50 results about "Fetal electrocardiogram" patented technology

The invention discloses a fetal electrocardiogram instantaneous heart rate recognition method and system based on non-negative blind separation. The method comprises the following steps that electrocardiosignals obtained through being collected by a fetal electrocardiogram machine are preprocessed, after the wavelet denoising, a coherent averaging method is used for removing electrocardiogram components of a mother to obtain the fetal electrocardiosignals, the fetal electrocardiosignals are converted to the time-frequency domain to obtain a Choi-Williams spectrum and a Born-Jordan spectrum, and then, the spectrums are converted into a non-negative frequency spectrum; non-negative matrix factorization is used for blind separation to obtain non-negative time frequency components of the fetal electrocardiosignals; the instantaneous heart rate is calculated, the non-negative time frequency components of the obtained fetal electrocardiosignals are subjected to maximum value detection, and a threshold value is set; an interval traversing method is adopted for obtaining the maximum value of signal intervals, and all peak value points of a electrocardiogram curve are obtained; all peak value coordinates of the obtained electrocardiogram curve are converted, the forward difference is sequentially carried out, and the instantaneous heart rate of the fetus is obtained through an instantaneous heart rate formula. The method and the system provided by the invention have the advantages that the recognition is fast and simple, and the accuracy is high.

A system for monitoring a fetus during gestation comprises an input for receiving a plurality of electric signals measured on a surface of a maternal body; and a processor for providing a fetal electrocardiogram based on the received electric signals and based on an orientation of the fetus, wherein the fetal electrocardiogram represents a projection of a fetal cardiac potential vector according to a predetermined projection direction that is fixed with respect to the fetus. The fetal vector electrocardiogram is projected according to the projection direction. An at least partial representation of a fetal vector electrocardiogram is provided in dependence on the plurality of electric signals and indicative of a time path of an electrical field vector generated by a fetal heart of the fetus.

The invention provides a fetal electrocardiogram signal detecting system. A first electrode set is arranged on a maternal shoulder part; a second electrode set is arranged on a maternal belly part, and is used for collecting a maternal belly signal; a signal acquisition module is used for acquiring the maternal belly signal and sending the maternal belly signal to an AD (Analog to Digital) conversion module; the AD conversion module is used for carrying out AD conversion on the maternal belly signal and generating the maternal belly signal in a digital signal manner; a control module is used for preprocessing and filtering the maternal belly signal and sending the maternal belly signal to a communication module; the communication module is used for forwarding the maternal belly signal to an upper computer; and the upper computer adopts a flank bipolar montage system for analyzing the maternal belly signal, and utilizes a component analysis method for separating a preliminary fetal electrocardiogram signal from the maternal belly signal. According to the fetal electrocardiogram signal detecting system provided by the invention, the weak fetal electrocardiogram signal can be extracted from a body surface, and the diagnosis of corresponding diseases is made according to relevant parameters of a fetal electrocardiogram.

The invention discloses a fetal electrocardiogram blind separation method based on a low signal-to-noise ratio. The method includes the steps that firstly, comb filtering is performed on multiple paths of source signals to eliminate 50 Hz power frequency interference, higher harmonic interference of 50 Hz and baseline drifts, and anti-aliasing low-pass filtering is performed on the multiple paths of source signals to remove high-frequency signal components with the frequency larger than half of sampling frequency; then, wavelet transformation is performed on the filtered source signals to obtain high frequency coefficients and low frequency coefficients of various dimensions, peak value function processing is performed on the high frequency coefficients of various dimensions to obtain high frequency coefficients containing electrocardiogram information of an expectant mother, and wavelet reconstruction is utilized for obtaining electrocardiogram signals of the expectant mother; then, the reconstructed expectant mother electrocardiogram signals containing noise are subtracted from the filtered source signals to obtain fetal electrocardiogram signals containing noise; finally, a blind separation algorithm is utilized for performing blind separation, and the multiple paths of fetal electrocardiogram signals containing noise are processed to obtain multiple paths of signals generated after blind separation. The method has great significance in monitoring perinatal fetuses, the fetal electrocardiogram extraction method is simple, calculation is fast, and accuracy is high.

The invention discloses a fetal electrocardiogram signal extracting method based on wavelet threshold denoising. The method comprises the following steps of: carrying out stationary wavelet transform processing on a maternal abdomen signal, and decomposing to obtain each layer of wavelet coefficient; independently processing each layer of wavelet detail coefficient, removing fetal electrocardiogram wavelet coefficients, reconstructing remained maternal electrocardiogram wavelet coefficients, and obtaining maternal electrocardiogram in the abdomen signal; removing the reconstructed maternal electrocardiogram from the abdomen signal to obtain a fetal electrocardiogram signal; and denoising the extracted fetal electrocardiogram by utilizing a wavelet correlation denoising algorithm to obtain a clear fetal electrocardiogram signal. Due to the method, the accurate extraction of the fetal electrocardiogram signal can be realized. The method is based on a single channel, the computation of wavelet transform modulus maxima is avoided, and better instantaneity is realized.

This invention provides a novel technique separating two mixed signals. The method is particularly useful for fetal electrocardiogram estimation. A maternal electrocardiogram signal recorded at the thorax area is nonlinearly mapped onto an electrocardiogram signal recorded at the abdomen using polynomial networks. The fetal electrocardiogram component is then estimated by subtracting the nonlinearly mapped maternal electrocardiogram signal from the abdominal electrocardiogram signal.

A system for the assessment and monitoring of the fetal electrocardiogram (ECG) and heart rate in a pregnant mother comprises wearable mechanical-electronic sensors, e.g., embedded in a wrist or arm band, which can measure the mechanical pulse signals from the mother, and an abdomen patch which can measure the combined ECG signals of the fetus and mother. The wrist or arm unit and the abdominal patch unit communicate wirelessly. By signal processing and gating out the maternal ECG signals as correlated with the mechanical maternal pulse signals, the fetal ECG and heart rate can be measured and monitored. These measurements may be displayed on the wrist or arm band device, or wirelessly through a remote device, mobile phone or computer. Electronic-mechanical sensors can also be embedded in the abdominal patch to measure uterine electromyogram (EMG), uterine contractions and fetal movements, to be correlated with the fetal ECG.

An apparatus for monitoring fetal positions and fetal movements is provided. The apparatus includes a plurality of sensors, a signal pre-processor, a signal post-processor, and a fetal position judging processor. The sensors are attached on the abdomen of a maternal body to provide at least three measuring leads. The signal pre-processor receives a plurality of sensing signals from the sensors, and the signal pre-processor reduces noises in the sensing signals and amplifies the sensing signals to output a plurality of characteristic sensing signals. The signal post-processor receives the characteristic sensing signals from the signal pre-processor and separates out a plurality of fetal electrocardiograms (FECGs) corresponding to the leads. The fetal position judging processor analyzes the FECGs to obtain a characteristic waveform for each of the FECGs or directly calculates a fetal heart axis vector with respect to a front-side coordinate of the maternal body according to the FECGs.