Patent ID: 9642966
Date: 2017-05-09
CPC Classifications: A61M,G01F

Claim:
1. A method of determining a flow rate in an intravenous fluid delivery system, the method comprising: emitting an input thermal signal into a source location of a fluid delivery channel at an emitting instant, wherein the fluid delivery channel forms a segment of the intravenous infusion system; receiving a first output thermal signal from a first sensor location of the fluid delivery channel at a first receiving instant, the first sensor location being positioned with a first interval downstream from the source location, wherein the input thermal signal, the first output thermal signal, the emitting instant, the first receiving instant and the first interval define a first measured thermal profile, and matching the first measured thermal profile with a reference thermal profile provided in a matrix, wherein the flow rate is determined based on an algorithm that selects a closest resemblance between the first measured thermal profile and the reference thermal profile; wherein the first measured thermal profile includes at least one of a peak temperature amplitude, a first time period to reach the peak temperature amplitude, a second time period for a leading edge to reach a predetermined level of the peak temperature amplitude, and a third time period for a trailing edge to reach the predetermined level of the peak temperature amplitude; wherein matching the first measured thermal profile with a reference thermal profile comprising: locating in the matrix a first minimum upper time limit and a first maximum lower time limit within which the first time period fits; locating in the matrix an upper temperature value corresponding to the first minimum upper time limit and a lower temperature value corresponding to the first maximum lower time limit; locating in the matrix a second upper time limit corresponding to the first minimum upper time limit and a second lower time limit corresponding to the first maximum lower time limit; locating in the matrix a third upper time limit corresponding to the first minimum upper time limit and a third lower time limit corresponding to the first maximum lower time limit; deriving an upper total deviation based on a sum of a first upper time deviation, an upper temperature deviation, a second upper time deviation and a third upper time deviation, deriving a lower total deviation based on a sum of a first, lower time deviation, a lower temperature deviation, a second lower time deviation and a third lower time deviation, wherein the reference thermal profile is one corresponding to the lesser of the upper total deviation and the lower total deviation.