approximately 3 French in diameter, allowing multiple sensors to be threaded through the guiding catheter and positioned in the small arteries of the coronary arterial tree.

Abstract: A catheter fluid-velocity flow probe is disclosed which has greater sensitivity and which dissipates less heat during operation than flow probes heretofore constructed. These significant results are achieved by providing two electromagnets in the probe to generate two separate magnetic fields. Each electrode is positioned between the poles of an electromagnet in the region of highest magnetic flux density of each electromagnet. The electromagnets are reduced in size, and a tubing may be inserted in the central portion of the probe during construction. This tubing permits the attachment of additional measuring devices to the distal end of the probe to permit multiple measurements in a fluid to be made simultaneously.