Split Piston Micropump With Axial Sealing for Compact Drug Dosing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing micropumps for subcutaneous drug delivery are complex and not cost-effective, with limited design flexibility due to rigid reservoirs and actuator precision dependencies, making them unsuitable for compact and economical designs.
Innovation Solution
A micropump design featuring a flexible reservoir, a motor, gear, drive rack, and tubular pump housing with axially oriented drive and floating pistons, where the motor engages the gear to translate the drive piston relative to the floating piston, creating a pump volume space for precise fluid delivery through apertures, allowing for compact and economical operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a rigid reservoir with lead screw is used for medication delivery, then dosing precision can be maintained, but the device complexity increases and design flexibility is limited
Solution Approach 1:
The patent extracts the lead screw mechanism from the reservoir and replaces it with a simpler piston-cylinder arrangement. The dosing precision function is maintained through the piston's controlled movement within the reservoir, eliminating the complex lead screw while preserving measurement accuracy.
Solution Approach 2:
The patent employs a disposable reservoir design where the reservoir itself becomes a single-use component. This eliminates the need for complex reusable mechanisms like lead screws, as the entire reservoir can be discarded after use, reducing overall device complexity while maintaining dosing precision during its service life.
2Measurement precision
If a rigid reservoir is used to provide calibrated dosages, then dosing accuracy is maintained, but the number of possible layouts for the pump is limited
Solution Approach 1:
The patent transitions from a rigid reservoir to a flexible reservoir that can be compressed by the piston. This dynamic design allows the reservoir to adapt to different spatial configurations and pump layouts, improving versatility while maintaining dosing accuracy through controlled piston movement.
Solution Approach 2:
The patent uses a flexible reservoir construction that can deform under piston pressure. This flexibility enables various pump layouts and orientations without compromising dosing accuracy, as the flexible material maintains the sealed chamber necessary for precise fluid displacement.
3Productivity
If existing micropump designs are used, then medication delivery is achieved, but the pump size and complexity are not compact and economical
Solution Approach 1:
The patent merges the reservoir, piston, and drive mechanism into a more integrated compact assembly. By combining these functions into a tighter configuration, the pump achieves smaller overall size while maintaining medication delivery capability, making it more suitable for portable and implantable applications.
Solution Approach 2:
The patent employs a nested arrangement where the piston moves within the reservoir chamber, and the drive rack is positioned within the pump housing. This nesting of components reduces the overall pump volume while preserving the full medication delivery function, achieving a more compact design.
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
The design enables precise and efficient delivery of medication with a smaller footprint, flexibility in reservoir type, and improved motor efficiency, reducing complexity and costs while maintaining dosing accuracy.
Implementation Method 1
comprising a pair of radially positioned O-ring seals on the floating piston frictionally engaged with an interior surface of the pump housing preventing movement of the floating piston due to positive and negative pressure within the pump volume space
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A micropump according to the invention uses axially oriented pistons to define a pump volume. Translating the pistons axially with respect to each other within a pump housing draws a metered amount of fluid into the pump volume from a reservoir port for delivery to a cannula port when the space is collapsed. Radially situated seals on the pistons cooperate with the axial movement to close off and open the cannula port and the reservoir port respectively at different positions of the piston stroke.