Roller Pump Occlusion Control for Variable Tubing Compression
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Solution Overview
Problem
Existing roller pumps face challenges in adjusting occlusion to accommodate varying fluid tubing diameters, leading to potential blood cell lysis or inadequate flow, with manual adjustment methods being time-consuming and imprecise, and current actuating mechanisms offering poor mechanical advantage.
Innovation Solution
A roller pump with an occlusion adjustment mechanism that includes a sensor arrangement to measure pressure or force exerted by each roller, allowing independent adjustment of roller blocks based on measured values, using linear actuators and encoders to maintain precise occlusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If manual adjustment of occlusion is used to accommodate varying fluid tubing diameters, then adaptability is improved, but adjustment precision and time efficiency deteriorate
Solution Approach 1:
The patent replaces manual mechanical adjustment with an automated actuating mechanism comprising a motor, encoder, and lead screw. The motor drives the lead screw to rotate, which moves the roller block radially to adjust occlusion. The encoder provides feedback on the roller block position, enabling precise control of occlusion levels without manual intervention.
Solution Approach 2:
The system performs self-adjustment through automatic occlusion detection and control. The sensor arrangement detects occlusion levels, and the control system automatically adjusts the roller block position via the actuating mechanism to maintain optimal occlusion, eliminating the need for manual adjustment by operators.
2Productivity
If complete compression of tubing is applied to ensure adequate fluid flow, then fluid flow is improved, but harmful effects on blood cells increase
Solution Approach 1:
The patent employs a sensor arrangement that detects the occlusion level by measuring parameters such as current, voltage, or power consumption of the roller motor. This feedback is sent to the control system, which adjusts the roller block position to maintain optimal occlusion—sufficient to prevent backflow but not so high as to cause complete tubing collapse and blood cell damage.
Solution Approach 2:
The system dynamically adjusts occlusion levels based on real-time feedback from the sensor arrangement. The actuating mechanism can modify the roller block position during operation to optimize the balance between achieving adequate fluid flow and preventing harmful compression that would cause blood cell lysis.
3Productivity
If multiple rollers are used to pump fluid, then pumping capability is improved, but consistency of compression across rollers becomes difficult to maintain
Solution Approach 1:
The patent extends the actuating mechanism to control multiple roller blocks, allowing each roller to be independently adjusted. The sensor arrangement monitors occlusion at each roller position, and the control system coordinates adjustments across all rollers to maintain consistent compression levels, enabling multi-roller pumps to achieve both high pumping capability and uniform compression.
4Speed
If rapid movement of rollers to engage tubing is required, then response time is improved, but fine adjustment capability deteriorates
Solution Approach 1:
The actuating mechanism provides dynamic control with variable resolution. During initial engagement, the motor can rotate the lead screw at higher speeds for rapid roller movement. Once engagement is achieved, the system transitions to fine-adjustment mode with slower, more precise movements, allowing operators or the control system to tune occlusion levels accurately without sacrificing initial response time.
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 precise and efficient adjustment of occlusion for fluid conduits, ensuring consistent fluid flow without damage, even with varying tubing diameters, by allowing individual actuation of each roller and continuous force measurement.
Implementation Method 1
an occlusion adjustment mechanism, connected to the roller block of each roller, wherein the occlusion adjustment mechanism operates to move each roller block radially with respect to a central axis of the pump head in order to compress and partially occlude a compressible fluid conduit disposed within the raceway
Data Source
AI summary
A roller pump including a pump head operably connected to be driven by a pump drive, wherein the pump head includes: a pump stator; a pump rotor disposed to rotate within the pump stator, wherein the pump rotor includes one or more rollers, wherein each roller is connected to a respective roller block that is moveable radially with respect to a central axis of the pump head; an occlusion adjustment mechanism, connected to the roller block of each roller, wherein the occlusion adjustment mechanism operates to move each roller block radially with respect to the central axis of the pump head in order to compress and partially occlude a compressible fluid conduit disposed within the raceway; and a sensor arrangement configured to measure a pressure exerted by the roller block of at least one roller when the compressible fluid conduit is compressed by one or more of the rollers.