Medicament Delivery Device Helical Dose Sleeve Sensor System
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Solution Overview
Problem
Existing medicament delivery devices, such as pen injectors, face challenges in accurately and reliably setting and dispensing doses without requiring complex mechanical operations, and often lack redundancy in dose measurement, which can lead to inaccuracies and user confusion.
Innovation Solution
A medicament delivery device equipped with first and second sensor arrangements that detect rotational and axial movements of the dose sleeve, allowing for precise determination of dose settings and dispensing, and distinguishing between dose setting and dispensing procedures, thereby enhancing accuracy and user accessibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a number sleeve rotates helically as a dose is dialled into the device, then the dose can be set, but the overall length of the pen injector increases
Solution Approach 1:
The patent transitions from a traditional helical rotation mechanism that requires axial extension to a planar rotational mechanism where the dose selector rotates within a fixed axial space. The dose indicator moves radially or tangentially across a dial face rather than extending axially, allowing dose setting without increasing the injector's overall length.
2Reliability
If the dose button is connected to a drive shaft and not directly connected to the number sleeve, then the dose delivery is improved, but the device complexity increases
Solution Approach 1:
The patent replaces complex mechanical linkages between the dose button and drive mechanism with a magnetic coupling system. Magnets in the dose button interact with corresponding magnets or magnetic sensors in the drive shaft, enabling force transmission and position detection without direct mechanical contact, thereby simplifying the overall structure while maintaining reliable dose delivery.
3Measurement precision
If both rotational and axial movements are detected, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The patent combines rotational and axial movement detection into a single integrated sensor system. A multi-functional encoder or sensor array simultaneously measures both the rotational position of the dose selector and the axial position of the plunger, providing redundant measurement data without requiring separate independent sensor systems, thus limiting the increase in device complexity.
Data Source
AI summary
A drug delivery device comprises a housing and a dose sleeve located within the housing, the dose sleeve being configured to move helically within the housing as a medicament dose is dialled into or delivered from the drug delivery device. A dose setting arrangement is coupled to the dose sleeve and is configured to cause helical movement of the dose sleeve as a medicament dose is dialled into the drug delivery device through rotation of a dose dial forming part of the dose setting component. A dose delivery arrangement comprising a dose button is coupled to the dose sleeve and is configured to cause delivery of medicament with helical movement of the dose sleeve and without rotation of the dose dial when the dose button is actuated. A first sensor arrangement is configured for detecting a rotation of the dose dial relative to the housing. A second sensor arrangement is configured for detecting movement of the dose sleeve relative to the housing. A processor arrangement is coupled to receive inputs from the first and second sensor arrangements and is configured to calculate therefrom the size of a medicament dose dispensed by the drug delivery device.