Pen-Type Injection Device Ratchet Brake for Dose Correction
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Solution Overview
Problem
Conventional pen-type injection devices often fail to simultaneously provide intuitive dose setting, dose correction, last dose control, and audible/tactile feedback, requiring cumbersome additional steps and not meeting user needs.
Innovation Solution
The injection pen incorporates a brake assembly with a ratchet member and driver system that allows for dose setting and correction without rotating the driver during these processes, while enabling rotation during injection, and includes mechanisms for last dose management and audible/tactile feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional devices provide dose correction capability, then users can correct oversized doses, but the devices require additional cumbersome steps that are not intuitive to the user
Solution Approach 1:
The ratchet member enables dynamic reversal of the driver rotation direction. During dose setting, the driver rotates in a first direction to advance the plunger. During dose correction, the driver can rotate in a second (reverse) direction to retract the plunger. This dynamic bidirectional rotation capability allows intuitive dose correction without requiring additional cumbersome steps, as the user can simply rotate the dose set knob in the opposite direction to correct an oversized dose.
2Reliability
If conventional devices provide last dose control, then users cannot set a dose greater than remaining medication, but many devices require additional steps that are not intuitive
Solution Approach 1:
The dose stop member provides mechanical feedback by physically blocking further rotation of the dose set knob when the remaining medication is insufficient. As the plunger advances and medication is depleted, the dose stop member engages with the dose set knob to prevent setting a dose larger than the remaining amount. This intuitive mechanical feedback automatically informs the user of the last dose limit without requiring additional steps or complex electronic interfaces.
3Ease of operation
If the driver rotates during dose setting, then the dosing mechanism can advance, but the driver should not rotate during dose correction to enable proper reversal control
Solution Approach 1:
The ratchet member enables dynamic engagement and disengagement based on operation phase. During dose setting, the driver engages the ratchet member to advance the plunger. During dose correction, the driver can disengage and rotate in reverse to retract the plunger. This dynamic engagement mechanism provides intuitive control during dose correction while managing the complexity through a well-designed ratchet interface.
4Ease of operation
If conventional devices provide audible and tactile feedback, then users receive signaling during operation, but the feedback mechanisms add to device complexity
Solution Approach 1:
The ratchet member and dose stop member generate audible clicking sounds and tactile resistance automatically during normal operation. When the driver engages the ratchet teeth during dose setting or correction, characteristic clicking sounds are produced, and tactile resistance is felt. This self-service feedback mechanism provides user signaling without requiring additional complex electronic feedback components, as the mechanical interaction itself generates the feedback.
Data Source
AI summary
The disclosure provides driver components, systems and drive methods that facilitate improved dose setting, correcting, and/or dispensing in a multiple use pen-type injection device. In particular, various novel braking systems are disclosed that can be implemented within the pen-type injection devices to help achieve the improved dose setting, correcting, and/or dispensing.