Expandable Mechanical Pump for Subcutaneous Infusion
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Solution Overview
Problem
Current infusion systems for primary humoral immunodeficiency treatment, such as IVIG, are costly, inconvenient, and often require frequent hospital visits due to the high cost and limited portability of infusion equipment, which can trigger flu-like symptoms with intravenous administration.
Innovation Solution
A lightweight, portable, and inexpensive pump assembly designed for subcutaneous administration of immune globulin preparations, utilizing an expandable base and cover system with a spring mechanism to provide constant pressure for safe and efficient fluid dispensing, compatible with conventional syringes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional infusion pumps are used, then reliable fluid delivery is achieved, but the device becomes large and expensive, limiting portability and accessibility
Solution Approach 1:
The pump assembly is divided into separate functional components: a reusable pump body with mechanical elements (pusher, puller, spring, linkages) and disposable chamber bodies containing the fluid. This segmentation allows the complex mechanical system to be manufactured once and reused, while the disposable portion handles the fluid directly, reducing overall system cost and complexity for the user.
Solution Approach 2:
The pump assembly uses self-contained mechanical elements including a spring mechanism that automatically provides return force, linkages that convert cover opening/closing motion into plunger movement, and a pusher that directly contacts the plunger. This self-service mechanical system eliminates the need for external power sources, electronics, or complex control systems, making the device portable and accessible.
2Ease of operation
If manual syringe administration is used, then simplicity and low cost are achieved, but constant pressure delivery and safety are compromised
Solution Approach 1:
The pump assembly acts as an intermediary device between the simple syringe/chamber body and the patient. The mechanical elements (pusher, puller, spring, linkages) mediate the force application to the plunger, ensuring constant pressure delivery and safe flow rates while maintaining ease of operation through simple cover opening/closing actions.
Solution Approach 2:
The invention replaces manual pushing mechanics with an automated mechanical system. The spring mechanism automatically provides return force to the puller, and the linkage system converts the cover's opening/closing motion into controlled plunger movement, ensuring constant pressure delivery without requiring manual effort or external power sources.
3Productivity
If intravenous administration is used, then rapid immune globulin delivery is achieved, but flu-like symptoms are triggered due to bolus administration
Solution Approach 1:
The pump assembly delivers immune globulin through controlled periodic action rather than rapid bolus injection. The mechanical elements (spring, puller, linkages) enable steady, continuous flow rates that can be maintained over extended periods, allowing the fluid to be administered subcutaneously in a manner that avoids triggering flu-like symptoms while still achieving therapeutic delivery.
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 pump assembly enables safe, portable, and cost-effective subcutaneous administration of therapeutic fluids, reducing the burden on patients by minimizing flu-like symptoms and increasing convenience through constant pressure delivery and compatibility with standard syringes.
Implementation Method 1
Moving the puller towards the distal end by lowering the cover when the chamber body having the plunger is seated in the base generates tension in the spring, thereby causing the pusher to slidingly move distally and contact and exert force on the head of the plunger
Implementation Method 2
a first linkage pivotally coupled to the cover at a first end of the first linkage and pivotally coupled to the puller at a second end of the first linkage, wherein the pivots of the first linkage are located to move the puller towards the distal end when the cover is lowered
Data Source
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AI summary
A compact mechanical pump is provided. The pump is adjustable between a compact form and an expanded form, where the pump can be reduced to a compact form for ease of portability and storage and to the expanded form for use as a pump.