LVAD Suction Detection via Pump Speed and Current Ratio
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Solution Overview
Problem
Current systems for detecting suction conditions in implantable blood pumps are delayed, increasing the risk of harm to patients due to their reliance on flow waveform analysis, which does not provide timely detection.
Innovation Solution
A system utilizing a controller with a control circuit that calculates data values within a hysteresis window to determine a suction detection threshold, comparing the present value of pump speed divided by current to this threshold, and generating an alert when exceeded, allowing for instantaneous detection and classification of suction condition severity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If flow waveform analysis is used to detect suction conditions, then detection accuracy is improved, but detection time is delayed
Solution Approach 1:
The system pre-calculates and stores baseline values and pulsatility values during normal pump operation before suction occurs. These pre-computed values are stored in memory and ready for immediate comparison when suction detection is needed, eliminating the delay of real-time calculation during critical events
Solution Approach 2:
The patent replaces the traditional flow waveform analysis method with a new detection mechanism based on the relationship between pump speed and current. By using the formula PV = RPM/M (where PV is present value, RPM is pump speed, and M is current), the system achieves instantaneous detection without relying on flow waveform processing
2Productivity
If pump speed is increased to maintain flow rate, then productivity is improved, but risk of suction condition increases
Solution Approach 1:
The system continuously monitors the relationship between pump speed and current by calculating present values and comparing them against pre-stored baseline and pulsatility values. When suction is detected (PV exceeds threshold), the system provides immediate feedback to alert the patient and clinician, enabling rapid response to prevent ventricle collapse
Solution Approach 2:
Baseline values and pulsatility values are pre-calculated during normal operation and stored in memory before suction conditions occur. This preliminary preparation allows for instantaneous comparison and detection when suction begins, enabling faster protective action
Data Source
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AI summary
A system for detecting a suction condition in an implantable blood pump including a controller in communication with the blood pump. The controller includes a control circuit configured to calculate a present value during a time period, the present value corresponding to a pump speed divided by a pump current, determine a plurality of data values during the time period based on the present value, and determine a suction detection threshold value using the plurality of data values. The control circuit is also configured to compare the present value during the time period to the suction detection threshold value and generate an alert when the present value exceeds the suction detection threshold value on a plurality of instances during the time period, the alert corresponding to a suction condition.