Drug Delivery Dose Setting Mechanism with Clutch Nut Safety Limits
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Solution Overview
Problem
Current drug delivery devices lack mechanisms to ensure that patients administer a minimum effective dose and prevent exceeding a maximum safe dose, leading to potential dosing errors and safety issues, especially for patients with impaired vision or limited dexterity.
Innovation Solution
A drug delivery device with dose setting mechanisms that restrict dosing to a predetermined minimum and maximum range, using a clutch nut and ratchet mechanism to prevent dosing below the minimum or above the maximum, ensuring that only the defined dose window can be set and administered.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a variable-dose mechanism allows users to select any dose from 1 unit up to maximum units, then the device provides flexibility and adaptability for different patient needs, but the risk of dosing errors increases and safety is compromised
Solution Approach 1:
The patent applies preliminary anti-action by pre-establishing minimum and maximum dose limits through mechanical constraints (clutch nut engagement with ratchet teeth, axial stops) that prevent the user from selecting doses outside the safe range. The clutch mechanism is designed to automatically engage at predetermined dose levels, creating a preliminary barrier against dosing errors before they can occur.
Solution Approach 2:
The clutch nut acts as an intermediary mechanism between the user's dose selection input and the actual dose delivery. It mediates the dose setting process by engaging with ratchet teeth at predetermined positions to enforce minimum and maximum dose limits, thereby protecting the system from unsafe user inputs without completely restricting user control within the safe range.
2Ease of operation
If the device allows dose dialing down from maximum to minimum, then the device provides ease of operation for correcting dosing errors, but the complexity of the dose setting mechanism increases
Solution Approach 1:
The patent applies dynamics by making the clutch mechanism's engagement state changeable based on the dialing direction and position. The clutch can engage to prevent dialing below minimum dose when dialing upward, and can disengage to allow dialing down from maximum to minimum. This dynamic behavior provides ease of operation for corrections while maintaining safety constraints, without requiring a completely complex redesign of the entire dose setting mechanism.
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
This solution reduces the risk of dosing errors by limiting the range of possible doses, preventing ineffective or unsafe administrations, and providing a safer user experience, especially for patients with diabetes or those using multiple types of insulin.
Implementation Method 1
a clutch nut having a proximal end and a distal end, wherein the proximal end is threadedly engaged with the clutch
Implementation Method 2
a dose setting mechanism that restricts dosing to a predetermined minimum and maximum range
Data Source
Figure 1~2
Figure 3~4
AI summary
The present invention relates to a dose setting mechanism for a drug delivery device and a method of using same. The mechanism comprises a drug delivery device housing (17), a dose dial sleeve (9) positioned at least partly in the housing (17) and being rotatable during dose setting and dose delivery, a clutch (13) rotatable during dose setting and non-rotatable during dose delivery, and a clutch nut (15), that is threadedly engaged with the clutch (13) and is splined to the housing (17) to prevent rotation of the clutch nut (15).