Infusion Pump Cartridge Plunger Barrel Precision Dispensing
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Solution Overview
Problem
Conventional ambulatory infusion pumps are limited by size, accuracy, and operational flexibility, particularly when dealing with high concentration insulins like U-500, which require precise fluid delivery and frequent refilling or replacement.
Innovation Solution
A medicament cartridge system with a plunger and barrel design that allows for precise dispensing of 0.1% or less of the total filled volume with single-dose precision better than ±20% within an eight-hour dispensing period, combined with a pump assembly and baseplate configuration that enables flexible deployment as either a patch or pocket pump.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional infusion pumps are used, then they can deliver medicament, but they are large in size and lack precision for high concentration insulins
Solution Approach 1:
The system is divided into separate components: a reusable pump assembly and a disposable cartridge containing the reservoir and plunger. This segmentation allows the pump to be smaller while maintaining precision through the specialized cartridge design with tight-tolerance plunger and barrel interfaces.
Solution Approach 2:
A plunger pusher acts as an intermediary between the motor and the plunger, providing precise force transmission. The pusher includes a face that contacts the plunger and a bearing surface that interfaces with the barrel, ensuring accurate medicament delivery without requiring the entire pump system to be large and complex.
2Productivity
If conventional pumps are used, then they can dispense medicament, but they require frequent refilling or replacement when dealing with high concentration insulins
Solution Approach 1:
The cartridge is pre-filled with high concentration insulin during manufacturing, eliminating the need for user refilling. The disposable nature of the cartridge allows for quick replacement rather than time-consuming refilling operations, improving productivity and reducing time loss.
3Manufacturing precision
If conventional pumps are used, then they can deliver medicament, but they lack single-dose precision better than ±20%
Solution Approach 1:
The cartridge features localized precision elements: tight-tolerance plunger-body rings that fit within the barrel, and an O-ring seal positioned at the critical interface between plunger and barrel. This concentrated precision in key areas achieves ±20% single-dose precision without requiring the entire device to be overly complex.
Solution Approach 2:
The system uses a stroke length to inner diameter ratio of about 1.0 or less, optimizing the geometric parameters of the plunger and barrel to achieve precise dosage delivery. The plunger stroke and barrel dimensions are carefully controlled to ensure accurate medicament dispensing.
4Adaptability or versatility
If conventional pumps are used, then they can provide operational flexibility, but they cannot easily be configured as either patch or pocket pumps
Solution Approach 1:
The pump assembly is designed as a universal platform that can accommodate different baseplate types, enabling the same core device to function as either a patch pump or pocket pump. This multi-functionality achieves operational flexibility without significantly increasing the base complexity of the pump assembly.
Data Source
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AI summary
Ambulatory infusion pumps, pump assemblies, cartridges, baseplates, cannulas, insertion tools, and related components as well as combinations thereof and related methods. An exemplary medicament cartridge may comprise: a barrel defining at least a substantial portion of a medicament reservoir that has a total filled volume; and a plunger movable with respect to the barrel to controllably dispense out of the reservoir an amount of medicament of 0.1% or less of the total filled volume of the reservoir and with a single-dose precision of better than plus or minus 20%; and the precision is obtained within a dispensing period of less than eight hours.