Fluid delivery system and flow control therefor

A method of detecting a blockage in a medical fluid delivery system arranged for delivering a medical fluid to a delivery point associated with a patient at a desired flow rate, the method comprising:

• operatively connecting a reservoir to a delivery mechanism, said reservoir containing the medical fluid to be delivered to the delivery point;
• operatively connecting the delivery mechanism to an administration tube, said administration tube being in fluid communication with the delivery point, said delivery mechanism receiving the medical fluid from the reservoir and supplying the medical fluid to the delivery point via the administration tube at an output flow rate;
• sensing the output flow rate of the medical fluid in the administration tube;
• determining if the sensed output flow rate is indicative of a blockage in the administration tube;
• and
• providing an alarm signal if it is determined that the sensed output flow rate indicates that the administration tube is blocked.

A system for delivering a fluid from a reservoir to a delivery point, said system comprising:

• a delivery channel between the reservoir and the delivery point through which the fluid is delivered to the delivery point;
• a pump associated with the delivery channel for operatively delivering the fluid to the delivery point at an adjustable output rate according to a desired flow rate;
• a flow sensor located along the delivery channel for sensing a flow of the fluid in the delivery channel and for generating a flow rate signal indicative of a rate of flow of the fluid in the delivery channel, said flow sensor comprising a positive displacement flow sensor;
• and
• a controller for generating a pump control signal as a function of the flow rate signal to control the pump, said controller causing adjustments to the output rate of the pump in response to the pump control signal whereby the desired flow rate is substantially achieved.

An infusion system for delivering fluid from a reservoir to a delivery point associated with a patient, said system comprising:

• a disposable administration set comprising:
• a delivery channel between the reservoir and the delivery point through which the fluid is delivered to the patient;
• a pump located along the delivery channel for operatively delivering the fluid to the delivery point at an adjustable output rate according to a desired flow rate;
• and;
• a positive displacement flow sensor located along the delivery channel for sensing a flow of the fluid in the delivery channel and for generating a flow rate signal indicative of a rate of flow of the fluid in the delivery channel;
• and
• a reusable control unit configured to receive the disposable administration set comprising a controller for generating a pump control signal as a function of the flow rate signal to control the pump, said controller causing adjustments to the output rate of the pump in response to the pump control signal whereby the desired flow rate is substantially achieved.