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What is Byteflies Building for People with Epilepsy and Why?

A personalizable seizure monitoring wearable for home use that extends the capabilities of specialized hospital equipment.

Summary epilepsy demographics: See references in the text; Incidence denotes the number of new cases worldwide per year (reference); # Prevalence denotes the number of people worldwide with active epilepsy (reference).

What is the unmet need in epilepsy?

If it was not clear from the introduction, there are quite a few unmet medical needs for people with epilepsy, ranging from:

  1. Delivering state-of-the-art care to a broader demographic and larger geographic areas, especially where comprehensive epilepsy centers are not available.
  2. Developing new treatment options for treatment resistant epilepsy.
  3. Reducing the unpredictability of epilepsy and the associated stress caused by not knowing when the next seizure will occur.
  4. Managing psychosomatic stress, treatment side effects and epilepsy comorbidities.

The “Why” should always guide the “What”.

In that spirit, before diving into some of the specifics of Byteflies’s technology in the next section, let’s focus first on these unmet needs.

State-of-the-art care

Most people with a suspected or confirmed diagnosis of epilepsy will at some point undergo a video-electroencephalography (video-EEG) observation. This test requires admission to a specialized epilepsy monitoring unit (EMU) for 1–7 days. During that time, the following data is typically recorded continuously:

  • Twenty or more channels of electroencephalography (EEG), i.e. brain activity as measured on the scalp
  • Video-audio feed
  • Electrocardiography (ECG), i.e. heart activity to derive heart rate and sometimes heart rate variability
  • Electromyography (EMG), i.e. muscle activity
Video-EEG system with scalp electrodes being set up for data capture.
Example of an EEG trace with video feed for identification of epileptic events. Vertical markers indicate one second of data. Biopotentials, such as EEG, EMG and ECG, are generated due to the electrochemical activity of groups of cells. EEG measures biopotentials generated by brain cells (neurons), EMG originates from skeletal muscle cells, and ECG from heart muscle cells (cardiomyocytes). Specialized biopotential electrodes and sensitive amplifiers are needed to record these signals on the skin surface.
The most common signals captured during a video-EEG observation.
  • A (potentially long) hospital admission is required.
  • It requires access to a hospital with a specialized epilepsy monitoring unit and it can be expensive.
  • There is no guarantee someone will have a seizure during their stay.
  • The person is monitored under artificial conditions that do not reflect their usual environment and activities.
  • More quickly identify an optimal and personalized treatment strategy
  • Understand if the dosing of a drug is right
  • Find a balance between seizure freedom and side effects
  • Track changes in quality of life and comorbidities over extended periods of time
  • Ambulatory EEG: Similar to the EEG equipment used in the hospital but typically in a more portable format so people can move around at home.
  • Subcutaneous EEG: One or two EEG channels are recorded under the scalp which holds promise for making ultra-long-term EEG recordings but requires a surgical intervention.
  • Consumer wearables: Fitness trackers or wellness devices may in some cases complement seizure diaries.
  • Specialized medical wearables: Medical devices that come in a wide variety of shapes, sizes, and functionality that are purposely built for people with epilepsy for mid-to-ultra long-term use.

Recent improvements in cost-effective and unobtrusive seizure monitoring devices are extending state-of-the-art epilepsy care to the home environment and geographic areas without access to specialized facilities.

New treatment options

Many different types of epilepsy and seizures are known but even in the most recent effort to improve their classification, an “unknown” category remains. As discussed previously, seizures vary in their location of onset and migration patterns in the brain, as well as the symptoms they elicit and their duration. Many occur without warning, but they can also be triggered by environmental factors, such as sleep quality, stress, alcohol, medication, hormonal changes, and the list goes on. Although most seizures only last for a few seconds to minutes, their effect on a person’s well-being can linger for hours (known as the post-ictal phase).

  • In many cases, treating epilepsy is more than treating seizures, especially for treatment resistant individuals. Put differently: existing care paths can be made more holistic with an increased focus on long-term outcomes and quality of life.
  • Collection of real-world data (i.e. RWD, data that is collected outside the lab or clinical trial) has a lot of potential to improve our ability to efficiently match existing treatments to the right individuals. Put differently: existing care paths can be made more personalized.

To understand how to make existing care paths more personalized and holistic with the treatment strategies currently available, we need to improve our ability to capture relevant long-term data unobtrusively in the real-world.

Reducing unpredictability

In that same survey mentioned previously, the unpredictability of seizures is one of the main factors identified as impacting quality of life by people experiencing frequent seizures.

The unpredictability of seizures is an especially insidious part of living with epilepsy. New seizure monitoring technology can play a crucial role in removing some of that unpredictability on the level of the individual. Over time, these data collection efforts may turn into more generalizable takeaways and pave the way to more robust seizure predicting capabilities.

Improving quality of life

Last but not least, a lot of the devices discussed in the state-of-the-art care section can also capture other objective digital measures such as sleep quality, stress levels, and even environmental parameters such as exposure to loud noise or light patterns. Overlaying this information on top of seizure patterns and other epilepsy symptoms may play a key role in tackling the three other unmet needs. Exactly how that information can be collected as unobtrusively as possible and integrated into care pathways, remains to be seen, and it will take an active effort from healthcare providers to not only reward the treating of core symptoms, but also long-term outcomes, including quality of life.

Adding objective quality of life measures to routine clinical care for people with epilepsy will require an active effort from the entire community, including regulators and payers.

How can Byteflies Sensor Dot meet this need?

We set the stage on some of the unmet clinical needs in epilepsy that could be met by advances in digital medicine and specifically remote monitoring technology. The number of devices and applications is diverse, and many already have or hopefully will soon have a positive impact on the management of epilepsy.

How it works

Sensor Dot is our multipurpose wearable that can record biopotential and motion (inertial) signals. It is cleared in the EU (CE) and US (FDA 510(k)) as a prescription medical device.

Byteflies Sensor Dot placed in the neck with bilateral EEG patches. This configuration also measures motion.
Byteflies Sensor Dot placed on the chest with a cardiorespiratory patch to record heart rate, respiratory rate, and motion. Image is used with permission from copyright owners Stad Antwerpen and Frederik Beyens.
  1. Making the recording of relevant medical-grade signals possible in a form factor that is small enough for use in daily life.
  2. Making a cost-effective device available that can be used in locations or under circumstances where video-EEG equipment is not available.
  3. Increasing the number of day-to-week long seizure observation periods that can be made.
  4. Recording data that is compatible with existing diagnostic video-EEG data review workflows, as well as future automated data processing pipelines.
Signal comparison of video-EEG (hospital) and Sensor Dot (home) observations. # Sensor Dot can record two channels of EEG data, typically behind-the-ears but other electrode placements are possible. Measuring ECG and/or EMG requires a second Sensor Dot.

The current generation of Sensor Dot is ready to tackle these goals in the real-world. Sensor Dot has monitored more than 150 people with epilepsy accounting for more than 2000 seizures.


We hope this post helps in clarifying why we are developing Sensor Dot for epilepsy the way we are. A seizure monitoring tool that extends the capabilities of the traditional video-EEG set up beyond the walls of the hospital a few weeks at a time.

Further reading

The introduction of this post only touches briefly on some important topics. If you are interested in learning more, we recommend the following sources:



Byteflies is on a mission to make virtual care available to all. Our Care@Home solutions leverage the power of remote patient monitoring and real-world data to generate actionable insights for healthcare providers and patients.

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