Method for detecting presence of tubing in pump assembly
Methods for detecting tubing in a pump assembly of a pump system are provided. For example, a method comprises connecting a power supply to each of a plurality of pump motors of the pump system. Each pump motor of the plurality of pump motors has a power supply cable configured to connect to the power supply and drives a pump head of a plurality of pump heads of the pump system. The method also comprises sensing a motor current from each of the power supply cables, determining whether tubing is loaded in each pump head, and, if tubing is not loaded in a pump head, then disconnecting from the power supply the power supply cable of the pump motor associated with the pump head in which tubing is not loaded. Systems for detecting the presence of tubing within a pump head of a plurality of pump heads also are provided.
1. A method for detecting tubing in a pump assembly, the pump assembly comprising a motor that drives a pump head, the method comprising:
measuring a motor current from a power supply cable that electrically couples the motor of the pump assembly to a power supply as the pump assembly is operating;
generating a filtered motor current signal by passing the measured motor current through a digital filter;
generating a frequency domain representation of the filtered motor current signal;
determining whether the tubing is loaded into the pump head of the pump assembly based on the frequency domain representation of the filtered motor current signal; and
terminating power delivery to the motor if it is determined that the tubing is not loaded into the pump head.
2. The method of claim 1 , wherein the digital filter is a low-pass filter.
3. The method of claim 1 , wherein the digital filter is a Kalman filter.
4. The method of claim 1 , wherein generating the frequency domain representation of the filtered motor current signal comprises passing the filtered motor current signal through a fast Fourier Transform (FFT) engine.
5. The method of claim 1 , wherein determining whether the tubing is loaded into the pump head of the pump assembly identifying fundamental frequencies in the frequency domain representation of the filtered motor current signal.
6. The method of claim 5 , wherein it is determined that the tubing is not loaded into the pump head if only one fundamental frequency is identified.
7. The method of claim 5 , wherein it is determined that the tubing is loaded into the pump head if two fundamental frequencies are identified.
8. The method of claim 1 , further comprising calculating a speed of the motor if it is determined that the tubing is loaded into the pump head.
9. The method of claim 8 , wherein the speed of the motor is calculated as
f_L
R
×
6
0
,
where R is a number of roller in a rotor assembly of the pump head and f_L is a lower of at least two fundamental frequency identified in the frequency domain representation of the filtered motor current signal.
10. The method of claim 1 , wherein the pump assembly is a peristaltic pump assembly.
11. The method of claim 1 , wherein the pump assembly is configured to transfer cooling fluid to a medical probe assembly for cooled radiofrequency ablation.
12. A method for detecting tubing in a pump assembly, the pump assembly comprising a motor that drives a pump head, the method comprising:
measuring a motor current from a power supply cable that electrically couples the motor of the pump assembly to a power supply as the pump assembly is operating;
generating a filtered motor current signal by passing the measured motor current through a digital filter;
generating a frequency domain representation of the filtered motor current signal;
determining whether the tubing is loaded into the pump head of the pump assembly based on the frequency domain representation of the filtered motor current signal; and
calculating a speed of the motor if it is determined that the tubing is loaded into the pump head.
13. The method of claim 12 , wherein the digital filter is one of a low-pass filter or a Kalman filter.
14. The method of claim 12 , wherein generating the frequency domain representation of the filtered motor current signal comprises passing the filtered motor current signal through a fast Fourier Transform (FFT) engine.
15. The method of claim 12 , wherein determining whether the tubing is loaded into the pump head of the pump assembly identifying fundamental frequencies in the frequency domain representation of the filtered motor current signal.
16. The method of claim 15 , wherein it is determined that the tubing is not loaded into the pump head if only one fundamental frequency is identified.
17. The method of claim 15 , wherein it is determined that the tubing is loaded into the pump head if two fundamental frequencies are identified.
18. The method of claim 12 , wherein the pump assembly is a peristaltic pump assembly.
19. The method of claim 12 , wherein the pump assembly is configured to transfer cooling fluid to a medical probe assembly for cooled radiofrequency ablation.
20. A controller for a pump assembly, the pump assembly comprising a motor that drives a pump head, the controller configured to:
measure a motor current from a power supply cable that electrically couples the motor of the pump assembly to a power supply as the pump assembly is operating;
generate a filtered motor current signal by passing the measured motor current through a digital filter;
generate a frequency domain representation of the filtered motor current signal;
determine whether tubing is loaded into the pump head based on the frequency domain representation of the filtered motor current signal; and
either:
terminate power delivery to the motor if it is determined that the tubing is not loaded into the pump head; or
calculate a speed of the motor if it is determined that the tubing is loaded into the pump head.