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.
tDCS is a highly versatile and adaptable treatment. Soterix tDCS stimulators and accessories can be simply customized to address a range of clinical needs. An important clinical challenge is the optimization of stimulation protocols, including to address disease specific and/or patient specific needs.
We provide custom multiphysics modelling for researchers and clinicians in need of individualized tDCS simulation analysis including:
Example areas include: tDCS optimization for the treatment of stroke and traumatic brain injury including consideration of patient specific lesions.
Every Soterix Medical Neurotargeting software is enabled for individual optimization of current flow. Using Soterix Medical solutions, simply upload subject-specific MRIs and the corresponding current flow head model will then appear inside the subject select drop-down menu in your software. It is that easy to consider how variations in your subjects anatomy may influence current flow. Then combine this with Soterix Medical Neurotargeting to optimize electrode montage. For each of the four stroke subjects below, see how optimized Soterix HD-tDCS dosage delivers current to target regions (black circle) as opposed to conventional stimulation.
With increased interest in the use of monitoring, such as EEG, PET, MEG, Eye-tracking, NIR and fMRI in conjunction with Soterix tDCS and HD-tDCS, Soterix Medical remains the only company with the technology and expertise to ensure successful integration. Stimulation generates artifacts in all monitoring modalities including fMRI (Antal A et. al 2012),such that use of technically compatible devices without also integrating rational trial design, can lead to errant findings.
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.
Soterix Medical biomedical engineers are available to discuss the combination of rational measurement with our industry standard Soterix tDCS and HD-tDCS. And only Soterix Neurotargeting allows co-registration of current flow and measured responses
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
Two fundamental issues underpin the rational integration of tDCS and EEG: mechanical compatibility and electrical compatibility.
Mechanical compatibility with HD-tDCS: 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.
Integrate HD-tDCS electrodes (HD-BSM model) with any EEG system. HD electrodes indicated with arrow.
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