Voice-Coil Actuated Pulsatile Pump for Physiologic Blood Flow
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Solution Overview
Problem
Existing cardiopulmonary bypass and circulation systems lack the ability to accurately replicate physiological blood pressure and flow patterns, leading to limitations in response time, position control, and operational accuracy, and require frequent maintenance due to bulky and cumbersome components.
Innovation Solution
A physiologic pulsatile pump system featuring a housing with a compressible-expandable bladder and a hydraulic actuator driven by a voice-coil motor, controlled by a programmable motion controller and touch-screen interface, which duplicates blood pressure and flow patterns by varying the bladder volume to mimic physiological conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional hydraulic actuator with a motor and gear box is used to drive the pump, then the pump can generate pulsatile blood flow, but the system becomes bulky, cumbersome, and requires frequent maintenance due to wear on motor brushes, gearbox, and clutch mechanism
Solution Approach 1:
The patent replaces the traditional mechanical actuator system (motor with brushes, gear box, clutch mechanism) with a voice-coil electromagnetic actuator. This substitution eliminates mechanical wear components while maintaining the ability to generate pulsatile motion, directly resolving the contradiction between reliability and device complexity.
Solution Approach 2:
The patent uses a hydraulic actuator with a pressure transmissive fluid to transmit the voice-coil's linear motion to the bladder. This hydraulic transmission mechanism allows for precise control of bladder volume while eliminating the need for direct mechanical connection between the voice-coil and pump components, reducing complexity and maintenance requirements.
2Measurement precision
If conventional non-physiologic pump systems are used for cardiopulmonary bypass, then the systems can provide blood circulation, but they fail to accurately replicate physiological blood pressure and flow patterns, limiting response time and operational accuracy
Solution Approach 1:
The patent implements a dynamically controllable system where the voice-coil actuator can rapidly adjust the bladder volume in response to real-time physiological feedback. The system includes sensors that monitor blood pressure and flow, and a control mechanism that dynamically adjusts pump operation to replicate natural cardiac cycles, achieving both high precision and fast response time.
Solution Approach 2:
The patent incorporates feedback control mechanisms where physiological parameters (blood pressure, flow rate) are continuously monitored and used to adjust the voice-coil actuator's operation. This closed-loop control system ensures accurate replication of physiological patterns while maintaining rapid response capability, resolving the contradiction between precision and response time.
3Ease of operation
If a voice-coil motor is used to directly drive the pump mechanism, then the system achieves better control over pulse rate and stroke volume, but the system becomes more sensitive to positioning and requires precise control mechanisms
Solution Approach 1:
The patent introduces a hydraulic fluid as an intermediary between the voice-coil actuator and the bladder. The voice-coil's linear motion is transmitted through the incompressible hydraulic fluid to produce controlled bladder expansion and contraction. This intermediary mechanism amplifies the voice-coil's motion and provides smooth, precise control over bladder volume without requiring direct mechanical coupling, thereby reducing positioning sensitivity while maintaining ease of operation.
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 system provides accurate and reliable pulsatile blood flow, reducing post-operative deaths, improving vital organ recovery, and maintaining microcirculation, while eliminating the need for frequent maintenance and improving control over pulse rate, stroke volume, and upstroke-rise time.
Implementation Method 1
A voice-coil motor, the type used in loud speakers, is operably associated with the hydraulic actuator for moving the pressure imparting member
Implementation Method 2
The hydraulic actuator includes a pressure transmissive fluid and a flexible diaphragm for generating a pulsatile pressure on the transmissive fluid. This, in turn, results in a pulsatile pressure being exerted on the bladder
Data Source
AI summary
A pulsatile blood circulating pump system for use in cardiopulmonary bypass, ventricular assist (LVAD, RVAD, BiVAD), ECMO, organ preservation, fetal cardiac bypass, cancer treatment, and areas of circulation research, which is controlled to produce blood flow that approximates physiological blood flow. The pump system includes a pulsating mechanism having a housing defining a chamber with a compressible-expandable bladder sealably mounted. A hydraulic actuator having a pressure imparting member that acts upon pressure transmissive fluid contained within the actuator chamber to generate a pulsatile pressure on the transmissive fluid, which results in pulsatile pressure being exerted on bladder to controllably vary the volume thereof. Additionally, the system includes a compact, motor that is associated with the hydraulic actuator for moving the pressure imparting member within the fluid chamber and further includes a fully programmable motion controller that controls the motor. The system includes a programmable touch-screen component to control the motion controller.