Disposable Dual-Action Reciprocating Pump Pulsation Reduction
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Solution Overview
Problem
Existing disposable medical pumps, particularly those designed for single-use, face challenges in providing a constant flow rate without generating electrical noise due to the flexing of plastic components, which can interfere with medical devices.
Innovation Solution
A disposable single-piston dual-action reciprocating pump part with integrated pulsation-reduction elements, including a balloon damper and mechanical smoothing mechanism, to regulate fluid flow and minimize pulsations, coupled with low-cost silicone O-rings for sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a disposable pump uses a single piston reciprocating mechanism, then the device complexity is reduced and manufacturing cost is lowered, but the output flow becomes pulsating rather than steady
Solution Approach 1:
The pump mechanism is segmented into two independent pistons that operate in parallel within separate cylinders. Each piston has its own valve assembly and driveshaft connection, allowing independent control and movement. This segmentation enables the system to achieve steady flow output while maintaining relatively simple individual components suitable for disposable use.
Solution Approach 2:
The two pistons operate with a phase difference of 180 degrees, creating periodic alternating action where one piston is compressing fluid while the other is expanding. This periodic alternation smooths out the overall flow output, converting the pulsating motion of individual pistons into a more steady continuous flow, which is essential for medical infusion applications.
2Reliability
If the pump uses traditional sealing mechanisms, then the sealing function is achieved, but electrical noise is generated due to flexing of plastic components
Solution Approach 1:
Traditional mechanical sealing components that flex and vibrate during operation are replaced with a magnetic coupling mechanism. The drive shafts are magnetically coupled to the pistons, eliminating the need for mechanical seals and flexible plastic components in the sealing path. This substitution removes the source of electrical noise generation while maintaining reliable sealing through the magnetic field transmission mechanism.
3Ease of manufacture
If the pump is designed for single-use disposable application, then manufacturing cost is reduced, but the ability to provide constant flow rate is compromised
Solution Approach 1:
The pump design merges the drive mechanism and pumping chambers into an integrated assembly where the two-piston system shares common structural elements. The drive shafts, magnetic couplings, and valve assemblies are combined in a unified configuration that maintains flow consistency while reducing component count and manufacturing complexity, making the device suitable for disposable application.
Solution Approach 2:
The dual-piston system provides continuous useful action by ensuring that at least one piston is always in the compression stroke, continuously pushing fluid through the system. This continuous operation eliminates dead time and maintains steady flow rate throughout the pump cycle, achieving consistent performance without requiring complex control mechanisms that would increase manufacturing cost.
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 pump achieves a steady fluid flow with reduced pulsations, suitable for medical procedures like intravenous infusion and radiofrequency cardiac ablation, while maintaining cost-effectiveness and avoiding electrical interference.
Implementation Method 1
a balloon configured to be compressed by surrounding fluid during a constant speed travel section of the piston, and to expand at the end-points of piston travel, when fluid pressure drops
Implementation Method 2
a balloon configured to be compressed by surrounding fluid during a constant speed travel section of the piston
Implementation Method 3
a piston configured to separate the input port from the output port to pump fluid through the cylinder
Implementation Method 4
Four non-return valves open and close interchangeably (in pairs) to provide dual-action pumping
Implementation Method 5
a rod configured to be coupled to the rotary motor, so as to drive the piston
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A pump device includes a rotary motor, a compartment for insertion of a disposable pump part, and one or more pulsation-reduction elements. The disposable pump part includes an input port, an output port, and a dual-action reciprocating assembly. The input port is configured for intaking fluid. The output port is configured for outputting the fluid. The dual-action reciprocating assembly is configured for pumping the fluid. The assembly includes a single piston and a rod configured to be coupled to the rotary motor, so as to drive the piston. The one or more pulsation-reduction elements are configured to reduce a pulsation in the outputted fluid, caused by the single-piston dual-action reciprocating assembly.