Injection Device Spring Tensioning Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Patients, especially older or inexperienced diabetics, face difficulties with existing injection devices due to battery drain and self-discharge issues, which can lead to delayed or unsuccessful drug delivery, as the energy required to tension the drive spring may deplete before the next injection.
Innovation Solution
An injection device with a rechargeable battery that uses an electric motor to tension a drive spring immediately after each use, ensuring the spring is ready for the next injection, and optionally includes a secondary lithium battery for control functions, integrated with a blood glucose measuring device and mobile phone for enhanced usability and convenience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electric motor tensions the drive spring immediately after injection, then the drive spring is ready for the next injection, but the battery charge level decreases
Solution Approach 1:
The drive spring is tensioned immediately after the injection is completed, before the patient leaves the injection site. This preliminary action ensures the device is ready for the next injection without delay, even though it consumes battery charge. The timing is optimized to perform the energy-consuming retensioning operation when the patient is still present and can be notified of low battery conditions.
2Reliability
If the battery charge level is monitored continuously, then low charge conditions are detected early, but the device complexity increases
Solution Approach 1:
The control means continuously or periodically monitors the charge level of the battery and provides feedback to the user interface. When the charge level falls below a threshold, the system notifies the patient through visual, acoustic, or haptic signals. This feedback mechanism ensures reliable detection of low charge conditions while using a relatively simple implementation that leverages existing battery management capabilities.
3Loss of energy
If the drive spring is tensioned only when battery charge is sufficient, then energy is conserved, but the next injection may be delayed
Solution Approach 1:
The system performs the retensioning operation as soon as the injection is completed, regardless of the current battery charge level. This preliminary action prioritizes readiness for the next injection over immediate energy conservation. The system accepts the energy cost of retensioning now in exchange for avoiding potential delays later when the battery might be too depleted to perform the operation.
4Reliability
If manual tensioning of the drive spring is allowed, then the device can be prepared without battery power, but the ease of operation decreases
Solution Approach 1:
The system is designed to automatically tension the drive spring using the electric motor without requiring manual intervention from the patient. This self-service approach maintains ease of operation while ensuring reliable preparation for the next injection. The automatic retensioning occurs in the background after the injection, so the patient does not need to perform any additional actions.
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 solution ensures reliable and efficient drug delivery by maintaining the drive spring's tension regardless of battery charge levels, allowing timely notification of low battery conditions and reducing user effort through integrated mobile phone features for compliance monitoring and assistance.
Implementation Method 1
an electric motor (7) powered by the electrical energy source (4) is arranged for tensioning the drive spring (6)
Implementation Method 2
a driver (5) is arranged to displace a dose of the drug from the container (3) through a nozzle (10) for delivering it to a patient under load of a drive spring (6) upon release
Data Source
Figure 1
AI summary
The invention relates to an injection device (1) for delivering a drug, comprising a housing arranged to receive a drug container (3) and an electrical energy source (4), wherein a driver (5) is arranged to displace a dose of the drug from the container under load of a drive spring (6) upon release, wherein an electric motor (7) powered by the electrical energy source is arranged for tensioning the drive spring, wherein control means (8) are arranged for controlling the electric motor so as to tension the drive spring when an injection has been performed.