Multi-stroke Drug Delivery Pumping Mechanism for Intradermal Injection
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Solution Overview
Problem
Existing drug delivery pens require high forces for intradermal injections, leading to medication leakage and dose inaccuracy due to the high pressures involved, which are not effectively managed by current designs.
Innovation Solution
A drug delivery device with a secondary chamber that amplifies injection force, diverting high pressures away from the original medication container, allowing for injection in small packets or pulses, thereby reducing the required pressure and improving usability and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high pressure is applied to deliver medication intradermally, then injection effectiveness is improved, but medication leakage and dose inaccuracy occur
Solution Approach 1:
The system divides the medication delivery process into two separate chambers: a primary chamber for storing medication and a secondary chamber for delivering it. This segmentation allows the high-pressure injection to occur in the secondary chamber while the primary chamber remains isolated, preventing leakage and ensuring accurate dosing.
Solution Approach 2:
The secondary chamber acts as an intermediary between the primary medication container and the injection site. It receives medication from the primary chamber at low pressure and then delivers it to the intradermal site at high pressure, decoupling the storage pressure from the injection pressure to prevent leakage and maintain dose accuracy.
2Productivity
If high force is applied to generate sufficient injection pressure, then intradermal injection capability is improved, but device components can be damaged
Solution Approach 1:
By separating the medication storage function (primary chamber) from the injection delivery function (secondary chamber), the system allows the secondary chamber to handle high forces and pressures without compromising the primary chamber or other sensitive components. The secondary chamber is specifically designed to withstand the mechanical stresses of high-pressure intradermal injection.
Solution Approach 2:
The secondary chamber serves as a dedicated intermediary that absorbs and withstands the high forces required for intradermal injection. It protects the primary chamber and other device components from damage by isolating the high-stress injection process within its own structure.
3Device complexity
If a single-chamber system is used, then device simplicity is maintained, but pressure management is insufficient
Solution Approach 1:
The two-chamber design provides a straightforward structural division that is relatively simple to manufacture and operate. The primary chamber stores medication while the secondary chamber handles injection, creating clear functional separation that improves pressure control without excessive complexity.
Solution Approach 2:
The secondary chamber acts as a simple intermediary vessel that receives medication from the primary chamber and delivers it to the injection site. This single additional component provides effective pressure management by decoupling storage pressure from injection pressure, achieving reliable pressure control with minimal added complexity.
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 device enables intradermal medication injections with lower input forces, reducing tissue damage and pain, and enhancing dose accuracy by decoupling the primary chamber from the injection mechanics, preventing leakage and inaccuracy.
Implementation Method 1
a compression spring that provides a force on the cartridge stopper
Implementation Method 2
The secondary chamber employs a smaller cross sectional area than the primary (original) medication container to amplify injection pressure at a given input force
Data Source
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AI summary
A dual-chambered drug delivery device (201) includes a cartridge (211) having a first chamber (212) for storing a medicament and a second chamber (221) in fluid communication with the first chamber (212). A dose setting member (241) is used to set a medicament dose to be injected at an injection site. A piston (281) is disposed in the second chamber (221). An upward stroke of the piston (281) draw a portion of the medicament dose into the second chamber (221) and a downward stroke of the piston (281) expels the portion of the medicament dose. A needle (205) communicates with the second chamber (221) for sequentially injecting the portions of the medicament dose into the injection site.