This data contains measurements of task duration, placement error and perceived task load (assessed via NASA TLX),
as well as basic information about participants and the order of conditions. The details of the measurement are
described in the article which this data is a supplement to. The .csv file uses semicolons as delimiters and commas
as decimal separators.

Participants performed two placements for each condition (with conventional monitor or with the head-mounted display
(HMD)). This is denoted in the suffixes _1 and _2 (such as acc_1 and acc_2). Participants only answered the TLX
questionnaire once per condition, so this does not apply to TLX data. The condition is denoted via the suffix 
_HMD (if the HMD was used); for example, acc_HMD_1 is the first accuracy measurement with the HMD.

The columns contain the following information:
- sono_xp: Number of ultrasound examinations or ultrasound-guided procedures the participants had performed
- acc: Placement error of the needle placement in millimeters.
- time: Task duration in seconds
- TLX: TLX score, calculated based on the questionnaire (no unit)
- Gender: Participant's gender
- HMD_first: Whether participants first performed placements with the HMD