Rate Responsive Pacemaker Posture Verification
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Solution Overview
Problem
Current pacemakers face challenges in accurately adjusting heart rate based on patient activity due to false signals caused by body posture, leading to inappropriate pacing rate adjustments.
Innovation Solution
An implantable rate responsive pacemaker system that uses activity and posture sensors to determine a sensor-indicated pacing rate, verifying the patient's posture before adjusting the pacing rate to ensure accurate heart rate responses to physical activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the pacemaker adjusts pacing rate based on activity sensor signals, then the pacing rate responds to metabolic demand, but false posture signals cause inappropriate pacing rate adjustments
Solution Approach 1:
The patent introduces posture verification as an intermediary check between the activity sensor signal and the pacing rate adjustment. The control module verifies that the posture signal indicates an exercising posture before allowing the activity-based pacing rate adjustment to take effect. This intermediary verification step filters out false activity signals caused by non-exercising postures, thereby improving the reliability of pacing rate adjustments while maintaining adaptability to genuine metabolic demand.
2Productivity
If the pacemaker uses activity sensor signals for rate responsive pacing, then heart rate meets metabolic demand, but body posture causes false signals leading to unnecessary rate adjustments
Solution Approach 1:
The patent implements a feedback mechanism where the posture sensor continuously monitors body posture and provides feedback to the control module. This feedback is used to validate or reject activity-based pacing rate adjustments. When the posture feedback indicates a non-exercising posture, the system withholds the activity-based rate adjustment despite activity sensor signals, thereby eliminating false signals caused by body posture while maintaining accurate response to genuine metabolic demand.
3Speed
If the pacemaker adjusts pacing rate without posture verification, then rate response is rapid, but false posture signals cause inappropriate adjustments
Solution Approach 1:
The patent applies preliminary action by performing posture verification before executing the pacing rate adjustment. The control module checks the posture signal in advance to confirm an exercising posture is detected before allowing the activity-based rate adjustment to occur. This preliminary verification ensures that only genuine exercise-induced activity signals result in pacing rate changes, maintaining both rapid response to valid metabolic demand and high reliability by preventing false adjustments from non-exercising postures.
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 effectively prevents unnecessary heart rate adjustments by confirming exercising posture, thereby maintaining an appropriate pacing rate that meets metabolic demands without false increases due to body position.
Implementation Method 1
an accelerometer sensor subjected to motion of the patient's body when the patient is active
Data Source
Figure 1
Figure 2A~2C
Figure 3
AI summary
An implantable rate responsive pacemaker includes a sensor module configured to produce an activity signal correlated to a metabolic demand of a patient and a posture signal correlated to patient posture. The pacemaker further includes a pulse generator configured to generate and deliver pacing pulses to a patient's heart via a pair of electrodes coupled to the pacemaker. A control module is coupled to the pulse generator and the sensor module and is configured to determine a sensor indicated pacing rate from the activity signal, compare the posture signal to verification criteria for confirming an exercising posture of the patient, and withhold an adjustment of a pacing rate to the sensor indicated pacing rate responsive to the verification criteria not being met.