In-lab Evaluation of New Tattoo Skin Electrodes for Measuring Masticatory Electromyographic Activity

Area of Science:

• Biomedical Engineering
• Wearable Technology
• Electrophysiology

Background:

• Electromyographic (EMG) assessment is crucial for diagnosing temporomandibular disorders (TMDs) and bruxism.
• Conventional EMG methods utilize complex equipment and wired electrodes, restricting use in everyday environments.
• Emerging electronic tattoos offer lightweight, flexible wearable sensors for accessible electrophysiologic recordings.

Purpose of the Study:

• To introduce and evaluate the EMG recording capabilities of novel, comfortable tattoo electrodes for masticatory muscles.
• To assess the feasibility of using wearable tattoo sensors for monitoring chewing biomechanics.

Main Methods:

• Ultra-thin tattoo electrodes with 4 x 3 mm diameter sensors were designed and fabricated using screen-printing technology.
• The tattoo electrodes were placed over the masseter and temporalis muscles.
• Simultaneous EMG recordings were conducted comparing tattoo electrodes to commercial ones during chewing tasks in 5 participants.

Main Results:

• An excellent correlation (0.95) was observed between EMG envelopes from tattoo and commercial electrodes, with highly similar signal morphology.
• The tattoo electrodes enabled precise automatic detection of masticatory EMG bursts with 97% sensitivity and 96% precision.
• Characterization of EMG burst amplitude and duration parameters was successfully performed.

Conclusions:

• Wearable tattoo electrodes demonstrate promising capabilities for unobtrusive masticatory EMG signal monitoring.
• This technology facilitates the assessment of chewing biomechanics and early detection of conditions like bruxism.
• The study establishes the feasibility of tattoo electrodes for real-life EMG recordings, supporting enhanced diagnosis of TMDs and bruxism.