Implantable Device Posture Bins for Arrhythmia Detection
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Solution Overview
Problem
Current implantable medical devices (IMDs) face challenges in accurately detecting arrhythmias due to shifts in position and orientation, which can lead to false positive or false negative declarations, affecting the reliability of arrhythmia detection algorithms.
Innovation Solution
A computer-implemented method and system that utilize cardiac activity signals, acceleration signatures indicative of heart sounds, and device location information to group cardiac beats into posture bins, allowing for the identification of changes in heart conditions and applying new parameter values to the arrhythmia detection algorithm based on patient posture, thereby improving the accuracy of arrhythmia detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the ICM continuously monitors cardiac activity, then the detection of arrhythmias is improved, but the reliability of detection deteriorates due to false positives and negatives caused by position and orientation shifts
Solution Approach 1:
The system uses the accelerometer to continuously monitor device position and orientation, providing feedback to the arrhythmia detection algorithm. When position or orientation changes are detected, the algorithm adjusts its analysis parameters accordingly, creating a closed-loop system that maintains reliability during continuous monitoring.
Solution Approach 2:
The arrhythmia detection algorithm is made dynamic by continuously adapting to changes in device position and orientation. The system adjusts detection parameters and analysis methods based on real-time accelerometer data, allowing the algorithm to maintain accuracy despite changing physical conditions during continuous monitoring.
2Adaptability or versatility
If the ICM housing shifts in position and orientation, then the device adapts to patient movement, but the electrode position changes cause inaccurate cardiac activity signals
Solution Approach 1:
The accelerometer provides continuous feedback on device position and orientation changes. This feedback is fed to the arrhythmia detection algorithm, which then adjusts its analysis parameters to compensate for the position changes, maintaining signal quality while allowing the device to adapt to patient movement.
Solution Approach 2:
The system changes detection parameters dynamically based on measured position and orientation. When the accelerometer detects a change in device orientation, the algorithm modifies its analysis parameters (such as signal thresholds and filtering characteristics) to maintain measurement precision despite the physical repositioning.
3Measurement precision
If the 3-D accelerometer detects device rotation and translation, then posture detection is improved, but the calibration accuracy deteriorates when the device is not in the expected position
Solution Approach 1:
The system performs preliminary calibration to establish the initial relationship between accelerometer readings and device orientation. During operation, when position changes are detected, the system uses the calibrated information to adjust posture detection, maintaining accuracy without requiring recalibration.
Solution Approach 2:
The accelerometer continuously monitors device position and provides feedback to the calibration system. This feedback allows the system to track position changes and adjust posture detection parameters accordingly, maintaining both measurement precision and calibration accuracy throughout the device's operational life.
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
Enhances the reliability of arrhythmia detection by reducing false positives and negatives, allowing for more accurate monitoring and treatment of heart conditions by accounting for changes in patient posture and device orientation.
Implementation Method 1
The 3-D accelerometers are calibrated with respect to a gravitational force of the earth, thereby defining the coordinate system of the IMD relative to gravity
Implementation Method 2
the 3-D accelerometer may detect rotation based on the position and/or orientation of the ICM and more generally the IMD. For example, the 3-D accelerometer may detect a difference in the position and/or orientation of the IMD, based on the heart sound difference
Data Source
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AI summary
A computer implemented method and system for detecting arrhythmias in cardiac activity are provided. The method is under control of one or more processors configured with specific executable instructions. The method obtains cardiac activity (CA) signals at the electrodes of an implantable medical device (IMD) in connection multiple cardiac beats and with different IMD orientations relative to gravitational force. The method obtains acceleration signatures at a sensor of the IMD that are indicative of heart sounds generated during the cardiac beats. The method obtains device location information at the IMD, with respect to the gravitational force during the cardiac beats. The method groups the acceleration signatures associated with the first and second set of cardiac beats into the corresponding one of first and second posture bins based on the device location information. The method identifies a difference between the acceleration signals in the first posture bin in connection with treating a heart condition.