Time of flight based tracheal tube placement system and method
According to various embodiments, a tracheal tube may employ optical sensing techniques for determining a distance between the inserted tube and an anatomical structure, such as a carina. The distance information may provide an indication as to whether or not the tracheal tube is properly placed within the trachea. The optical techniques may include time of flight techniques.
1. A method for determining placement of a tracheal tube in a subject comprising the steps of:
emitting a light from a plurality of optical conductors circumferentially spaced about a beveled distal end of a tracheal tube disposed in a subject, wherein the beveled distal end is slanted relative to a wall of the tracheal tube;
receiving the light returned from an anatomical structure within the subject;
measuring a time of flight of the light from each of the plurality of optical conductors; and
determining an orientation of the tracheal tube based upon the time of flight of the light from each of the plurality of optical conductors and a difference in path length between the plurality of optical conductors, wherein the difference in path length is representative of a position of each respective optical conductor about the beveled distal end.
2. The method of claim 1 , comprising measuring a time of flight of a reference, and wherein the orientation is determined based upon the time of flight of the returned light from the plurality of optical conductors and the time of flight of the reference.
3. The method of claim 1 , wherein the orientation is representative of a comparison of a distance between the plurality of optical conductors circumferentially spaced about the beveled distal end tracheal tube and the anatomical structure.
4. The method of claim 3 , wherein the anatomical structure comprises a carina.
5. The method of claim 4 , comprising triggering an alarm when a distance between the tracheal tube and the carina is less than a predetermined distance or when the distance between the tracheal tube and the carina falls outside of a predetermined range.
6. The method of claim 1 , wherein the steps are performed during intubation of the subject.
7. The method of claim 1 , wherein the steps are performed after intubation of the subject.
8. A system for determining placement of a tracheal tube in a subject comprising:
a tracheal tube comprising a plurality of optical conductors circumferentially spaced apart on a beveled distal end of the tracheal tube, wherein the beveled distal end of the tracheal tube is angled relative to a wall of the tracheal tube;
a light source configured to emit a light through each of the respective plurality of optical conductors when the tracheal tube is disposed in a subject;
a photodetector configured to receive the light emitted from each of the respective plurality of optical conductors after interaction with an anatomical structure within the subject; and
a processor configured to determine an orientation related to a placement of the tracheal tube in the subject based upon a time of flight of the light from each of the respective plurality of optical conductors and a difference in path length between the plurality of optical conductors, wherein the difference in path length is representative of a position of each respective optical conductor about the beveled distal end.
9. The system of claim 8 , comprising a beam splitter configured to split a portion of the light into a reference beam.
10. The system of claim 9 , comprising a second photodetector configured to receive the reference beam.
11. The system of claim 8 , wherein the anatomical structure comprises a carina.
12. The system of claim 11 , wherein the processor is configured to trigger an alarm when a distance between the tracheal tube and the carina is less than a predetermined distance or when the distance between the tracheal tube and the carina falls outside of a predetermined range.
13. The system of claim 8 , wherein the light source comprises a laser diode configured to emit pulses of light.
14. The system of claim 8 , wherein the light source comprises a tunable laser.
15. A device for determining placement of a tracheal tube in a subject comprising:
a processor configured to:
drive a light source configured to emit light through a plurality of optical conductors circumferentially spaced about a beveled distal end of a tracheal tube disposed in a subject;
receive a signal from a photodetector configured to receive returned light from an anatomical structure within the subject; and
determine an orientation of the tracheal tube in the subject based upon a time of flight of the returned light from each of the plurality of optical conductors and a difference in path length between the plurality of optical conductors, wherein the difference in path length is representative of a position of each respective optical conductor about the beveled distal end; and
a display configured to provide an indication of the orientation.
16. The device of claim 15 , wherein the processor is configured to trigger an alarm based on the orientation of the tracheal tube in the subject.