Implantable Blood Pump Speed Modulation for Low-Pulsatility MAP
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Solution Overview
Problem
Determining mean arterial pressure (MAP) in patients with implantable blood pumps is challenging due to low pulsatility, as traditional methods struggle to detect weak pulse signals, leading to potential medical complications.
Innovation Solution
A method and system that adjusts the speed of the impeller in an implantable blood pump based on current and blood flow measurements during the cardiac cycle to amplify and attenuate arterial pressure, allowing for accurate MAP measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional blood pressure measurement methods are used, then the measurement process is simple, but the measurement precision is insufficient due to weak pulse signals in low pulsatility patients
Solution Approach 1:
The patent uses the implantable blood pump itself as an intermediary device to amplify the weak pulse pressure signals. By modulating the pump speed in synchrony with the cardiac cycle, the pump creates detectable variations in blood flow that serve as a mediator between the weak physiological signal and the measurement instrument, enabling accurate MAP determination without requiring external complex measurement equipment
Solution Approach 2:
The patent applies periodic modulation of the blood pump speed synchronized with the cardiac cycle. The controller increases pump speed during systole and decreases it during diastole, creating periodic variations in blood flow that amplify the pulse pressure signal. This periodic action transforms the weak, undetectable pulse pressure into a strong, detectable signal pattern that can be reliably measured to determine MAP
2Measurement precision
If the blood pump operates at constant speed, then the device operation is simple, but the signal strength for blood pressure detection remains insufficient
Solution Approach 1:
The controller modulates the blood pump speed periodically in synchrony with the detected cardiac cycle. During systole, the pump speed is increased to amplify the pulse pressure signal, and during diastole, it is decreased. This periodic speed modulation creates detectable variations in blood flow that significantly enhance the pulse pressure signal strength, enabling accurate MAP measurement while maintaining relatively simple pump control logic
Solution Approach 2:
The system employs feedback control where the controller continuously monitors blood flow or current variations that correlate with cardiac cycle phases. Based on this feedback, the controller automatically adjusts the pump speed to amplify pulse pressure signals during systole and attenuate them during diastole. This feedback mechanism enables automatic signal enhancement without requiring complex manual intervention, maintaining ease of operation while improving measurement precision
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 MAP determination by synchronizing impeller speed with the cardiac cycle, enhancing signal strength for reliable blood pressure readings and reducing medical complications.
Implementation Method 1
measuring at least one from the group consisting of a current drawn by the implantable blood pump and a blood flow from the implantable blood pump during operation
Implementation Method 2
adjusting a speed of an impeller of the implantable blood pump relative to a predetermined speed to correspond to an increase in the at least one from the group consisting of the current and the blood flow during a systolic phase of a cardiac cycle and a decrease in the at least one from the group consisting of the current and the blood flow during a diastolic phase of a cardiac cycle
Data Source
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AI summary
An implantable blood pump system including a blood pump, an impeller in communication with the blood pump, and a controller in communication with the blood pump. The controller is configured to measure a current drawn by the blood pump and a blood flow from the blood pump during operation, correlate the current to a systolic arterial pressure and a diastolic arterial pressure, and adjust a speed of the impeller relative to a predetermined speed and the blood flow to correspond to an increase in the current correlated to the systolic arterial pressure and a decrease in the current correlated to the diastolic arterial pressure.