Handheld Device for Identification of Microbiological Constituents in the Middle Ear

Abstract

Methods and apparatus for identifying microbiological constituents in the middle ear. A spectrometer receives Raman-scattered light from the region of the tympanic membrane and resolves spectral features of the Raman-scattered light. A processor receives the interferometry signal and the Raman signal, and generates a Raman spectrum of the tympanic membrane and material adjacent thereto. In some embodiments of the invention, low-coherence light and substantially monochromatic excitation light are directed onto a tympanic membrane of the ear of a person via an otoscopic tip that abuts the ear canal. An interferometer combines scattered low-coherence light from the ear tissue with a reference signal to generate an interferometric signal.

We claim: 
     
         1 . An otoscopic diagnostic system comprising:
 a. a source of substantially monochromatic excitation light;   b. an otoscopic tip for abutment with the ear canal for directing the substantially monochromatic excitation light to a tympanic membrane of an ear of a person and for collecting Raman scattered light from the tympanic membrane and material behind the tympanic membrane and from material adjacent to the tympanic membrane;   c. a spectrometer for receiving the Raman-scattered light, for resolving spectral features of the Raman-scattered light, and for generating a Raman signal; and   d. a processor for receiving the Raman signal, and for generating therefrom a Raman spectrum of the tympanic membrane and the material behind the tympanic membrane and the material adjacent to the tympanic membrane.   
     
     
         2 . The otoscopic imaging system in accordance with  claim 1 , wherein the otoscopic tip is an earbud. 
     
     
         3 . The otoscopic diagnostic system in accordance with  claim 1 , wherein the otoscopic tip is a speculum coupled to a hand-held otoscope. 
     
     
         4 . The otoscopic diagnostic system in accordance with  claim 1 , wherein the substantially monochromatic excitation light is guided to the ear canal via a first optical fiber. 
     
     
         5 . The otoscopic diagnostic system in accordance with  claim 1 , wherein the source of substantially monochromatic excitation light is disposed within a core imaging unit. 
     
     
         6 . The otoscopic diagnostic system in accordance with  claim 6 , wherein the spectrometer is also disposed within the core imaging unit. 
     
     
         7 . The otoscopic diagnostic system in accordance with  claim 4 , wherein the first optical fiber is a dual-cladding fiber having a central core. 
     
     
         8 . The otoscopic diagnostic system in accordance with  claim 8 , wherein the substantially monochromatic excitation light is guided to the ear canal via the central core of the dual-cladding fiber. 
     
     
         9 . The otoscopic diagnostic system in accordance with  claim 8 , wherein the Raman-scattered light is guided to the spectrometer via cladding of the dual-cladding fiber. 
     
     
         10 . The otoscopic diagnostic system in accordance with  claim 1 , further comprising first focusing optics for coupling the excitation light to a vicinity of the tympanic membrane of the person and for collecting the Raman-scattered light. 
     
     
         11 . The otoscopic diagnostic system in accordance with  claim 10 , wherein the first focusing optics include a first micro-gradient-index lens. 
     
     
         12 . The otoscopic diagnostic system in accordance with  claim 4 , further comprising an ear bud coupled to a tip of a hand-held otoscope, the ear bud encompassing a portion of the first optical fiber. 
     
     
         13 . The otoscopic diagnostic system in accordance with  claim 1 , further comprising:
 e. a source of low-coherence light; and   f. an interferometer for combining the scattered low-coherence light from the ear tissue with a reference signal derived from the low-coherence light for generating an interferometry signal   wherein the processor is adapted for receiving the interferometry signal and the Raman signal, and for generating therefrom a Raman spectrum of the tympanic membrane and material in the vicinity thereof.   
     
     
         17 . The otoscopic diagnostic system in accordance with claim  16 , wherein the source of low-coherence light is a superluminescent diode. 
     
     
         18 . The otoscopic diagnostic system in accordance with claim  16 , wherein the low-coherence light includes an infrared component. 
     
     
         19 . The otoscopic diagnostic system in accordance with claim  16 , further comprising second focusing optics for coupling the low-coherence light to a vicinity of the tympanic membrane of the person. 
     
     
         20 . The otoscopic diagnostic system in accordance with  claim 19 , wherein the second focusing optics include a first micro-gradient-index lens. 
     
     
         21 . An otoscopic tip for insertion into an ear canal, the otoscopic tip comprising:
 a. an earbud assembly adapted for insertion into an ear canal;   b. first focusing optics adapted for directing low-coherence light to ear tissue via the ear bud into the ear canal and for collecting scattered low-coherence light and Raman-scattered light from a vicinity of a tympanic membrane of a person; and   c. second focusing optics adapted for directing excitation to the vicinity of the tympanic membrane of the person via the ear bud and through the ear canal and for collecting Raman-scattered excitation from the vicinity of the tympanic membrane of the person.   
     
     
         22 . The otoscopic tip in accordance with  claim 21 , wherein the earbud assembly is coupled to a hand-held otoscope. 
     
     
         23 . The otoscopic tip in accordance with  claim 21 , wherein the low-coherence light and the excitation light are coupled from respective remote sources disposed remotely with respect to the hand-held otoscope. 
     
     
         24 . The otoscopic tip in accordance with  claim 21 , wherein both the low-coherence light and the excitation light are coupled from the remote source via optical fiber. 
     
     
         25 . The otoscopic tip in accordance with  claim 21 , wherein the first focusing optics include a first micro-gradient-index lens. 
     
     
         26 . The otoscopic tip in accordance with  claim 21 , wherein the second focusing optics include a second micro-gradient-index lens. 
     
     
         27 . A method for characterizing at least one of a middle ear fluid, a middle ear effusion, and a biofilm adjacent to a tympanic membrane of a person, the method comprising:
 a. illuminating the tympanic membrane with a broadband optical beam;   b. interfering light scattered by the tympanic membrane with a reference beam derived from the broadband optical beam to generate an interferometric signal;   c. illuminating the tympanic membrane with a monochromatic excitation beam;   d. coupling Raman-scattered light from the tympanic membrane to a spectrometer;   e. dispersing the Raman-scattered light to obtain a Raman spectrum characterizing the Raman-scattered light;   f. ascertaining a first specified characteristic of any material adjacent to the tympanic membrane on the basis of the interferometric signal; and   g. ascertaining a second specified characteristic of any material adjacent to the tympanic membrane on the basis of the Raman spectrum signal.   
     
     
         28 . The method in accordance with  claim 27 , wherein the first specified characteristic is a measure of geometrical thickness of the tympanic membrane and any attached biofilm. 
     
     
         29 . The method in accordance with  claim 27 , wherein the first specified characteristic is a measure of at least one of viscosity and turbidity. 
     
     
         30 . The method in accordance with  claim 27 , wherein the first specified characteristic is an image. 
     
     
         31 . The method in accordance with  claim 27 , wherein the material adjacent to the tympanic membrane of the person is at least one of a biofilm and effusion material. 
     
     
         32 . The method in accordance with  claim 27 , wherein the second specified characteristic is at least one of a bacterial type, viral type and fungal type. 
     
     
         33 . The method in accordance with  claim 27 , wherein the second specified characteristic is an identification of an extracellular polymeric substance.