Compact Needle Actuation Mechanism for Patch Drug Delivery
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Solution Overview
Problem
Existing drug delivery devices with needle actuation mechanisms are not compact enough for small devices, such as patch devices, which require efficient operation for delivering small quantities of drugs like concentrated insulin, as they necessitate a certain lever size for efficient operation.
Innovation Solution
A subcutaneous delivery mechanism with a compact needle actuation system using a first and second lever, where the first lever is pivotally mounted and engages a rotary actuator, causing the second lever to rotate, and the needle holder is moved between retracted and extended positions, maintaining a large distance of travel while being economical, safe, and easy to use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional needle actuation mechanism is used, then the device is reliable and safe, but the device size becomes too large for small patch devices
Solution Approach 1:
The needle actuation mechanism is divided into two separate levers: a first lever that rotates about a first axis and a second lever that rotates about a second axis. This segmentation allows each lever to be optimized for its specific function, reducing the overall space required while maintaining the reliability of the actuation mechanism.
Solution Approach 2:
The invention introduces a second rotational dimension by adding the second lever that rotates about a second axis perpendicular to the first axis. This dimensional change allows the mechanism to achieve the required needle travel distance through combined rotational movements rather than requiring a single large lever, thus compacting the device volume.
2Volume of moving object
If the lever size is reduced to compact the device, then the device volume decreases, but the needle actuation efficiency is compromised
Solution Approach 1:
The mechanism uses dynamic coupling between the two levers where the first lever's rotation drives the second lever's rotation. This dynamic interaction allows small levers to achieve large needle displacement through the mechanical advantage provided by the coupled rotational movements, maintaining actuation efficiency without requiring large lever sizes.
Solution Approach 2:
The second lever acts as an intermediary between the first lever and the needle holder. It translates and amplifies the rotational movement from the first lever into the linear displacement needed for needle actuation, allowing compact lever dimensions while maintaining sufficient actuation efficiency.
3Volume of moving object
If a compact configuration is used, then the device volume is reduced, but the needle travel distance between retracted and extended positions is reduced
Solution Approach 1:
By introducing rotation about a second axis perpendicular to the first axis, the mechanism achieves needle displacement in a different dimensional direction. The combined effect of first lever rotation and second lever rotation produces sufficient linear needle travel distance even though each individual lever is compact in size.
Solution Approach 2:
The dynamic coupling of the two levers creates a mechanical advantage where small rotational movements of the first lever are translated into larger linear displacement of the needle through the second lever's rotation, maintaining adequate needle travel distance in a compact configuration.
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 mechanism provides a compact, reliable, and efficient needle actuation system that ensures a large distance of needle travel between positions, enhancing the usability and effectiveness of small drug delivery devices without increasing size, ensuring optimal subcutaneous penetration and ease of use.
Implementation Method 1
The needle actuation mechanism comprises a first lever pivotally mounted relative to the housing and a rotary actuator rotatably mounted relative to the housing configured to engage a distal portion of the first lever to cause the first lever to rotate
Implementation Method 2
rotation of the first lever causes rotation of the second lever in an opposite rotation direction, an engagement end of the second lever engaging the needle holder to move the needle between the retracted position and extended delivery position
Data Source
AI summary
A subcutaneous delivery mechanism for a drug delivery device (1), comprising a needle (10), a needle holder (12) holding the needle (10), and a needle actuation mechanism (20) configured to actuate in translation the needle holder (12) to move the needle (10) from a retracted position to an extended delivery position. The needle actuation mechanism (20) comprises a first lever (30) pivotally mounted on a first support member (33) and a rotary actuator (22) rotatably mounted on a second support member (43). The first lever (30) is configured to engage the rotary actuator (22). The needle actuation mechanism (20) also comprises a second lever (40) pivotally mounted on the second support member (43) or around a circumferential outer rim (24) of the rotary actuator (22). The first and second levers (30, 40) are coupled to each other such that rotation of the first lever (30) causes rotation of the second lever (40). The second lever (40) is coupled to the needle holder (12) in order to move the needle (10) from the retracted position to the extended delivery position upon rotation of the second lever (40).