Basic Point of Care Ultrasonography (POCUS)

The link points to a series of presentations on Point of Care Ultrasound (POCUS) and its various applications by the Hospital Kuala Lumpur Emergency and Trauma Department Critical Ultrasound in Emergency Medicine (SONOCEM) team. It is not basic; there is almost 4 hours of content. This is the first of this series:

Do show your support for the production of open and free medical education.

Point of Care Ultrasound (POCUS) for Regional Anaesthetists

The following presentation was given by Dr Shahridan Fathil during the KoreAnesthesia 2020 International Conference on 7 November 2020. If you came here just for the video, here you go:

If you’re interested in how this presentation was made and how it affected the conversion into video, then follow on.

The presentation was actually a PowerPoint presentation with prerecorded audio. You can do this by using the Record Slide Show feature. Transitions are automatically added and played in accordance to the audio duration. Issues and tips to make it work better in the future:

1. The best transition between slides is…..none in my opinion. The presence of transitions puts gaps between the audio clips when the transition is in progress. This may not be a problem if there is no background sound in between periods of talking, which in the majority of setups naturally will have some wind noise (that I removed in post); the lack of wind noise between slides when it is present in the background actually sounds unnatural. But even if there was no wind noise in the original recording…

2. The timing needs to be perfect: transitions need to happen exactly after the end of each recorded audio. The way recorded slideshows work in PowerPoint is that each slide has an audio segment when you decide to record a presentation. But the problem with PowerPoint itself (and not the author) is that the app does not exactly match the timing of transitions with the actual duration of the audio clip. I noticed this when I tried to record while talking non stop and click through the slides: the slide duration was always shorter than the audio duration. On top of that in one of the slides, the audio was playing in the automated slideshow but not when exported as a video. And in another slide (in the video export), the transition occurred much later after the audio had already ended (despite setting the transitions manually and the part working when played as an automatic slideshow). These are all killer bugs with PowerPoint itself if you want to use it for public presentations with prerecorded presentations. Small deviations in the timing of transitions are seen (heard, actually) as clipped audio, along with the instances of no audio and delayed transition. In the final version above there was still some unusual weird sound effects even after matching the times. As for the missing audio, I simply copied from the presentation file and pasted it in. The case of the delayed transition was simply cropped out. The best way to get the exact time duration (if you want to fix it in post) is by playing the clip till it stops; I found that scrolling to the end of the audio clip does not actually show the duration of the audio clip (it’s off by fractions of a second). Even small deviations in the timings make the difference between hearing “ball rolling” versus “balll-”. But if you want to get it right the first time…

3. …I suggest that you pause before making any transitions. Trying to be mindful of this is annoying, but so is fixing the timings of all slides. And if you decided to play your presentation as a video instead of a slideshow, you may have audio that is not transitioned over or have buggy transitions. Going through your presentation before public consumption will have to be a must because of these bugs; Microsoft needs to fix them.

The timing here…

…And here need to match exactly. PowerPoint will mistime the duration short by fractions of a second. But fractions count.

No audio in one slide, and in another the transition came much later after the audio

Once the timings (including playing of video clips) are set, all you have to do is just play the presentation (if you want to stream with PowerPoint) or export as video (e.g. for uploading to video playing sites). If possible, I suggest playing the slideshow directly versus playing it as a movie whenever possible (due to the aforementioned bugs).

COVID-19 has brought out creativity in trying out solutions for teleconferencing, and we are seeing the pros and cons of the available solutions. Microsoft PowerPoint certainly has its uses for prerecorded presentations, but personally the bugs present can’t make me recommend it.