초록 ▼

Flow parameters in a fluid delivery assembly are determined by monitoring pressure responses and processing those responses along with information regarding the fluid flow. In one aspect, a processor controls the pump to pump flow quantities in accordance with a pseudorandom code. Portions of the re

Flow parameters in a fluid delivery assembly are determined by monitoring pressure responses and processing those responses along with information regarding the fluid flow. In one aspect, a processor controls the pump to pump flow quantities in accordance with a pseudorandom code. Portions of the resulting pressure signal sensed at the conduit is averaged, and the averaged values are then decoded in accordance with the pseudorandom code. An estimate of the equilibrium pressure is generated from the decoded average pressure values, while a summation of the pressure samples is generated from the undecoded pressure signals. The resistance to fluid flow of the system is determined from the estimated equilibrium pressure and pressure summation. For low flow rates, a processor controls the pump to pump fluid in a series of fluid boluses, with each fluid bolus delivered in the beginning of a separate timeslot. The equilibrium pressure is measured at the end of each timeslot, and a summation of the pressure samples is generated from the pressure signals. For high flow rates, the pump is controlled to vary the flow rate and the change in pressure is divided by the change in flow to directly determine the resistance. A resistance display continuously displays the resistance of the system. The pseudorandom coding and decoding can be used to filter out pressure-response crosstalk caused by multiple fluid infusion segments feeding into a common line.

대표청구항 ▼

1. A method for monitoring a flow parameter in a fluid delivery system in which a flow control device acts on a fluid conduit to control the flow of fluid through the conduit, the method comprising the steps of:outputting a pseudorandom code; controlling the flow control device to act on the fluid c

1. A method for monitoring a flow parameter in a fluid delivery system in which a flow control device acts on a fluid conduit to control the flow of fluid through the conduit, the method comprising the steps of:outputting a pseudorandom code; controlling the flow control device to act on the fluid conduit to cause a pattern of flow variation in the conduit in accordance with the pseudorandom code; monitoring pressure of the fluid in the conduit and generating pressure signals representing said monitored pressure; determining average pressure values for at least some of the pressure signals; decoding the average pressure values in accordance with the pseudorandom code; and processing the decoded average pressure values to determine the flow parameter.