Abstract: The invention is directed to a device for obtaining flow rate measurements including a sensor assembly and a housing. The sensor assembly includes a body defining a first fluid flow passage having an inlet, an outlet, a flow restricting element in the first fluid flow passage between the inlet and the outlet, an upstream fluid pressure sensor, a downstream fluid pressure sensor, an upstream signal contact connected to the upstream fluid pressure sensor, and a downstream signal contact connected to the downstream fluid pressure sensor. The housing has an upstream portion defining an upstream port, a downstream portion defining a downstream port, and a probe access port configured to provide access of a probe to at least one of the upstream signal contact and downstream signal contact. The housing can also define a second fluid flow passage in parallel with the first fluid flow passage. The device can be disposable.

Abstract: The invention is directed to a device for obtaining flow rate measurements including a sensor assembly and a housing. The sensor assembly includes a body defining a first fluid flow passage having an inlet, an outlet, a flow restricting element in the first fluid flow passage between the inlet and the outlet, an upstream fluid pressure sensor, a downstream fluid pressure sensor, an upstream signal contact connected to the upstream fluid pressure sensor, and a downstream signal contact connected to the downstream fluid pressure sensor. The housing has an upstream portion defining an upstream port, a downstream portion defining a downstream port, and a probe access port configured to provide access of a probe to at least one of the upstream signal contact and downstream signal contact. The housing can also define a second fluid flow passage in parallel with the first fluid flow passage. The device can be disposable.

Abstract: The invention is directed to a device for obtaining flow rate measurements including a sensor assembly and a housing. The sensor assembly includes a body defining a first fluid flow passage having an inlet, an outlet, a flow restricting element in the first fluid flow passage between the inlet and the outlet, an upstream fluid pressure sensor, a downstream fluid pressure sensor, an upstream signal contact connected to the upstream fluid pressure sensor, and a downstream signal contact connected to the downstream fluid pressure sensor. The housing has an upstream portion defining an upstream port, a downstream portion defining a downstream port, and a probe access port configured to provide access of a probe to at least one of the upstream signal contact and downstream signal contact. The housing can also define a second fluid flow passage in parallel with the first fluid flow passage. The device can be disposable.

Abstract: The invention is directed to a device for obtaining flow rate measurements including a sensor assembly and a housing. The sensor assembly includes a body defining a first fluid flow passage having an inlet, an outlet, a flow restricting element in the first fluid flow passage between the inlet and the outlet, an upstream fluid pressure sensor, a downstream fluid pressure sensor, an upstream signal contact connected to the upstream fluid pressure sensor, and a downstream signal contact connected to the downstream fluid pressure sensor. The housing has an upstream portion defining an upstream port, a downstream portion defining a downstream port, and a probe access port configured to provide access of a probe to at least one of the upstream signal contact and downstream signal contact. The housing can also define a second fluid flow passage in parallel with the first fluid flow passage. The device can be disposable.

Abstract: Apparatus and a method for monitoring a percentage of the oxygen saturation in the hemoglobin of blood flowing through a blood vessel. An optical sensor that detects the percentage oxygen saturation in blood is disposed proximate a proximal end of the catheter. A thermistor is disposed adjacent to the distal end of the catheter and it is employed to detect changes in blood temperature that indicate the position of the catheter's distal end in the blood vessel. Indicia or marks visible at intervals on the outer surface of the catheter enable a medical practitioner to determine the length of the catheter that has been introduced into the blood vessel. A strain relief that is flexible and resists stretching extends along the length of the catheter. For flushing the distal end of the catheter, a fluid supply may be connected to a lumen running through the catheter to provide the flushing fluid.

Abstract: A multi-lumen, multi-purpose cardiac catheter which incorporates optical filaments and an optical coupler for use with external apparatus for determining the oxygen concentration in the blood of a patient under critical care conditions, as well as incorporating therein a thermal element useable with a second external apparatus for measurement of continuous cardiac output. The thermal element is disposed at a necked down portion of the catheter at the distal end thereof, with at least one of the lumens of the catheter substantially compressed at the necked down portion thereof. The catheter also includes a thermistor and at least one injectate port for enabling the user to also conduct thermal dilution readings and obtain intermittent measurements of cardiac output. The combination of a thermal dilution catheter with a SVO.sub.

Abstract: A catheter oximeter includes a fiber optic catheter for supplying radiation to blood under test at a plurality of wavelengths and detecting the intensities of the radiation back-scattered from the blood at each of the wavelengths. The oxygen saturation level of the blood is then computed by deriving it with a formula which uses the ratio of one pair of intensity signals when the oxygen saturation level is relatively low and with a formula which uses the ratio of another pair of intensity signals when the oxygen saturation level relatively is high.

Abstract: An optical connector for connecting photometric analysis equipment which includes a transmitting and receiving light pipe to a material such as flowing blood wherein the blood is not contaminated by the light pipe. The connector has a flow passage therethrough for connection to the blood flow conduit and a light pipe receiving passage extending at a right angle thereto. At the intersection of the passages there is provided an image transferring window, and the light pipe is arranged to be snugly received in the pipe receiving passage in abutment with the window. The image transferring properties of the window are such that no optical distortion occurs as light is transmitted from one face to the opposite face thereof. This is accomplished by forming the window of a coherent bundle of optical fibers of very small individual diameters in the order of 0.003 inches or less.

Abstract: An optical scattering reference medium is formed of a plurality of scattering particles substantially uniformly dispersed in a substantially compliant, non-compressable transparent solid medium which is selectively positionable against the distal end of an optical catheter for use therewith within a sterilizable disposable package for performing repeatable photometric measurements to standardize the performance of the photometric measuring instrument.

Abstract: An improved catheter oximeter operates on radiation at three or more different wavelengths applied to and scattered back from blood under test to provide an indication of oxygen saturation and is considerably less sensitive to accuracy-degrading variations in the blood and its environment and in the oximeter measuring system.