Looking for help?

What is ECochG?
Electrocochleography (ECochG) is a measure of the electrical potentials of the cochlea. Typically, the measurement is characterized by the stimulus onset (baseline), the response of the cochlea to the stimulus (summating potential - SP), and response to the synchronous firing of nerve fibers (action potential - AP). The AP is also known as Wave I. The cochlear microphonic (CM) is also part of the ECochG and has its own protocol. Measuring the CM requires slightly different test parameters than the SP and AP and for this reason it is described in a separate quick guide.

Why Perform an ECochG?
Certain vestibular and auditory conditions may be diagnosed with ECochG. The ECochG is primarily used to

diagnose Meniere’s Disease, particularly Cochlear Hydrops. The SP and AP amplitudes, latencies and their

relationship are used to diagnose these conditions. Perilymph Fistula, sudden hearing loss and other pathologies may result in abnormal ECochG results. Recent studies indicate that Superior Canal Dehiscence (SCD) may also result in elevated SP/AP ratios (Devaiah et al., 2009).

How to Test?
Surface electrodes are not adequate for recording ECochG. It is recommended to use Tiptrodes, TM-trodes or Transtympanic electrodes to measure the electrocochleogram. While transtympanic electrodes will result in the most robust response but are not feasible for most clinics. Gold foil Tiptrodes are sometimes used but TM- trodes will produce larger responses as it is closer to the site of generation. The following is an example of preparation and electrode placement performed with a TM-trode. Note the procedure should only be performed by trained professionals.

Patient Preparation is very important. The patient must lie down and should be relaxed or sleeping in a quiet environment during the procedure. An examination of the ear canal and TM must be performed prior to performing the test.

The electrode sites must be prepared and cleaned in order to obtain acceptable low skin impedance. It is recommended to have impedance values be 5kΩ or lower for Tiptrodes. The impedance values between one another should be balanced or similar in value. For TM-trodes the impedance should be 20kΩ or lower. It may be quite difficult to obtain such low impedance on the ECochG test ear electrode and higher levels may be accepted.

Electrode Placement: The ECochG test leads must be used to acquire the waveform. Below is an example of the electrode placement using the TM-trode with the EPA4 and an example of the EPA3 with a TM-trode.
For both examples the TM-trode and the test ear must be prepared prior to placing the TM-trode on the tympanic membrane. To reduce impedance a solution of saline can be used. Drain the ear prior to inserting the TM-trode. The TM-trode can be placed in a saline solution for a few minutes prior to placing it on the TM and should be dipped in electrode contact gel (e.g. Sonaville) prior to placing it at the TM.

EPA4 TM-trode example
When using EPA4 together with a TM-trode the red TM-trode cable is moved when switching ear.

EPA3 TM-trode example
Only 1-channel is needed to perform an ECochG with the TM-trode and for simplicity EPA3 can be used.

Basic ECochG Testing Procedure
The procedure discussed below is simply a suggested process to be used as a guideline. Consult your Instruction for Use or Eclipse Additional Information to learn how to create or modify a protocol.

Choose the protocol ECochG Click
Manual Mode: To begin the manual mode, choose the intensity and select the ear to test on the Record sheet. Next choose Start (or hit F2).

During testing monitor the EEG to assure a collection with minimal noise. The EEG levels should be low and consistent. As averaging commences, the waveform will appear on the screen.

Hint: Waveform Scaling can be increased or decreased by using the arrows on the top left side of the recording window or on your keyboard.
Hint: Window sizing may be changed during testing by selecting one of the arrow keys on the bottom, right side of the recording window or using the arrows on your keyboard.

Marking Peaks and Areas
Waveforms are marked from the Edit sheet during or after testing either manually or automatically. Amplitude Ratio or Area Ratio Calculation will automatically be computed once the required labels are assigned. The ratio selection is found in the General Setup.

To mark a selected waveform, click the appropriate waveform marker in the Edit sheet (or select 1-6 on the keyboard). Now bring the mouse to the correct position on the waveform and click to place the marker (or hit Enter).

Hint: You can use the digital filters to “clean up” noisy data even after a completed test or run. You’ll find this feature in the bottom of the Edit sheet.

Example of Marked Points for Amplitude Ratio

PBSL=Baseline, SP= Summating Potential, AP=Action Potential, BLst=start of baseline, Blend=end of baseline, AP1=start of AP, AP2=end of AP

Example of Marked Points for Area Ratio

PBSL=Baseline, SP= Summating Potential, AP=Action Potential, BLst=start of baseline, Blend=end of baseline, AP1=start of AP, AP2=end of AP

Amplitude ratio: Amplitude ratio is simply marked with the baseline, the summating potential and the action potential. A ratio between the BSL/SP and BSL/AP is calculated automatically by the system.
Abnormal SP/AP amplitudes are exceeding a ratio of 0.53 as the critical value (Devaiah et al., 2009).

Area Ratio: Area Ratio is marked by first marking the start of the baseline (BLst). The BL end will be marked automatically at the next point in the waveform where the amplitude crosses this baseline. If the waveform does not allow this, you can place the BL end manually. Now mark the SP and the AP1 (the beginning of the AP). Next mark the AP peak. Finally mark the AP2, which is where the AP ends and “changes direction”. A ratio is calculated automatically by the system. Abnormal SP/AP area ratios are exceeding a ratio of 1.94 as the critical value (Devaiah et al., 2009).

Reporting
Choose the Report Icon. When complete, choose Save and Exit. 

References
Devaiah, A.K., Dawson, K.L., Ferraro, J.A., & Ator, G.A. (2009). Utility of area curve ratio electrocochleography inearly meniere disease. Arch Otolaryngol Head Neck Surg, 129, 547-551.

What is ABR?
The Auditory Brainstem Response is an Evoked Potential that originates at the auditory nerve (Cranial Nerve VIII). This test is used to assess the auditory system’s function from the cochlea through the brainstem. The response is identified by “peaks” that occur typically between 1 and 15 milliseconds from the stimulus onset. The ABR peaks are measured and marked traditionally as I, II, III, IV, and V. Each peak has an expected latency to be considered “normal”. Delayed or missing peaks are consistent with abnormal auditory function. The amplitudes and latencies (both absolute and inter-peak) are used to diagnose certain auditory pathologies.

Why ABR?
ABR testing is traditionally used to help determine the degree of hearing loss in pediatric or difficult to test populations. It is also used for testing the auditory pathway as related to acoustic neuromas and some nervous system abnormalities.

How to Test?
Patient Preparation is very important. The patient should be relaxed or sleeping in a quiet environment. It is preferable that the patient lie down during the procedure to facilitate a calm and comfortable environment. The electrode sites must be prepared and cleaned in order to obtain acceptably low skin impedance. It is re- commended to have impedance values be 3kΩ or lower. The impedance values between one another should be balanced or similar in value.

Electrode Placement: The electrodes must be placed as indicated below. The must be a few centimetres between the white and black electrode. Alternatively the black electrode can be placed at the cheek.
Check the impedance on the preamplifier and place the transducers. Make sure the patient is relaxed prior to starting the test. You can monitor this by watching the EEG Window on the top right of the recording window.

Setting up the Eclipse
The Eclipse comes with pre-programmed protocols so the system is ready to use immediately. Protocols can be created or modified easily to fit your clinical needs. Consult your Additional Information to learn how to create or modify a protocol. The procedure discussed on the next page is simply a suggested process to be used as a guideline.

Basic ABR Testing Procedure

1. Choose ABR Threshold e.g. Threshold CE-Chirp LS 
2. Select ear and intensity
   AutoTest Mode: To begin the Automatic Test Protocol simply click on Start or use the F2 key. This will begin the Auto Sequence set up in the Protocol Setup.

   Hint: To move to the next intensity prior to completion of maximum sweeps choose Next Intensity or F3.
   Manual Mode: To begin the manual mode choose the intensity and select the ear to test on the Record sheet. Next choose Start or hit F2 if needed.

3. Monitor the EEG during testing to assure a collection with minimal noise.
4. Monitor the Fmp and Residual Noise to verify that a true response is detected.
   
   Note: Bayesian Weighting, Fmp, and Residual Noise Calculation are important additional features that are described in dedicated Quick Guides.
5. Monitor the waveform reproducibility
   The line should be black and relatively flat and consistent. As averaging commences, the waveform will appear on the screen. As averaging continues note the Wave Re-reducibility score.

   When a test is performed, an A and B buffer exist. Each receives half of the responses. An automatic calculation of the correlation (similarity) between the two curves is indicated in this area (above left). The time window over which this correlation calculation occurs is part of the test parameter setup. It is indicated by the bold part of the time scale seen above (right). You may change the width or position of this bold bar by dragging it by its ends or by grabbing it with the mouse and sliding it back and forth along the time scale. Wave reproducibility will be recalculated immediately.

   HINT Waveform Scaling can be increased or decreased by using the arrows on the top left side of the recording window.

   HINT Window sizing may be changed during testing by selecting one of the arrow keys on the bottom, right side of the recording window.

Marking Peaks
Waveforms can be marked during a recording or afterwards from the Recording or Edit sheet. Waveforms can be marked manually or automatically. To mark a waveform automatically, use the Suggest Waveform marker:

This feature will place markers within the latency ranges that may be entered in the Latency template.
To mark a selected waveform manually, choose the appropriate marker or select 1-5 on the keyboard. Now drag the mouse to the correct position on the waveform and click to place the marker (or push Enter). The same function is available if you right click in the graph area with the curve selected.

Hint: If you hold down Crtl key while using the Arrow keys the Waveform Marker will jump from peak to peak!
Hint: You can use the digital filters to “clean up” noisy data even after a completed test or run! You’ll find this feature on the bottom of the Edit sheet.

Latency Data and Latency Intensity graphs
The system has an option to load default latency data during installation. You may also create your own (consult your Additional Information for instruction). While marking waveforms manually, a shaded area will appear indicating such latency data to assist with marking.
Once the waveforms are marked, choose the Latency sheet. The shaded area indicates the range of the latency data.

Reporting
Choose the Report Icon
When complete, choose Save and Exit.

What is cVEMP?
The cervical Vestibular Evoked Myogenic Potential (cVEMP) is an evoked potential measured from the sternocleidomastoid (SCM) muscle and is used to assess the vestibular system (the saccule and its afferent pathways). An amplitude asymmetry ratio is then calculated to assess if the vestibular system is working normally. VEMP tracings are easily recorded and provide valuable information to medical practitioners to assist them in the diagnosis of various disorders. Loud tone bursts, at slow rates are used to elicit this response.

Why cVEMP?
The cVEMP is a test used in addition to traditional vestibular testing (e.g., VNG) to assist in the assessment of vestibular function. The cVEMP provides information about the saccule and inferior vestibular nerve, assisting medical practitioners in the diagnosis of disorders such as Superior Semicircular Canal Dehiscence (SSCD) (Milojcic et al., 2013) and Meniere’s disease (Rauch et al., 2004).

How to test?
Patient Preparation is very important. The electrode sites must be prepared and cleaned in order to obtain acceptably low skin impedances. It is recommended to have impedance values of 3kΩ or lower. The impedance values between each electrode should be balanced or similar in value.

There are different suggested activation techniques for the SCM muscle. The patient can either be sitting and instructed to turn the head only to contract/activate the SCM muscle as shown in the image below.
Alternatively, the patient can be in a reclined position and asked to lift the head and turn the neck to contract the SCM muscle. Use of the patient EMG monitor will ensure consistent activation during testing.

Electrode placement (example):

The reference electrodes should be placed on the upper belly of the SCM muscle on both sides. The vertex electrode is placed on the clavicular joint (or on the high forehead) and the ground/common on the low forehead.

Typically, the air-conduction stimulus used is a 500Hz tone burst at high intensity level (e.g., 90/95dBnHL). Ensure that the patient is relaxed prior to starting the test. After confirming impedances.

Setting up the Eclipse
The Eclipse comes with pre-programmed cVEMP protocols so the system is ready to use immediately. Protocols can be created or modified easily to fit your clinical needs. Consult the Eclipse Additional Information manual to learn how to create or modify a protocol. The procedure described below is simply a suggested test process and to be used only as a guideline.

Patient monitor
An adequate contraction of the SCM muscle is essential for a good cVEMP recording. The patient monitor provides information to the patient during testing to ensure a correct head turn/lift and informs the patient about the test time and contraction of the SCM muscle. The information provided on the patient monitor is a guide to the patient and constitutes to a more accurate test procedure which may shorten the overall test time.

EMG controlled stimulus/recording
when the patient contracts the SCM muscle adequately. This can be monitored by the patient either visually Patient EMG Monitor or audibly Monitor Tone. Please see Additional Information manual for a more detailed explanation of monitoring options.

cVEMP testing procedure
Choose a cVEMP protocol from the dropdown menu 
The cVEMP test should be run in the Manual Mode controlling/selecting stimuli manually.

Manual mode

1. To begin in manual mode, choose the intensity and select the ear to test on the Record sheet. Instruct the patient to turn their head to the right or left to activate the muscle on the testing side. You should pay particular attention to the ongoing EEG and the target range if needed.
2. Next choose Start or hit F2.
3. 100-200 sweeps are typically collected per waveform.

Setting up L & R waveform partners
After collection, choose a left or right ear waveform by double clicking the waveform handle. Next, right click the waveform handle of the opposite ear and select Set as VEMP Partner. The selected waveforms are used in the Asymmetry Ratio Calculation.

EMG scaling
The default protocol is setup to scale the curves automatically. Some prefer to scale after the recordings are completed. After the recording is complete, you can right click on the waveform and choose EMG Scaling. Waveforms will then be scaled according to the average prestimulus EMG values recorded throughout the collection. This will make individual recordings comparable, even though slightly different degrees of muscle tonus may have been applied during the different recordings, which provides a reliable tool in calculation of the amplitude asymmetry (McCaslin et al., 2014).

HINT Display Scaling can be increased or decreased by using the arrows on the top left side of the recording window or by using your keyboard arrows.

Marking peaks
The cVEMP response is well documented and is said to be represented by two distinct peaks; P1 occurring at approximately 13 ms and N1 occurring at approximately 23 ms.

Waveforms can be marked from the Record sheet or the Edit sheet. To mark a waveform double click on the waveform handle you would like to mark. Right click and then choose the correct marker. Drag your mouse to the correct area and click. You can also choose 1-4 on the keyboard to bring up the appropriate marker and use Enter to place it.

Normative data
A number of studies report upper limits of normal for cVEMP recordings between 35 – 45% depending on the use of EMG monitoring and scaling of the response. In a study by McCaslin and colleagues (2013), the upper limit of normal was reported as ~31-37 % when both EMG monitoring and scaling was applied.

Example of a cVEMP where P1 and N1 are marked for both ears. The asymmetry ratio is calculated at 0.06. Curves are scaled.

Example of scaled cVEMP waveforms indicating an abnormal asymmetry ratio (0.80) between left and right side, along with lowered cVEMP thresholds on the right. (Curves in the above example are inverted).

Reporting
Choose the Report Icon .
When complete, choose Save and Exit.

References
McCaslin, D. L., Fowler, A., Jacobson, G. P. (2014). Amplitude normalization reduces cervical vestibular evoked myogenic potential (cVEMP) amplitude asymmetries in normal subjects: proof of concept. J Am Acad Audiol, 25(3), 268-277.

McCaslin, D. L., Jacobson, G. P., Hatton, K., Fowler, A. P., & DeLong, A. P. (2013). The effects of amplitude normalization and EMG targets on cVEMP interaural amplitude asymmetry. Ear Hear, 34(4), 482-490.

Milojcic, R., Guinan, J.J., Rauch, S.D., & Herrmann, B.S. (2013). Vestibular evoked myogenic potentials in patients with superior semicircular canal dehiscence. Otol Neurotol, 34(2), 360-367.

Rauch, S. D., Zhou, G., Kujawa, S. G., Guinan, J. J., Herrmann, B. S. (2004). Vestibular evoked myogenic potentials show altered tuning in patients with Ménière’s disease. Otology & Neurotology, 25(3), 333-338.

Young, Y. H., Wu, C. C., & Wu, C. H. (2002). Augmentation of vestibular evoked myogenic potentials: an indication for distended saccular hydrops. Laryngoscope, 112(3), 509-512.

1 Introduction: eABR overview.

1.1 What is eABR?
An electrical Auditory Brainstem Response (eABR) is a measurement of the ABR using an electrical stimulus. Instead of a traditional acoustic stimulus the cochlear implant (CI) or auditory brainstem implant (ABI) provides the stimuli that evokes the eABR.

1.2 Why eABR?
eABR testing may be performed for the following reasons:

• To verify adequate placement of the cochlear implant or auditory brainstem implant electrodes during surgery.
• To estimate electrical thresholds in infants, young children or other patients who cannot be assessed using behavioral techniques.
• To assist in mapping the cochlear implant or auditory brainstem implant device.
• To assess interactions between electrode channels.

2 System setup

Stimulation system and acquisition system are required to complete the basic system setup to proceed with eABR test.

2.1 Cochlear device used for stimulation
For stimulation you need the following materials:

1. Computer.
2. CI Software.
3. CI programming device USB interface
4. Processor connected to the CI programming device.

2.2 Eclipse device used for recording

1. Eclipse 1.1 (with EP15 or EP25 license), hereafter referred to as ‘Eclipse’.
2. Eclipse EP software.
3. USB interface.
4. Trigger cable for Eclipse 1.1 (see Figure 1).
5. Preamplifier (manufactured from June,2019 or above serial number # ID114077).
6. EPA3 cable collector.
7. Three electrode cables.

Figure 1

3 Hardware set-up

• Ensure all the hardware components are arranged as guided in Figure 2.
• Ensure recording electrode cables are twisted to reduce the artefact from the stimulator.
• Ensure the cables used for stimulation are well separated from the recording cables in order to reduce the artefact.

Figure 2

3.1 Setting up CI programming software:

• Ensure the ‘CI Software’ is installed on the computer and available for use.
• Open the CI software, create a new patient profile if needed or access the existing patient profile¹.
• Connect the processor.
• Proceed an Impedance Measurement for CI and make sure all electrodes are connected before testing eABR.
• Proceed with eABR test.

3.2 Setting up Eclipse:

• Turn on the Eclipse and double-Click on OtoAccess icon.
• Create a new client profile/access the existing one².
• Click on the EP icon and the acquisition window appears
• Choose the eABR protocol for integrity tests and/or eABR recordings see Figure 3 and footnote No. 2).
• Now the Eclipse is ready to proceed with the eABR test.

Figure 3

4 Patient Preaparation

Patient preparation is very important to achieve the best test results. Optimally, the patient should be lying down, asleep and in a quiet environment. Minimally, the patient should be relaxed with their eyes closed during testing (Note: Usually eABR is not affected by anesthesia but consult with local physician).
Clean the patient skin with the abrasive gel (e.g. Nuprep.) to reduce the impedance. Impedance values at or below 3kΩ will produce cleaner recordings. Arrange electrode cables away from the cochlear implant connections to minimize interference.
Check the impedance (at or below 3kΩms) on the preamplifier (Note: If the impedances are higher than 5 kΩ, remove the surface electrodes, clean the skin and place new surface electrodes. Refer additional information manual for the detailed procedure of preparation of skin and impedance check).

4.1 Eelctrode placement:
Three (3) electrodes are connected to pre-amplifier as shown in the Figure 4.

• Positive: indicated by white color.
• Negative: indicated by yellow color.
• Ground: indicate by black color.

Figure 4

4.2 For eABR test:

• Positive: High forehead.
• Negative: Chin.
• Ground: Place on the side close to the implant.

Note: this is the recommended electrode montage position for eABR test (Figure 5)

Figure 5

An alternative method (see Figure 6) of electrode position, recording from the contralateral side.

• Positive: High forehead.
• Negative: Contralateral side.
• Ground: Low forehead.

Figure 6

5 Test Procedure:

5.1 eABR test:
In general, for eABR testing, few CI-electrodes are tested, from where a general electrical threshold is set across remaining CI-electrodes.

1. From Eclipse application select the CI side (right/left), click on the intensity level corresponding to the CI electrode number, e.g. if the CI electrode to test is 4, then choose intensity 4dB to match electrode number and the recording label.
2. Click on ‘Start’ button (now the eclipse is waiting for the Ci software to send the trigger signal to initiate the eABR recordings).
3. Come back to CI software and set the test parameters for ‘eABR’ testing. Please refer to the CI manufacturer manual see footnote 2.

Note: when conducting post operation eABR, test amplitude and impulse duration should be defined at the comfortable level of the patient.

• Electrode to test: 4 (recommended are 4,8,12,16).
• Stimulation rate: 26 Hz.
• Stimulation starting current level: 80CL (steps of 10³).
• No of Stimulations to average: 4000.
4. Now Click on Stimulation button (CI software).
5. The recording has started on Eclipse.
6. Open EP application on Eclipse.
7. When sufficient data has been collected (e.g. when residual noise has reached a level of 50nV), press ‘STOP’ button.
8. Repeat the steps from 1 to 7 of section 5.1 with different electrode number (in CI software, e.g: 4, 8, 12, 16) to cover all the 4 measurements required to complete the eABR test. The example of the eABR, in this case, electrode No. 4 was selected for eABR test and tested to threshold, is shown in the Figure 7.

Figure 7

5.2 Troubleshooting: (in case of recording problems in eABR test)
In case of too many rejections, change the EEG rejection level.

• Check the electrodes impedances of both the Eclipse surface electrodes and the CI electrodes.
• Be sure that recording and stimulation cables are well separated to minimize cross talk.

6 Result interpretation

6.1 How to interpret the eABR results?
The eABR test is to measure the electrical threshold of the individual CI electrode band. In optimum, a stimulus with the current level of 80 CL is used as starting point, from where it is decided to increase or decrease the amplitude/duration based on the presence of the response. The steps are typically increased/decreased in steps of 10.
In the example, electrical threshold of electrode no.4 was measured and typical result is shown in Figure 8.

Figure 8

Labels to each waveform can be added. In the example, current level was labeled, see Figure 9.

Figure 9

When comparing eABR to ABR, the following differences can be noted:

• eABR latency is approx. 2ms seconds earlier than ABR, hence, eABR Wave V is found typically around the 4ms.
• A minimal latency shift is seen in eABR with decreased stimuli duration.

Note: For more information about the Eclipse, please refer to the Eclipse User Manual.

¹ Refer to CI manufacturer Medical User Manual for further details.
² Refer to Eclipse User Manual for further details.
³ The steps are typically increased if there is no eABR response and decreased if there is an eaBR response.

What is oVEMP?
The Ocular Vestibular Evoked Myogenic Potential (oVEMP) is an evoked potential measured from the inferior oblique muscle and is used to assess the vestibular system. There is still some debate over the origin of the response (Piker et al., 2011), however, the oVEMP is largely dependent on the integrity of the superior vestibular nerve (Jacobson et al., 2011).

The oVEMP is recorded using surface electrodes at four sites on the face and an Amplitude Asymmetry Ratio is calculated to determine if the above-mentioned parts of the vestibular system are intact and working normally.

The figure shows oVEMP recordings from a normal young adult (Murnane & Aki, 2009).

Why oVEMP?
The oVEMP is a test used in addition to traditional vestibular testing (e.g., VNG) to assist in the assessment of vestibular function. oVEMP recordings provide value information to medical practitioners to assist them in the diagnosis of disorders such as Superior Semicircular Canal Dehiscence (SSCD) (Watters et al., 2006) and Meniere’s disease (Sandhu, 2012).

How to test?
Patient Preparation is very important. The electrode sites must be prepared and cleaned in order to obtain acceptably low skin impedances. It is recommended to have impedance values of 3kΩ or lower. The impedance value between each electrode should be balanced or similar in value.

The subject is either seated or in a reclined position and is instructed to maintain an upward gaze at 35 degrees for the duration of the recording (Kantner & Gürkov, 2014). Placing a static visual target on the wall or ceiling for the patient to look at during testing will ensure consistent activation of the inferior oblique muscle.

Electrode placement (example)

Use of this electrode montage does not require the active (white) electrode to be shifted during testing and is reported to provide the largest oVEMP amplitude (Piker et al., 2011).

The reference electrodes should be placed as close as possible underneath the eye in the orbital midline. Avoid placement close to the medial canthus (inner corner of the eye) as a null-point exists where there is no oVEMP response present (Sandhu, George & Rea, 2013).

The oVEMP response is recorded from the inferior oblique muscle underneath the contralateral eye. Therefore, the right (red) electrode is placed under the left eye while the right ear is stimulated. Correct positioning of the electrode on the inferior oblique muscle is essential in obtaining a response (Sandhu, George & Rea, 2013).

Alternative electrode placement (examples)

Electrode montage for testing the left ear. For testing of the right ear, move the active (white) electrode to the other side (underneath the red electrode).

Typically, the air-conduction stimulus used is a 500Hz tone burst at high intensity level (e.g., 90/95dBnHL). Ensure that the patient is relaxed prior to starting the test. After confirming impedances.

Setting up the Eclipse
The Eclipse comes with pre-programmed protocols so the system is ready to use immediately. Protocols can be created or modified easily to fit your clinical needs. Consult the Eclipse Additional Information manual to learn how to create or modify a protocol. The procedure described below is simply a suggested test process and to be used only as a guideline. 

oVEMP testing procedure
Choose an oVEMP protocol from the dropdown menu 
The oVEMP test should be run in the Manual Mode controlling/selecting stimuli manually. For more collection parameters details, please refer to instruction for use manual.

Manual mode

1. To begin in manual mode, choose the intensity and select the ear to test on the Record sheet. Instruct the patient to look up and hold their gaze without moving their head.
2. Next choose Start or press F2.
3. 100-200 sweeps are typically collected per waveform.

Setting up L & R waveform partners
After collection, choose a left or right ear waveform by double clicking the waveform handle. Next, right click the waveform handle of the opposite ear and select Set as VEMP Partner. The selected waveforms are used in the Asymmetry Ratio Calculation.

EMG scaling
The EMG scaling is not to be used in the oVEMP testing, as there is no contracted muscle as in cVEMP. The reason for gazing up, is not to contract the oblique muscle, but instead to positioning the inferior oblique muscle closer to to the recording electrode.

Marking peaks
The oVEMP response is well documented and is said to be represented by two distinct peaks; N1 occurring at approximately 10 ms and P1 occurring at approximately 15 ms.

Waveforms can be marked from the Record sheet or the Edit sheet. To mark a waveform double click on the waveform handle you would like to mark. Right click and then choose the correct marker. Drag your mouse to the correct area and click. You can also choose 1-4 on the keyboard to bring up the appropriate marker and use Enter to place it.

Example of an oVEMP where N1 and P1 are marked for both ears.

Normative data
A large study investigating the normal characteristics of the oVEMP by Piker and colleagues (2011) defined an upper limit of oVEMP amplitude asymmetry to be 34% (mean + 2 SD).

Example of scaled oVEMP waveforms indicating an abnormal asymmetry ratio between left and right side, along with lowered oVEMP thresholds on the right.

Reporting
Choose the Report Icon 
When complete, choose Save and Exit.

References
Kantner, C., Gürkov, R. (2014). The effects of commonly used upward gaze angles on ocular vestibular evoked myogenic potentials. Otology & Neurotology, 35(2), 289-293.

Jacobson, G. P., McCaslin, D. L., Piker, E. G., Gruenwald, J., Grantham, S. L., & Tegel, L. (2011). Patterns of abnormality in cVEMP, oVEMP and caloric tests may provide topological information about vestibular impairment. J Am Acad Audiol, 22, 601-611.

Murnane, O. D., & Akin, F. W. (2009). Vestibular-evoked myogenic potentials. Seminars in Hearing, 30(4), 267-280. Piker, E.G., Jacobson, G.P., McCaslin, D.L., & Hood, L.J. (2011). Normal characteristics of the ocular vestibular evoked

myogenic potential. J Am Acad Audiol, 22, 222-230.
Sandhu, J. S., George, S. R., & Rea P. A. (2013). The effect of electrode positioning on the ocular vestibular evoked

myogenic potential to air-conducted sound. Clinical Neurophysiology, 124(6), 1232-1236.
Sandhu, J. S., Low, R., Rea, P. A., & Sauders, N. C. (2012). Altered frequency dynamics of cervical and ocular vestibular

evoked myogenic potentials in patients with Meniere’s disease. Otology & Neurotology, 33(3), 344-440.
Watters, K. F., Rosowski, J. J, Sauter, T., & Lee, D. J. (2006). Superior semicircular canal dehiscence presenting as postpartum vertigo. Otology & Neurotology, 27(6), 576-768.

The Auditory Brainstem Response (ABR) is an evoked potential that originates at the auditory nerve (Cranial Nerve VIII) and the response is picked up by surface electrodes typically placed at Vertex and Left and Right mastoids. An ABR test is used to assess the auditory system’s function from the cochlea through the brainstem.

The response to auditory broad band or frequency specific stimuli is identified by “peaks” that occur typicallybetween 1 and 15 milliseconds from the stimulus onset. The ABR peaks are measured and marked traditionally as I, II, III, IV, and V. Each peak has an expected latency range to be considered “normal”. Delayed or missingpeaks are consistent with abnormal auditory function. The presence or absence of responses can be used to estimate hearing thresholds. An ABR threshold is an electrophysiological threshold that can be used to predict the behavioral audiogram. The difference between the two may vary quite a lot, but correction of 20dB at 500Hz, 15dB at 1kHz, 10dB at 2kHz and 5dB at 4kHz are typically applied correction factors.

Threshold recording using 2kHz Tone Burst. Note the large PAM response from the right side caused by the loud stimulus of 80dBnHL. The ABR threshold at 20dB nHL at 2kHz found here would be well within the range of normal hearing - applying a typical correction factor would estimate the behavioral audiogram threshold to be 10dBHL at 2kHz.

Improving Threshold testing with Eclipse
Challenges arise when evaluating hearing thresholds. They can include:

CE-Chirp® Stimulus Family
We know that as we get closer to threshold, the waveform latencies increase and the amplitudes decrease. This presents a challenge in “peak picking”. A solution is the implementation and use of the CE-Chirp^® LS and NB CE-Chirp^® LS. The CE-Chirp^® LS Stimulus Family compares to the traditional click while the NB CE-Chirp^® LS compares to traditional tone burst. Research indicates that the use of the CE-Chirp LS^® and NB CE-Chirp^® LS particularly at modest stimulation levels results in waveform amplitudes up to double that of traditional stimuli (Elberling & Don, 2008; Ferm et al., 2013). This is achieved by simply accounting for timing issues within the cochlea. If amplitudes can be increased, the ability of the user to quickly and accurately identify waveform peaks near threshold increases. This clearly reduces test time and increases user confidence. Please see example below.

The larger amplitudes of the CE-Chirp^® LS when compared to the traditional Click allows for faster and more reliable testing. Similar benefits can be found when substituting traditional Tone Bursts with the NB CE-Chirps^® LS.

Residual Noise Calculation

Noise levels also create a challenge as noise can eliminate the ability to obtain or view the necessary waveform peaks. Lower noise levels increase the ability to identify the waveform peaks and increase the confidence of the presence or absence of a response.

Traditionally, users run a set number of sweeps in an effort to reduce the amount of noise in the recording. However, the number of sweeps may tell us little about the Residual Noise in the tracing. An objective Residual Noise measure should be used instead. Typically, if Residual Noise levels are 40nV or less, the tracing is sufficiently clean to be able to reveal a response if present. Therefore, Interacoustics implemented the Residual Noise calculation. The use of Residual Noise calculation either by monitoring or as a stop criterion greatly improves the certainty. The Residual Noise bar placed on the right side of the Fmp graph indicates the Residual Noise level and will turn green with a checkmark when the criterion for residual noise is reached (e.g. 40nV).

The Fmp value (red curve) has at this point of testing passed the 99% response confidence criteria, and the Residual Noise level (black curve) has not yet reached the 40nV residual noise level suitable for quality recordings around threshold.

Fmp Calculation & Response Confidence
The Fmp is an indication of the Response Confidence of the recorded response. While looking at the waveform being recorded, a confidence level is calculated, and provided as a percentage of statistical certainty of a response being present in the recorded waveform. This statistical analysis assists the clinician in that it can reduce test time since it relies on statistical information and not solely on the experience of the user. The experienced user can encompass the Fmp values when evaluating response presence or absence. Often the Fmp will detect strong responses sooner than confident eyeballing can reach the same conclusion. On the other hand, Fmp may not identify smaller responses close to threshold, in which case eyeballing is to be applied, being the golden standard in response detection at threshold. When the response confidence reaches the set criteria (e.g. 99%) the bar indicating the Response Confidence turns green with a checkmark indicating that the Response Confidence criterion is met.

Bayesian Weighting
In the best testing scenario that one should always try to obtain, the patient will be very quiet or sleeping and the EEG at a constant and low level throughout the data acquisition. This is not always the case and Bayesian Weighting is of great help in such test situations. It is an averaging technique that weighs each sweep individuallygiving more “weight” or importance to quiet sweeps and less “weight” to sweeps with more noise. This is different from traditional averaging since traditional averaging simply accepts or rejects each sweep and not weighing them individually.

The use of Bayesian Weighting will assist the clinician in situations that are not ideal testing conditions, and will not alter the response waveform’s morphology.

A few additional practical hints

The Rearrange Curves and Group Curves functions in the upper tool bar ensure easy manual positioning of waveforms.

The A&B tool in the upper tool bar allows waveform reproducibility to be evaluated without the need to run repeated waveforms.

Important highlights

• Use eyeballed (or Fmp based) response identification or Noise Level as stop criteria, not a fixed number of sweeps.
• Use Bayesian Weighting for lowest residual noise.
• Use CE-Chirp® LS rather than click for larger response amplitudes.
• Neither Click nor CE-Chirp® LS is sufficient information on which to fit a hearing aid.
• Use NB CE-Chirps® LS rather than Tone Bursts for larger response amplitudes, when doing the frequency specific testing needed for hearing aid fitting.
• Consider typically using a relatively fast rate, as the time to get a low noise level rather than wave morphology is of the essence in threshold testing. If in doubt then lower the rate.
• Spend your time close to threshold rather than trying to obtain overly beautiful responses at loud intensities.
• Tough filtering (e.g. Low Pass display filtering at 1500Hz) may help eyeballing responses.
• Consider using the A&B buffers as your reproducibility tool, rather than spending time actually running double sweeps.
• Remember Fmp is typically not capable of picking out response presence close to threshold, but may be a valuable tool confirming response quickly well above threshold.
• A typical good threshold practice requires waveforms around threshold to have a residual noise level of 40nV or less, and requires eyeballing of a repeated responses (or similar A&B) at threshold and no visible response just below threshold.

References
Don, M. & Elberling, C. (1996). Use of quantitative measures of auditory brain-stem response peak amplitude and residual background noise in the decision to stop averaging. J. Acoust. Soc. Am., 99(1).

Elberling, C. & Don, M. (1984). Quality Estimation of averaged auditory brainstem responses. Scand Audiol. (13) 187-197.

Elberling, C., & Don, M. (2008). Auditory brainstem responses to a chirp stimulus designed from derived-band latencies in normal-hearing subjects. J. Acoust. Soc. Am. (124) 3022-3037.

Elberling, C. & Wahlgreen (1985). Estimation of auditory brainstem response, ABR, by means of Bayesian interference. Scand. Audiol (14) 89-96.

Ferm, I., Lightfoot, G. & Stevens (2013). J. Comparison of ABR response amplitude, test time, and estimation of hearing threshold using frequency specific chirp and tone pip stimuli in newborns. International Journal of Audiology, (52) 419-423.

What is OAE 
Distortion Product Otoacoustic Emissions (DPOAEs) are acoustic signals that can be detected in the ear canal of a person with normal outer hair cell function, subsequent to stimulation of the auditory system with a pair of pure tones.

Transient Evoked Otoacoustic Emissions (TEOAEs) are acoustic signals that can be detected in the ear canal of a person with normal outer hair cell function, subsequent to stimulation of the auditory system with a series of wideband clicks.

Why do OAE?
Available evidence suggests that Otoacoustic emissions (OAEs) are generated by the cochlea’s outer hair cells, and that the presence of OAEs is an indication that the outer hair cells are normal. Although OAE test data provide no indication of inner hair cell function, or of hearing ability, current research indicates that the majority of hearing-impaired individuals will be identified by a simple OAE test. Patients who fail to generate OAEs should be rescreened and/or referred for additional audiological testing.

How to Test?
Patient Preparation is very important. Otoscopic examination of the patient’s ear canal should be performed prior to testing. Excessive cerumen or vernix in the ear canal may interfere with the test and give invalid or incomplete results. Patients with excessive cerumen, debris, or foreign bodies in the ear canal should be referred to an audiologist or physician for removal of the blockage prior to testing. Place the patient in a position that will allow the OtoRead™ to be held steady while testing is in progress. The patient should remain still and quiet while the test is performed.

How to perform the test?

Step 1 Place an ear tip as far down as possible on the probe tip.

Step 2 Turn on the OtoRead™ by pressing the large DOWN arrow button.

Step 3 Select the test ear by pressing the LEFT or RIGHT arrow key.

Step 4 Insert the ear tip deeply into the patient’s ear canal to obtain a seal. The ear tip must seal the ear canal. The best test results are obtained when the eartip is inserted deeply into the ear canal instead of flush with the ear canal opening. Caution must be taken, however, to ensure that the eartip does not extend too deeply into the ear canal. When a seal is obtained, the OtoRead™ will automatically begin the test - first calibrating and then testing emissions.
Once the testing is finished, the unit will display “PASS” or “REFER” on the LCD display.

Step 5 When testing is completed on both ears, turn the printer on by pressing the round button on the top and place the hand-held unit in the cradle. The most recent test results for both ears will automatically print out.

Additional Information on the OtoRead™

Ear Tips

	The OtoRead™ instrument comes with a box of disposable ear tips that fit a variety of ear canal sizes. The probe tip must have an ear tip attached before inserting it into an ear canal. The ear tip kit has 12 different size ear tips from 3 mm infant ear tips to 13 mm eartips for adult testing. After selecting an ear tip, push it onto the probe tip until it is flush against the base of the probe tip. The sound outlet tubes on the probe tip are recessed to minimize the likelihood of clogging.
	Use only the eartips approved for use with the instrument. The eartips are disposable and should be replaced after each patient. Do not attempt to clean or reuse these eartips.
	If the probe tip becomes plugged or clogged, it must be replaced. See below for how to replace the probe tip.

Probe tip replacement
To replace the probe tip, squeeze the tabs as shown in the pictures below. The tabs should audibly snap off the probe assembly. Pull the probe tip directly off the probe and discard it.

Obtain a replacement probe tip and orient the tip as shown in the pictures below. The probe tip will only fit on one way; be careful not to force the tip into place. Push the tip directly down onto the probe. Once the probe tip is in place on the probe, push firmly downward on the top of the tabs one at a time until a click is heard. Tug lightly on the probe tip to verify that the tip is securely attached.

If the probe tip is not connected completely, the OtoRead™ will not perform a test.

Test techniques
As with other otoacoustic emission test instruments there is a technique to learn when using the OtoRead™ instrument, especially for newborns and infants.

When testing a newborn or infant with the OtoRead instrument, the following suggestions might be helpful:

Hint 1: The newborn has to be relatively quiet and calm; it is usually preferred for the infant to be asleep.

Hint 2: When testing a newborn, gently pull down and back on the pinna to straighten out the ear canal.

Hint 3: The cone-shaped eartips tend to insert deeper down into the ear canal than the mushroom-shaped eartips. This deeper insertion into the ear canal allows for the measurement of larger emissions due to the reduced ear canal volume.

Hint 4: Warming the ear tips prior to insertion also helps to keep the baby calm during testing.

1. Test Environment
   The ideal test environment is a quiet room.
   
   
2. Preparing the Patient
   Place the patient in a position that will allow easy access to the ear canal. Use the shirt clip on the probe cable to secure the probe to clothing or bedding. The patient should remain still and quiet while the test is being performed. If a baby is tested, ensure it is sleeping or in quiet relaxed state. Sucking, blinking, crying or movement may affect testing.
   
   
3. Preparing the Equipment
   Turn on the OtoRead™ by pressing the down button
   
   
   To change the selected protocol press CHANGE at the Main Menu. The Change Protocol Display will appear. Use the CHANGE arrow buttons to change the selected protocol. Press theUP arrow to return to the Main Menu to begin testing.
    
   
   To begin a test, insert the probe into the ear and select either the LEFT or RIGHT arrow key to indicate the ear to be tested.
   
   
   
4. The Probe
   Place the probe in the ear and then press the LEFT or RIGHT arrow key to begin the test – the test will proceed automatically if the probe fit is stable.
   
   
   To replace the probe tube, use the ear tip to grasp the probe tube (the clear plastic tube) and twist slightly while pulling the probe tube straight out of the probe head.
   
   
   Dispose of the used probe tube immediately to avoid confusing used tubes with new tubes. Take a new probe tube from the package and insert the tube into the probe head until it is fully seated. A properly inserted probe tube will snap securely into place when it is fully seated in the probe head.
   
   
   
5. Test Results

PASS result	REFER result

PASS – when the set criterion for a pass is reached, PASS is displayed in green above the measurement.

REFER – when the set criterion for a pass is not reached within the measurement time, REFER is displayed in amber above the measurement.

1. Test Environment
The ideal test environment is a quiet room.

2. Preparing the Patient
Place the patient in a position that will allow easy access to the ear canal. Use the shirt clip on the remote probe to secure the probe to clothing or bedding. The patient should remain still and quiet while the test is being performed. If a baby is tested, ensure it is sleeping or in quiet relaxed state. Sucking, blinking, crying or movement may affect testing.

3. Preparing the Equipment

Turn on the OtoRead™ by pressing the down button

To change the selected protocol pressCHANGE at the Main Menu. The Change Protocol Display will appear. Use the CHANGE arrow buttons to change the selected protocol. Press the UP arrow to return to the Main Menu to begin testing.

To begin a test, insert the probe into the ear and select either the LEFT or RIGHT arrow key to indicate the ear to be tested.

4. The Probe

Place the probe in the ear and then press the LEFT or RIGHT arrow key to begin the test – the test will proceed automatically if the probe fit is stable.

To replace the probe tube, use the ear tip to grasp the probe tube (the clear plastic tube) and twist slightly while pulling the probe tube straight out of the probe head.

Dispose of the used probe tube immediately to avoid confusing used tubes with new tubes. Take a new probe tube from the package and insert the tube into the probe head until it is fully seated. A properly inserted probe tube will snap securely into place when it is fully seated in the probe head.

5. Test Results

PASS result	REFER result

PASS – when the set criterion for a pass is reached, PASS is displayed in green above the measurement.

REFER – when the set criterion for a pass is not reached within the measurement time, REFER is displayed in amber above the measurement.

Prepare the equipment

1. Turn on Sera^TM by pressing the home/power button
2. Select a new or existing patient on the device or use the Quick Test option.
3. Select the ABR test protocol from the list.
4. Select the ear for testing
5. Pressing the Test button  starts the test.

Test environment
The ideal test environment is a quiet room where lights and other electronic equipment are turned off.

Prepare the baby

Place transducer
Place the probe or inset earphones in the baby’s ear/s or place the EarCups around the baby’s ears.

Run test
Press the Test button 

Impedance check 
An impedance check will begin. Impedances are indicated by the green/amber dots on the montage picture as well as in numerical format on the screen.

When a dot is amber, it means the impedance is poor (> 40kΩ) for the indicated electrode. Check that the surface electrode and cables are connected correctly. It may be necessary to re-clean the skin or use a conductive gel with the surface electrodes to achieve an acceptable impedance. Testing cannot begin until impedance indictors are green (< 40kΩ).

Results

PASS result		REFER result		INCOMPLETE result
When the pass criteria for the test is reached, a  is displayed in green above the measurement, indicating the test has PASSED.		When the pass criteria for the test is not reached within the measurement time,  is displayed in amber above the measurement, indicating the test is a REFER.		If the test is stopped before a PASS or REFER is generated by the system,  is displayed above the measurement indicating that the test is INCOMPLETE.

Prepare the equipment

1. Turn on Sera^TM by pressing the home/power button
2. Select a new or existing patient on the device or use the Quick Test option.
3. Select the TEOAE test protocol from the list.
4. Select the ear for testing
5. Pressing the Test button  starts the test.

Test environment
The ideal test environment for OAE testing is a quiet room. Loud ambient background noise adversely affects OAE measurements.

Prepare the baby
The baby should be sleeping or in a quiet and relaxed state. Sucking, blinking, crying or movement may affect testing.

Place transducer
Place an ear tip onto the probe tip and place the probe in the ear. Avoid holding onto the probe during the measurement as this can produce noise that may affect the test result.

Run test
Press the Test button 

Results

PASS result		REFER result		INCOMPLETE result
When the pass criteria for the test is reached, a  is displayed in green above the measurement, indicating the test has PASSED.		When the pass criteria for the test is not reached within the measurement time,  is displayed in amber above the measurement, indicating the test is a REFER.		If the test is stopped before a PASS or REFER is generated by the system,  is displayed above the measurement indicating that the test is INCOMPLETE.

Prepare the equipment

1. Turn on Sera^TM by pressing the home/power button
2. Select a new or existing patient on the device or use the Quick Test option.
3. Select the DPOAE test protocol from the list.
4. Select the ear for testing
5. Pressing the Test button  starts the test.

Test environment
The ideal test environment for OAE testing is a quiet room. Loud ambient background noise adversely affects OAE measurements.

Prepare the baby
The baby should be sleeping or in a quiet and relaxed state. Sucking, blinking, crying or movement may affect testing.

Place transducer
Place an ear tip onto the probe tip and place the probe in the ear. Avoid holding onto the probe during the measurement as this can produce noise that may affect the test result.

Run test
Press the Test button 

Results

PASS result		REFER result		INCOMPLETE result
When the pass criteria for the test is reached, a  is displayed in green above the measurement, indicating the test has PASSED.		When the pass criteria for the test is not reached within the measurement time,  is displayed in amber above the measurement, indicating the test is a REFER.		If the test is stopped before a PASS or REFER is generated by the system,  is displayed above the measurement indicating that the test is INCOMPLETE.

About this quick guide

This quick guide provides instructions about how to place and attach the Sera™ and accessories on the cart. Follow the cart manufacturer’s instructions to assemble the cart prior to installing the Sera™ and accessories.

Installing the cradle

1. Set the cradle on the cart with the front under the fall prevention plate.
   
2. Pass the cradle power supply cable through the pass-through hole and connect it to the port on the back of the cradle.
   
3. Attach the stabilizer plate over the cradle’s metal bar and fasten with screws.
   
4. Plug the power supply into a power strip¹ securing the cables with the post cable clips and tie wraps to create a neat appearance and prevent rolling over the cords during transport.

¹  The power strip is not included with the cart. The customer must supply an appropriate power strip that meets local standards and has at least 2 outlets that can accommodate the plugs of the printer and cradle.

Installing the cables

1. For storage/transport, place the preamplifier, electrode cables and transducers as shown.
   
2. For storage/transport, place the probe as shown.
   
3. For storage/transport, set the plug of power strip into the edge pocket as shown securing any hanging cables in attached bin to prevent rolling over the cord.
   

Installing the printer

1. Attach custom plate with the pictured 5/16-18 screws to the printer.
   
2. Insert the printer with the custom plate attached into the recess and fasten with the knob.
   
3. Pass the printer power supply cable through the pass-through hole behind the printer and connect it to the charger port on the right side of the printer.
   
4. Plug the power supply into the power strip securing the cables with the post cable clips and tie wraps to create a neat appearance and prevent rolling over the cords during transport.

Introduction
This Quick Guide is intended to provide guidelines on how to use the Interacoustics SKS10 Skull Simulator for bone anchored hearing devices.

Background Info
How do bone anchored systems work?
Bone anchored hearing systems transfer sound to the cochlea via direct bone conduction, bypassing the outer and middle ear. This is similar to the way that sound is transmitted to the inner ear when conducting bone conduction audiometry. With bone-anchored hearing devices, however, it is direct bone conduction; that is, the vibrations do not have to pass through the skin. They are sent directly to the cochlea via the bones of the skull. Therefore, the way that sound is conducted to the inner ear is completely different compared to traditional air conduction hearing aids. With air conduction hearing aids, the output of the hearing aid is measured in dB SPL (sound pressure level). With bone anchored devices, the output needs to be measured as output force level, in dB μN (micro Newton).

What is a skull simulator?
Similar to a 2cc coupler used with traditional air conduction hearing aids, the skull simulator is a coupler on which bone anchored hearing devices can be attached. It will convert the force output of the bone-anchored device to an electrical signal. With this new device, end users will be able to perform measurements on bone anchored hearing devices and evaluate if they are functioning as expected or not.

How does it work?

Setup and Test Instructions

• Required items:
• The Affinity 2.0 hardware.
• The Interacoustics SKS10 Skull Simulator and its power supply.
• The HIT440 Software license.
• The SKS10 Skull Simulator license.
• A bone anchored device.
• Optional: the TBS25 passive HIT box.

Installing the Skull Simulator License in the HIT440 Software:

1. After purchasing the SKS10 and the license, please send Interacoustics (service@interacoustics.com) the serial number.
2. To copy the serial number: go to Menu/Help/About, click on License and select “Copy s/n”; this will copy the serial number to the Clipboard.
3. Paste the serial number in the body of an email and mail it to Interacoustics.
4. Interacoustics will then email a new HIT license.

Activating the new HIT license:

1. Go to HIT module/Menu/Help/About.
2. Click on License.
3. Paste the new license number under
   HIT/New license.

The Skull protocol might be hidden in the software. To activate it:

1. Go to HIT/Menu/Setup/HIT440 setup.
2. Choose “Skull Simulator” under “Selected Protocols”.
3. Under “General Settings”, ensure that “Skull Simulator” is chosen under “Coupler”

Setting up the bone anchored devices Using the SKS10 with the Affinity

1. Connect the skull simulator to its external power supply.
2. Plug the power supply into the wall socket.
   
3. Place the skull simulator in the test chamber.
4. Plug it into the measurement microphone plug of the Affinity 2.0 test chamber.
   
   Note: it is also possible to use the SKS10 with the TBS25 test chamber.
5. Snap the bone anchored device onto the abutment of the skull simulator.
6. If checking battery drain, insert the battery pill in the sound processor and connect it in the red socket.
7. Ensure that the sound processor microphones are in the center of the cross.
   
8. Launch the Affinity 2.0 software.
9. When Affinity 2.0 software is open, select the HIT tab.
    
10. Choose a test protocol from the drop down menu.
11. Click START to begin the test.
    

Note: The Affinity 2.0 has a default Skull Simulator protocol, which takes element from the ANSI standard for Hearing Instruments. This protocol can easily be edited or modified in the setup menu of the HIT module. It is also possible to create your own protocol.

Skull Simulator Setup Guide in the Affinity 2.0

1. The setup guide window will appear as soon as the skull simulator protocol is chosen. To deactivate it, insert checkmark in the “Do not show this setup guide again” box.
2. To re-initiate the Skull Coupler Setup Guide startup window, go to Menu/Setup/General Setup and insert checkmark in the “Show setup guide” box.

For further information on the SKS10 and creating or customising protocols, please refer to the Interacoustics Additional Information document.
For further information on how to setup the bone anchored device, please refer to the respective bone anchored hearing device manufacturers’ product information documents.

Probe performance is crucial to TEOAE test results. We recommend that you conduct a probe test at the beginning of each day before starting to test on patients to ensure that the probe is functioning correctly.

• Before conducting the probe test, ensure that the probe tip is clean and free of wax and/or debris.
• Always conduct the probe test in a quiet test environment.
• Only use the recommended cavity for testing. Using a different type of cavity may either not detect probe faults or may incorrectly indicate a faulty probe.

Performing the Probe Test

1. Select the Probe Test TEOAE protocol on the handheld device or in the PC software.
   
   
   
2. Insert the probe tip without an ear tip attached into the Probe Test Cavity* or the 0.5cc** cavity provided with the Titan. Press the Start button and let the test run until it stops (approx. 30 seconds). Do not stop the test manually.
   
   
3. If the probe is functioning correctly, none of the TE bands will have a checkmark above them when the test ends. It is possible to continue with daily testing.
   
   
   
4. If error messages appear during testing or if one or more of the TE bands has a checkmark above it at the end of the test, the probe test has failed. Check and clean the probe tip for wax or debris and redo the probe test. If the probe test fails a second time, the Titan must not be used to test on patients. Contact your local distributor for assistance.
   

Note: Failure of the daily probe test also indicates that TEOAE measurements performed since the last successful probe test may be invalid and patients may need to be retested. Hence, the importance of performing the probe test daily.

For more information about the probe test, please refer to the Titan Instructions for Use Manual.

* A specifically designed Probe Test Cavity will be available for use shortly. Until such time, please use the 0.5cc cavity provided with Titan. **The 0.5 cc cavity simulates the impedance of neonate and adult ears to an acceptable level for the daily Probe Test. We discourage the use of smaller cavities for the daily check in neonatal screening as such a cavity is not representative of a neonate ear due to soft tissue in the ear canal.

Source
The information presented here is based on clinical examples as well as modeled patterns. Text and accompanying. Absorbance sketch is authored by Navid Shahnaz, PhD, Aud, Associate Professor of Audiology in the School of Audiology & Speech Sciences at the University of British Columbia (UBC).

Note
It should be noted, that recordings on ears with negative middle ear pressure will vary between patients – the shown Absorbance pattern is a sketched example only.

Absorbance characteristics to look for:
The Absorbance at lower frequencies tends to be at a very low level – close to a flat reading. This effect might increase with the amount of fluid in the middle ear. With pressures as high as plus or minus 300daPa, the low absorbance might extend up to the 2 kHz area.
Higher frequencies are often not affected by positive pressure in the ear canal. Negative pressure might cause a higher Absorbance at higher frequencies. These high frequency effects are not consistent across all ears.
In general, it can be difficult to distinguish between the condition of Negative Middle Ear Pressure and the condition of partial Fluid in the Middle Ear. If, however, the Absorbance reading is made at tympanometric peak pressure, for purely Negative Middle Ear Pressure condition the Absorbance reading, may not be distorted by the effects of a Negative Middle Ear Pressure.

Consequences of probe fit
All Absorbance measures need to have a good probe fit to be reliable. Evaluating Absorbance as provided by the 3D Tympanometry test ensures that a reasonably air tight probe seal was accomplished, as the air pressure sweep would not have been performed otherwise. In addition to an air tight probe seal, a deeper rather than a shallower probe insertion ensures the most accurate Absorbance measures. Shallow insertions tend to provide more elevated Absorbance readings at lower frequencies. This is somewhat similar to normal Tympanometry measures that are also influenced by probe fit and probe insertion depth.

Suggested reading
Effects of Middle-Ear Disorders on Power Reflectance Measured in Cadaveric Ear Canals, Voss, Susan E., Merchant, Gabrielle R.,Horton, Nicholas J., Ear & Hearing. 33(2):195-208, March/April 2012.

Acoustic Immittance Measures, Basic and Advanced Practice, 2013, Lisa Hunter, Phd, FAAA, Navid Shahnaz, PhD, Aud. (C), Plural Publishing. ISBN10: 1-59756-437-0, ISBN13: 978-1-59756-437-3.

Source
The information presented here is based on clinical examples as well as modeled patterns. Text and accompanying. Absorbance sketch is authored by Navid Shahnaz, PhD, Aud, Associate Professor of Audiology in the School of Audiology & Speech Sciences at the University of British Columbia (UBC).

Note
Unless the Absorbance is evaluated at tympanometric peak pressure, any positive or negative middle ear pressure will influence the absorbance characteristics and obscure a direct interpretation.
It should be noted, that recordings on ears with negative middle ear pressure will vary between patients – the shown Absorbance pattern is a sketched example only.

Absorbance characteristics to look for:
The Absorbance exhibits a very pronounced peak somewhere in the range slightly below 1 kHz. Absorbance in general increases in the frequency range below 900 Hz and decreases in the frequency range between 2.5 kHz and 3.5 kHz.

Consequences of probe fit
All Absorbance measures need to have a good probe fit to be reliable. Evaluating Absorbance as provided by the 3D Tympanometry test ensures that a reasonably air tight probe seal was accomplished, as the air pressure sweep would not have been performed otherwise. In addition to an air tight probe seal, a deeper rather than a shallower probe insertion ensures the most accurate Absorbance measures. Shallow insertions tend to provide more elevated Absorbance readings at lower frequencies. This is somewhat similar to normal Tympanometry measures that are also influenced by probe fit and probe insertion depth.

Suggested reading
Effects of Middle-Ear Disorders on Power Reflectance Measured in Cadaveric Ear Canals, Voss, Susan E., Merchant, Gabrielle R.,Horton, Nicholas J., Ear & Hearing. 33(2):195-208, March/April 2012.

Acoustic Immittance Measures, Basic and Advanced Practice, 2013, Lisa Hunter, Phd, FAAA, Navid Shahnaz, PhD, Aud. (C), Plural Publishing. ISBN10: 1-59756-437-0, ISBN13: 978-1-59756-437-3.

Source
The information presented here is based on clinical examples as well as modeled patterns. Text and accompanying absorbance sketch is authored by Navid Shahnaz, PhD, Aud, Associate Professor of Audiology in the School of Audiology & Speech Sciences at the University of British Columbia (UBC).

Note
Unless the Absorbance is evaluated at tympanometric peak pressure, any positive or negative middle ear pressure will influence the absorbance characteristics and obscure a direct interpretation.
It should be noted, that recordings on ears with negative middle ear pressure will vary between patients – the shown Absorbance pattern is a sketched example only.

Absorbance characteristics to look for:
The Absorbance at lower frequencies (lower than 1-2 kHz) reduces as the fixation increases. Total fixation does not, however, bring the Absorbance down to a flat line to the same degree as middle ear pressure or fluid in the middle ear tends to do.
Frequencies higher than 1-2 kHz are typically not much affected.

Consequences of probe fit
All Absorbance measures need to have a good probe fit to be reliable. Evaluating Absorbance as provided by the 3D Tympanometry test ensures that a reasonably air tight probe seal was accomplished, as the air pressure sweep would not have been performed otherwise. In addition to an air tight probe seal, a deeper rather than a shallower probe insertion ensures the most accurate Absorbance measures. Shallow insertions tend to provide more elevated Absorbance readings at lower frequencies. This is somewhat similar to normal Tympanometry measures that are also influenced by probe fit and probe insertion depth.

Suggested reading
Effects of Middle-Ear Disorders on Power Reflectance Measured in Cadaveric Ear Canals, Voss, Susan E., Merchant, Gabrielle R.,Horton, Nicholas J., Ear & Hearing. 33(2):195-208, March/April 2012.

Acoustic Immittance Measures, Basic and Advanced Practice, 2013, Lisa Hunter, Phd, FAAA, Navid Shahnaz, PhD, Aud. (C), Plural Publishing. ISBN10: 1-59756-437-0, ISBN13: 978-1-59756-437-3.

Source
The information presented here is based on clinical examples as well as modeled patterns. Text and accompanying. Absorbance sketch is authored by Navid Shahnaz, PhD, Aud, Associate Professor of Audiology in the School of Audiology & Speech Sciences at the University of British Columbia (UBC).

Note
Absorbance measures under more or less blocked conditions will vary. The displayed Absorbance pattern is a sketched example only.

Absorbance characteristics to look for:
The condition obviously has great variability due to the many ways the probe can be loosely fit. In general, the Absorbance will be at an unusually high level at frequencies below 2 kHz, and the pattern might be jerky.

Consequences of probe fit
All Absorbance measures need to have a good probe fit to be reliable. Evaluating Absorbance as provided by the 3D Tympanometry test ensures that a reasonably air tight probe seal was accomplished, as the air pressure sweep would not have been performed otherwise. In addition to an air tight probe seal, a deeper rather than a shallower probe insertion ensures the most accurate Absorbance measures. Shallow insertions tend to provide more elevated Absorbance readings at lower frequencies. This is somewhat similar to normal Tympanometry measures that are also influenced by probe fit and probe insertion depth.

Suggested reading
Effects of Middle-Ear Disorders on Power Reflectance Measured in Cadaveric Ear Canals, Voss, Susan E., Merchant, Gabrielle R.,Horton, Nicholas J., Ear & Hearing. 33(2):195-208, March/April 2012.

Acoustic Immittance Measures, Basic and Advanced Practice, 2013, Lisa Hunter, Phd, FAAA, Navid Shahnaz, PhD, Aud. (C), Plural Publishing. ISBN10: 1-59756-437-0, ISBN13: 978-1-59756-437-3.

Source
The information presented here is based on clinical examples as well as modeled patterns. Text and accompanying. Absorbance sketch is authored by Navid Shahnaz, PhD, Aud, Associate Professor of Audiology in the School of Audiology & Speech Sciences at the University of British Columbia (UBC).

Note
Absorbance measures under more or less blocked conditions will vary. The displayed Absorbance pattern is a sketched example only.

Absorbance characteristics to look for:

• The Absorbance will be very low across the frequency range
• Depending on the degree of blockage against the ear canal, the Absorbance might be more or less jerky

Suggested reading
Effects of Middle-Ear Disorders on Power Reflectance Measured in Cadaveric Ear Canals, Voss, Susan E., Merchant, Gabrielle R.,Horton, Nicholas J., Ear & Hearing. 33(2):195-208, March/April 2012.

Acoustic Immittance Measures, Basic and Advanced Practice, 2013, Lisa Hunter, Phd, FAAA, Navid Shahnaz, PhD, Aud. (C), Plural Publishing. ISBN10: 1-59756-437-0, ISBN13: 978-1-59756-437-3.

Source
The information presented here is based on clinical examples as well as modeled patterns. Text and accompanying absorbance sketch is authored by Navid Shahnaz, PhD, Aud, Associate Professor of Audiology in the School of Audiology & Speech Sciences at the University of British Columbia (UBC).

Note
Firstly, it must be noted that a perforated ear is easiest recognized by the flat curve and high equivalent ear canal volume of the traditional tympanogram. Similarly, the 3D absorbance measure allows recognizing that the measures are constant over the pressure range.
Secondly it should be noted, that recordings on ears with perforations will vary between patients – the shown Absorbance patterns for smaller and larger perforations shown here are sketched examples only. Please see Susan Voss’ article referenced below for more details.

Absorbance characteristics to look for:
The Absorbance generally increases compared to normal ears, and mostly so below 2 kHz as the middle ear cavity absorbs most of the energy. The increase in Absorbance is most pronounced with the smallest(!) perforations. The bump of higher absorbance around 1 kHz shown in this sketch can be very pronounced with a very small perforation and may shift to higher frequencies as the size perforation increases. With larger perforations, the low frequency Absorbance gets closer and closer to normal absorbance levels, but might remain above the Absorbance level the ear would have exhibited without the perforation.

Consequences of probe fit
All Absorbance measures need to have a good probe fit to be reliable. Evaluating Absorbance as provided by the 3D Tympanometry test ensures that a reasonably air tight probe seal was accomplished, as the air pressure sweep would not have been performed otherwise. In addition to an air tight probe seal, a deeper rather than a shallower probe insertion ensures the most accurate Absorbance measures. Shallow insertions tend to provide more elevated Absorbance readings at lower frequencies. This is somewhat similar to normal Tympanometry measures that are also influenced by probe fit and probe insertion depth.

Suggested reading
Effects of Middle-Ear Disorders on Power Reflectance Measured in Cadaveric Ear Canals, Voss, Susan E., Merchant, Gabrielle R.,Horton, Nicholas J., Ear & Hearing. 33(2):195-208, March/April 2012.

Acoustic Immittance Measures, Basic and Advanced Practice, 2013, Lisa Hunter, Phd, FAAA, Navid Shahnaz, PhD, Aud. (C), Plural Publishing. ISBN10: 1-59756-437-0, ISBN13: 978-1-59756-437-3.

Source
The information presented here is based on clinical examples as well as modeled patterns. Text and accompanying. Absorbance sketch is authored by Navid Shahnaz, PhD, Aud, Associate Professor of Audiology in the School of Audiology & Speech Sciences at the University of British Columbia (UBC).

Note
Unless the Absorbance is evaluated at tympanometric peak pressure, any positive or negative middle ear pressure will influence the absorbance characteristics and obscure a direct interpretation.

It should also be noted, that recordings on ears with fluid in the middle ear will vary between patients – the shown Absorbance pattern is a sketched example only.

Absorbance characteristics to look for:
The Absorbance at lower frequencies tends to be at a very low level. This effect might increase with the amount of fluid in the middle ear which might also extend the effected frequency range upwards. At the highest frequencies the Absorbance may be reduced as well (as shown in this sketch), but this effect is not seen in all ears.

Consequences of probe fit
All Absorbance measures need to have a good probe fit to be reliable. Evaluating Absorbance as provided by the 3D Tympanometry test ensures that a reasonably air tight probe seal was accomplished, as the air pressure sweep would not have been performed otherwise. In addition to an air tight probe seal, a deeper rather than a shallower probe insertion ensures the most accurate Absorbance measures. Shallow insertions tend to provide more elevated Absorbance readings at lower frequencies. This is somewhat similar to normal Tympanometry measures that are also influenced by probe fit and probe insertion depth.

Suggested reading
Effects of Middle-Ear Disorders on Power Reflectance Measured in Cadaveric Ear Canals, Voss, Susan E., Merchant, Gabrielle R.,Horton, Nicholas J., Ear & Hearing. 33(2):195-208, March/April 2012.

Acoustic Immittance Measures, Basic and Advanced Practice, 2013, Lisa Hunter, Phd, FAAA, Navid Shahnaz, PhD, Aud. (C), Plural Publishing. ISBN10: 1-59756-437-0, ISBN13: 978-1-59756-437-3.

Perform test

Disclaimer, all patient data is randomly generated for demonstration purposes.

Overview

Prerequisites

• Compatible equipment software installed, is visible in toolbar
• Patient created, see Quick guide create/delete/edit patient

Perform tests

1. Choose patient in the patient list
1. If there are existing sessions on the patient, these will be visible in the Session list.
2. Choosing sessions will show session preview if available and you can open the test report if available.
3. Double-clicking the session will open the session in the equipment software.
2. Click on the software tool that you want to use in the Toolbar. Perform tests on the selected patient.When you save a session it will automatically be saved to OtoAccess® Database

Create/delete/edit patient

Create Patient

1. Choose patient view.
2. Click the create patient icon .
3. Fill out patient information, note that fields marked with an arrow are mandatory. The unmarked fields and the remark fields are optional.
   Date can be filled out manually or by clicking the calendar button .
   By clicking the plus icon you can add a photo to the profile.
   
4. When done press the save button .
5. The patient has now been created.

Available patient fields

In the OtoAccess® Database administration tool you can set up what fields you want to make available, set as mandatory or even set up custom fields.

Delete/edit patient

Simply select the patient and choose delete or edit in the patient view.

When you choose delete you are prompted before deletion.

Basic workflow

1. Choose patient
2. Perform measurement
3. Send result

1. Choose patient

Patient and appointment information will automatically appear in the worklist. The information is sent from the main electronic patient journal system and will appear in state New.

Using the search options, you can filter the worklist by name, date, patient id, state or the configurable category fields.

Click on the relevant patient to continue.

Note: The search fields Category 1 and 2 can be labeled to your needs in the OtoAccess® Worklist HL7 server configuration.

2. Perform measurement

In the Order details view you click the blue ‘Create new' button to choose a suite. Then perform your test(s).

A test session will appear in the results list with the state unattached.

Note: Depending on your configuration, you may be able to perform multiple tests per patient.

Click on the test that you want to send to the electronic patient journal system.

3. Send result

Preview the selected result and press send to deliver the result to the electronic patient journal system.

Note: Depending on your configuration, you may be able to resend results..