Medical Delivery Device Linear to Rotational Conversion

The patent combines multiple functions into a single integrated cartridge assembly that includes the fluid container, movable wall, plunger rod, and valve mechanism. This merging of components achieves advanced drug delivery functionality while avoiding the complexity of multiple separate parts interacting together.

The manually operated push means serves multiple functions: it transforms linear movement to rotational movement, drives the plunger rod, and controls fluid expulsion through the valve. This multi-functionality reduces the need for separate components, thereby reducing device complexity while maintaining advanced functionality.

The device is divided into distinct functional modules: a reusable body and a disposable cartridge. The cartridge contains all precision-critical components (container, movable wall, plunger rod, valve) that require high manufacturing precision. This segmentation allows precision manufacturing to be focused only on the cartridge, which can be mass-produced at lower cost, while the body uses simpler, lower-cost components.

The cartridge is designed as a disposable component that contains all precision-critical parts. By making the cartridge disposable rather than reusable, the patent eliminates the need for expensive precision manufacturing in the reusable body, thereby reducing overall manufacturing cost while maintaining high precision in the critical drug delivery function.

The valve is automatically actuated by the linear movement of the plunger rod without requiring additional user actions. The push means simply moves linearly, and the mechanical linkage automatically opens the valve at the appropriate moment. This self-service mechanism ensures reliable drug delivery while keeping the user interface simple and easy to operate.

The patent introduces a mechanical intermediary system (the linkage between linear push movement and rotational plunger drive) that translates simple user input into complex mechanical actions. This intermediary mechanism handles the complexity internally, allowing the user to operate the device with a simple linear push while maintaining reliable and precise drug delivery through the complex mechanical transformation.

The patent extracts and eliminates the problematic residual tension effect by using a valve that closes automatically when pressure drops. Instead of relying on springs and rubber stoppers that maintain residual tension, the valve mechanism is designed to respond to pressure changes, closing reliably when the driving pressure is gone, thereby preventing drooling while maintaining necessary system resiliency.

The patent changes the operational parameter from relying on residual mechanical tension (springs and rubber stoppers) to relying on pressure differential control. The valve opens and closes based on pressure changes during operation, eliminating the harmful residual tension effect that causes drooling while maintaining system resiliency through pressure-responsive operation.