Sim4Life Release V7.0

Sim4Life V7.0 offers powerful new features and important enhancements that strengthen the in silico tool set our customers use for research, device design and optimization, and compliance evaluations.

The highlights of Sim4Life V7.0 in a nutshell:

• Module T-NEURO: faster by >10×, a new axon model, and an improved user interface guided by neuroscientists
• IMAnalytics Suite V1.0: now includes a novel Test Field Diversity (TFD) method for in vitro measurements
• Sim4Life and DASY8/6: numerical models created with DASY8/6 Module mmWave V3.0+ can now be directly imported – without cumbersome validation – for further in silico evaluation
• New solver-enhanced phantoms: accurate simulations of body-mounted 5G NR FR2 devices as well as computation of over-the-air performance and absorbed power densities without limitations
• Smaller file sizes: results from full-wave simulations can now be automatically compressed, resulting in massive savings of up to 20× in file size
• Eddie cV3.1: a new high-quality posable human male anatomical phantom has been added to the Virtual Population library

Additional highlights include new CAD modeling tools for extraction of flexible surfaces as well as for generation of implant routings for MRI safety evaluations, support for the latest Ampere GPU architecture, and optimization of speed performance on multi-GPU machines!

Finally, the new release includes various new productivity features, general improvements as well as bug fixes, making your simulations once again more effective.

Feedback, as always, is warmly welcomed – we listen!

Neuronal Dynamics Simulation: T-NEURO Module

In Sim4Life V7.0 the T-NEURO module has received a huge performance and applicability boost – pushing your neurostimulation applications to the next level.

PERFORMANCE BOOST: >10× SPEEDUP AND REMOTE SOLVING

• Neural simulations can now be run remotely, offloading time and resource-intensive simulations to any machine in your network
• Axon discretization has been generated in pure C++ code, boosting performance by more than an order of magnitude; 1,000 axons discretize in 180s in V7.0, compared to 2250s in V6.2
• Enhancements of the user experience include a shift of the axon model and parameter assignment to the modeling stage and various improvements to sensor and point process creation tools

In Silico modeling of neurovascular bundle stimulation in Sim4Life V7.0: Watch the movie here.

Neurostimulation modeling in Sim4Life V7.0: Visualization of the electromagnetic field distribution resulting from activation of an intravascular stent electrode in a model of the median nerve neurovascular bundle.

Neurostimulation modeling in Sim4Life V7.0: Each fascicle in the model is populated with 50 linear axon trajectories representing two axon subpopulations: myelinated McIntyre-Richardson-Grill double-cable fibers, and unmyelinated Tigerholm fibers.

NEW NEURON MODEL: A-DELTA FIBERS

• The T-NEURO Module of Sim4Life V7.0 now features a new class of axon models, the A-Delta class, of spinal afferents
• A-Delta fibers carry information from peripheral nociceptors to the dorsal horn of the spinal cord
• A dedicated tool for modeling A-Delta fibers supports nonlinear morphologies with central and peripheral branches

Sim4Life V7.0 makes it easy to transform spline-based sketches into functional models with only a few mouse clicks. Draw any three splines that meet at a point, then multi-select them to reveal the “A-delta” neuron tool: the tool allows you to conveniently adjust model parameters and automatically discretizes your splines into functional sections for simulation.

ANISOTROPIC DISTRIBUTIONS

• An improved image importer now supports additional formats for multi-component (tensor) images
• DWI-based tensor fields can now be converted into conductivity tensor fields
• Several additional evaluators allow analysis of tensor fields for user verification of the plausibility of DWI reconstructions 

Slice viewer in Sim4Life V7.0 depicting the fractional anisotropy (a measure of how anisotropic the tissue is), overlayed with the direction vectors of the largest eigenvector of the electrical conductivity tensors.

MRI Safety Assessment

IMANALYTICS SUITE V1.0

The FDA-qualified IMAnalytics V1.0 is now part of the IMAnalytics Suite software package!

• IMAnalytics Suite V1.0 – containing ready-to-use IMAnalytics V3.0, IMAnalyticsLab V1.0, and an integrated Python environment – still goes hand in hand with Sim4Life but can now be installed and used independently as standalone software
• The MRIxLAB dataset from the IT’IS Foundation of pre-computed induced fields in the Test Field Diversity (TFD, Yao et al., 2020) phantom is applied in IMAnalyticsLab V1.0 to predict the ISO 10974 Tier 3 in vitro deposited power or induced voltage for different test routings, incident field polarizations, and tissue-simulating media, making the experimental transfer function validation process faster and error-proof
• The streamlined graphical user interface (GUI) – with the tabs removed, all tools available from the main windows, and Jupyter notebooks that can be launched directly from the main interface – improves the overall user experience
• Computation of Tier 3 induced voltage is available directly in the GUI of IMAnalytics and no longer requires the use of Jupyter notebooks
• Results, including all plots, raw data, and study parameters, are conveniently exported packaged into a single zip file for full traceability and easy archiving

NEW MODELING TOOLS – MRI SAFETY

New modeling features have been added in Sim4Life V7.0:

• A new tool to draw splines on the surface of triangle mesh models
• A tool to check implant routings that splits the spline into sections corresponding to the solid region passed through, for example, tissue material

The new Draw Line Tool in V7.0 allows users to draw the shortest path connecting a sequence of points on a complex surface, such as a ViP model. The loop can be closed automatically and three options are provided: a) create a spline or polyline from the path, b) create a patch of the surface area enclosed by the path, or c) create a surface mesh that covers the loop.

5G Toolkit Simulation Enhancements

NEW mmWAVE MATERIAL MODEL

The 5G Toolkit of Sim4Life V7.0 has been extended with a novel solver-enhanced phantom model technique, making Sim4Life the only electromagnetic (EM) software platform that can speedily perform realistic and accurate simulations with phantoms at mmWave frequencies

• Realistic and accurate simulation of handheld or body-mounted devices operating in the mmWave range requiring modeling of very thin structures to simulate skin is managed in Sim4Life V7.0 with solver-enhanced phantoms that eliminate any limits in simulating mmWave devices
• Sim4Life V7.0 features automated setup of simulation for mmWave devices with SPEAG’s mmWave hand phantoms that starts with a simple drag and drop of the phantom CAD file, which is then automatically assigned to a new solver-enhanced material model with parameters obtained from the integrated SPEAG database (this technique has been successfully verified, and the verification report is available upon request)
• All SPEAG hand phantoms developed for mmWave applications are currently available for import into Sim4Life V7.0, with support for additional phantoms (e.g., POPEYE, Head Phantoms) and ViP models. planned for future releases

New solver-enhanced body models in Sim4Life V7.0 for Accurate Simulations of 5G NR FR2 Devices: Watch the movie here.

5G SIMULATION AND mmWAVE COMPLIANCE ASSESSMENT

Simulations and measurements are brought even closer together: Sim4Life V7.0 and DASY8/6 Module mmWave V3.0 combine the best of both worlds. Data acquired in the physical world by DASY8/6 Module mmWave V3.0+ can now take an active role in the digital world too!

• The auxiliar sources reconstructed by DASY8/6 Module mmWave V3.0+ based on measurements constitute a complete in silico model of a physical device that can be imported into Sim4Life for detailed simulations
• The workflow can be used, for example, to evaluate incident power density (PD) generated on the surface of a human model exposed to a 5G mobile phone, particularly useful when the phone itself cannot be simulated or when comparisons between numerical or experimental results cannot be performed
• A new Sim4Life tool that extracts the outer surfaces of computer aided design (CAD) models in the form of simplified triangulated meshes of the outer hull for export in a format that can be used by DASY users to perform measurements
• A new file format whereby information pertaining to a given device is stored in a single file that can be enriched with data from the digital or physical world in Sim4Life or DASY8/6, respectively, allows seamless data exchange between Sim4Life and DASY8/6

Simplified PD evaluations at 6–10 GHz using the enhanced 5G Simulation Toolbox in Sim4Life V7.0: Watch the movie here.

Equivalent Source Reconstruction algorithm used on reference patch antenna operating at 5.77 GHz measured on two planes at 2 mm and 14.5 mm. The resulting digital device under test model, fully portable between DASY8/6 and Sim4Life, is used to propagate mmWave fields on the skin of a human model (Duke) to compute incident PD distribution.

Extended ViP Library

NEW HUMAN MODEL EDDIE

• The Virtual Population (ViP) has been extended to include the new full-body Eddie cV3.1 model
• Eddie cV3.1 is based on the Visible Human Male data set developed from cryosection images of a single male cadaver (38 years old at the time of death) by the National Library of Medicine
• The Eddie computable model is 1.81 m tall and weighs 106 kg, featuring 323 tissues fully compatible with the IT’IS Material Properties Database
• The Eddie model's vasculature tree and the peripheral nervous system are particularly detailed
• Eddie offers posing functionality and is suitable for a wide range of real-world applications.

The new ViP model Eddie cV3.1: Visible Human Male data set in full detail: Watch the movie here.

Eddie cV3.1 in Sim4Life V7.0: The model featuring 323 tissues supports the Poser function in Sim4Life, which allows the user to easily change Eddie's posture.

Productivity AND Performance Tools

NEW POWERFUL MODELING ENHANCEMENTS

• A new tool for reconstruction of exterior surfaces of complex model assemblies may be useful for computing the outer shapes of mobile phones and other complex devices
• Sim4Life V7.0 includes a Key-Frame tool to record camera and model visualizations settings enabling the use of screen capture software for replay and record, making trivial the creation of animations to present your models
• A simple annotation tool has been added to allow identification tissue labels to be entered in image segmentation (label field) entities
• Sim4Life V7.0 includes many modeling-related bug fixes as well as extended and improved Python API for scripting and automating modeling workflows

Straightforward extraction of the outer surface from complex CAD models in an example 5G mobile phone, useful when measurement probes need to know accurately where the surface of a device is located, but do not reach inside the device itself.

ANALYSIS RESULTS OF FIELD COMPRESSION

• Sim4Life V7.0 now offers new functionality to compress 3D field data in finite-difference time-domain (FDTD) simulations for output files that consume far less disk space and are even easier to manage, with no loss of data accuracy
• Both lossless and lossy compression options, with compression ratios of 50% down to 12.5%, are available; lossy compression schemes make use of a fixed rate of bits per scalar value
• Extensive validation of the available compression schemes demonstrates that, even with the highest compression, only negligible deviations of typically less than 0.1% are observed in electric/magnetic field values

Field compression in Sim4Life V7.0: Two representative examples showing how the output file size can change drastically depending on the level of compression.

ANALYSIS IMPROVEMENT FOR LF-SIMULATIONS [CURRENT NORMALIZER]

• In Sim4Life V7.0, low-frequency simulations driven by a potential difference can now be scaled according to the total current flux at postprocessing, including, for example, electro-quasistatic simulations where two electrodes at different potentials induce an electric current through a human body
• Normalization options available at postprocessing time allow fields to be scaled such that the current flux between two electrodes attains a prescribed value

OS EXTENSIONS – UBUNTU

• Sim4Life’s V7.0 numerical solver can now be used on Linux machines running the operating system Ubuntu: please consult our user manual for further details, including installation, usage, and list of supported GPU cards
• Although CentOS Linux 8 has reached end-of-life, temporary support by Sim4Life V7.0 for CentOS Linux 8 will be extended to guarantee a smooth transition to Ubuntu
• Please note that, with the next major release in Q3 2022, CentOS Linux 8 will no longer be supported and will be fully replaced by Ubuntu support

NVIDIA AMPERE AND MULTI-GPU SUPPORT FOR CUDA SOLVER

• Sim4Life V7.0 now supports the latest and most advanced GPU architectures on the market to solve EM simulations at never-before-seen speeds
• Both the CUDA and the AxWare libraries can now compute on NVIDIA cards with Ampere architecture and are optimized for multi-GPU parallelization to achieve the highest possible throughput