System, method, and computer program for occlusion detection and improved pressure limiting behavior for fluid injector devices
A system, method, and computer program product are disclosed for occlusion detection and/or pressure limiting in a fluid injector system. A fluid injector system may include at least one fluid injector device, one or more drive components, and a control device. The control device may comprise at least one processor programmed or configured to: provide instructions to the fluid injector system to deliver fluid from the at least one fluid injector device at a predetermined fluid flow rate, determine a first fluid pressure measurement within the at least one fluid injector device at a first time, determine a second fluid pressure measurement within the at least one fluid injector at a second time, determine a pressure differential between the first fluid pressure measurement and the second fluid pressure measurement, calculate a change in compliance volume of the at least one fluid injector device based on the determined pressure differential, compare the calculated change in compliance volume with the predetermined fluid flow rate, repeat the steps throughout the fluid injection procedure, and determine whether an occlusion or a partial occlusion has occurred downstream of the at least one fluid injector device.
1 . A fluid injector system configured for use in administering at least one fluid in a fluid injection procedure, the fluid injector system comprising:
at least one fluid injector device having at least one piston to administer the at least one fluid;
one or more drive components; and
a control device comprising at least one processor programmed or configured to:
provide instructions to the fluid injector system to deliver the at least one fluid from the at least one fluid injector device at a predetermined fluid flow rate,
determine a first fluid pressure measurement within the at least one fluid injector device at a first time,
determine a second fluid pressure measurement within the at least one fluid injector at a second time,
determine a pressure differential between the first fluid pressure measurement and the second fluid pressure measurement,
calculate a change in compliance volume of the at least one fluid injector device based on the pressure differential,
compare the calculated change in compliance volume with the predetermined fluid flow rate;
repeat the steps throughout the fluid injection procedure, and
determine whether an occlusion or a partial occlusion has occurred downstream of the at least one fluid injector device if the calculated change in compliance volume is equal to or greater than a predetermined threshold of a volumetric component of the predetermined fluid flow rate; and
if the occlusion or the partial occlusion is determined to have occurred, the at least one processor is programmed or configured to reduce or stop a delivery rate of the at least one piston of the at least one fluid injector device.
2 . The fluid injector system of claim 1 , wherein the calculated change in compliance volume is compared with the predetermined fluid flow rate to determine a calculated true fluid flow rate measurement.
3 . The fluid injector system of claim 2 , wherein if the calculated true fluid flow rate is less than or equal to a predetermined percentage of the predetermined fluid flow rate, it is determined that an occlusion has occurred downstream of the at least one fluid injector device.
4 . The fluid injector system of claim 1 , wherein if the calculated change in compliance volume is within or approaching the predetermined threshold of the volumetric component of the predetermined fluid flow rate, it is determined that an at least partial occlusion may have occured or has occurred downstream of the at least one fluid injector device.
5 . The fluid injector system of claim 4 , wherein the at least one processor is programmed or configured to reduce a delivery rate of the at least one piston of the at least one fluid injector device if the change in calculated compliance volume is within or approaching the predetermined threshold of the volumetric component of the predetermined fluid flow rate.
6 . The fluid injector system of claim 1 , wherein the at least one processor is programmed or configured to determine when a pre-programmed pressure limit of the at least one fluid injector device has been reached, and
wherein the at least one processor is programmed or configured to subtract the calculated change in compliance volume from a volumetric component of the delivery rate of the at least one piston of the at least one fluid injector device to determine a calculated true fluid flow rate out of the at least one fluid injector device.
7 . The fluid injector system of claim 6 , wherein the at least one processor is programmed or configured to adjust the delivery rate of the at least one piston of the at least one fluid injector device so the calculated true fluid flow rate is substantially the same as the predetermined fluid flow rate.
8 . A computer-implemented method of at least partial occlusion detection and pressure limiting for a fluid injector system configured for use in administering at least one fluid in a fluid injection procedure, the method comprising:
providing, with a control device comprising at least one processor, instructions to the fluid injector system having at least one piston to administer the at least one fluid to deliver the at least one fluid from at least one fluid injector device at a predetermined fluid flow rate;
determining a first fluid pressure measurement within the at least one fluid injector device at a first time;
determining a second fluid pressure measurement within the at least one fluid injector device at a second time;
determining, with the control device, a pressure differential between the first fluid pressure measurement and the second fluid pressure measurement;
calculating, with the control device, a change in compliance volume of the at least one fluid injector device based on the pressure differential;
comparing, with the control device, the calculated change in compliance volume with the predetermined fluid flow rate;
repeating the method steps throughout the fluid injection procedure; and
determining whether an occlusion or a partial occlusion has occurred downstream of the at least one fluid injector device if the calculated change in compliance volume is equal to or greater than a predetermined threshold of a volumetric component of the predetermined fluid flow rate; and
if the occlusion or the partial occlusion is determined to have occurred, the at least one processor is programmed or configured to reduce or stop a delivery rate of the at least one piston of the at least one fluid injector device.
9 . The computer-implemented method of claim 8 , further comprising comparing the calculated change in compliance volume with the predetermined fluid flow rate to determine a calculated true fluid flow rate measurement.
10 . The computer-implemented method of claim 9 , further comprising determining, with the control device, that an occlusion has occurred if the calculated true fluid flow rate is less than or equal to a predetermined percentage of the predetermined fluid flow rate.
11 . The computer-implemented method of claim 8 , further comprising determining if the at least partial occlusion has occurred and reducing, with the control device, a delivery rate of the at least one piston of the at least one fluid injector device if the calculated change in compliance volume is within or approaching the predetermined threshold of the volumetric component of the predetermined fluid flow rate.
12 . The computer-implemented method of claim 8 , further comprising determining, with the control device, when a pre-programmed pressure limit of the at least one fluid injector device has been reached, and
wherein the first time at which the first fluid pressure measurement is determined is a time before the pre-programmed pressure limit is reached, and wherein the second time at which the second fluid pressure measurement is determined is a time at which or after the pre-programmed pressure limit is reached.
13 . The computer-implemented method of claim 8 , further comprising subtracting, with the control device, the calculated change in compliance volume from a volumetric component of the delivery rate of the at least one piston of the at least one fluid injector device to determine a calculated true fluid flow rate out of the at least one fluid injector device.
14 . The computer-implemented method of claim 13 , further comprising adjusting, with the control device, a delivery rate of the at least one piston of the at least one fluid injector device so the calculated true fluid flow rate is substantially the same as the predetermined fluid flow rate.