Soterix Medical MXN-33 High Definition-transcranial Electrical Stimulator

The first fully software-controlled stimulation system with unmatched specification. The first stimulator that allows simultaneous multiple-region targeting. The first stimulator with sub-gyri targeting. The first stimulator with image-guided neuronavigation. A system so advanced, it could only have been made by Soterix Medical, the world leader in non-invasive neuromodulation and integrated imaging technologies.

Soterix Medical MXN-33 High Definition-transcranial Electrical Stimulator

The MXN-33 HD-tES / HD-tDCS Stimulator provides upto 32 isolated programmable current sources (channels) with a common reference to ensure current conservation at all times. The channels are completely independent in waveform, sample duration, and the number of samples. The stimulator is fully software-controlled. The system allows easy access to Matlab allowing researchers unprecedented flexibility to control stimulation based on their protocols.

Simultaneous multiple-region targeting: The case for increased independent current-controlled channels

Soterix Medical MXN-33 High Definition-transcranial Electrical Stimulator

It is known that multiple brain regions / networks are involved in the pathogenesis of certain conditions, making it rational to simultaneously target these regions. Infact, stimulation of multiple brain targets have already been shown to be beneficial by other non-invasive brain stimulation approaches like rTMS and ECT. In the case of HD-tDCS/tES, it has been shown that optimal montages that allow simultaneous targeting of as many as 5 brain targets, require ~30 electrodes (Huang 2018). Now MXN-33 Stimulator with our Neurotargeting software allows to achieve that.

Targeting on five point-like ROIs (red circles in the MRI on left ) and five brain structures (red regions in the MRI on right). For the current intensity of the individual electrodes and the induced electric field distribution, refer to the two colormaps at the bottom. The sum of electric field intensities across targets are noted below each plot. See Huang 2018 for more information.

Sub-Gyri Targeting

With current flow patterns produced by transcranial electrical stimulation modulated by cortex convolutions, and the resulting neuromodulation highly directionally sensitive, Soterix Medical created the only technology capable of sub-gyri specific control of electric field magnitude and direction (Rawji 2018)

Sub-Gyri current control requires:

  1. High-Definition (HD) tES to articulate current delivery
  2. MRI guided current flow using Neurotargeting
  3. Neuronavigated HD-MRI registration

The Soterix Medical MXN-33 system is the only neuromodulation system capable of non-invasive Sub-Gyri targeting.

Comparison of electric field modeling for montages directing current across and along the cortical surface. Study confirmed that orthogonal, but not parallel, oriented tDCS modulates TMS -MEPs. See Rawji 2018 for more information.

Broadest waveform range of any integrated system

The Soterix Medical MXN-33 allows generation of any waveform you want and through any electrode combination you want. The system allows loading sample values from a text file to generate arbitrary waves. The system will deliver the arbitrary wave as long as the sample period is > 2 š¯›¨secs. The system supports Matlab integration to fully control stimulation, supports standard TTL triggers to start / abort stimulation (either generated by third party triggering solution or by our custom triggering interface), and can be configured to deliver complex protocols (deliver electrical stimulation at a certain delay from an event onset).

MxN-33 waveform interface GUI

Integration with monitoring technologies

The Soterix Medical MXN-33 Stimulator allows for the first time - dense stimulation (upto 33 channels) combined with dense recording applications. Leverage our integrated technology solutions to pair with research-grade EEG, fNIRS, PET, fMRI options that you want and trust. Use the full software control option to plan real-time closed-loop application. Use the triggering option to implement experiments that allow closing the loop. Use our unique electrode holders to hold HD-tES / HD-tDCS stimulation electrode and the recording electrode at the same scalp location by either: a) holding both at the same time or b) holding either one, one at a time. The possibilities are endless.

MxN-33 Brain Products EEG
MxN-33 Artinis fNIRS

Integration with monitoring technologies. Left: Brain Products EEG; Right: Artinis fNIRS

The MXN-33 system works in two basic modes:

MxN-33 Basic Mode GUI

Basic Mode

  • Program typical tES waveforms (tDCS, tACS, tRNS), intensity, duration, frequency (1-5 KHz) where applicable, ramp time, and ramp occurrence.
  • Single channel selection- Same stimulation settings are applied automatically for all channels.
  • Multiple channel selection- Allows application of individual waveforms through selected channels.
  • Single or Double blind operation.
MxN-33 Arbitrary Mode GUI

Arbitrary Mode

  • Load any waveform from samples in a text file.
  • Single channel selection.
  • Multiple channel selection.
  • Single or Double blind operation.