Many individuals may be unaware of the fact that the consumer tDCS device industry is relatively new, with the first “commercial” tDCS device hitting the market in 2013. Over the past few years, interest in tDCS has exploded, and subsequently the market has been flooded with new companies producing tDCS devices. Many of the early companies are still around today, but there are also numerous tDCS devices that show up on the market, only to disappear a few months later.
The reason this article is called “Choosing A tDCS Device” is because we suggest you read then copy, print, or download the information below and refer to it as you do your own research into purchasing a device. We suggest that you read all company product descriptions, and if they don’t provide detailed data to compare to the minimum standards below, then ASK FOR THEM! We encourage everyone to reach out to tDCS suppliers via email, twitter, facebook, etc. and ask them if their products conform to these minimum standards of safety and operation.
Minimum Standards for Consumer tDCS Devices
The following list includes the minimum standards by which all tDCS devices should meet or exceed. We welcome input and feedback from all sources, including tDCS companies, as we continue to build and refine this list of standards.
- No Self Adhesive Electrodes – the device should not be sold, packaged, or marketed to be used with adhesive or “stick on” electrodes. Adhesive electrodes have been widely documented as a safety concern as they can cause burns and lesions at the site of the electrodes. (read more)
- Adjustable Current Output – The ability to adjust the device to a desired level of stimulation (ex: 1mA and 2mA), as opposed to only one current setting (ex: 2mA).
- Maximum Current Output of 2.2mA – The device should not be manufactured to output more than 2 milliamps of electrical current.1 However, due to the precision qualities of electronic components, an acceptable error tolerance of 0.2mA is acceptable.
- Low Battery Indicator or Voltage Regulation
- A Low Battery Indicator in the form of an LED light, LCD readout, or audio cue should alert the user once the battery/batteries need to be replaced. The indicator should trigger when the battery has discharged to a level at which the device can no longer overcome an acceptable amount of external resistance while producing an accurate and consistent level of current.
- Voltage Regulation – Voltage regulation, technically referred to as “boost voltage,” sets the output of the battery to a constant voltage level. With a constant & reliable power supply, the tDCS device’s ability to overcome external resistance will not decrease as the battery/batteries discharge over time. If a tDCS device uses Boost Voltage, the manufacturer of the device should publicly state the maximum level of external resistance the device can handle before it is no longer able to produce an accurate level of current..
- Ability to produce 2mA with 4k External Resistance3
- At the very minimum, the device should be able to produce an accurate current level of 2mA with a montage resistance of 4k (4,000 ohms), ensuring the device can operate as intended at the most common tDCS electrode placement montages.
- Timer – A timer is absolutely essential for tDCS device safety in addition to being a very convenient feature.
1 2mA is recommended as the maximum limit due to the lack of substantial research into the utilization of current levels above 2mA.
2 If proper low battery detection is not included in a tDCS device, the user is not alerted when the battery reaches a level at which is it no longer effective in powering the device and overcoming external montage resistance. If the battery is not replaced appropriately, the user will be using a non functional device, potentially without realizing so. “many applications do not allow enough current to flow through a load when voltage decreases. This voltage decrease occurs as batteries become depleted, and is a characteristic of the ubiquitous alkaline battery.” -Wikipedia.
3 This is based on our preliminary testing
We encourage individuals to contact us if they have any questions or are unsure about a specific tDCS device. Fill out the following form to reach a member of the Total tDCS team: