The EAVI ExG Board: An Open-Source Wireless Platform for Hybrid Physiological Sensing of Muscle and Brain Signals

Kernekoncepter

The EAVI ExG board is an open-source, wireless, microcontroller-based hardware design for the acquisition and processing of bioelectrical signals, including muscle electromyogram (EMG) and brain electroencephalogram (EEG).

Resumé

The EAVI ExG board is a hybrid physiological sensing platform that combines muscle electromyogram (EMG) and brain electroencephalogram (EEG) signals in a single, unified signal processing chain. The hardware design features a specialized biosignal acquisition chip (Texas Instruments ADS129x) mated with a general-purpose microcontroller (STMicroelectronics STM32F427) for high-quality signal digitization and real-time digital signal processing.
The key highlights of the EAVI ExG board include:

Multichannel EMG and single-channel EEG acquisition with high resolution (24-bit) and low noise floor (< 5μV RMS).
Flexible signal processing capabilities, including sample rate conversion, high-pass/low-pass filtering, notch filtering, and data conversion.
Wireless data transmission via Bluetooth Low Energy (BLE) or USB, enabling integration with a wide range of host devices and music systems.
Integration with the OWL Microcontroller Framework, which provides an abstraction layer between digital signal processing and firmware development, allowing for fast prototyping, development, and testing cycles.
Open-source hardware design, published on GitHub, enabling customization and adoption by the broader community.

The EAVI ExG board has been used in various applications, including user studies with neuro-diverse musicians and trained instrumentalists, as well as in live performances, demonstrating its versatility and potential for physiological computing and digital musical instrument (DMI) development.

Statistik

The EAVI ExG board captures ExG data at a sample rate of 16 kHz and a resolution of 20-bits.
The system has a noise floor of less than 5μV RMS.
The board can transmit up to 16 channels of data via Bluetooth Low Energy (BLE) at 125 Hz with 14-bit resolution.

Citater

"The hardware/firmware system interfaces with host software carrying out feature extraction and signal processing."
"The demo will show multichannel EMG, and single channel EEG. We call this hybridization 'ExG'."
"The EAVI board captures ExG data at a sample rate of 16 kHz and a resolution of 20-bits."

Vigtigste indsigter udtrukket fra

The EAVI EMG/EEG Board: Hybrid physiological sensing

by Atau Tanaka ... kl. arxiv.org 10-01-2024

https://arxiv.org/pdf/2409.20026.pdf

Dybere Forespørgsler

How can the EAVI ExG board be further integrated with existing music production and performance software to enable novel physiological-based musical interactions?

The EAVI ExG board can be integrated with existing music production and performance software through several strategies that leverage its capabilities in physiological sensing. Firstly, by utilizing its MIDI and audio class compliance, the EAVI board can seamlessly connect to Digital Audio Workstations (DAWs) such as Ableton Live, Logic Pro, or Max/MSP. This integration allows for real-time mapping of physiological signals, such as EMG and EEG, to control various parameters within the software, such as effects, instrument parameters, or even triggering samples based on muscle or brain activity.
Moreover, the implementation of custom plugins or Max for Live devices can facilitate advanced signal processing and feature extraction directly within the DAW environment. For instance, developers could create algorithms that interpret specific muscle contractions or brainwave patterns as musical gestures, enabling performers to manipulate sound in innovative ways. Additionally, the use of open-source frameworks like OWL allows for dynamic patch loading, which can be utilized to create interactive performance setups that adapt to the musician's physiological state in real-time.
Furthermore, collaboration with existing physiological computing platforms and communities can enhance the EAVI ExG board's functionality. By sharing protocols and developing standardized interfaces, the board can be integrated into a broader ecosystem of physiological musical instruments, fostering a community of artists and developers focused on exploring the intersection of technology and embodied interaction in music.

What are the potential limitations or challenges in using the EAVI ExG board for real-time, low-latency musical applications, and how can these be addressed?

One of the primary challenges in using the EAVI ExG board for real-time, low-latency musical applications is the inherent latency introduced during signal acquisition, processing, and transmission. The need for high-resolution data, particularly with EMG and EEG signals, can lead to delays that may disrupt the flow of live performance. To address this, optimizing the signal processing algorithms for speed and efficiency is crucial. This can involve simplifying the pre-processing steps, such as reducing the complexity of filtering or employing faster algorithms for feature extraction.
Another potential limitation is the bandwidth constraints associated with wireless transmission, particularly when using Bluetooth Low Energy (BLE). While BLE allows for convenient wireless communication, it may not support the high data rates required for transmitting multiple channels of high-resolution physiological data simultaneously. To mitigate this, the EAVI ExG board can implement adaptive data transmission strategies, such as dynamically adjusting the sample rate and bit depth based on the performance context, ensuring that critical data is prioritized while maintaining overall system responsiveness.
Additionally, environmental factors such as electromagnetic interference (EMI) can affect the quality of the signals being captured, leading to noise and artifacts that can hinder performance. Employing robust shielding techniques and utilizing advanced digital filtering methods can help minimize these issues, ensuring cleaner signals for real-time applications.

What other physiological signals, beyond EMG and EEG, could be incorporated into the EAVI ExG board to expand its capabilities for multimodal sensing and interaction?

To expand the capabilities of the EAVI ExG board for multimodal sensing and interaction, several other physiological signals could be incorporated. One promising area is the integration of electrocardiogram (ECG) signals, which can provide insights into the performer's emotional state and physiological responses during musical performance. By analyzing heart rate variability and other ECG metrics, musicians could create soundscapes that reflect their emotional journey, enhancing the expressiveness of their performances.
Additionally, incorporating galvanic skin response (GSR) sensors could allow for the measurement of skin conductance, which is indicative of arousal and emotional engagement. This data could be mapped to control parameters such as reverb or modulation effects, creating a more immersive and responsive musical experience.
Another potential signal is respiratory rate, which can be captured using respiratory inductance plethysmography (RIP) or other non-invasive methods. By tracking breathing patterns, the EAVI ExG board could enable musicians to control dynamics or tempo based on their breath, fostering a deeper connection between the performer and the music.
Lastly, integrating motion capture data from additional accelerometers or gyroscopes could enhance the board's capabilities for spatial interaction. This would allow for the mapping of physical movements to sound parameters, creating a rich, multimodal performance environment that combines physiological signals with physical gestures, ultimately leading to innovative forms of musical expression.