TIP Research V5.4: More capable personalization, more robust simulation

TIP Research V5.4 (TIP V5.4), the latest release of our online platform for planning temporal interference stimulation studies, builds personalized plans for study-specific custom targets, diffusion data protocols, and electrode sizes – in addition to the wealth of functionalities offered by TIP V5.2 (see this video for an overview of the workflow). User-provided regions of interest become optimization targets, and processing options for diffusion weighted image data (DWI) support a broad range of acquisition protocol. The new universal current normalizer automatically and robustly handles inter-electrode impedances, even with large and proximal electrodes.

Core capabilities carried forward

• Guided TI planning workflow: Move from subject and target definition to optimized stimulation protocols and report generation in a few steps

• Personalized and precomputed models: Plan with established head and animal models or with subject-specific models generated from magnetic resonance imaging (MRI) data

• Advanced TI modes: Support for classic TI, multi-channel TI, and phase-modulation TI workflows

• Privacy-first local personalization: Run MRI processing locally – only the anonymized model is uploaded

• Full Sim4Life environment in Exposure Analysis: Model, simulate, and analyze in one place

• Exposure visualization and reporting: Inspect field distributions, calculate derived exposure quantities, and export detailed protocol reports

• Surrogate-Model-Based Optimization: Explore trade-offs between stimulation strength, selectivity, and collateral exposure with the surrogate model workflow, including the native constraint handling, parallel multi-seed search, and selectable precision introduced in TIP V5.2

Basic Functionality of TIP

What is new in TIP V5.4?

• Extended DWI processing: If available, diffusion data can be used for superior modeling the heterogeneous anisotropy of white matter in personalized models. The personalizer now supports a broader DWI processing workflow: diffusion weighted imaging data can be denoised before tensor extraction and optionally registered to the subject’s T1 image.Users can choose between two tensor-extraction configurations:
  - Maximum b-Value Cap: Exclude shells above a user-selected maximum b-value and fit the diffusion tensor to the remaining data.
  - Diffusion Kurtosis Model: Extract the tensor from a diffusion kurtosis fit, which remains valid at high b-values, where the standard tensor model does not.
  A wide range of diffusion imaging protocols (including multi-shell ones) can thus be processed to apply the desired conductivity model – flexibly adapting to the DWI data available to a specific study..

• Custom regions of interest: Many studies target structures that a standard segmentation or atlas does not provide – a lesion, a nucleus sub-region, or a region defined in a separate analysis pipeline. TIP V5.4 allows users to provide custom regions of interest to the personalizer. Each region is supplied as a pair of files:
  - a registered label-field NIfTI file containing the segmentation,
  - a tissue-list text file describing the labels in the corresponding field.
  The personalizer extracts surfaces from the supplied files and adds them to the Sim4Life model. Multiple file pairs can be supplied to support different (even overlapping) target regions-of-interest. The optimization then evaluates stimulation strength, selectivity, and collateral exposure for these regions.

• Universal current normalization: TIP uses voltage boundary conditions followed by conductance-matrix-based current normalization to offer superior electrode modeling accuracy, e.g., of edge enhancement effects. A new universal current normalizer automatically and reliably handles any study-relevant electrode shape and placement, including large and proximal electrodes.
  
  A validation study first confirmed that for previously supported electrode configurations, results obtained with the new universal current normalizer are consistent with those obtained using the established sensor-based method. It then used reference data obtained using manually optimized current density integration surfaces to confirm reliable handling of configurations that couldn’t be handled previously . TIP V5.4 therefore improves robustness without sacrificing the quality of the current normalization results.

What these improvements mean in practice

• More flexible diffusion processing: Configure denoising, DTI-to-T1 registration, b-value handling, and tensor extraction according to the dataset and intended analysis.
• Study-specific targets: Optimize for the region your study addresses – custom anatomical or experimental regions, including overlapping ones.
• Plan with the electrodes you will use: Reliable handling of inter-electrode impedances by the validated universal current normalizer ensures superior field prediction quality, whatever the electrode shape, size, and montage your study uses.

Request & Inquiries

TIP V5.4 is available to groups enrolled in the TI Solutions Early Adopter Program, including eligible TIBS-R users and participating IT'IS research partners. Access to the tool is provided at no cost for eligible users. Personalized cloud simulations are charged according to the applicable Amazon Web Services (AWS) simulation cost, currently approximately US$60 per personalized subject. Precomputed models remain free-of-charge to explore.

For access requests, technical questions, or support, please contact tip@itis.swiss.

Make sure to also check out the latest version of the TI Brain Stimulator for Research (TIBS-R) from our Z43 partner TI Solutions AG. 

Reference for Citation

Please, cite the use of TIP in your publications, as follows: "IT'IS Foundation, (2026, Oct. 8), Temporal Interference Planning Tool TIP V5.4. https://tip.science"

Disclaimer

By using the TI Planning Tool (TIP) (the "Software"), the End User agrees and acknowledges that the Software is a novel and experimental online tool developed for neuroscientists and brain stimulation experts to determine optimized electrode placement and stimulation conditions for targeting deep brain regions. The Software does not provide binding results and is not a substitute for the expert End User's own calculations of electrode placement and stimulation conditions for targeting deep brain regions. The Software is only intended to assist the expert End User in his/her own calculations. Therefore, the expert End User shall always ascertain the Software's results by doing his/her own calculations. DO NOT ACT SOLELY ON THE RESULTS OF THE SOFTWARE. The expert End User uses the Software and its results at his/her own risk. As a consequence, IT'IS Foundation does not give any representations and warranties for the Software and the liability of IT'IS Foundation in connection with the Software and its use and application is excluded to the full extent possible under the applicable law. IT'IS is not liable for any damages (including without limitation consequential, incidental, direct, indirect, special or punitive damages, damages for loss of profits, loss of use, business interruption, loss of information or data, or pecuniary loss) resulting from the use of or reliance on the Software. In particular, IT'IS Foundation is not responsible for (a) the correctness, completeness, integrity and accuracy of any data calculated by the Software, (b) any conclusions drawn by the End User or any third party from any simulation, calculation, modelling or other process or operation executed by the Software or by End User using the Software, (c) the technical, scientific, legal and commercial feasibility of any project, product and undertaking of the End User or any third party, and (d) the economic and financial viability of any project, product and undertaking of the End User or any third party.
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