Needle-Free Injection Drive Assembly With Independent Pistons
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Solution Overview
Problem
Existing needle-free injection devices face issues with energy accumulators that wear out due to strain, require additional components, and deliver inconsistent injections due to human error in operating valves, and the attachment of power and medicine pistons increases energy requirements and drag.
Innovation Solution
The injection device features independent pneumatic and injectate pistons with separate resilient members, a valve assembly with a user-independent movement rate, and no energy accumulator, allowing instantaneous energy application for the injection cycle without prior storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If energy accumulators are used to store potential energy for rapid piston acceleration, then injection speed and initial hydraulic pressure are improved, but device complexity increases and component wear increases
Solution Approach 1:
The patent removes the energy accumulator component from the injection device entirely. Instead of storing potential energy in a compressed spring or other energy storage mechanism, the system applies energy directly to the piston through a valve-controlled fluid pressure system, eliminating the need for energy storage components while maintaining rapid acceleration capability
Solution Approach 2:
The system prepares for rapid piston acceleration by pre-positioning the valve in a ready state and having pressurized fluid available in the supply line. When activation occurs, the valve opens to allow immediate fluid pressure application to the piston, achieving rapid acceleration without requiring energy storage components
2Speed
If energy accumulators are used to store potential energy, then injection speed is improved, but reliability decreases due to wear on retention mechanisms
Solution Approach 1:
The patent eliminates the energy accumulator and its associated retention mechanisms (springs, locks, clamps) that are subject to wear. The direct fluid pressure actuation system has fewer moving parts and no energy storage components, reducing wear points and improving reliability
Solution Approach 2:
The fluid pressure system automatically recharges the piston chamber after each injection cycle without requiring manual intervention or complex retention mechanisms. The system uses the fluid supply line to automatically replenish pressure, eliminating the need for wear-prone energy storage and retention components
3Device complexity
If power piston and medicine piston are attached to move in unison, then device complexity is reduced, but energy consumption increases due to additional drag
Solution Approach 1:
The patent divides the piston system into separate functional components: a power piston for generating pressure and a medicine piston for delivering the injection. These pistons operate independently with separate chambers, allowing the power piston to move freely without the drag of attached medicine, thereby reducing energy consumption while maintaining structural simplicity
4Ease of operation
If power piston and medicine piston are attached to move in unison, then ease of operation is improved, but injection consistency decreases due to encumbrance on power piston movement
Solution Approach 1:
The patent separates the power piston and medicine piston into independent components with separate chambers. This segmentation allows each piston to perform its specific function optimally without the encumbrance of attachment, resulting in more consistent and reliable injections while maintaining ease of operation through the coordinated action of separate components
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 design reduces wear and tear, minimizes human error, and ensures consistent injections by eliminating the need for energy accumulators and direct piston attachment, enhancing injection quality.
Implementation Method 1
separate resilient members for each piston, allowing instantaneous energy application without storing potential energy
Implementation Method 2
The valve is configured to provide pressurized fluid to the pneumatic piston chamber
Data Source
AI summary
Disclosed are an injection device and a method of using the same. The injection device includes an injection drive assembly including a pneumatic piston chamber, dose chamber, pneumatic piston slidably positioned in the pneumatic piston chamber and an injectate piston slidably positioned in the dose chamber. The injection drive assembly is configured so that any energy resulting from an application of force to the injection drive assembly is instantaneously available for the initiation of injection. In another aspect, the injection device includes separate respective resilient members for each of the pistons that are configured to position each piston in their respective pre-injection positions. In still another aspect, the injection device includes a valve assembly configured to provide pressurized fluid to the pneumatic piston chamber. The rate of the movement of the valve between open and closed positions is independent of control by a user of the injection device.