SYSTEMS AND METHODS FOR MEASURING FETAL CEREBRAL OXYGENATION

• US 20160007895A1
• Filed: 07/08/2015
• Published: 01/14/2016
• Est. Priority Date: 04/11/2007
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: ESENALIEV, Rinat, PROUGH, Donald S., PETROV, Yuriy, PETROV, Irene, SAADE, George, OLSON, Gayle L.
• Granted Patent: US 9,380,967 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/0271 Thermal or temperature sensors
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/1464 specially adapted for foetal tissue
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: A61B 5/6875 Uterus
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence

Abstract

Optoacoustic diagnostic systems, devices, and methods are described. A system may comprise a console unit and a handheld probe. The console unit comprises a controller, a processor, a photodiode array, an acoustic processing subsystem, and a cooling subsystem. The probe directs light signals from the photodiode array to patient tissue. The light signals each have different wavelengths selected based on the physiological parameter of interest. The probe further comprises an acoustic transducer that receives acoustic signals generated in response to the directed light signals. The probe may comprise a finger-held working end that can be directed to the skull of a fetus within the uterus during labor. The probe can then accurately determine blood oxygenation of the fetus to determine if a caesarian section is necessary.

Claims

1. A method of monitoring oxygenation of a fetus, the method comprising:

inserting a sensor into a vagina, the sensor comprising a light output and an acoustic transducer;

advancing the sensor through a cervix and into a uterus; and

positioning the sensor over a head of the fetus,

wherein the light output of the sensor emits light to the head of the fetus and the acoustic transducer of the sensor detects acoustic pressure generated in response to the emitted light, and

wherein the sensor determines oxygenation of the fetus in response to the detected acoustic pressure.

2. The method of claim 1, wherein the sensor comprises a probe head, and wherein inserting the sensor into the vagina comprises inserting the probe head of the sensor into the vagina.

3. The method of claim 2, wherein the sensor comprises an oxygenation monitor configured to display the determined oxygenation of the fetus and a cable connecting the probe head with the oxygenation monitor.

4. The method of claim 3, wherein the oxygenation monitor and at least a portion of the cable remain outside the uterus as the probe head is inserted into the vagina.

5. The method of claim 3, wherein the light output comprises a waveguide in the probe head, wherein the cable comprises one or more optical fibers, and wherein the oxygenation monitor comprises one or more laser diodes or light emitting diodes coupled to the waveguide through the one or more optical fibers.

6. The method of claim 2, wherein inserting the sensor into the vagina comprises grasping the probe head between two finger tips of a user.

7. The method of claim 2, wherein positioning the sensor over a head of the fetus comprises positioning the light output and the acoustic transducer to face a superior sagittal sinus of the fetus.

8. The method of any of claim 1, wherein positioning the sensor over a head of the fetus comprises contacting a tip of the light output extending from the probe head to skin of the head of the fetus.

9. The method of claim 7, wherein the light output of the sensor emits light to a superior sagittal sinus of the fetus, wherein the acoustic pressure generated in response to the emitted light is generated by the superior sagittal sinus, and wherein the sensor determines oxygenation of the superior sagittal sinus.

10. A method of monitoring oxygenation of a fetus, the method comprising:

emitting light from a light output of a sensor positioned over a head of a fetus in a uterus;

detecting acoustic pressure with an acoustic transducer of the sensor, the acoustic pressure being generated in response to the emitted light;

determining oxygenation of the fetus in response to the detected acoustic pressure; and

displaying the determined oxygenation of the fetus to the user with the sensor.

11. The method of claim 10, wherein the sensor comprises a probe head comprising the light output and acoustic transducer.

12. The method of claim 10, wherein the light output comprises a tip extending out from an outer body of the probe head.

13. The method of claim 10, wherein the sensor comprises an oxygenation monitor configured to display the determined oxygenation of the fetus and a cable connecting the probe head with the oxygenation monitor.

14. The method of claim 10, wherein the light output comprises a waveguide in the probe head, wherein the cable comprises one or more optical fibers, and wherein the oxygenation monitor comprises one or more laser diodes or light emitting diodes coupled to the waveguide through the one or more optical fibers.

15. The method of claim 10, wherein the light output and the acoustic transducer face a superior sagittal sinus of the fetus.

16. The method of claim 10, wherein the light output of the sensor emits light to a superior sagittal sinus of the fetus, wherein the acoustic pressure generated in response to the emitted light is generated by the superior sagittal sinus, and wherein the sensor determines oxygenation of the superior sagittal sinus.

17. A system for monitoring oxygenation of a fetus, the system comprising:

a monitor comprising a processor, a light source, and a display;

a cable; and

a probe head configured to be held between two finger tips of a user and coupled to the monitor through the cable, the probe head comprising a light output and an acoustic transducer,

wherein the light source is configured to generate a light emitted to the fetus through the light output of the probe head,

wherein the acoustic transducer is configured to detect acoustic pressure generated in response to the emitted light,

wherein the processor is configured to determine oxygenation of the fetus in response to the detected acoustic pressure, and

wherein the display is configured to display the determined oxygenation.

18. The system of claim 17, wherein the light output comprises a tip extending out from an outer body of the probe head.

19. The system of claim 17, wherein the light source of the monitor comprises one or more laser diodes or light emitting diodes.

20. The system of claim 17, wherein the cable comprises one or more optical fibers configured to direct light generated by the light source to the light emitter of the probe head.

21. A fetal cerebral oxygenation probe comprising:

a probe head including a light output configured to emit light into a head of the fetus and an acoustic transducer configured to detect acoustic pressure generated in response to the emitted light; and

a cable extending out from the probe head to couple to a monitor.

22. The probe of claim 21, wherein the probe head is adapted to be held between two finger tips of a user.

23. The probe of claim 21, wherein the light output comprises a tip extending out from an outer body of the probe head.

24. The probe of claim 23, wherein the light output comprises an optical waveguide comprising a continuous rounded groove encircling a center of the probe head.

25. The probe of claim 21, wherein the acoustic transducer comprises a piezoelectric transducer.

26. The probe of claim 21, wherein the probe head comprises a housing defining an interior space where the acoustic transducer is positioned and through which the light output passes.

27. The probe of claim 21, wherein the probe head further comprises an amplifier for the acoustic transducer.

28. The probe of claim 27, wherein the probe head comprises an electromagnetic shield that shields the acoustic sensor and amplifier from electromagnetic interference.

29. The probe of claim 21, wherein the probe head further comprises an acoustic attenuator configured to absorb undesired ringing in the probe head.

30. The probe of claim 21, wherein the light output is configured to channel light generated by a light source in the monitor.