Diagnosis of the presence of cochlear hydrops using observed auditory brainstem responses

• US 7,223,246 B2
• Filed: 06/07/2004
• Issued: 05/29/2007
• Est. Priority Date: 06/06/2003
• Status: Expired due to Fees

• Current Assignee: House Ear Institute
• Original Assignee: House Ear Institute
• Inventors: Don, Manuel
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): Apanius; Michael
• Application Number:
  US10/863,559
• Publication Number:
  US 20050273018A1
• Time in Patent Office: 1,086 Days
• Field of Search: 600/544, 600/545, 600/559
• US Class Current: 600/559
• CPC Class Codes: A61B 5/121 evaluating hearing capacity
• CPC Class Codes: A61B 5/38 Acoustic or auditory stimuli

Abstract

A procedure for diagnosing cochlear hydrops is based, in part, on an analysis of the patient'"'"'s auditory brainstem response (ABR) to stimuli. The patient'"'"'s ABR to a broadband click stimulus is recorded. A plurality of masked ABR'"'"'s are also recorded, wherein the stimulus is masked by high-pass noise with a plurality of high-pass cut-off frequencies. The latency difference between the wave V component in the unmasked click alone response and the undermasked wave V component of a low cut-off frequency high-pass response is then calculated. If an undermasked component is not present, the normal wave V component is used. The measured latency difference is combined with another measure, such as the wave V amplitude ratio. A distribution of the combined measure is then plotted for the population and a threshold established for diagnosing cochlear hydrops. Alternatively, the joint distribution of the individual measures may be used in situations where the individual measures are known to be independent.

Claims

1. A procedure for diagnosing cochlear hydrops comprising:

recording a patient'"'"'s auditory brainstem response to an unmasked broadband click stimulus;

recording a plurality of masked auditory brainstem responses, wherein each of the masked auditory brainstem responses is responsive to a broadband click stimulus that is masked by high-pass noise with a high-pass cut-off at a respective one of a plurality of cut-off frequencies;

calculating a latency difference between a wave V peak of the unmasked response and a wave V peak of a masked response having a low cut-off frequency;

diagnosing the likely presence of cochlear hydrops if the latency difference is less than a threshold value based on results in an appropriate control population.

2. The procedure of claim 1 wherein the wave V peak of the masked response having a low cut-off frequency is an undermasked wave V component.

3. The procedure of claim 1 wherein the plurality of cut-off frequencies comprise 8 kHz, 4 kHz, 2 kHz, 1 kHz and 500 Hz.

4. The procedure of claim 1 wherein the low cut-off frequency is a lowest of the plurality of cut-off frequencies.

5. The procedure of claim 1 wherein the low cut-off frequency is 500 Hz.

6. The procedure of claim 1 wherein the latency difference is combined with another measure of cochlear hydrops to diagnose the likely presence of cochlear hydrops.

7. The procedure of claim 6 wherein the other measure of cochlear hydrops comprises a ratio of a sum of wave V peak amplitudes of the plurality of masked responses to a wave V peak amplitude of the unmasked response.

8. The procedure of claim 6 wherein the other measure of cochlear hydrops comprises a cross correlation between the masked response having a low cut-off frequency and the unmasked response.

9. The procedure of claim 6 wherein the other measure of cochlear hydrops comprises an amplitude difference between the unmasked response and a sum of the masked responses.

10. The procedure of claim 6 wherein the other measure of cochlear hydrops comprises a ratio of the difference between a wave V peak amplitude of the unmasked response and a wave V peak amplitude of the masked response having a low cut-off frequency to the wave V peak amplitude of the unmasked response.

11. The procedure of claim 6 wherein the other measure of cochlear hydrops comprises a product of:

a ratio of the difference between a wave V peak amplitude of the unmasked response and a wave V peak amplitude of the masked response having a low cut-off frequency to the wave V peak amplitude for the unmasked response multiplied by

a latency difference between the wave V peak of the unmasked response and a wave V peak of a masked response having a low cut-off frequency.

12. The procedure of claim 11 wherein the wave V peak of the masked response having a low cut-off frequency is an undermasked wave V component.

13. The procedure of claim 6 wherein the other measure of cochlear hydrops comprises a ratio of a wave V peak amplitude of the masked response having a low cut-off frequency to a wave V peak amplitude of the unmasked response.

14. The procedure of claim 13 wherein the wave V peak of the masked response having a low cut-off frequency is an undermasked wave V component.