Auto-Injector Sensor Attachment Using Inductive Dwell-Time Detection
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Solution Overview
Problem
Existing injection devices, particularly auto-injectors, face challenges such as user errors in administering medicaments due to improper use, including underdosing, high injection forces, hand trembling, and incorrect timing of injections, which can lead to incomplete doses and needle removal before the desired dwell time.
Innovation Solution
A supplementary device that attaches to an auto-injector, utilizing non-contact sensors to monitor the injection process and provide visual and auditory cues to ensure proper administration, including a dwell time, and track injection history.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a manual injection device with button/plunger is used, then the user can control the injection process, but the user must exert high injection forces and maintain continuous pressure, leading to hand trembling and discomfort
Solution Approach 1:
The patent replaces the manual mechanical button/plunger system with an automated spring-loaded mechanism. The spring provides the injection force automatically when triggered, eliminating the need for the user to exert continuous manual pressure. This substitution of mechanical systems resolves the contradiction by maintaining ease of operation (simple trigger activation) while eliminating the harmful high injection forces that cause hand trembling.
Solution Approach 2:
The injection device is designed to perform the injection action automatically once activated. The spring mechanism self-generates the required injection force without continuous user input, and the device automatically maintains pressure throughout the injection process. This self-service capability eliminates the need for user effort during the critical injection phase, resolving the force-related discomfort.
2Reliability
If the button/plunger extension is made longer to ensure complete dose delivery, then the full dose can be administered, but it becomes inconvenient for users to reach the fully extended button
Solution Approach 1:
The patent replaces the long manual button extension with a compact spring-loaded trigger mechanism. The trigger requires minimal displacement to activate, making it easily accessible to users with limited dexterity. The spring mechanism then provides the extended force delivery needed for complete dose administration. This substitution resolves the contradiction by maintaining dose completeness through automated force application while improving button accessibility.
Solution Approach 2:
The spring mechanism is pre-loaded during device assembly, storing the energy required for complete dose delivery. When the user activates the trigger, this pre-stored energy is released to provide the full injection force without requiring the user to exert prolonged or extensive manual effort. This preliminary action resolves the contradiction between reliable dose delivery and ease of activation.
3Reliability
If the user presses the button continuously to maintain injection flow, then the medicament is delivered, but stopping pressure results in incomplete dose delivery
Solution Approach 1:
The spring-loaded mechanism automatically maintains injection pressure throughout the entire dose delivery process without requiring continuous user input. Once triggered, the spring forces the plunger to move at a controlled rate, automatically compensating for any variations in user pressure. This self-service operation ensures accurate and complete dose delivery while simplifying the user's task to a single activation action.
Solution Approach 2:
The patent replaces the manual continuous-pressure system with an automated spring-driven system. The spring provides consistent, controlled force throughout the injection, eliminating the need for user monitoring and adjustment of pressure. This mechanical substitution ensures dose accuracy through automated pressure maintenance while dramatically simplifying the operation to a single trigger pull.
4Productivity
If the needle is removed immediately after injection, then the user can proceed with normal activities, but the medicament may not have sufficient dwell time for proper absorption
Solution Approach 1:
The patent incorporates sensors that detect the completion of the injection process and provide feedback to control the needle retention mechanism. When the injection is complete, the system automatically extends the dwell time by keeping the needle in place for the required period. This feedback-controlled approach ensures proper medicament absorption while allowing the user to prepare for needle removal in advance, resolving the contradiction between injection speed and absorption reliability.
Solution Approach 2:
The device automatically maintains the needle in the patient's body for the required dwell time immediately after injection completion, without requiring user intervention. This preliminary action of extended needle retention ensures proper medicament absorption before the user removes the device. The system proactively manages the dwell time requirement, resolving the contradiction between quick procedure completion and reliable medicament absorption.
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 supplementary device enhances the reliability of auto-injector use by ensuring complete doses and correct timing, reducing user errors and improving adherence to medical regimens.
Implementation Method 1
a first non-contact sensor configured to output signals indicative of the position of a first moveable component within the drug delivery device
Implementation Method 2
a processor configured to: receive the signals output from the first non-contact sensor; determine based on the signals the moment at which the drug delivery device changes from a pre-ejection state to a post-ejection state
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 2a~2b
AI summary
A supplementary device configured to be releasably attached to an auto injector type device. The supplementary device is suitable for use with disposable one-shot auto injectors and re-usable one-shot auto injectors. The supplementary device has at least one inductive proximity sensor which outputs signals indicative of the position moveable components within the auto injector. The supplementary device is configured to determine based on the outputted signals the moment at which the auto injector changes from a pre-ejection state to a post-ejection state. In response to determining that the auto injector has changed from the pre-ejection state to the post ejection state, the supplementary device displays a visual indication that a user should hold the auto injector in its current position for a predetermined period of time.