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: In a cosed-loop process, a controller uses a flow sensor to monitor the flow of a medicinal fluid being infused into a patient, to achieve a desired rate of flow. A relatively inexpensive peristaltic pump or electronically controlled valve can be used to vary the flow of the medicinal fluid through a fluid line. A Y site within the fluid line includes an integral flow sensor having an orifice. The flow sensor includes proximal and distal pressure sensors disposed on opposite sides of the orifice to monitor the distal and proximal pressure, producing a signal indicative of the rate of flow of the medicinal fluid through the fluid line. A signal produced by the controller is input to a motor driving the pump or to the valve to vary the rate of flow as required to achieve the desired infusion rate of the medicinal fluid.

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: In a closed-loop process, a controller uses a flow sensor to monitor the flow of a medicinal fluid being infused into a patient, to achieve a desired rate of flow. A relatively inexpensive peristaltic pump or electronically controlled valve can be used to vary the flow of the medicinal fluid through a fluid line. A Y site within the fluid line includes an integral flow sensor having an orifice. The flow sensor includes proximal and distal pressure sensors disposed on opposite sides of the orifice to monitor the distal and proximal pressure, producing a signal indicative of the rate of flow of the medicinal fluid through the fluid line. A signal produced by the controller is input to a motor driving the pump or to the valve to vary the rate of flow as required to achieve the desired infusion rate of the medicinal fluid.

Abstract: In a closed-loop process, a controller uses a flow sensor to monitor the flow of a medicinal fluid being infused into a patient, to achieve a desired rate of flow. A relatively inexpensive peristaltic pump or electronically controlled valve can be used to vary the flow of the medicinal fluid through a fluid line. A Y site within the fluid line includes an integral flow sensor having an orifice. The flow sensor includes proximal and distal pressure sensors disposed on opposite sides of the orifice to monitor the distal and proximal pressure, producing a signal indicative of the rate of flow of the medicinal fluid through the fluid line. A signal produced by the controller is input to a motor driving the pump or to the valve to vary the rate of flow as required to achieve the desired infusion rate of the medicinal fluid.

Abstract: An electronic circuit and a method for accurately measuring intermittent current pulses supplied by a storage battery to energize a load. In the preferred embodiment, an analog integrator accumulates current pulses in response to a voltage drop across a sense resistor that is connected in series between the storage battery and the load. The voltage drop is proportional to the flow of current from the battery through the load. The output of the integrator is filtered with a low pass filter to block high frequency noise, and the output of the filter is coupled to an analog to digital (A/D) converter that transforms the filtered analog signal into a corresponding digital signal. The output of the A/D converter is supplied to a port of a processor. The processor provides a signal to actuate a reset switch coupled across the integrator. When closed at the end of each integration time period, this switch zeroes the output of the analog integrator.