Wearable Infusion Pump Volume Sensing for Precise Fluid Delivery
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Solution Overview
Problem
Existing wearable infusion pump devices for delivering therapeutics are prone to malfunction, are bulky, costly, and require frequent re-location, and lack efficient volume measurement and control mechanisms.
Innovation Solution
A wearable infusion pump assembly with a reservoir, optical sensors, and a pump system that includes a volume sensor assembly and valve assemblies for precise fluid delivery, utilizing shape-memory actuators and a computer-readable medium for automated control and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If wearable infusion pump devices are designed to be compact and wearable, then portability and user convenience are improved, but device complexity and malfunction rate increase
Solution Approach 1:
The pump device is divided into separate functional modules: a reusable pump unit containing the motor and control electronics, and disposable cartridges containing the fluid reservoir and delivery mechanism. This segmentation allows the complex reusable portion to be refined for reliability while keeping the disposable portion simple and replaceable, reducing overall malfunction rates in wearable form factors.
Solution Approach 2:
The patent employs disposable cartridges that are discarded after a single use. These cartridges contain the reservoir, tubing, and delivery tip. By making these critical fluid-handling components disposable rather than reusable, the system eliminates wear-related failures and contamination issues, significantly improving reliability without compromising the wearable compact design.
2Measurement precision
If optical sensors and volume measurement mechanisms are added to the pump system, then fluid delivery precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces a light-guiding structure that acts as an intermediary between the optical sensor and the fluid column. This structure channels light through the fluid in a controlled manner, enabling accurate volume measurement via optical density or light transmission changes without requiring complex sensor arrays or multiple measurement points, thus maintaining simplicity while achieving precision.
Solution Approach 2:
Traditional mechanical volume measurement mechanisms (such as moving parts, gears, or displacement indicators) are replaced with optical sensing. The system uses light transmission or reflection properties of the fluid to determine volume, eliminating mechanical wear and complexity while providing precise, non-contact measurement capability in the wearable pump.
3Reliability
If automated control systems with computer-readable media are implemented, then operational reliability is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The reusable pump unit is designed as a universal platform that can accommodate multiple different disposable cartridges for various medications and delivery schedules. The automated control system with computer-readable media is programmed to handle diverse infusion protocols, making the same hardware applicable to many therapeutic scenarios. This multi-functionality amortizes the manufacturing cost of the complex automated system across many uses and applications.
Solution Approach 2:
The system is designed so that the expensive, complex reusable pump unit with automated control can be recovered and reused indefinitely, while only the simple disposable cartridges are discarded. This strategy allows the high manufacturing cost of the automated control system to be justified by its extended service life and repeated use, while the disposable components bear the lower manufacturing cost.
4Reliability
If valve assemblies are added to isolate pump and sensor components, then system reliability and leak prevention are improved, but device complexity increases
Solution Approach 1:
The valve functions are merged into the disposable cartridge design rather than being separate components in the reusable pump. The cartridge incorporates integrated valves or check valves that automatically control fluid flow direction and prevent backflow or leakage. This integration eliminates the need for additional valve assemblies in the reusable pump, reducing overall device complexity while maintaining reliable leak prevention through the disposable portion.
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 provides a reliable, compact, and cost-effective wearable infusion pump system that accurately measures and delivers therapeutic fluids, reducing malfunctions and improving user convenience by enabling automated and precise control of fluid administration.
Implementation Method 1
at least one optical sensor assembly configured to sense the position of the pump plunger
Implementation Method 2
a volume sensor assembly configured to measure a volume of fluid in the reservoir
Implementation Method 3
utilizing shape-memory actuators and a computer-readable medium for automated control and operation
Data Source
AI summary
A wearable infusion pump assembly includes a reservoir for receiving an infusible fluid, and an external infusion set configured to deliver the infusible fluid to a user. A fluid delivery system is configured to deliver the infusible fluid from the reservoir to the external infusion set. The fluid delivery system includes a volume sensor assembly, and a pump assembly for extracting a quantity of infusible fluid from the reservoir and providing the quantity of infusible fluid to the volume sensor assembly. The volume sensor assembly is configured to determine the volume of at least a portion of the quantity of fluid. The fluid delivery system further includes at least one optical sensor assembly configured to sense the movement of the pump assembly, a first valve assembly configured to selectively isolate the pump assembly from the reservoir, and a second valve assembly configured to selectively isolate the volume sensor assembly from the external infusion set.