Autoinjector Plunger Rod Optical Sensing for Full-Dose Tracking
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Solution Overview
Problem
Existing autoinjectors lack accurate tracking of medicament delivery and needle insertion depth, which can result in incomplete dosing or improper administration.
Innovation Solution
Incorporation of optical transmission regions on the plunger rod within an autoinjector to enable optical signal tracking, combined with a sensing assembly to monitor the dispensing movement and needle insertion, ensuring complete medicament delivery and adequate needle depth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical transmission regions are added to the plunger rod to enable tracking, then measurement precision of dispensing movement is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical tracking mechanisms with an optical sensing system. Optical transmission regions (apertures or transparent sections) on the plunger rod allow optical sensors to detect plunger position and dispensing movement through light transmission, eliminating the need for mechanical encoders or complex mechanical feedback systems while achieving precise measurement.
Solution Approach 2:
The patent introduces optical transmission regions as an intermediary element between the plunger rod and the optical sensor. These regions (apertures or transparent materials) mediate the detection process by allowing light to pass through at specific positions, enabling the sensor to track plunger movement without direct mechanical contact or complex coupling.
2Reliability
If sensing assembly is added to track dispensing movement, then reliability of dose delivery is improved, but device complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where the optical sensor continuously monitors the plunger rod's position and dispensing movement. The sensor signals are processed to determine when the plunger has completed its full stroke and when medicament delivery is complete, providing real-time feedback that ensures reliable dose delivery and allows the system to respond to incomplete dispensing events.
Solution Approach 2:
The patent replaces complex mechanical feedback systems with an optical sensing approach. The optical sensor and transmission regions provide a non-contact, reliable method for monitoring plunger movement and determining dose completion, improving reliability while avoiding the complexity and potential failure points of mechanical switches or encoders.
3Measurement precision
If needle insertion depth sensing is added, then measurement precision of insertion depth is improved, but device complexity increases
Solution Approach 1:
The patent uses the needle guard as an intermediary element for sensing needle insertion depth. Electrical contacts on the needle guard interact with corresponding contacts on the plunger rod assembly to detect when the needle has been inserted to the required depth and whether the depth is maintained during medicament delivery, providing precise measurement without complex mechanical depth gauges.
4Ease of manufacture
If optical transmission regions are made transparent or with apertures, then ease of manufacture is improved, but object-generated harmful factors increase due to potential light interference
Solution Approach 1:
The patent applies local quality by making only specific regions of the plunger rod optically transparent or incorporating apertures at precise locations, rather than making the entire rod transparent. This localized approach simplifies manufacturing (only specific sections need special processing) while minimizing potential light interference from other parts of the device, as the transparent regions are confined to where optical sensing is required.
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
Ensures accurate delivery of the full medicament dose and proper needle insertion, enhancing the reliability and efficacy of autoinjector administration.
Implementation Method 1
an optical emitter configured to emit a first optical signal through at least one of the one or more optical transmission regions of the plunger rod; and an optical receiver configured to receive the first optical signal, where a dispensing movement of the plunger rod enables transmission of the first optical signal
Data Source
AI summary
Systems, devices, and methods include an autoinjector including a housing; a needle arranged at a distal end of the housing; a container disposed within the housing and configured to contain medicament; and a plunger slidably disposed within the container. A plunger rod is configured to push the plunger through the container to dispense the medicament through the needle when the container contains medicament. The plunger rod includes one or more optical transmission regions. A mechanism is configured so that a dispensing movement of the plunger rod causes the mechanism to generate a first optical signal and transmit the first optical signal through at least one of the one or more optical transmission regions; and an optical sensor is configured to detect the first optical signal generated by the mechanism.