This should get rid of peaks arising from shifting the probe or applying more gel. 1 standard deviation from the rest of the window should be helpful in removing noise. Remove extra noise? If the data is particularly noisy, a second threshold excluding values that are greater/smaller than e.g.I tend to visualise the datafile whenever using thresholds, to make sure the data looks fine, and I use the same threshold for all subjects. I prefer to automate as much as possible, both because I don’t want the hassle and I want to avoid the potential bias that comes with manual changes. These can be removed manually or you can use a threshold (lower and higher, outside of the physiological range). Remove any gaps. There may be gaps in the data file where the probe had to be shifted for gel application or similar.While smoothing helps getting rid of some of these issues, I prefer to smooth as little as possible. Smooth the data. No data is perfect, and TCD data can be quite noisy for a number of reasons.This helps figuring out the quality, and making sure I’ve measured what I think I have measured. I always look at my data before I start working on it. Read the data file in MATLAB (or similar), then follow these processing steps.This will depend on the software, and I have found it easiest to work with machines that allow direct (during data collection) connection with a computer, feeding into Spike, LabChart or similar programs, as I know how to export data from such software without any fuss. I have used custom Matlab scripts to analyse these, using quite simple steps: In my research, I analyse beat-by-beat blood flow velocity in healthy participants, looking how this changes over time. The custom software may not always be what we are looking for, and diagnosis may not always be the end-game. For research purposes, however, things are a bit different. Usually, it requires training and experience to interpret ultrasound results for diagnostic or healthcare purposes, even with custom software. Now what? How do we analyse this? Some ultrasound machines have their own analysis software that can be used to determine whether the blood flow is normal. In a previous post I described how to use ultrasound to measure brain blood flow.
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