Infusion Pump Plunger Valve Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Infusion pumps face issues with unwanted suction of a patient's blood due to the ascending of the pump's downstream valve and undesired bolus delivery due to the descending of the downstream valve.
Innovation Solution
The infusion pump includes a controller that synchronizes the movement of the plunger with the ascending and descending of the downstream valve, compensating for the flow caused by the valve's movement to prevent backflow and bolus delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the downstream valve ascends to allow fluid flow, then fluid delivery is enabled, but blood backflow occurs due to suction caused by valve movement
Solution Approach 1:
The plunger performs a preliminary downward movement before the downstream valve ascends, creating a volume compensation that prevents the suction effect. This preliminary action ensures that when the valve opens, there is no negative pressure gradient to cause blood backflow, while still enabling fluid delivery when needed.
Solution Approach 2:
The system applies a counteracting force through the plunger's downward movement that opposes the suction effect generated by the valve's upward movement. This preliminary anti-action neutralizes the harmful suction effect before it can cause blood backflow, while maintaining the ability to deliver fluid when the valve opens.
2Reliability
If the downstream valve descends to inhibit fluid flow, then bolus delivery is prevented, but undesired bolus flow occurs due to valve movement
Solution Approach 1:
The plunger performs a preliminary upward movement before the downstream valve descends, creating a volume compensation that prevents the bolus effect. This preliminary action ensures that when the valve closes, there is no positive pressure gradient to cause undesired bolus delivery, while maintaining reliable flow control.
Solution Approach 2:
The system applies a counteracting force through the plunger's upward movement that opposes the bolus effect generated by the valve's downward movement. This preliminary anti-action neutralizes the harmful bolus effect before it can occur, while maintaining reliable flow control during infusion.
3Ease of operation
If the plunger moves independently of valve movement, then simple control is maintained, but flow rate accuracy deteriorates due to uncompensated valve-induced flow variations
Solution Approach 1:
The control of the plunger and downstream valve is merged into a coordinated system where the plunger's movement is synchronized with the valve's movement. This combination ensures that the plunger compensates for valve-induced flow variations, maintaining accurate flow rate control while keeping the overall control mechanism integrated and relatively simple.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution ensures a consistent and controlled flow rate of infusion fluid, minimizing spikes and backflow, thereby improving the accuracy and reliability of fluid delivery to the patient.
Implementation Method 1
a plunger configured to squeeze a section of an infusion tube
Implementation Method 2
a distal valve located distally to said plunger, said distal valve configured to: ascend and thereby allow infusion fluid flow past the distal valve, and descend and thereby inhibit infusion fluid flow past the distal valve
Implementation Method 3
a controller configured to control said plunger, said proximal valve, and said distal valve and thereby, to control infusion fluid intake from the reservoir and infusion fluid delivery to a subject, wherein controlling delivery of infusion fluid to the subject includes initiating descending of said plunger concurrently with or prior to the ascending of said distal valve, such that the descending of said plunger compensates for suction produced by the ascending of said distal valve
Data Source
AI summary
An infusion pump (100) includes a plunger (110) configured to squeeze a section of an infusion tube (150). A proximal valve (120), proximal to the plunger, ascends to allow infusion fluid intake from a reservoir to the infusion tube and descends to inhibit infusion fluid intake from the reservoir to the infusion tube. A distal valve (125), distal to the plunger, ascends to allow infusion fluid flow past the distal valve, and descends to inhibit infusion fluid flow past the distal valve. A controller (141) controls the plunger, proximal valve, and distal valve by initiating descending of the plunger concurrently with or prior to the ascending of the distal valve, such that the descending of the plunger compensates for suction produced by the ascending of the distal valve, thereby reducing backflow of fluid from the subject. Other applications are also described.