SimTech: A/V Lifesavers and general Toolbox

Those of you who do in-situ simulations may know this problem: You are setting up the A/V-system, but suddenly you realise that a vital cable is missing. Or one of the facilitators needs to hook his phone to a PC to transfer an important file for the debriefing. Or the old projector that you’re using only has VGA input…

In short, there are many situations where you need just a simple cable or an adapter to solve one of these nasty connection problems. So it is a good idea to have a selection of spares and often used parts ready.

That’s why I put together a small bag with A/V-“life savers” for me. You will find the contents listed below. Maybe you can use it as an idea for your own practice or maybe you will even find something I have missed -> if so, please put your suggestions in the comments!


  • HDMI cable male/male 3m
  • VGA cable male/male 3m
  • Adapter HDMI -> VGA
  • Adapter VGA -> HDMI
  • Adapter DP -> VGA
  • Adapter DP -> HDMI
  • Adapter DVI -> VGA
  • Adapter VGA female -> VGA female
  • Audio cable male/female 3.5mm Jack 10m
  • Adapter Jack 6.3mm -> 3.5mm
  • Adapter Jack 3.5mm -> 6.3mm
  • USB extension cables male/female 1m and 5m
  • USB B cable 20cm
  • USB Mini cable 1m
  • USB Micro cable 1m
  • USB Micro on-the-go adapter

Another thing I always take along is a small general toolkit. I use it for the installation of the A/V-system on the location and minor repairs on the spot.



  • Duct tape
  • Masking tape (for temporary installations on sensitive surfaces)
  • Skin tape
  • Cable ties (3 sizes)
  • String
  • Superglue
  • Thumbtacks
  • Nails
  • Caution tape
  • Cheap soldering iron
  • Electronic solder
  • Some wire (different sizes)
  • Electrical tape
  • Heat-shrink tubing (different sizes)
  • Lighter
  • Cheap multimeter
  • Battery tester
  • Marker
  • Basic tools (pliers, cutter, bit-set, adjustable spanner, hex keys)…
  • …and in addition I always carry my trusted Swiss-Tool X on my belt!

CT-scan your manikin!

In the age of the 3D-printer, you can print nearly everything. If you need a spare part, the printer will even copy things for you – if you have the right “blueprint”. And that’s where most of the work waits: In designing the 3D-model of the thing you want to copy. Sometimes you are lucky and someone has already done it for you. Sites like are full of, well, things.

But sometimes all you have is the original. If the part has a simple geometry, cubic for example, it can still easily take some hours to draw it right with a CAD-program. If the geometry is unregular, rounded or not accessible for measurements, it’s nearly impossible to do it by hand. Of course there are quite a few 3D-scanners on the market, but most are really expensive, don’t really work, or both.

20170918_124831.jpgBut many of you might have access to a 500’000 $ high-end 3D-scanner: The CT at your hospital! Just put whatever you want to print on the stretcher, fry the shit out of it, get the resulting DICOM-file, process it on and ten minutes later you have a high-resolution, printable .stl-file! Other than a conventional optical 3D-scanner, a CT can even reproduce the internal structure of your stuff!

In my case, I wanted to copy the lower leg of a Laerdal Resusci Anne Simulator (I’ll tell you why in a later post, work in progress). I asked the friendly techs from my radiology department if they could scan the leg for me, and they agreed right away. They scanned the leg in extra thin slices, processed and burned the resulting DICOM-file on a DVD for me. As described in this excellent basic tutorial, I transformed the DICOM- to a NRRD-file an uploaded it to embodi3d. Ten minutes later I could download a perfect .stl-file – completely free! On embodi3d you also find more tutorials on how to get a good CT-scan of your objects. Of course, your rad-techs also know a lot about this!

The scanned Leg in the three planes.

So be nice to your radiology guys, fire up the CTs and scan your simulation equipment! The resulting files can be printed 1:1 as spare parts, but also be modified using a CAD-program. You could design a printable i.o.-leg, a bleeding arm or a fractured skull for your manikin – the possibilities are endless.

The .stl-file as seen on

But please, if you do this: SHARE YOUR DESIGNS!!! Put the original files and any modifications you make online, so others can profit too!

You can find my .stl-file here.

VSS: Improved control-panel for the trainees

In the past, I used a modified keyboard to let the trainees control the Vital Sign Simulator (VSS) defibrillator function. I just put appropriate stickers on the function-related keys (e.g. a red flash-symbol and “SHOCK” on the “enter”-key), and covered the unused keys with a white sheet. A simple, but rather clumsy solution.

To make the controls more compact and easier to use (and give my lazy 3d-printer something to do…), I recently constructed this shiny new control-panel.DSC_7652_1024x678

It is made of the electronic innards of a normal USB-keyboard, some buttons, lots of colorful wires and a 3d-printed housing. See this new section for the detailed description.

Next step will be to take a wireless keyboard apart and build a similar control panel with it. Together with an android tablet and the SpaceDesk-App it will make VSS fully mobile!!!

The old control panel:ImageKey1


VSS 1.4.2: Automatic gradual change for HF

Good things take their time…

In the newest version of my Vital Sign Simulator, you can let the program change the heartrate to a target value over  a specific time (0-600 sec). Every 5 seconds the rate will change, every 10 seconds the documentation will be updated. Hope it all works well, the program is becoming more and more complicated with all the additions, sometimes this leads to unexpected complications under certain conditions. So please let me know if you experience problems!

Vital Sign Simulator 1.4.2! Free as always! Download available on

Gradual spO2-change for VSS

Vital Sign Simulator newest Version 1.4.0 out now:

Now more hasty clicking every few seconds if your patient is crashing, thanks to this new function: Automatic gradual increase/decrease of the spO2-value over a specific time (choose from 10-600 sec)! Every 2.5 sec the value will change, every 10 seconds an automatic log in the documentation will be made!

I will implement it for every parameter over the next week or so, but couldn’t wait to bring it to you. Have fun and check out version 1.4.0! Free as always! Download available on

Alternative to FFsplit for recording simulation sessions: OBS

Due to a prolonged downtime of the FFsplit download-page, I searched and found a good (or even better) alternative for recording simulation sessions: The Open Broadcaster Software.

I am testing it right now on an old pc with three webcams, and it looks good so far. Unlike FFsplit, it is still supported and development is going on.

I will keep you updated and maybe post a OBS-specific installation guide.

Vital Sign Simulator updated – again!

I promised you a further Vital Sign Simulator update soon. Soon is now!

VSS goes into version 1.2.0, one more function was added: The CPR-artefact!

Ever been annoyed by trainees interpreting the cristal-clear ECG during CPR without waiting for the break after 2 min? Well, fear no more! By clicking the yellow “CPR Start”-button, the current ECG-rhythm is replaced by a meaningless typical CPR-artefact. Press the button again when CPR stops, and the original ECG will reappear. See the manual for a detailed description.

So check out version 1.2.0! Free as always! Download available on