TENSAEROCONF

Citation Author(s):
jose
berengueres
Mariam
al Kuwaiti
Submitted by:
Jose Berengueres
Last updated:
Thu, 10/05/2023 - 02:22
DOI:
10.21227/b97s-x142
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Abstract 

Abstract Spacesuits are essential for ensuring the safety and functionality of astronauts during space missions. However, they can introduce challenges such as sensory deprivation, reduced dexterity, and lower cognitive performance, which can increase the risk of error. In our previous research, we have shown that adding sound transparency to a suit improves cognitive scores with the block design task. Building upon these findings, here we evaluate use of electro haptics feedback in place of traditional haptics. We took a spacesuit and placed pressure sensors the outside two fingertips of the glove. In the inside we placed a transcutaneous electrical nerve stimulation patch on the skin. The evaluation focused on assessing the effect of the electro haptic feedback on cognitive performance in the context of the same test. The outcome of the study indicates that when the electro haptic gloves are switched on participants do not significantly improve completion times. The NASA TXL test test was also administered. The results are coherent with the Koh Block test outcome.

Instructions: 

 

An IVA training suit (Terra-Suit) from Final Frontier Design [31-32] (NY) was rented from startup Zero2infinity S.A and connected to a Stanley FATMAX air compressor (30 L/min, 59dB noise). A digital air regulator (LEMATEC DAR02B) maintained a constant pressure inside the suit between 1.01 and 1.03 bars. Test days had temperatures of 22-24°C, and the suit had a sound insulating characteristic of 21dB. The experiments were carried out in room E1-3071 on the campus of the first author. This room was windowless and had a relatively high background noise level of 42.5dB stemming from the HVAC, which was always on. During the experiments, the noise level was 49.5dB, owing to the compressor that sat 3m away. The compressor was always on. Flooring: carpet flooring. Lighting: fluorescent bulbs. The table used: standard 1m by 40cm. Chair, standard issue wood and steel chair.

Hardware setup

For each glove an Arduino controlled relays that closed the circuit of the TENS depending on a pressure threshold.

Koh Block Test Protocol

Procedure: Participants were briefed, given consent forms, and informed of the procedure. They were instructed to solve three different Koh block puzzles in sequence. All participants solved the puzzles in the same order, with an approximate duration of 23 minutes per participant.

Preparation Phase

1.     Briefing and consent form signing.

2.     Participant Preperation:

The participant is partially in the spacesuit, with only the head and arms not yet inside the spacesuit. Electrode patches are placed on the index and thumb of both hands.

 

3. TENS Device Setup

o   The TENS device is set to mode 25, starting at level 1.

o   The experimenter touches the sensor to trigger the electrode, asking the participant if they feel anything.

o   If the participant responds "no," the TENS level is increased to level 2, and the question is repeated.

o   The process continues until the participant responds "yes." Most participants typically begin to feel sensations around level 3.

o   If the participant experiences pain and discomfort, then voltage level is decreased.

o   The goal is to reach a level where the participant can feel the sensations without experiencing pain, which is noted down as the ideal level.

 

4.     Entering the spacesuit preparation:

Once the ideal TENS level is determined, the participant is fully placed in the spacesuit, visor is lowered and the air compressor is connected to the suit and activated.

 

Experiment Phase

 

1.     Final TENS Device Check:

o   A final check is conducted to ensure that the participant still feels the sensors when touched.

 

2.     Puzzle Sequence:

o   1st Puzzle: Participants from both Group A and Group B solve the 'offset diamond' puzzle with TENS devices active for both groups.

o   Participants familiarize themselves with the Koh block test mechanics.

o   The objective is to get participants comfortable and exposed to the electrode sensations.

o   2nd Puzzle: Participants from both Group A and Group B solve the 'diagonal stripes' puzzle with TENS devices active for both groups.

o   3rd Puzzle: Participants from both Group A and Group B solve the 'checkered pattern' puzzle with TENS devices active for Group A and inactive (no sensors) for Group B.

 

3.     Experiment Conclusion:

o   The visor is raised, and the air compressor is turned off.

o   Participants are removed from the spacesuit.

o   A participant is given a laptop to complete the NASA TXL LOAD Test.

o   Qualitative feedback is requested and collected from the participant.

 

Participant demographic

N=23 participants were recruited from UAE University (19 female, 4 male), with a mean age of 20 (SD=2.8, min 18, max 33). All participants were right-handed. None reported medical condition. Of these, 4 participant data was discarded because technical errors occurred during the tests.