Wearable cardioverter defibrillator (WCD) system detecting QRS complexes in ECG signal by matched difference filter

Inventors

Sullivan, Joseph L.

Assignees

West Affum Holdings DAC • Kestra Medical Technologies Inc

Abstract

In embodiments, a wearable cardioverter defibrillator (WCD) system includes electrodes that render an ECG signal of the patient, and a processor that receives ECG data are derived from the rendered ECG signal. The processor may filter the received ECG data with a matched difference filter to detect QRS complexes, and compute a heart rate from the detected QRS complexes. The matched difference filter itself can have coefficient values associated with a baseline QRS complex, which improves detection.

Core Innovation

The disclosure relates to a wearable cardioverter defibrillator (WCD) system that renders an electrocardiogram (ECG) signal of a patient while the patient is wearing a support structure. The system includes an energy storage module configured to store an electrical charge and a discharge circuit coupled to the energy storage module. Electrodes render the ECG signal, and a processor receives ECG data derived from the rendered ECG signal having values f(m).

The processor computes outputs for multiple values of a positive integer n according to an equation comprising a matched difference term (MDT). The MDT is a function of a difference of a first function F[] of the values f(m) and a second function G[] of coefficient values g(m) associated with a baseline QRS complex. The processor detects QRS complexes from the computed outputs and computes a heart rate from the detected QRS complexes, then determines whether a shock criterion is met.

Responsive to the shock criterion being met, the processor controls the discharge circuit to discharge the stored electrical charge through the patient while the support structure is worn, so as to deliver a shock to the patient. Additional aspects assess agreement between the detected heart rate and the computed heart rate and update the MDT for subsequent computing of the outputs when agreement is high. Further refinements include assessing agreement to set ECG signal quality high and updating an adaptive matched filter kernel when ECG signal quality is high.

Claims Coverage

The partial document provides four independent claim sets. Across these independent claims, the main inventive features include using an MDT defined by functions F[] and G[] with baseline QRS-associated coefficient values g(m) to detect QRS complexes, computing a heart rate from the detected QRS complexes, determining whether a shock criterion is met, and controlling discharge of stored electrical charge through the patient while a WCD support structure is worn.

Across the independent claims in the partial content, the common inventive structure is the use of MDT-based (or adaptive matched filter-based) processing of ECG data to detect QRS complexes, compute heart rate(s), determine whether a shock criterion is met, and control discharge of stored electrical charge through the patient while the WCD support structure is worn. Additional claim coverage includes updating MDT or an adaptive matched filter kernel when agreement and/or ECG signal quality is high.

Stated Advantages

Documented Applications