초록 ▼

A thermal flow meter for use in dialysis is described, that uses a thermal wave to generate a signal in the fluid for which the flow rate is to be measured. The phase angle of the thermal wave signal changes when traversing downstream. The phase difference between the signals received downstream, co

A thermal flow meter for use in dialysis is described, that uses a thermal wave to generate a signal in the fluid for which the flow rate is to be measured. The phase angle of the thermal wave signal changes when traversing downstream. The phase difference between the signals received downstream, compared with a reference excitation source signal is measured, and used to determine the flow rate of the fluid.

대표청구항 ▼

We claim: 1. A flow rate sensor for sensing the flow rate of a fluid passing through a channel of a disposable manifold that is installed in a dialysis machine, comprising:a. An excitation probe having a body and a contact surface, wherein said excitation probe is integrated within said disposable m

We claim: 1. A flow rate sensor for sensing the flow rate of a fluid passing through a channel of a disposable manifold that is installed in a dialysis machine, comprising:a. An excitation probe having a body and a contact surface, wherein said excitation probe is integrated within said disposable manifold and physically positioned within said channel and the excitation probe generates a thermal wave within said fluid in response to a first electrical signal;b. A receiver probe having a body and a contact surface, wherein said receiver probe is integrated within said disposable manifold and physically positioned within said channel and wherein said receiver probe senses a thermal wave within said fluid;c. A reference signal generator, wherein said reference signal generator outputs a reference signal;d. A heat source in said dialysis machine, wherein said heat source receives said reference signal from said reference signal generator, comprises a contact surface that is on a surface of a portion of said dialysis machine and is configured to electrically engage with said excitation probe only when said portion of said dialysis machine is placed in physical contact with said disposable manifold, and generates said first electrical signal, having a frequency derived from said reference signal;e. A temperature sensor in said dialysis machine, wherein said temperature sensor comprises a contact surface that is on the surface of the portion of said dialysis machine and is configured to thermally engage with said receiver probe only when said portion of said dialysis machine is placed in physical contact with said disposable manifold, and generates a second electrical signal, having a frequency derived from said thermal wave;f. A multiplier for receiving an input signal from said reference signal generator, for receiving said second electrical signal and for outputting a third signal; andg. A filter for receiving a fourth signal, wherein said fourth signal is a function of the third signal, and for receiving an input signal from said reference signal generator, wherein said low pass filter modulates its cutoff frequency based upon the input signal from said reference signal generator.