Every Soterix Medical device is fully supported by Soterix Medical Solutions and Services. From individualized dose optimization, clinical trial design and regulatory support, to integration with monitoring technology such as EEG, Soterix Medical provides unmatched quality and depth of support.
Technology-informed integration of tDCS with monitoring technologies such as EEG, PET, MEG, NIR, fMRI, and eye tracking, is essential. tDCS⁺ is a free service to every Soterix Medical tDCS and HD-tDCS user. Soterix Medical tDCS⁺ leverages the experience of our clinical partners and our unmatched biomedical expertise. And tDCS⁺ is open to cross-platform compatibility so that you can use the monitoring technology you want and trust.
In many instances, tDCS can be applied directly in a PET/CT without concern for artifact as occurs during EEG (link to EEG section) or fMRI (link to fMRI section) monitoring. Soterix Medical biomedical engineers work with leading clinical investigators to ensure scanner specific compatibility and trial rigor. For example, when investigators at University of Michigan initiated their landmark study to investigate the actions of tDCS on release endogenous opioids, Soterix Medical provided support on instrumentation designing including ensuring full electrode saturation during extended scanning sessions, custom EasyStrap (link to EasyTrap) head-gear for supine resting subjects, and co-registration of imaging and current flow data. Soterix Medical is ready to assist in the rational design of PET and tDCS studies ensuring every experimental confound from subject tolerability and stimulation stability is controlled. Clinical researchers and subjects enrolled in PET studies deserve the best equipment and rational experimental design. As needed, Soterix Medical is on site.
Technical set-up images from DosSantos (2012) study.
The difference between advertised “compatibility” and rational experimental design in clear in the combination of tDCS and fMRI when Soterix Medical biomedical engineers contributed to analysis of scanner induced artifact. As a result, without proper integration of scanning and stimulation protocols, fundamental experimental confounds not controlled for by a sham-arm or control-montage arm are introduced. Soterix Medical biomedical engineers are ready to work with clinical researchers and their medical physics team to identify and address concerns before an expensive study us conducted, and to support researchers through every step of the study, from risk assessment (IRB), to sequence design, to evaluation of current coupling through wires and impedance load, to data analysis including spatial co-registration with current flow. In our commitment to support the highest quality tDCS research, Soterix Medical is adamant that integration with any imaging modality but be approach rationally and in a trial specific manner. We are ready to discuss how.
fMRI imaging artifacts during tDCS in post-mortem subjects
Soterix Medical is the world-leader in noninvasive neuromodulation. NIRx Medical Technologies is the world-leader in NIRS tomographic imaging. Soterix Medical and NIRx Medical have formed a partnership to provide clinical researchers with the most advanced and high-fidelity integrated tDCS+NIR system.
The fNIRS and HD-tDCS systems are integrated seamlessly in a convenient head-gear. Larger systems allowing up to 96 IR sources, 64 detectors, and 16 HD stimulation channels. Company systems are designed to minimize complexity while focusing on brain regions of interest. Our exclusive HD-NIRS inset is the only integrated stimulation and recording plastic holder.
Soterix Medical Neurotargeting software allows precise current navigation with NIRx NAVI software images resulting brain changes. Since tDCS can produce changes in skin blood flow, proper experimental design and signal processing is critical for meaningful data. For immediate set-up and quality recording, Soterix Medical biomedical engineers are available to provide guidance through every step.
Two fundamental issues underpin the rational integration of tDCS and EEG: mechanical compatibility and electrical compatibility.
Electrical compatibility with optimized stimulator and rational experimental design. It is not prudent to assume that simple high-pass filtering of the EEG signal will remove confounds from EEG recording. Especially given that DC artifact may be non-stationary due to unknown electrode impedance changes during stimulation and that EEG amplifier active electronics can induce non-linear distortion, Soterix Medical biomedical engineers have developed protocols to implement and validate EEG+tDCS compatibility. It is not prudent to ignore noise that is not measured under the assumption is it not an experimental confound. Note that conventional experimental control arms, such as using sham stimulation or a control-montage, will not in themselves control for EEG+tDCS distortion precisely because the stimulation has been changed (e.g. only the active arm will experience artifact). Soterix Medical’s unmatched technical support is ready to guide you through a straightforward validation process that allows you to use your EEG system of choice.
Noise Comparision between SMI device and Other Commercial Devices
Insertion of large sponge electrodes under an EEG cap will not only block the access of EEG electrodes precisely in the area of interest, but also ejection of fluid from the sponges will shunt neighboring EEG electrodes. Soterix Medical offers a simple and unique solution to tDCS+EEG through the use of High-Definition (HD) tDCS electrodes. Compact in size and gel-based, with validated tolerability, HD electrodes can be inserted between EEG electrodes without compromising mechanical compatibility.
HD electrodes are compatible with any Soterix Medical tDCS or HD-tDCS stimulator. Moreover, Soterix Medical provides HD electrode holders for integration with any commercial EEG headgear including Brain Products (HD1-BP) and Biosemi (HD1-BS). HD-tDCS electrode models are designed to fit existing EEG system adaptor and are the only electrodes validated in multiple clinical trials to produce tolerated stimulation.
WARNING: HD electrodes were developed at The City College of New York and Soterix Medical to allow safe and tolerated DC stimulation. Soterix Medical can no longer provide technical or equipment support for the use of non-validated “small” electrode designs.
Soterix Medical Inc. is proud to announce a partnership with Brain Vision LLC to provide a completely integrated HD-tDCS+EEG. This provides you with unparalleled technical support and integration with a partnership that remains the industry standard for concurrent stimulation and recording.
Soterix Medical HD-tDCS and Brain Products EEG systems are used when the highest standard in precision and signal fidelity are required. Don't compromise with a hybrid system with neither quality stimulation nor sufficient electrode density. With Soterix+Brain Products you get the only validated HD-tDCS hardware, integrated Neurotargeting support, embedded seamlessly with EEG. Our joint technical support team can develop an optimal solution around the equipment you have, or quote a single integrated system. Whatever the application, Soterix+Brain Products ensures immediate productivity and validated quality and safety.
Soterix Medical engineers worked with ANTNeuro to develop the first fully integrated HD-tDCS and EEG system. Embedded HD electrode holders interlaced with EEG electrodes in a easy-to-use head-gear allows research grade stimulation and recording.
The fully-integrated cap is unique in having all positions pre-loaded as opposed to custom loading of HD holders only in locations of interest. This allows tremendous flexibility in the number and position of HD-Stimulation electrodes desired. In the configuration layout below, orange indicates 25 possible HD stimulation electrode locations. Combine with stacks of MxN (hyperlink to MxN page) modules to obtain as many independent channels as desired for your application.
Fully integrated Soterix Medical and ANTNeuro cap for HD-tDCS plus EEG
Soterix Medical Inc. and Biosemi Instrumentation are both companies founded by engineers and physicists to advance medical science. With Soterix Medical and Biosemi there is no need to compromise on stimulation or recording as a full electrode compliment is needed for state-of-the-art research. Use the data analysis software you know and trust while leveraging the Soterix Medical + Biosemi integrated platform. For the most advanced and automatic clinical imaging of brain disorders Soterix Medical Inc. and Elminda have formed a partnership providing on-site installation, hands-on training (with the HD-tDCS/Biosemi system), and ongoing data analysis support.
If you are familiar with Biosemi Active2 EEG system then Soterix Medical HD-tDCS can be directly integrated with your existing system. Three models of HD-BSM electrodes are available 1) HD-BSM Mini-stim, the smallest form factor HD electrodes ever designed; 2) The standard HD-BSM Macro-1 which allows concurrent EEG and tDCS from the same location; 3) HD-BSM Macro-2 which balances increased size with enhanced tolerability for prolonged clinical trials.