Variable Speed Irrigation Pump for Cardiac Ablation
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Solution Overview
Problem
Medical irrigation pumps face challenges in controlling fluid flow rates during cardiac ablation procedures, which can introduce electrical noise interfering with magnetic position tracking systems and fail to maintain consistent irrigation parameters, affecting patient safety and procedure quality.
Innovation Solution
A dual-action irrigation pump with variable speed control, featuring a cylinder and piston system with first and second inlet-outlet ports, and a controller that adjusts piston movement speed between predefined intervals to maintain constant fluid flow, oscillate during non-ablation modes, and adjust speeds based on tissue ablation site conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the piston moves at constant speed during ablation, then the fluid flow rate is simplified to control, but the irrigation parameters become inconsistent and electrical noise increases
Solution Approach 1:
The piston speed is dynamically adjusted based on the operational mode (ablation vs. non-ablation) and the specific phase of the ablation cycle. During ablation, the piston operates at a first speed for a first duration, then transitions to a second speed for a second duration, creating a variable speed profile that maintains consistent irrigation parameters while reducing electrical noise interference with magnetic position tracking.
Solution Approach 2:
The pump employs periodic variation of piston speed within each ablation cycle. The controller alternates between different piston speeds during the ablation phase, creating a periodic action that prevents continuous electrical noise generation while maintaining adequate fluid flow for irrigation during the ablation procedure.
2Object-affected harmful factors
If the piston oscillates during non-ablation mode, then electrical noise is minimized, but the fluid flow rate becomes variable and harder to control
Solution Approach 1:
The system dynamically adjusts piston behavior based on operational mode. During non-ablation mode, the piston oscillates at a lower speed to minimize electrical noise generation. The controller monitors the operational state and adjusts the oscillation parameters accordingly, balancing noise reduction with adequate fluid delivery capability.
3Productivity
If the piston speed is increased during ablation, then the fluid flow rate increases, but electrical noise interferes with magnetic position tracking
Solution Approach 1:
The piston speed is dynamically optimized based on the ablation phase. The controller implements a two-speed strategy during ablation: a first speed for a first duration to maintain adequate fluid flow, followed by a second speed for a second duration to reduce electrical noise. This dynamic adjustment allows the system to maximize productivity while minimizing harmful electrical noise interference with magnetic position tracking.
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
Improves patient safety and procedure quality by precisely controlling irrigation parameters during and between ablations, minimizing electrical noise and ensuring consistent fluid flow, thus enhancing the effectiveness of cardiac ablation procedures.
Implementation Method 1
The piston is configured to be moved within the cylinder in a periodic cycle that alternately reverses a direction of movement of the piston, so as to pump the fluid through the first and second inlet-outlet ports
Implementation Method 2
The controller is configured to control the movement of the piston within the cylinder, including setting to the piston: (a) a first speed, during a first predefined interval that precedes reversing the direction of movement, (b) a second speed, larger than the first speed, during a second predefined interval that follows reversing the direction, and (c) a baseline speed, smaller than the first speed, outside the first and second intervals
Implementation Method 3
The outlet valve is connected to an exit chamber, which is separated from the exit valve by an elastomeric membrane. The elastomeric membrane encloses an accumulation chamber which is filled with a fluid such as air under atmospheric pressure. Pulsations in outlet pressure caused by stroking of the piston are dampened by the flexing action of the elastomeric membrane
Implementation Method 4
The electrode includes passages positioned to allow saline flow out of an inner cavity of the electrode. This fluid flow is pulsatile to increase turbulence, reducing areas of stagnant flow, and produces a desired cooling effect
Data Source
AI summary
A pump includes a cylinder, a piston and a controller. The cylinder has first and second ends and includes first and second inlet-outlet ports, each of the first and second inlet-outlet ports is configured to alternately intake a fluid to the cylinder and output the fluid from the cylinder. The piston is configured to be moved within the cylinder between the first and second ends by alternately reversing a direction of movement of the piston, so as to pump the fluid through the first and second inlet-outlet ports. The controller is configured to control the movement of the piston within the cylinder, including: (a) choosing between first and second operational modes, (b) in the first operational mode, controlling the piston to oscillate over a predefined interval that does not exceed a predefined distance from the first end or from the second end, and (c) in the second operational mode, controlling the piston to move at a selected speed between the first end and the second end.