Infrared otoscope for characterization of effusion
An otoscope uses differential reflected response of optical energy at an absorption range and an adjacent wavelength range to determine the presence of water (where the wavelengths are water absorption wavelength and adjacent non-absorption excitation wavelengths). In another example of the invention, the otoscope utilizes OCT in combination with absorption and non-absorption range for bacteria and water.
1 . A method for diagnosing otitis media of a patient, the method comprising:
(a) directing a first optical energy along a measurement path, wherein the measurement path crosses a tympanic membrane and the first optical energy interacts with one or more of the tympanic membrane or a fluid adjacent the tympanic membrane;
(b) directing a second optical energy along a reference path;
(c) combining the first optical energy and the second optical energy at a detector after the first optical energy has interacted with the one or more of the tympanic membrane or the fluid adjacent the tympanic membrane and the first and second optical energies have traversed the measurement and reference paths, respectively, the combined first and second optical energies generating a detector response at the detector;
(d) comparing the detector response with a first contents of a template memory corresponding to an effusion fluid with a bacterial effusion, and comparing the detector response with a second contents of the template memory corresponding to the effusion fluid with a viral effusion, wherein the template memory stores one or more characteristics for a type of the effusion fluid; and
(e) characterizing the type of the effusion fluid, wherein the characterizing comprises distinguishing the type of the effusion fluid between the effusion fluid with the bacterial effusion and the effusion fluid with the viral effusion based on the one or more characteristics.
2 . The method of claim 1 , wherein the detector response comprises a wavelength dependent response.
3 . The method of claim 2 , further comprising comparing the wavelength dependent response to a template response of at least one known material, the template response being stored in the template memory.
4 . The method of claim 3 , wherein the template response comprises a template response of at least one of cerumen, healthy tympanic membrane, inflamed tympanic membrane, bacterial fluid, effusive fluid, or adhesive fluid.
5 . The method of claim 1 , further comprising indicating a presence of at least one of cerumen, healthy tympanic membrane, inflamed tympanic membrane, bacterial fluid, effusive fluid, or adhesive fluid to a user.
6 . The method of claim 1 , wherein the type of the effusion fluid comprises stored characteristics for a bacterial ear infection and a viral ear infection.
7 . The method of claim 1 , further comprising, before (a), directing a non-contact force through an air medium to one or more of a tympanic membrane or a fluid adjacent the tympanic membrane.
8 . The method of claim 7 , wherein the characterizing comprises determining a membrane metric from the detector response in response to the non-contact force.
9 . The method of claim 8 , wherein the membrane metric comprises at least one of an elasticity or a viscosity of the tympanic membrane or the fluid adjacent the tympanic membrane.
10 . The method of claim 9 , wherein the membrane metric is based on at least one of: a width of the detector response, a pedestal width of the detector response, or a reflected wavelength profile of the detector response.
11 . The method of claim 9 , wherein the non-contact force comprises an air puff or a pressure excitation.
12 . The method of claim 7 , wherein the non-contact force comprises an impulsive excitation.
13 . The method of claim 7 , wherein the non-contact force comprises a periodic excitation.
14 . The method of claim 13 , wherein a frequency of the periodic excitation is within a range from 20 Hz to 20 kHz.
15 . A system for diagnosing otitis media of a patient, the system comprising:
an interferometer configured to direct light energy along a reference path and a measurement path, wherein the measurement path comprises a tympanic membrane; and
a controller; and
a memory comprising a template memory storing one or more characteristics for a type of an effusion fluid, and wherein the memory is coupled to the controller and stores instructions for the controller to:
receive a detector signal from the interferometer,
compare the detector signal with a first contents of the template memory corresponding to the effusion fluid with a bacterial effusion, and compare the detector signal with a second contents of the template memory corresponding to the effusion fluid with a viral effusion, and
characterize the type of the effusion fluid, wherein the characterizing comprises distinguishing the type of the effusion fluid between the effusion fluid with the bacterial effusion and the effusion fluid with the viral effusion based on the one or more characteristics.
16 . The system of claim 15 , wherein the memory further stores instructions for the controller to determine a membrane metric in response to a non-contact force, and wherein the type of the effusion fluid is distinguished between one of the bacterial effusion and the viral effusion based on the membrane metric.
17 . The system of claim 16 , wherein the membrane metric comprises at least one of an elasticity or a viscosity of the tympanic membrane or a fluid adjacent the tympanic membrane.
18 . The system of claim 16 , wherein the membrane metric is based on at least one of: a detector response width, a pedestal width, or a reflected wavelength profile.
19 . The system of claim 15 , further comprising, an excitation generator configured to generate a non-contact force to be directed through an air medium to one or more of the tympanic membrane or the fluid adjacent the tympanic membrane.
20 . The system of claim 19 , wherein the non-contact force comprises an air puff or a pressure excitation.
21 . The system of claim 19 , wherein the interferometer comprises a light source.
22 . The system of claim 21 , wherein the light source comprises a light emitting diode.
23 . The system of claim 15 , wherein the interferometer comprises a broadband detector.
24 . The system of claim 23 , wherein the broadband detector is configured to generate a plurality of outputs, each output responsive to a unique range of wavelengths.
25 . The system of claim 15 , wherein the interferometer comprises a first splitter, which divides the light energy into the reference path and the measurement path, and a second splitter, which combines the reference path and the measurement path.
26 . The system of claim 25 , wherein the first splitter and second splitter comprise partially reflective mirrors.
27 . The system of claim 25 , wherein the first splitter and second splitter comprise optical fibers.
28 . The system of claim 15 , wherein a length of the reference path or a length of the measurement path is modulated using a voltage or current controlled actuator coupled to a mirror.
29 . The system of claim 15 , wherein a length of the reference path or a length of the measurement path is modulated using a PZT actuator coupled to an optical fiber.
30 . The system of claim 15 , wherein the template memory stores a template response of one of a plurality of known biological materials.
31 . The system of claim 30 , wherein the template response comprises one or more characteristics for at least one of cerumen, healthy tympanic membrane, inflamed tympanic membrane, bacterial fluid, effusive fluid, or adhesive fluid.
32 . The system of claim 14 , wherein the type of the effusion fluid comprises stored characteristics for a bacterial ear infection and a viral ear infection.