Q. Can computerized ENG really make my ENGs easier to perform and interpret? A. Absolutely! It's a given that the PC has revolutionized the way we deal with the more mundane tasks in our personal and professional lives. The PC is designed to handle those tedious tasks that take up our time and energy. This feature applies to ENGs just like it does to typing a letter or report, creating statistical reports and balancing the checkbook. Consider the following advantages of a computerized ENG system: - Calibration is automatic and fast, usually taking less than 15 seconds per channel - Precision controlled optical stimuli for oculomotor testing enhances test validity and reliability - Oculometer tests (saccade, pursuit, OPK) can be analyzed in seconds and compared to age and gender dependant reference data thereby reducing the subjective component of interpretation - Nystagmus is automatically measured for all nystagmus-based tests (gaze, Dix-Hallpike, positional, calorics) - Unilateral weakness and directional preponderance are automatically calculated after completion of all four caloric tests - Test segments are automatically selected and printed as part of the normal analysis routines - Text reports can be quickly comprised by generating a library of "canned comments" that are selected for insertion into the report document - Hard copy final reports can be in the process of being printed during the time the electrodes are being removed from the patient - Electronic data storage reduces operating costs by eliminating the purchase of recording paper Q. What are the advantages of using infrared/video technology for vestibular testing? A. The most exciting innovation in vestibular testing since the introduction of computerized ENG in 1986 is the use of infrared technology. Through the use of infrared illumination it is now possible to track and record eye movement, convert it into a conventional "ENG" recording and analyze the data as in conventional computer-based ENG. This eliminates the need for the electrodes as the cameras "lock on" to the pupils and track their movement. Think of the time saved by not having to prep the patient and deal with myogenic and electrical interference. The eye tracings are noise and artifact free (except for eyeblinks). Some instruments even eliminate the need for calibration as the eyes are at a fixed difference from the cameras. Data is analyzed and reports are generated in the same fashion as is done in traditional PC-based ENG systems. All tests can be performed with the eyes open as the use of the video goggles place the patient in a "darkened" environment without the possibility for fixation. In addition, infrared/video technology can be used to monitor and videotape eye movement during routine examination of the dizzy patient in an exam room. Gaze, positional and Dix-Hallpike testing can be quickly and easily performed in a non-laboratory setting. Infrared/video technology is also very useful when performing canolith repositioning techniques. As the patient is moved through the various positions the eyes can be visualized until such time the nystagmus disappears at which time the patient can be repositioned. By videotaping the eyes it is also possible to bill third party payers for this procedure. Q. What are the differences between measuring otoacoustic emissions via the transient and distortion product techniques? A. It is agreed that both TEOAEs and DPOAEs represent the same cochlear phenomenon. Otherwise, there are several misconceptions about TEOAE measures as compared to DPOAE measures. Perhaps none more so than frequency specificity. It is generally assumed that the DPOAE is more frequency specific than TEOAE data. Certainly if one considers the spectral makeup of the test stimuli, the DPOAEs are more frequency specific since DP measures are generated by the presentation of two pure tones while a click is typically used as the stimulus for TEOAE measurements. However, when analyzing the response, the stimulus is irrelevant. If a spectral analysis is performed on the TEOAE response, the result is highly frequency/place specific information from within the cochlea. Most authorities now agree that although the spectra of the stimuli used to elicit TEOAEs and DPOAEs are quite different, the place within the cochlea that is responsible for the OAEs are vey similar. Used in tandem, TE and DP measurements can be quite complimentary. It is generally agreed that TEOAEs are more efficient at collecting low frequency information (500Hz - 1.5KHz) and DPOAEs are better at collecting data above 4KHz. The latter is due to limitations presented by the TE stimulus (click) and filter settings of the instrumentation. TEOAEs provide a quick look at the speech frequency region of the cochlea. However, it may be necessary to assess cochlear integrity at higher frequencies and at multiple test levels. DPOAEs are more suitable for this purpose. In combination, TEOAEs and DPOAEs may allow for a gross estimation of hearing loss of coclear origin. Q. The personal computer is here to stay. How can i put a PC to use for me in my audiology/hearing aid practice? A. These days the sky is really the limit. It becomes a matter of how much you want the PC ivolved in your practice. The technology is now available to allow you to control all aspects of your audiology and hearing aid practice from the PC. You can schedule, generate test report documents, bill patients and third party payers, track your business, collect, store, and print data. Complete audiologic test systems can now be purchased that integrate all of the above components including programming, fitting and analyzing hearing aids.

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