Spring-Actuated Injection for Precise Hydrogel Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing injection devices struggle with precision and speed in delivering shape adaptable materials, particularly those with unique properties, leading to potential subversion of their intended function due to rapid changes in material properties or administration speed.
Innovation Solution
An injection device with a spring-actuated mechanism that controls the ejection of shape adaptable materials through a junction component, utilizing a stopper sealed by a compression spring to manage injection force and rate, allowing for precise delivery of volumes ranging from 0.01 μL to 10 mL.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional injection device is used to deliver shape adaptable materials, then the injection procedure can be completed, but precision and speed are insufficient leading to potential subversion of material function
Solution Approach 1:
The patent applies parameter changes by using a compression spring to dynamically adjust injection force and rate parameters. The spring constant and compression distance are optimized to match specific material properties (viscosity, elasticity), enabling precise control of injection parameters that adapts to different shape adaptable materials, thereby ensuring both precision and material function integrity
Solution Approach 2:
The injection device implements dynamics through a mechanically actuated compression spring system that provides controlled, dynamic force application during injection. The spring can be compressed to varying degrees and released at controlled rates, enabling dynamic adjustment of injection speed and force to match the specific requirements of different materials, preventing premature gelation or property changes
2Productivity
If injection speed is increased to improve efficiency, then productivity increases, but material properties may change too rapidly subverting intended function
Solution Approach 1:
The compression spring mechanism enables parameter changes by allowing precise control of injection rate through adjustment of spring compression distance and force. This dynamic parameter control ensures that injection speed can be optimized for productivity while simultaneously maintaining material property stability by preventing excessively rapid injection that would cause premature gelation or loss of shape adaptability
Solution Approach 2:
The device incorporates feedback mechanisms through the mechanical properties of the compression spring and stopper system. The spring force naturally adjusts based on material resistance, providing passive feedback control that prevents over-speed injection. The stopper mechanism also provides feedback by limiting maximum injection distance, ensuring the injection process remains within parameters that maintain material integrity
3Force
If injection force is increased to deliver viscous materials, then delivery capability improves, but control over injection rate decreases
Solution Approach 1:
The compression spring enables parameter changes by providing a controllable force that can be adjusted through compression distance and spring constant selection. This allows the system to generate sufficient injection force for viscous materials while maintaining precise control over injection rate, as the spring force is applied gradually and controllably rather than as a sudden high-force impulse
Solution Approach 2:
The dynamic spring-mass system provides inherent rate control through the relationship between spring force, mass, and acceleration. The injection rate is naturally regulated by the mechanical dynamics of the system, allowing high force application to viscous materials while maintaining precise rate control through the physical laws governing spring-mass systems
4Ease of manufacture
If a simple injection mechanism is used to reduce device complexity, then ease of manufacture improves, but precision and control capability deteriorate
Solution Approach 1:
The compression spring mechanism applies self-service by using the material's own resistance and the spring's elastic properties to automatically regulate injection force and rate. The system requires minimal external control mechanisms while achieving precise injection control through the inherent physical properties of the spring-material interaction, thereby maintaining both manufacturing simplicity and injection precision
Solution Approach 2:
The compression spring acts as an intermediary between the actuation mechanism and the injection process. It translates simple actuation input into precisely controlled injection force and rate, serving as a mechanical mediator that enhances control precision without requiring complex control systems, thus maintaining ease of manufacture while improving injection precision
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 ensures accurate and efficient delivery of shape adaptable materials, maintaining control over injection force and rate, suitable for single-use and low-volume applications, especially with materials like polymer hydrogels, achieving up to 90% delivery within 5 seconds.
Implementation Method 1
an actuation mechanism comprising a stopper that engages with and seals the reservoir, where activation of the actuation mechanism forces the stopper into the reservoir thereby controlling ejection of the shape adaptable material through the injection port. In one or more aspects of these embodiments, the actuation mechanism can comprise a spring that forces the stopper into the reservoir via a plunger.
Implementation Method 2
The spring can be a compression spring sized to provide an axial force based upon properties of the shape adaptable material being ejected. The spring can be compressed to a fully loaded length in a range from about 10% to about 50% of a free length of the spring before activation.
Implementation Method 3
Extension of the spring can impart a force to a rear portion of the stopper that radially expands the stopper thereby increasing an interference fit with an inner surface of the reservoir.
Data Source
AI summary
Described herein is a generalized injection device for delivering formulations of various mechanical properties to precise locations. Of particular interest is the manifestation intended for the application of a thermally responsive hydrogel to the tear duct for the purpose of occlusion, as a treatment for symptoms associated with dry eye syndrome. Further, a modular solution to the need for an injection device across a variety of applications, mechanism, and physical considerations is provided. This disclosure provides examples of methods for precise injection of low volumes, moisture retention in pre-filled injection devices, and actuation for automatic or manual injection, to name a few.