Sim4Life V9.6 Release Notes

Sim4Life V9.6 is the second release in our application-driven computational neurostimulation series. It addresses one of the field's most persistent bottlenecks: the time required to predict neural activation with biophysical realism.

Items apply to both editions unless tagged (Desktop) or (Web). Each release includes everything listed below it for the same edition. Desktop hardware and OS: see System Requirements.

Known Issues (Desktop B24047, Web V9.6.0)

• Instability for some rare dispersive material configurations.
• Potentially decreased accuracy in rare cases for the sensor combiner of the far-field sensor.
• Improper surface refinement or isosurface settings may lead to non-converged current values and inaccurate current normalization in some quasi-static simulations.
• In FDTD post-processing, the Poynting vector S(x,y,z,t) of a time-domain field sensor is formed from E and H as if sampled at the same instant; because FDTD staggers them by half a time step, it is a first-order approximation. Frequency-domain and time-averaged power results are unaffected.

V9.6.2 · 7 September 2026

Desktop B24047 (text version) · Maintenance release based on V9.6.1 B23206.

Fixed

Modeling

• Fixed projects with very large unstructured meshes (above about 100 million tetrahedra) saved in V9.6 failing to reopen with a "free store overflow" error.
• Fixed Import local copy in the Model and Phantom download tool, which sometimes failed depending on the version the model was downloaded with.
• Restored the missing Move Tool view in the Controller window.

Meshing

• Fixed incorrect octree meshing of overlapping solid regions.
• The octree mesher now validates user-provided meshes before proceeding, and can be cancelled faster.
• Fixed inconsistent triangle orientation when extracting surfaces from prism meshes.

Simulation and Analysis

• Time-domain sensors no longer report zero values when results diverge in rare cases with an insufficient CFL margin; new error messages help avoid such divergence.
• Fixed hidden normalization options of the Maximum Exposure Optimizer and other missing Controller options, including Auto-Group for the gridder.
• The Poynting vector of time-domain sensors is now labelled as a time-domain quantity.

V9.6.1 · 21 July 2026

Desktop B23206 (text version) · Maintenance release based on V9.6 B22570.

Fixed

• Fixed model objects not appearing in the multi-tree under certain conditions.
• Faster faceting of large meshes.
• Fixed transparency not being preserved in 3D screen captures exported as PNG or TIFF.
• The Model Download Tool detects models that have already been downloaded.
• Local Tetrahedral Remesh accepts regions outside the mesh dragged into the mask.
• Fixed "Unknown" mesh domains caused by unassigned tetrahedra, and mesh corruption in an internal mesh-improvement step.
• Maximum Exposure Optimizer: phase values in configuration tables are now interpreted in degrees, as documented, giving correct field reconstruction and maximum sPD.
• Fixed an offset in the Core Heating blood temperature increase.

V9.6 · 4 June 2026

Desktop B22570 (text version) · Web V9.6.0, Platform V1.93.0 (platform notes)

Added

Modeling

• Model anonymization for privacy-aware data handling, compatible with the TIP tool.

Simulation

• Fast prediction of neural responses for detailed biophysical models used in treatment-planning workflows.
• The accelerated GAF predictor supports MRG-type double-cable axon models representing sensory and motor fibers.
• Neural activation thresholds predicted up to 1000x faster than conventional neuron simulations.
• Automated recruitment-curve analysis to evaluate fiber activation by stimulation amplitude and compare stimulation strategies.

• Enhanced interpolation handling in the thermal solver, and a check that EM source domains overlap the thermal simulation domain.
• Check for sufficient padding around far-field sensors.
• Standardized edge-normal computation across the Topological and Intersection voxelers.

Analysis

• Dosimetry algorithms reorganized by output field type, such as SAR and E-field.
• (Web) Algorithm subcategories in the algorithm tree.

Python

• Extended To Python export for complex analysis workflows, aligned with evaluator outputs and table results configured in the UI.
• Stricter type handling and compatibility helpers. Writes to inactive settings follow a policy (ignore, warn, raise), and non-existing settings raise AttributeError right away.
• Extended Waveguide and Acoustics APIs.
• Running Python scripts can be interrupted with the Stop button.
• (Web) New Scripter panel with auto-save before run, running-tab indication, improved file dialogs, and a status bar.

User Experience

• Meshing and rendering no longer block the interface. Projects open faster, loading shows better feedback, and the 3D view responds faster.
• NVIDIA Blackwell GPUs for cloud-based optimization, and faster download of cloud results.
• (Web) Welcome screen with quick actions, recent files, embedded user manual, walkthroughs, and release notes.
• (Web) Improved tool-selection dialog for large entity sets.
• (Web) Faster startup through compressed backend/frontend transport; documentation and tutorials served from a dedicated documentation service.

Fixed

• Fixed corrupted files when saving large meshes in ACIS formats (.sab, .sat, .smash).
• Fixed the tissue list being saved to the wrong directory when exporting a segmentation.
• Fixed To Python for the RCS evaluator flow.
• More reliable geometry snapping and picking; fixed edge normals in the Topological Voxeler and patch selection on unstructured meshes.
• (Web) Hover and focus highlighting is back, picker windows resize with the screen, plot legends show only visible traces, and the video stream no longer goes black when the welcome page is toggled.