A method of operating an infusion pump includes transmitting light through or around a drop of fluid suspended from an end of a drip tube for the infusion pump, the end of the drip tube located in a drip chamber for the infusion pump, wherein the drip tube is configured for connection to a source of the fluid; receiving, using an optical system for the pump, light transmitted through or around the drop; transmitting, to a specially programmed microprocessor and using the optical system, data regarding the received light; and, using the microprocessor to calculate a volume of the drop using the data.

A method of adjusting a pressure distribution within an administration set to minimize an inadvertent delivery of a large bolus of infusate upon a sudden release of the occlusion, while ensuring that a maximum safe pressure limitation of the administration set is not exceeded.

A portable system and method for infusing liquid medicaments to a patient through an elastomeric fluid channel includes an airtight pressure shell for holding a collapsible bag of the fluid medicament to be infused. A pressure sensor connected to the pressure shell monitors decreases below ambient pressure inside the shell to determine when the sub-ambient pressure becomes insufficient to continue assisting the withdrawal of fluid from the collapsible bag to an external pinch/squeeze unit. An equilibration valve is synchronized with the pinch/squeeze unit to reestablish ambient pressure in the pressure shell for continued operation as the pinch/squeeze unit acts to sequentially push liquid medicament for infusion into the patient.

An apparatus, method, and system for detecting a leaking occluder valve is disclosed. Upper and lower occluder elements of an infusion pump are activated to compress a fluid tubing filled with a fluid to isolate the fluid in an upstream portion of the tubing from a downstream portion of the tubing. While the fluid tubing is compressed by the occluder elements, a pumping element of the infusion pump is activated to compress an intermediate portion of the tubing, between the downstream portion and the upstream portion, to cause a pressure increase within the fluid tubing. Using at least one pressure sensor, a determination is made as to whether the pressure increase is present in a portion of the fluid tubing on a side, of an activated occluder element, opposite the intermediate portion of the tubing.

A system for delivering a medicinal fluid to a patient includes a variable volume pressure delivery chamber, a variable volume medication chamber, an optional medication reservoir, a movable delivery element, a fixed reference volume chamber, a pressure source, and a control sub-system. The variable volume pressure delivery chamber is configured to store pressure controllably. The variable volume medication chamber is fluidically isolated from the pressure delivery chamber and is configured to store medicinal fluid. The movable delivery element is disposed between the medication chamber and the pressure delivery chamber. The pressure source is coupled to the pressure delivery chamber. The control system is configured to selectively cause the pressure source to deliver pressure to the pressure delivery chamber causing the movable delivery element to apply pressure to the medicinal fluid in the medication chamber thereby causing the medicinal fluid to exit the medication chamber at an outlet along the fluid communication path to the patient.

In some embodiments, a self-monitoring intravenous catheter system is provided. An alarm controller is provided that receives signals representing a pH value, an oxygen saturation value, and a pressure value in proximity to the distal end of the catheter. By performing a fuzzy logic analysis of the values, the alarm controller is able to detect that the catheter is about to fail or has failed, and can cause alerts to be presented. In some embodiments, an intravenous catheter is provided that has a pH sensor and an oximeter disposed at a distal end of the catheter to obtain the pH value and oxygen saturation values analyzed by the alarm controller. Embodiments of the catheter and self-monitoring intravenous catheter system may be particularly useful in treating neonates, who are sensitive to catheter failure and are not capable of detecting the signs of failure themselves.

A dialysis machine (e.g., a peritoneal dialysis (PD) machine) can include a pressure sensor mounted at a proximal end of a patient line made of a distensible material that provides PD solution to a patient through a catheter. During treatment, an occlusion can occur at different locations in the patient line and/or the catheter. When an incremental volume of additional solution is provided to the patient line while the occlusion is present, a change in pressure results. The change in pressure depends on dimensions and a distensibility of a non-occluded portion of the patient line. If the change in pressure, the incremental volume, properties related to the distensibility of the patient line, and some of the dimensions of the patient line are known, a location of the occlusion can be inferred. An occlusion type can be inferred based on the location of the occlusion.

An occlusion detection device detects an occlusion of a flexible fluid path on either of upstream and downstream sides of a pump mechanism, the pump mechanism transporting a liquid through the fluid path by elastically deforming the fluid path. The occlusion detection device is provided with: an occlusion sensor that is disposed on the downstream side of the pump mechanism and detects an internal pressure of the fluid path during a liquid transporting operation of the pump mechanism; and a data processing circuit that analyzes on which side of the upstream and downstream sides of the pump mechanism the occlusion of the fluid path occurs, based on a change of the internal pressure of the fluid path detected by the occlusion sensor and outputs an analysis result.

A pump for pumping fluid includes a tube platen, a plunger, a bias member, inlet and outlet valves, an actuator mechanism, a position sensor, and a processor. The plunger is configured for actuation toward and away from the infusion-tube when the tube platen is disposed opposite to the plunger. The tube platen can hold an intravenous infusion tube. The bias member is configured to urge the plunger toward the tube platen.

A pump for pumping fluid includes a tube platen, a plunger, a bias member, inlet and outlet valves, an actuator mechanism, a position sensor, and a processor. The plunger is configured for actuation toward and away from the infusion-tube when the tube platen is disposed opposite to the plunger. The tube platen can hold an intravenous infusion tube. The bias member is configured to urge the plunger toward the tube platen.