Rotary Pump Occlusion Detection via Optical Rotor Position
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current fluid infusion devices with rotary micropump mechanisms lack effective methods for reliably detecting upstream and downstream occlusions, which are critical for ensuring accurate and safe medication delivery.
Innovation Solution
The implementation of a fluid infusion device with a rotary pump mechanism that includes a stator and rotor with cam elements, a sensor contact element, and a sensing element, which cooperate with a detection circuit to monitor the angular position and detect occlusions through contact and non-contact sensing technologies, such as electrical, optical, and force sensors, to determine operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a rotary micropump mechanism is used for fluid delivery, then precise volume delivery with each cycle is achieved, but reliable detection of upstream and downstream occlusions becomes difficult
Solution Approach 1:
A sensor contact element is introduced as an intermediary between the rotor cam element and stator cam surface. This mediator enables indirect detection of occlusion conditions by sensing changes in the mechanical interaction between pump components, thereby solving the contradiction between maintaining precise micropump operation and enabling reliable occlusion detection
Solution Approach 2:
The patent replaces direct mechanical observation of pump operation with optical or electrical sensing. The sensor contact element converts mechanical state changes (contact vs. non-contact) into detectable signals, substituting mechanical detection methods with more reliable sensor-based detection while preserving the precision of the rotary micropump mechanism
2Reliability
If sensor contact element is placed on rotor reference surface in area unoccupied by rotor cam element, then downstream occlusion detection is enabled, but device complexity increases
Solution Approach 1:
The rotor structure is designed to serve multiple functions: the rotor cam element performs the primary pumping function while the reference surface with sensor contact element provides occlusion detection. This multi-functionality approach enables occlusion detection without adding separate dedicated components, thereby reducing the net increase in device complexity
Solution Approach 2:
The sensor contact element is merged with the rotor structure, specifically placed on the reference surface. This integration combines the sensing function with the existing rotor component rather than adding a separate sensing mechanism, thereby enabling occlusion detection while minimizing the increase in overall device complexity
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
Enables reliable detection of occlusions, preventing medication delivery errors and ensuring safe operation by triggering alerts or adjusting the pump mechanism accordingly, thus maintaining the integrity of the fluid delivery process.
Implementation Method 1
an optical sensor to detect the angular position of the rotor
Data Source
AI summary
A fluid infusion device includes a fluid pump mechanism having a rotor and a stator. The rotor includes an optically detectable feature, a reference surface, and a cam element rising from the reference surface. The stator includes a cam element having a stator cam surface. The cam elements cooperate to axially displace the rotor as a function of angular position of the rotor, wherein the detectable feature rotates and axially translates as a function of angular position of the rotor. A biasing element provides force to urge the rotor cam element toward the stator cam element and toward the reference surface. A drive motor actuates the rotor to pump medication fluid from a fluid cartridge module to a body, via a subcutaneous conduit. An optical detection circuit interrogates the detectable feature during operation of the fluid pump mechanism to determine an operating condition of the fluid pump mechanism.