Probe structure for physiological measurements using surface enhanced Raman spectroscopy

Patent metadata

Field	Value
Publication number	US-10694951-B2
Application number	US-201615293267-A
Country	US
Kind code	B2
Filing date	Oct 13, 2016
Priority date	Oct 13, 2016
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

Surface enhanced Raman spectroscopy is employed to obtain chemical data with respect to body tissue and cells. The chemical environments of stimulation implants and drug-delivery catheters are spectroscopically monitored in real time using an implantable probe. The probe includes a surface enhancer that facilitates surface enhanced Raman spectroscopy in opposing relation to an array of optical fibers. Light emitted by the optical fibers can be employed for chemical detection and/or tissue stimulation. Wavelength and optical power are selected based on whether the probe is employed for such detection or stimulation. Fabrication of a probe assembly that enables surface enhanced Raman spectroscopy is further disclosed.

First claim

What is claimed is:

1. A method comprising:
obtaining a probe assembly including a needle-shaped probe housing, a cavity extending laterally through the probe housing, a plurality of optical fibers within the probe housing, and a metal-containing probe surface comprising nanostructures adjoining the cavity and configured for enhancing Raman spectroscopy via surface plasmon resonance, the optical fibers including distal ends adjoining the cavity and in opposing relation to the probe surface;
positioning the probe assembly within body tissue;
causing monochromatic light having a first wavelength to be emitted by one or more of the optical fibers through the cavity and towards the nanostructures;
generating surface enhanced Raman scattered light within the cavity; and
conveying, via one or more of the optical fibers, the surface enhances Raman scattered light generated within the cavity to a detector for spectral analysis of the scattered light.

2. The method of claim 1 , wherein the distal end of one or more of the optical fibers includes a gradient index lens, further including focusing the emitted monochromatic light using the gradient index lens on the nanostructures configured for enhancing Raman spectroscopy.

3. The method of claim 2 , further including positioning a catheter having a distal end in proximity to the probe assembly and introducing a pharmaceutical preparation into the body tissue through the distal end of the catheter.

4. The method of claim 1 , further including causing light stimulation of the body tissue by causing the one or more of the optical fibers to emit monochromatic light at a target displaced from the nanostructures configured for enhancing Raman spectroscopy and through a transparent region of the probe housing and into the body tissue, the transparent region of the probe housing including an anti-reflection coating.

5. The method of claim 1 , wherein the probe assembly further includes one or more electrodes mounted to the probe housing, further including subjecting the body tissue to electrical stimulation using the electrodes.

6. The method of claim 5 , wherein the electrodes comprise metal rings positioned distal to the cavity and attached to an outer surface of the probe housing.

7. The method of claim 5 , wherein the electrodes comprise metal rings positioned proximal to the cavity and attached to an outer surface of the probe housing.

8. The method of claim 2 , further including causing light stimulation of the body tissue by causing the one or more of the optical fibers to emit monochromatic light having a second wavelength different from the first wavelength into the body tissue.

9. The method of claim 2 , wherein the nanostructures are comprised of nanorods extending within the cavity.

10. The method of claim 9 , wherein the nanorods have a pitch ratio of at least four, further including admitting inter-cellular fluids or the body tissue within the cavity and between the nanostructures and the distal ends of the optical fibers.

11. The method of claim 9 , further including anchoring the probe assembly within the body tissue using the nanorods.

12. The method of claim 1 , wherein positioning the probe assembly within body tissue is conducted in vivo.

13. The method of claim 1 , wherein the monochromatic light is in the terahertz spectrum, further including causing macromolecules to enter the cavity.

14. The method of claim 1 , wherein the probe housing includes a distal housing portion, the distal housing portion including a proximally facing surface bounding a distal end of the cavity and having a first area, the probe surface comprising the nanostructures being adjacent to the proximally facing surface and having a second area, the first area greatly exceeding the second area, further including emitting light from one of the optical fibers towards and focused on a target within the proximally facing surface and displaced from the probe surface comprising the nanostructures.

Assignees

• IBM

Inventors

• Kinser Emily R
• Knickerbocker John U
• Yu Roy R

Classifications

• A61N5/067

  using laser light · CPC title

• A61N1/36071

  Pain · CPC title

• A61N2005/063

  comprising light transmitting means, e.g. optical fibres · CPC title

• A61N5/0622

  Optical stimulation for exciting neural tissue · CPC title

• A61N5/0601

  Apparatus for use inside the body · CPC title