Apparatus and method for tooth pulp vitality detection

Patent metadata

Field	Value
Publication number	US-11666223-B2
Application number	US-201816487775-A
Country	US
Kind code	B2
Filing date	Feb 22, 2018
Priority date	Feb 22, 2017
Publication date	Jun 6, 2023
Grant date	Jun 6, 2023

Abstract

An apparatus provided for detecting tooth pulp vitality includes a handle, a pivot and a caliper. A pair of fiber optic lines pass through an interior of the handle, the pivot and the caliper. One of the fiber optic lines is a source line with a connector at an end of the source line and another of the fiber optic lines is a detector line with a connector at an end of the detector line. The source line is single mode in the handle and the detector line is multi mode. A system is also provided for detecting tooth pulp vitality that includes the apparatus. Additionally, a method is provided for detecting tooth pulp vitality that employs the apparatus.

First claim

What is claimed is:

1. A system comprising:
a probe with a tip configured to engage opposite sides of a sample, said probe including a pair of fiber optic lines passing through an interior of the probe, said pair of fiber optic lines including;
a source line that is single mode and includes a connector at one end, and
a detector line that is multi mode and includes a connector at one end,

an optical source to emit output light with an adjustable bandwidth, wherein the optical source is coupled to the source line connector to transmit the output light into the source line;
a reference path with an adjustable delay line coupled to the optical source to receive the output light from the optical source;
a detector coupled to the adjustable delay line to receive the output light from the reference path and further coupled to the detector line connector to receive scattered light;
at least one processor; and
at least one memory including one or more sequences of instructions,
the at least one memory and the one or more sequences of instructions configured to, with the at least one processor, cause the system to perform at least the following,
adjust the adjustable delay line of the reference path such that a zero delay plane is positioned in a target volume of the sample, wherein the zero delay plane is defined such that an optical path of output light through the reference path to the detector is equal to an optical path of scattered light from the zero delay plane through the detector line to the detector;
adjust the bandwidth of the output light to vary a coherence length of the output light such that scattered light from the target volume and output light through the reference path generate an interference signal at the detector and such that scattered light from outside the target volume and output light through the reference path do not generate an interference signal at the detector; and
determine motion within the target volume based on a Doppler shift between scattered light from the target volume and output light through the reference path, wherein said Doppler shift is based on the generated interference signal.

2. A system as recited in claim 1 , wherein the probe is a tooth probe such that the tip is configured to engage opposite sides of a tooth of the sample, wherein the target volume is a pulp region within the tooth and wherein the scattered light from outside the target volume includes scattered light from gum tissue of the sample.

3. A system as recited in claim 2 , wherein the tip is further configured to push aside a gum tissue at a base of the tooth to access a cemento-enamel junction (CEJ) of the tooth.

4. A system as recited in claim 2 , wherein the coherence length of the output light is in a range from about 2 mm to about 4 mm.

5. A system as recited in claim 2 , wherein the bandwidth of the output light is a band of wavelengths in a range between about 0.02% and 0.08% of a center wavelength of the band of wavelengths.

6. A system as recited in claim 2 , wherein the probe further comprises:
a handle;
a pivot;
a caliper; and
wherein the pair of fiber optic lines pass through an interior of the handle, the pivot and the caliper;
wherein the source line is single mode in the handle.

7. A system as recited in claim 6 , wherein the caliper is removable and wherein the source line is multi mode in the caliper.

8. A system as recited in claim 1 , further comprising:
a single mode coupler configured to direct a first portion of the output light from the optical source into the source line connector and further configured to direct a second portion of the output light from the optical source into the reference path; and
a multi mode coupler configured to direct scattered light from the detector line connector and output light from the reference path to the detector.

9. A system as recited in claim 1 , wherein the at least one memory and the one or more sequences of instructions is further configured to cause the system to adjust an intensity of the output light from the optical source based on an intensity of the scattered light.

10. A method comprising:
engaging opposite sides of a tooth with a tip of a probe, wherein the probe includes a pair of fiber optic lines passing through an interior of the probe, said pair of fiber optic lines including;
a source line that is single mode and includes a connector at one end, and
a detector line that is multi mode and includes a connector at one end,

emitting output light having an adjustable bandwidth with an optical source, wherein a first portion of the output light is coupled into the source line connector and a second portion of the output light is coupled into a reference path with an adjustable delay line;
receiving, at a detector, output light from the reference path and scattered light from the detector line connector;
adjusting, with a processor, the delay line of the reference path such that a zero delay plane is positioned in a pulp region of the tooth, wherein the zero delay plane is defined such that an optical path of output light through the reference path to the detector is equal to an optical path of scattered light from the zero delay plane through the detector line to the detector;
adjusting, with the processor, the bandwidth of the output light to vary a coherence length of the output light such that scattered light from the pulp region and the output light through the reference path generate an interference signal at the detector and such that the scattered light from gum tissue and the output light through the reference path do not generate an interference signal at the detector; and
determining, with the processor, motion within the pulp region based on a Doppler shift between the scattered light from the pulp region and the output light through the reference path, wherein the Doppler shift is based on the generated interference signal.

11. A method as recited in claim 10 , wherein the engaging opposite sides of the tooth comprises engaging at or below a cemento-enamel junction (CEJ) of the tooth with the tip of the probe such that output light is emitted from the tip and scattered light is received by the tip at or below the CEJ of the tooth.

12. A method as recited in claim 10 , wherein the engaging opposite sides of the tooth comprises pressing gum tissue downward with the tip of the probe such that the output light coupled into the source line connector is emitted from the tip and the scattered light from the pulp region is received by the tip within about 0.5 mm of the gum tissue after being pressed downward by the tip of the probe.

13. A method as recited in claim 10 , wherein the tip is removable and wherein the source line is multi mode in the tip and wherein the method further comprises removing the tip.

Assignees

• Univ Maryland
• Us Gov Veterans Affairs
• Us Gov Veterans Affairs

Inventors

• Tang Cha-Min
• Schmitt Joseph

Classifications

• A61B5/682

  Mouth, e.g., oral cavity; tongue; Lips; Teeth · CPC title

• A61B5/0261

  using optical means, e.g. infrared light · CPC title

• A61B5/4547

  Evaluating teeth · CPC title

• A61B5/0066 Primary

  Optical coherence imaging · CPC title

• A61B2090/3614

  using optical fibre · CPC title