Fluid delivery system and sensing unit therefor

An infusion system comprising a fluid source and an inline sensing unit, the sensing unit comprising:

• a housing comprising an inlet for receiving a fluid from the fluid source, an outlet for discharging the fluid from the housing, and at least one cavity between the inlet and the outlet;
• a sensing element mounted within the at least one cavity of the housing, the sensing element comprising:
• a freestanding tube portion through which the fluid flows;
• means for vibrating the freestanding tube portion at a resonant frequency thereof that varies with the density of the fluid flowing therethrough, the Coriolis effect causing the freestanding tube portion to twist to a degree that varies with the mass flow rate of the fluid flowing therethrough while the freestanding tube portion is vibrated at resonance;
• and
• means for sensing movement of the freestanding tube portion to sense the resonant frequency and the degree of twist of the freestanding tube portion as the fluid flows therethrough;
• electronic circuitry within the at least one cavity of the housing, the electronic circuitry producing an electrical output based on the density and the mass flow rate of the fluid flowing through the sensing element, the electrical output comprising at least one of specific gravity, dose, dose rate, and volume of the fluid delivered through the sensing element;
• means for providing communication between the electronic circuitry and an electronic device remote from the housing;
• means disposed within the housing for stopping flow of the fluid through the housing in response to the electrical output of the electronic circuitry;
• and means on the housing for displaying a visual output based on the electrical output of the electronic circuitry.

An infusion system comprising:

• an intravenous pole;
• an intravenous tube hanging alongside the intravenous pole;
• an inline sensing unit coupled to the intravenous tube and comprising a housing, an inlet for receiving a fluid from the intravenous tube, an outlet for discharging the fluid from the housing, at least one cavity between the inlet and the outlet, and a sensing element mounted within the at least one cavity, the sensing element having a first response to the density of the fluid flowing between the inlet and the outlet of the housing, the sensing element having a second response to the mass flow rate of the fluid flowing between the inlet and the outlet of the housing;
• a module attached to the intravenous pole, the module comprising electronic circuitry that produces an electrical output based on at least one of the first and second responses of the sensing element, means for displaying a visual output based on the electrical output of the electronic circuitry, and means for producing an audible output based on the electrical output of the electronic circuitry;
• means for providing communication between the sensing unit and the module;
• means in communication with the module for stopping flow of the fluid through the intravenous tube in response to the electrical output of the electronic circuitry;
• and a computer remote from the module and coupled to the module for communication therewith.