Integrated capacitive flowmeter for infusion pump

A method for measuring a flow rate of an infusion pump, comprising:

• causing at least one hammer element of a pumping mechanism of an infusion pump to move according to a cam motion to periodically compress an flexible infusion line loaded in a pumping mechanism of the infusion pump, according to a cycle speed, to fill the flexible infusion line with a fluid from a fluid reservoir during a filling phase of the cam motion and to deliver the fluid downstream of the hammer element during a delivery phase of the cam motion;
• measuring, during the cam motion, a first capacitance between a conductive plate coupled to the hammer element and a conductor opposite the flexible infusion line when the flexible infusion line is loaded in the pumping mechanism, between the conductive plate and the conductor;
• determining, based on the measured first capacitance, a volume of the fluid within the flexible infusion line during the filling phase;
• determining a flow rate based on the determined volume and the cycle speed;
• and
• adjusting a speed of the infusion pump based on a difference between the determined flow rate and a programmed flow rate.

A non-transitory machine readable medium comprising instructions stored thereon that, when executed by a machine, causes the machine to perform a method, comprising:

• causing at least one hammer element of a pumping mechanism of an infusion pump to move according to a cam motion to periodically compress an flexible infusion line loaded in a pumping mechanism of the infusion pump, according to a cycle speed, to fill the flexible infusion line with a fluid from a fluid reservoir during a filling phase of the cam motion and to deliver the fluid downstream of the hammer element during a delivery phase of the cam motion;
• measuring, during the cam motion, a first capacitance between a conductive plate coupled to the hammer element and a conductor opposite the flexible infusion line when the flexible infusion line is loaded in the pumping mechanism, between the conductive plate and the conductor;
• determining, based on the measured first capacitance, a volume of the fluid within the flexible infusion line during the filling phase;
• determining a flow rate based on the determined volume and the cycle speed;
• and
• adjusting a speed of the infusion pump based on a difference between the determined flow rate and a programmed flow rate.