An infusion device includes a pump for pumping a medical fluid from a fluid container through a delivery line towards a patient at a flow rate, a sensor for measuring a force on the pump or the delivery line, and a processor device configured to derive, from the force measured by the sensor, a pressure value indicative of the pressure in the delivery line and to compare the pressure value to a threshold value for determining whether an occlusion in the delivery line is present. A storage device stores a compliance value associated with the pump and/or the delivery line, and the processor device is configured to compute, from the stored compliance value, the flow rate and the threshold value, an estimate of a duration between the time of an occurrence of an occlusion and the time at which the pressure value exceeds the threshold value.

A method and a system are provided for detecting a condition indicative of a dislodged needle in a hemodialysis procedure. A venous return pressure for a patient undergoing dialysis is measured. The venous return pressure is analyzed via a controller, and an intravascular blood pressure in proximity to a location of needle insertion into the patient is derived. A lower limit is calculated as a function of the intravascular blood pressure via the controller. An average of the venous return pressure is calculated via the controller during a predetermined time window. The average is compared to the lower limit via the controller, and if the average is within a specified range of the lower limit, the controller determines that a condition indicative of a dislodged needle is present.

A system and method is provided for detecting fluid low-volume and occlusion in a device using force sensing resistor (FSR) sensor. One or more force sensing resistors are positioned in communication with a fluid channel at one or more of a pump intake and pump outlet to detect pressure in the fluid channel. The pressure is detected through communication with the force sensing resistor and indicates an irregular system condition including but not limited to, fluid low-volume level and occlusion. Also provided are a fluid flow sensor (e.g., FSR or MEMS sensor) disposed relative to an embedded fluid channel in the base of a wearable medicine delivery pump.

A method of predicting peak pressure within a fluid path, which includes a tubing set and a catheter into which at least one fluid is introduced under pressure by a pressurizing system of a fluid injection apparatus, includes (a) inputting an initial injection protocol into the fluid injection apparatus according to which the at least one fluid is intended to be introduced into the fluid path; (b) predicting an expected peak pressure level that would result in the fluid path if the initial injection protocol were to be used as intended to introduce the at least one fluid into the fluid path. The expected peak pressure level is determined before commencement of the initial injection protocol according to at least one model on the basis of a flow rate of the at least one fluid, at least one catheter characteristic, and a viscosity of the at least one fluid. The at least one model is determined experimentally for a plurality of fluids of different viscosities, for a plurality of catheters of different catheter characteristics, and for at least one tubing set of like kind to the tubing set of the fluid path.

The systems, methods and articles described herein are directed to at least one pressure sensor along a downstream fluid line which senses fluid pressure and assists an occlusion detection feature in determining the presence of occlusions in the downstream fluid line. In addition, the system can dynamically adapt the occlusion detection feature based on a delivery of fluid, such as a bolus, in order to prevent the system from creating a false alarm regarding an occlusion of the downstream fluid line.

A system includes a drip chamber. The drip chamber has a proximal end coupled with a drug container and a distal end coupled with fluidic tubing. The drip chamber has a proximal check valve configured to prevent fluid flow in a proximal direction and to allow fluid flow in a distal direction when a cracking pressure threshold is overcome. The drip chamber also includes a distal check valve configured to prevent fluid flow in the proximal direction and to allow fluid flow in the distal direction when a cracking pressure threshold is overcome. The cracking pressure threshold of the proximal check valve and the cracking pressure threshold of the distal check valve in combination is greater than or equal to 1 PSId. The system also includes a pneumatic port between the check valves that is configured to pneumatically couple with a pneumatic feedback control system.

A method of predicting peak pressure within a fluid path, which includes a tubing set and a catheter into which at least one fluid is introduced under pressure by a pressurizing system of a fluid injection apparatus, includes (a) inputting an initial injection protocol into the fluid injection apparatus according to which the at least one fluid is intended to be introduced into the fluid path; (b) predicting an expected peak pressure level that would result in the fluid path if the initial injection protocol were to be used as intended to introduce the at least one fluid into the fluid path. The expected peak pressure level is determined before commencement of the initial injection protocol according to at least one model on the basis of a flow rate of the at least one fluid, at least one catheter characteristic, and a viscosity of the at least one fluid. The at least one model is determined experimentally for a plurality of fluids of different viscosities, for a plurality of catheters of different catheter characteristics, and for at least one tubing set of like kind to the tubing set of the fluid path.

A system and method is provided for detecting fluid low-volume and occlusion in a device using force sensing resistor (FSR) sensor. One or more force sensing resistors are positioned in communication with a fluid channel at one or more of a pump intake and pump outlet to detect pressure in the fluid channel. The pressure is detected through communication with the force sensing resistor and indicates an irregular system condition including but not limited to, fluid low-volume level and occlusion. Also provided are a fluid flow sensor (e.g., FSR or MEMS sensor) disposed relative to an embedded fluid channel in the base of a wearable medicine delivery pump.

Capillary-based pressure threshold sensors are provided for liquids that exploit the properties of hydrophobic, superhydrophobic, oleophobic and amphiphobic porous membranes to detect when fluid passes through the membrane in the event of the pressure across the membrane rising above the breakthrough pressure of a fluid. Example implementations are provided of different configurations for a capillary-based pressure threshold sensor, and of how a capillary-based pressure threshold sensor is used in a medication delivery device or other fluid delivery devices to detect occlusion or other fluid flow condition.

In a chemical liquid injection conduit, there is a need to prevent a backflow of body fluid of a subject reaching the inside of a common conduit portion. This is solved by the chemical liquid injecting apparatus that includes: a common conduit portion that flows a chemical liquid from a chemical liquid injector to a replaceable conduit portion; a control device that controls the chemical liquid injector; and a flow blocking unit that is arranged inside the replaceable conduit or in a conduit of a boundary portion between the replaceable conduit and the common conduit portion, and by receiving a command from the control device, is switchable between an open state allowing a flow of the chemical liquid and a closed state blocking a flow of the chemical liquid.