Systems and methods for fetal monitoring

1. A computer-implemented method, comprising:

obtaining, by a system of one or more computers, a maternal electrocardiogram (ECG) signal that represents an ECG of a pregnant mother during a first time interval, wherein the maternal ECG signal is acquired from one or more electrodes affixed to at least one of an abdominal region of the mother or a chest region of the mother;

obtaining, by the system, a mixed maternal-fetal ECG signal that represents a combined ECG of the mother and her fetus during the first time interval, wherein the mixed maternal-fetal ECG signal is acquired from one or more electrodes of a vaginal probe located within a vaginal canal of the mother;

processing, by the system, the maternal ECG signal and the mixed maternal-fetal ECG signal to generate a fetal ECG signal that represents the ECG of the fetus during the time interval, the fetal ECG signal substantially excluding the maternal ECG signal; and

providing, by the system, an output based on the fetal ECG signal.

2. The computer-implemented method of claim 1 , wherein the system comprises a smartphone or a tablet computing device.

3. The computer-implemented method of claim 1 , further comprising synchronizing the maternal ECG signal with the mixed maternal-fetal ECG signal.

4. The computer-implemented method of claim 1 , wherein processing the maternal ECG signal and the mixed maternal-fetal ECG signal to generate the fetal ECG signal comprises subtracting the maternal ECG signal from the mixed maternal-fetal ECG signal to generate the fetal ECG signal.

5. The computer-implemented method of claim 1 , further comprising applying an adaptive filter to the maternal ECG signal before subtracting the maternal ECG signal from the mixed maternal-fetal ECG signal.

6. The computer-implemented method of claim 1 , wherein the adaptive filter comprises a Wiener filter.

7. The computer-implemented method of claim 1 , wherein processing the maternal ECG signal and the mixed maternal-fetal ECG signal to generate the fetal ECG signal comprises using a blind source separation technique to separate the fetal ECG signal from the maternal ECG signal.

8. The computer-implemented method of claim 1 , wherein processing the maternal ECG signal and the mixed maternal-fetal ECG signal to generate the fetal ECG signal comprises using at least one of principal component analysis (PCA) or independent component analysis (ICA) techniques.

9. The computer-implemented method of claim 1 , further comprising analyzing the fetal ECG signal to determine a distress level of the fetus; and

wherein providing the output comprises generating an alert for presentation to a human user in response to a determination that the determined distress level of the fetus exceeds a threshold distress level.

10. A computer-implemented method, comprising:

receiving, by a system of one or more computers, a first ECG signal, wherein the first ECG signal is a mixed maternal-fetal ECG signal that represents a combined ECG of a pregnant mother and her fetus, wherein the mixed maternal-fetal ECG signal was acquired using one or more electrodes from within a vaginal canal of the mother;

processing, by the system, the first ECG signal to determine values for one or more features of the first ECG signal;

determining, based on the determined values for the one or more features of the first ECG signal, a condition of at least one of the mother or the fetus; and

providing, by the system, an output based on the determined condition of the at least one of the mother or the fetus.

11. The computer-implemented method of claim 10 , wherein the features of the first ECG signal comprise features of a waveform for a beat from the first ECG signal, the features of the waveform including a slope or an area of a portion of the waveform for the beat.

12. The computer-implemented method of claim 10 , wherein determining the condition of the at least one of the mother or the fetus comprises accessing a model that correlates at least one of maternal conditions or fetal conditions with ECG signal features.

13. The computer-implemented method of claim 12 , wherein the model comprises an artificial neural network.

14. A vaginal probe for sensing information about a patient from within a vaginal canal of the patient, the probe comprising:

a ring-shaped body structured and dimensioned for placement within the vaginal canal of the patient;

a set of ECG sensors comprising one or more electrodes disposed on the ring-shaped body, the set of ECG sensors configured to abut walls of the vaginal canal when the ring-shaped body is placed within the vaginal canal of the patient, the set of ECG sensors configured to detect a maternal ECG signal if the patient is not pregnant or to detect a mixed maternal-fetal ECG signal if the patient is pregnant in at least the second or third trimesters;

a wireless communications interface configured to wirelessly transmit RF signals that encode information about the maternal ECG signal or the mixed maternal-fetal ECG signal; and

a controller configured to activate or deactivate ECG signal acquisition and transmission.

15. The vaginal probe of claim 14 , further comprising at least one of a temperature sensor, a pH sensor, an accelerometer, a gyroscope, electromyography (EMG) sensors, or electrochemical sensors.

16. The vaginal probe of claim 14 , wherein the ring-shaped body is made of a nitinol alloy.

17. The vaginal probe of claim 14 , further comprising an induction coil that is configured to energize the vaginal probe when an external inductive power source is brought into proximity of the induction coil of the vaginal probe.