Apparatus and method for using ECG to recover pulse waveform and other hemodynamics

Inventors

Segman, Yosef • SEGMAN, Yehonatan

Assignees

CNOGA Medical Ltd

Abstract

An apparatus generates a pulse (or other hemodynamic) signal from an ECG signal, and displays a waveform of that signal. An ECG unit comprises electrode(s) for receiving an ECG signal waveform from live tissue and for generating a digital ECG signal; a memory storage; hardware processor(s) configured to constantly apply an integral function to the digital ECG signal and display a waveform of the integral function during a time period. The waveform of the integral function has a shape of a pulse signal waveform of the subject during the time period. The integral function comprises PWF(t)T=A∫tt+TF(ECG(u))du ECG(u) represents an ECG over a specific time period using a specific time resolution. T is determined from the ECG(u) time resolution and pulse frequency, T satisfies the Nyquist sampling theory, t, u are time variables and A is a positive constant. The memory stores the integral function waveform. A weight function PWF(t)T=A∫tt+TF(ECG(u))·W(u−t)du may be included.

Core Innovation

The invention generates, from an ECG signal, a signal corresponding to a pulse signal waveform of a mammalian subject and displays a waveform of that signal. An ECG unit comprising at least one electrode obtains and outputs the ECG signal from live tissue and configured to generate a digital ECG signal during a period of time if the waveform of the ECG signal is not already digital. The digital ECG signal is stored in a memory storage during the period of time.

One or more hardware processors constantly apply an integral function to the digital ECG signal and initiate a display signal to a digital display device to display the waveform of the integral function during the period of time. The waveform of the integral function has a shape of the pulse signal waveform of the subject taken during the period of time, where the integral function comprises PWF(t)T=A∫t^(t+T)F(ECG(ν))du. The pre-processing operator F is applied to reduce or eliminate noise before integration or to smooth or sharpen the digital ECG signal before integration, and the integration interval T is determined from the ECG(u) time resolution and from a pulse or ECG peak rate in which T satisfies the Nyquist sampling theory.

The apparatus and the method continuously store the waveform of the integral function having the shape of the pulse signal waveform and constantly display the waveform. The document also describes that the ECG unit, the memory storage, one or more hardware processors, and a digital display device may be located remotely from at least one other component. Further embodiments derive additional hemodynamic parameters from the recovered pulse waveform, including systolic blood pressure, diastolic blood pressure, stroke volume, cardiac output, blood vessel properties, and peripheral blood perfusion and related variations.

Claims Coverage

The independent claims cover three implementation forms: a medical apparatus, a method, and a non-transitory computer-readable storage medium. Across these forms, the claims share an integral-function transformation that continuously generates a pulse-shaped waveform from a digital ECG signal with Nyquist-consistent integration interval selection and pre-processing via a pre-processing operator F.

Taken together, the independent claims require continuous generation of a pulse-shaped waveform from a digital ECG signal using an integral function with pre-processing operator F and an integration interval T determined to satisfy Nyquist sampling theory, with continuous storage and display (and in the apparatus, also printing). Optional refinements include weighted integration and remote/distributed placement of system components, and the same integral-function computation is implemented via a non-transitory computer-readable storage medium.

Stated Advantages

Documented Applications