🧵 How to change your ultrasound settings
- Run AAA if it is not already running.
-
Right-click
the Ultrasonic Display and click "Ultrasonic Setup" → "EchoB, Micro & Art...".
These controls affect the behavior of your ultrasound probe.
You cannot retroactively change these settings for a recording you have already made. It is important to choose settings which let you see everything that you want to gather data about. If you make a recording and find that it is too hard to see, then you will have to change the ultrasound settings and/or change how you use the probe with your participant, and then make the recording(s) again.
(Click here for help with how to hold the ultrasound probe.)
How you use the probe depends on what research question you want to answer. Most speech and swallowing research uses ultrasound to look at a midsaggital plane through the vocal tract (which means front-to-back and top-to-bottom, but unable to see left-to-right). To do this, hold the probe under the chin so that the curve of the probe surface follows the curve of the neck. Push the probe into the neck so that it is touching the skin. You might need to adjust how much force you use to push the probe into the neck so that you can see a good ultrasound image, but don't use too much force or it will be uncomfortable. Please try it on yourself before using it on a participant. You can move the probe around on your neck while looking at the ultrasound image on screen, and you can rotate the probe front-to-back. For a good midsagittal image, the probe should be symmetrically in the middle in the left-to-right axis.
You can also hold the probe in the coronal plane (which means left-to-right and top-to-bottom, but unable to see front-to-back) by spinning the probe 90o around the handle. This lets you see rolling of the tongue and left-to-right movement.
This is how far the ultrasound probe can 'see'. It is the largest distance from the probe surface that data is visible.
Increasing depth allows anatomy further from the probe to be visible, but it decreases the sample rate of recording (also known as the framerate) slightly.
Decreasing depth increases the sample rate of recording slightly, but means you cannot see as far into the body.
We recommend a depth of 80mm for adult humans. If your participant is a smaller person you might need to decrease the depth, otherwise the tongue might look too small in the image.
(Click here for more explanation.)
The depth should be enough so that you can see the tongue surface when it is pushed against the palate. 80mm is large enough for the tongue to always be in view for most adult human males. However, if your participant has a lot of fat on their neck then you might need to increase this because the probe is further from the vocal tract. If possible, use the probe on your largest participant while asking them to repeat a /k/ sound and adjust the depth so that the tongue touching the palate is always visible.
This is how wide an arc the ultrasound probe can 'see' in. It is shown as a percentage of the maximum field of view that the ultrasound probe can offer.
Increasing field of view allows more of the vocal tract to be visible at the same time, but it decreases the sample rate of recording (also known as the framerate) slightly.
Decreasing field of view increases the sample rate of recording slightly, but means you cannot see as much of the vocal tract at once.
We recommend a field of view of 100% for the 2-4MHz convex probe. If you have the 5-10MHz micro-convex probe, please adjust this to an appropriate width for the anatomy you want to record. For recording speech, we recommend making it just wide enough to see the mandible shadow and the hyoid shadow at the same time.
(Click here for more explanation.)
If you are recording speech, you should try to change your field of view until you see both the mandible shadow and the hyoid shadow. 'Shadow' means a dark region of the image that stretches outwards from a bone in your participant. Bone absorbs ultrasound instead of reflecting it, so you cannot see bones. However, you can infer the position of bones based on the long black shadow they cast away from the probe. The mandible bone is underneath the tongue tip. The hyoid bone is at the base of the tongue at the back of the mouth. When you swallow, the hyoid moves.
Think about your research question. What human anatomy do you want to observe during recordings? You can use the ultrasound probe in many ways. For example, although most researchers use the probe in the midsagittal, you could spin the probe round 90o to see a left-to-right slice through the tongue to observe how it grooves.
This is how much ultrasonic energy is being fired out of the probe into the body. It is analogous to how bright a flashlight is: a brighter light illuminates further into darkness but is also blinding if it is too bright.
High ultrasound probe power is harmful. Ultrasound energy can heat tissue inside the body and cause cavitation. Please read the documentation for your specific ultrasound system before setting the power to any value above the lowest level.
Increasing Power increases the brightness of ultrasound reflections, making them more visible, but you should only increase power if you are using maximum Gain and the image is still too dark.
Decreasing Power reduces the brightness of ultrasound reflections.
You should set the Power as low as possible while still being able to get a viable ultrasound image for your research. If the image looks too dark you can use Gain and Dynamic Range to make it brighter without increasing the Power.
This controls the 'brightness' of the image.
Increasing Gain makes everything look brighter.
Decreasing Gain makes everything look darker.
Using ultrasound gel makes the image look much brighter and clearer! Check that you’re using enough gel across the whole probe surface for a clear image.
We recommend that you initially set the Gain to approximately 88% Then, adjust both the Gain and the Dynamic Range until the image looks like the image at the top of this page.
(Click here for more explanation.)
The ultrasound probe fires out sound waves and then listens for them to come back, like how a bat or dolphin echolocates. The Power controls how loud the sound waves are that the probe fires out, similar to how loud the clicks are that a bat or dolphin make. The Gain controls how loud the echoes sound in the probe's 'ear' when they come back. The Dynamic Range controls the 'hearing range' of the probe: what frequencies of sound it can hear, such as making low pitched sounds audible but not be able to hear high-pitched sounds.
This controls the 'contrast' of the image.
Increasing Dynamic Range reduces 'contrast'. It lets you see smaller reflections that would otherwise be invisible.
Decreasing Dynamic Range increases 'contrast'. It hides smaller reflections so you only see the biggest reflections.
We recommend that you initially set the Dynamic Range to approximately 56dB. Then, adjust both the Dynamic Range and the Gain until the image looks like the image at the top of this page.
(Click here for more explanation.)
The ultrasound probe fires out sound waves and then listens for them to come back, like how a bat or dolphin echolocates. The Power controls how loud the sound waves are that the probe fires out, similar to how loud the clicks are that a bat or dolphin make. The Gain controls how loud the echoes sound in the probe's 'ear' when they come back. The Dynamic Range controls the 'hearing range' of the probe: what frequencies of sound it can hear, such as making low pitched sounds audible but not be able to hear high-pitched sounds.
This controls how far into the body the ultrasound can travel, and how grainy the image is.
Increasing Probe Frequency lets you see more clear detail in the top/bottom axis (radial resolution) of the image, but the image gets darker and more faded further from the probe.
Decreasing Probe Frequency makes it brighter further from the probe, but the image becomes grainier in the top/bottom axis of the image.
We recommend that you set the Probe Frequency to 2 or 3 Mhz for adults and 4 or 5 MHz for small children. Larger participants need lower probe frequency because their vocal tracts are bigger. Small participants have smaller vocal tracts, so you can make the image clearer by increasing the probe frequency.
(Click here for more explanation.)
Frequency affects how long the sound waves are that come out of the probe. When sound waves travel through the body, they make the body vibrate. High frequency makes the body vibrate more, which causes the sound wave to lose energy as it turns into heat. This means that high frequency causes the waves to fade more quickly.
The ultrasound system sends out many pulses very close together. If the pulses are long then they can overlap each other if they are too close together. This means when two bits of anatomy in the vocal tract are very close together, a low frequency will cause them to blur together into one reflection. In other words, a lower frequency means less radial resolution, but the angular resolution stays the same.
This smooths the image to remove noise, but it hides details that could be important.
Enabling Pureview makes the image less noisy, but hides details that could be important.
Disabling Pureview lets you see details in the image, but it looks noisier.
We recommend that you disable Pureview so it is
OFF. This lets you record important details. If you make a recording without smoothing then you can safely smooth it afterwards using AAA, which has a different kind of smoothing that protects your data.(Click here for more explanation.)
Image smoothing does not understand the anatomy inside the human body. It naively smooths everything in an image, which means it can smudge and blur important details that would help you see the anatomy inside the body. If you use this Pureview it is permanently applied to every recording you make, so you cannot remove it afterwards. We recommend that you use AAA's smoothing instead, which you can enable and disable freely on recordings you have made. This means you can use AAA's smoothing without worrying that you are hurting your recordings. To use AAA's smoothing, you can enable it using the "Display Options & Live Tracker" dialog. Please disable Pureview if you want to record data.
This controls which distance from the probe looks clearest in the image.
Increasing Focus Depth makes the parts of the image further from the probe look clearer.
Decreasing Focus Depth makes the parts of the image closer to the probe look clearer.
We recommend that you use a Focus Depth that is 10mm less than your Depth.
This controls how many fan-lines the probe sends out sound waves on and listens for reflections on.
Increasing Line Density lets you see more clear detail in the left/right axis (angular resolution) of the image, but greatly reduces the sample rate (framerate).
Decreasing Line Density greatly increases the sample rate, but makes the image look grainier in the left/right axis of the image.
We recommend setting Line Density to low. This is because a high sample rate is very important to record data on fast tongue movements, but it's still quite easy to determine the shape and position of the tongue surface even on a low Line Density.
(Click here for more explanation.)
Increasing the Line Density by one step doubles its angular resolution compared to the previous step: 1x → 2x → 4x → 8x.
The ultrasound probe can send out sound waves at many different angles fanning out from the probe surface. Each time it sends out sound waves on a fan line it has to wait for the reflections to come back before it can start again on a different fan line. When using low Line Density the ultrasound probe only records a fraction of these possible fan-lines. Although this means that it can't observe as much angular detail, it is able to send out new sound waves on the fan lines again much sooner: this means that it has a much higher sample rate (framerate) when Line Density is low.
The 20mm 2-4MHz convex probe has 64 scanlines on the lowest Line Density, and 128 scanlines on the standard density. If you lower the Field of View, this will result in fewer of these scanlines being used.
The “Delay Acq.” (Delay Acquisition) controls are for synchronisation. They don’t affect how your ultrasound image looks and they don’t affect the sample rate (framerate).
If you are using a lip video camera then you should tick the box, and set the number to 1000 milliseconds. If you are not using a lip video camera then you should untick the box.
If you are recording lip video and ultrasound at the same time then the ultrasound must wait before starting. This is so that the video and the ultrasound can both synchronise with the audio correctly. The
Delay acq.checkbox controls whether AAA should wait before starting to record ultrasound so it doesn't interfere with video synchronization.If the checkbox is ticked then AAA will wait before starting to record ultrasound. If the box is not ticked then AAA will start recording ultrasound immediately when you click 'Record'.
The number is how many milliseconds AAA will wait before starting to record ultrasound, if the checkbox is ticked.
(Click here for more explanation.)
If you are recording ultrasound and/or video then these kinds of data need to be synchronised with the audio. We synchronise data using the 2nd audio channel by broadcasting electronic signals ("sync signals") onto it from the PStretch and the SyncBrightUp. If you are recording both ultrasound and video then it is important that the sync signals aren't sent at the same time or else they will interfere. To do this, these Delay Acquisition controls let you delay the start of ultrasound recording so its sync signals begin after the sync signal from the video has been successfully broadcast.
If you have changed the settings, you should make a test recording to check that they work correctly for you.
