wavEMS

EMS controls via audio signals

EMS waves generated by audio.

RN-52, piezo amp, DC-DC convertors, powered by 3.7V Li-ion battery.

How to Use

Connect to wavEMS via Bluetooth and use audio output for controls.
"wavEMS.pde" provides a simple UI, where you can test typical EMS waveforms.
You can use any kind of audio, but always be careful that some signals can be painful/dangerous.
Please also go through these terms before usage.

Components

RN-52: Bluetooth Module
Breakout+Amp
or any other breakouts (but requires to remove the input resistor from the following Amplifier)

IFJM-001: Piezo Amplifier
IFJM-001

LTC3124: DC-DC Covertor (used to convert 3.7V input to 12V)
LTC3124

MIWI06-24D05: DC-DC Convertor (used to convert 12V to +5V and -5V)
MIWI06-24D05

Implementation

Connect battery to LTC3124.
Connect 12V output of LTC3124 to MIWI06-24D05 and IFJM-001.
Connect +5V output of MIWI06-24D05 to IFJM-001 and RN-52, and -5V to IFJM-001.
Connect RN-52 output to IJFM-001 input.
Use 3.9kΩ resistor for the IJFM-001 bus voltage adjusting pins.
Include a current limiting fuse etc. for safety.

Issues

due to the filter, the amplitude are not the same for all waveforms
consumes high current. maybe changing the resistor (bus voltage) can slightly solve this.

Publications

See the following for more details:
Michinari Kono, and Jun Rekimoto. 2019. wavEMS: Improving Signal Variation Freedom of Electrical Muscle Stimulation. 2019 IEEE Conference on Virtual Reality and 3D User Interfaces Workshop on Human Augmentation and its Applications (IEEE VR ’19). 4 pages. https://arxiv.org/abs/1902.03184

Also see...
Michinari Kono, Yoshio Ishiguro, Takashi Miyaki, and Jun Rekimoto. 2018. Design and Study of a Multi-Channel Electrical Muscle Stimulation Toolkit for Human Augmentation. In Proceedings of the 9th Augmented Human International Conference (AH '18). ACM, New York, NY, USA, Article 11, 8 pages. DOI: https://doi.org/10.1145/3174910.3174913
and multi-ems

The following article includes a survey of EMS in HCI, and safety topics.

Michinari Kono, Takumi Takahashi, Hiromi Nakamura, Takashi Miyaki, and Jun Rekimoto. 2018. Design Guideline for Developing Safe Systems that Apply Electricity to the Human Body. ACM Trans. Comput.-Hum. Interact. 25, 3, Article 19 (June 2018), 36 pages. DOI: https://doi.org/10.1145/3184743

Authors

Michinari Kono, U-Tokyo ( mchkono[at]acm.org )

rkmtlab / wavEMS