Thank you for your interest in human-centric design and Santos’ human simulation software. The FAQ and resources here are provided by SantosHuman for designers, engineers, ergonomists, kinesiologists and human factors and human systems integration professionals. This media is intended to help those who work to improve products and processes in which people are involved. If you have any other questions about SantosHuman and our software, please contact us.
What is the difference between Santos Lite and Santos Pro?
Santos Pro was designed from the ground up to be a feature-rich, human simulation software environment that can virtually evaluate the human-in-the-loop elements of any product or process. Santos Pro includes the full suite of features and capabilities necessary for detailed human-in-the-loop evaluation and can be used to inform optimal design for any product, process or workstation within a CAD workflow.
Santos Lite offers a pared-down version of Santos Pro targeted to users looking for a budget friendly human simulation software and biomechanical model to evaluate and assess exposure to ergonomics hazards by using current methods like the Arm Force Field (developed by Dr. Jim Potvin and Dr. Nick La Delfa) and Duty Cycle (developed by Dr. Jim Potvin) methods.
Key Technical Differences Between Santos Lite and Santos Pro
|Feature||Santos Pro||Santos Lite|
|Access to the powerful Santos predictive model||☑||☑|
|Access to a database of avatars||☑||☑ a subset of 4 height scalable avatars (2 male, 2 female)|
|Access to the Hand Force Acceptability Calculator (based on the Arm Force Field and Duty Cycle methods)||☑||☑|
|Access to a library of default “drag and drop” grasps||☑||☑ a subset of the most common grasps used within a manual materials handling context|
|Access to spine compression and shear visualizers||☑||☑|
|Access to joint torque visualizers||☑||☑|
|Ability to import .OBJ geometry||☑||☑|
|Access to Zone differentiation tool (trade-off analysis) to inform optimal design||☑||X|
|Access to obstacle avoidance constraint||☑||X|
|Ability to change performance measures used to define how behaviours are predicted||☑||☑ a subset of the most common performance measures can be manipulated|
|Ability to constrain specific joints when predicting behaviours||☑||☑ the pelvis can be constrained relative to the global reference frame|
|Access to the ZMP viewer (whole body balance check)||☑||☑|
If you have further questions about capabilities of Santos Pro or Santos Lite, please contact us.
How is the Santos approach different from other digital human models?
Santos technologies provide predictive human models that can be used by many industries to place virtual humans in the loop with their products. Learn more about the problem Santos was designed to solve.
What are the minimum hardware and operating system requirements for Santos Lite and Santos Pro?
Following are the minimum and recommended requirements for running Santos Lite or Santos Pro.
|Platform||Pentium 4 at 3.0GHz|
|Operating System||Windows XP Home Edition, Service Pack 2|
|Video Card||ATI Radeon Xpress 200|
|Video RAM||256 MB|
|Hard Drive Space||3 GB|
|Mouse||3 Button with Mouse Wheel|
|Display||800 x 600|
|Operating System||Latest Version Windows 7 SP1, Windows 8.1 Update, Windows 10 –w– .NET 4.0 Client Installed|
|Video Card||DirectX 9 or later WDDM 1.0 Driver|
|Video RAM||512 MB|
|Hard Drive Space||5 GB|
|Mouse||3 Button with Mouse Wheel|
|Display||1600 x 1024|
How do we become a Santos University partner?
The Santos University Program provides institutions of higher education with free access to Santos® technologies for non-commercial, educational, and non-commercial research purposes. Learn more
The requirements for becoming a Santos University partner include:
- agreeing to ensure that SantosHuman Inc. products are only used for academic and/or research and/or non-commercial purposes
- agreeing to publicly list SantosHuman Inc. as a sponsor of your educational and/or research programs (along with our logo which we would provide)
- agreeing to allow SantosHuman Inc. to include your University logo among our Santos University Partners (which you would provide)
- agreeing to work towards incorporating Santos technologies within your education and/or research programs
- agreeing to work towards developing Santos expertise within your education and/or research programs
- agreeing to our non-commercial-use end-user agreement license
- agreeing to work with SantosHuman Inc. to create a press release that is mutually acceptable to both your University and SantosHuman Inc.
If interested in becoming a Santos University Partner, please contact us at email@example.com.
What kind of training and support is available to learn Santos software?
Santos Support provides users with access to several training options. Two free and convenient options for support include:
- Video demos, tutorials, Master Classes and more — View playlists now
- Email support – firstname.lastname@example.org
Contact us to discuss custom, on-site training needs and to get a quote.
Why was Santos created?
The reason Santos was created and the types of problems it was designed to solve was the topic of a recent blog post. Read it here.
SantosHuman is US based, but is the company involved with foreign countries that are adversarial to the US (i.e. controlled, headquartered, has research/development, or is developed by an individual with citizenship in that country)?
No, SHI is 100% owned by US Citizens and while we do have global clients, we are careful to ensure that we only work with businesses in US-friendly nations.
Using Santos Lite and Santos Pro
Santos Lite Usage: When is it appropriate to use Santos Lite vs. Santos Pro?
Santos Lite was designed to provide human factors and ergonomics professionals with a budget friendly solution to access the human simulation software and biomechanical model required to conduct essential human factors and ergonomics hazard assessments.
Santos Lite enables users to predict or simulate human task behaviours, the estimate acceptable hand force requirements (Arm Force Field and Duty Cycle methods), see calculated joint torques or see calculated spine compression and shear forces. These insights are often essential to human factors and ergonomics professionals who conduct ergonomic hazard assessments.
Santos Pro Usage: How can our team learn to use Santos Pro?
Our Introductory Santos Pro course is designed to provide new Santos users with basic concepts, techniques, and conventions for using Santos Predictive Models. This hands-on course is typically taught at the client’s site; over 2 consecutive business days; for up to 5 course attendees; and costs $6,500 (USD). If training occurs within the Continental USA, the instructor’s travel expenses are included in that price. If the course is taught outside the US, the instructor’s travel expenses must be covered by the client.
We also provide customized, advanced training, which is the most effective way to ensure new users can hit the ground running with the Santos capabilities most relevant to their requirements. Our advanced training courses are based on client use cases that our expert users work through to completion and then turn into customized training modules that demonstrate every aspect of how each use case was completed. These engagements start at $10,000 and can vary based on the scope and number of use cases the client wishes to pursue.
What can I save and export from Santos?
You can export avatars, objects, analysis information, marker information/locations, and joint information (length, rotation, and weights).
Is Santos a web-based product?
The software is not web-based. It must be physically installed on each computer. Also, there are 2 different methods of licensing. One method (node-locked) locks the software to a specific computer. The other method (floating) allows the software to be used on any computer but only 1 person per subscription can use the software at any given time.
Can I run Santos on Mac?
All SantosHuman products are designed to run on Windows-based machines. However, we have found that installing Windows on an Apple computer equipped with sufficient RAM and 3D Computer Game-quality graphics capabilities, and then booting the Apple computer up as a Windows machine, typically allows very good performance with Santos Pro and Santos Lite.
What is the difference between a Node-Locked and a Floating license?
Node-Locked License Use-Case Example
If a 1-year node-locked subscription to Santos Pro or Lite is purchased, User-1 installs Santos Pro or Lite on a computer and is provided with a key code that locks the software to that computer which allows the software to run on that computer for the duration of the subscription period. If User-1 wishes to allow User-2 to use the software, User-1 must loan User-2 the Santos Lite-installed computer.
- Least technical method of licensing
- Lest expensive method of licensing per subscription.
- Node-locked licenses do not require the host computer to communicate with a floating license server (no inter-net or intra-net connection is required)
- The software is locked to 1 and only 1 computer per node-locked subscription
Floating License Use-Case Example
If a 1-year subscription to a floating license seat of Santos Pro or Lite is purchased, Santos Pro or Lite can be installed on as many computers as desired and the license server is provided with a key code allowing any computer that can communicate with the floating license server to run Santos Lite for the duration of the subscription period. However, only 1 computer per floating license seat subscription can use the software at any given time. If User-1 is using Santos Pro or Lite, no other Santos users can use the product until User-1 exits software.
- If 2 or more users do not need to use Santos Pro or Lite at the same time, the cost of each floating license seat subscription is less expensive than 2 node-locked licenses.
- 1 floating license seat is more expensive than 1 node-locked license.
- Each Santos Pro or Lite-installed computer must be able to communicate with the floating license server via inter-net or intra-net.
- If a company wishes to use its own license servers to manage the floating license seats, installation is a bit more complicated but:
- Our Support people are very good at this, do it all the time, and are happy to assist.
- An Inter- or intra-net connection is required.
- Installation is easier if SHI’s license servers are used (at no additional charge) and an inter-net connection is required.
Please note that SHI DOES NOT track, monitor, or accumulate end-user data.
For floating licenses, will someone be able to sign in while online with an internet/intranet connection and then work with Santos while offline?
The short answer is no, you can’t do that. However, we are working to implement a “roaming” option that will allow a floating license to be “checked out” so look for this in a future update to both Santos Lite and Santos Pro.
How do we access Santos Pro on additional host IDs with our floating license?
- The license file originally provided is all that is required to allow any computer to use its one (1) Santos Pro floating license seat.
- Once the software is installed, please copy and paste the attached file to locations on each computer’s local hard drive.
- Upon attempting to use Santos Pro for the first time, the end-user will be prompted to provide an activation code or license file.
- Use the Licensing Window’s browser to locate and select the copied and pasted license file and Santos Pro will start up as expected, providing no other end-user is already using its one (1) floating license seat.
How do students access the software when working and studying remotely?
We currently license our products to our Santos University Partners in two ways.
The first, easiest to understand method is node-locking which is exactly what it sounds like. The software is locked to a specific computer.
The other method is to use floating licenses which allow any predefined number of computers to run the software concurrently. This requires each computer that will run the software to be connected to the internet or to a local area network so that the number of floating license seats can be administered by a license server. Santos University Partners can use their own license server or they can use SantosHuman’s.
Either method will allow students to work remotely, but it’s up to you to ensure that students agree to only use the software for non-commercial, educational, and/or research purposes.
Is there any advantage to using an in-house license server -vs- SHI’s license server?
We don’t think of these two options as competing in performance. They exist solely because of client IT requirements.
If your security requirements are not violated by being connected to the internet, using SHI’s servers is by far the easiest approach.
However, if security requirements DO NOT allow your computers to be connected to the internet, you likely already have servers hosting applications on a local intra-net so hosting the Santos licenses on your own servers would be the only option.
In some cases, IT departments prefer greater control over the applications used and choose to host their own licenses. We can assist you regardless of which option you choose.
Technical Capabilities – Modifying Avatars
Can the end-user modify the shape of an avatar’s head?
There are few commercially available software solutions that include end-user-modifiable head shapes for industrial design. We did, however, find a few resources that may be useful to you. This one seems more game-character oriented, but the heads look reasonably realistic, so perhaps there is more to this solution than just visual aesthetics, although we could not find any evidence of that.
Also, we tend to use Turbosquid when we need representative geometry that the client either does not have or is not allowed to provide. For example, if we need a drill press, computer workstation, robotic arm, etc., a quick search on this site typically provides a good quality 3D model for a lot less than it would cost to build it ourselves or hire someone to build for us. Since we can import geometry from any source into our products, this is a cost-effective approach we’ve used for many years. The point here is that the Turbosquid site also includes human heads, and some of them are based on bodyscan data so if you find head geometry on Turbosquid that fits within your target anthropometric design boundaries, this could provide a solution either within your design environment – or within ours, if there are human performance criteria associated with the head-worn equipment designs, of course.
Finally, this page contains a variety of links (some head geometry-related) that may be useful to you.
One of our contacts at a University that teaches kinesiology, ergonomics, and human factors said that while there does not currently appear to be any commercially available solutions, this is probably going to change as head shape is becoming an important topic.
What anthropometric databases are available for Santos?
ANSUR II and NHANES are both available inside of the software for anthropometric modifications of the avatars.
Technical Capabilities – Measurements and Scaling
When avatars are looking at a computer monitor, are there tools to measure the angle between the line of sight and the monitor surface?
Can the user select a feature (face, edge, vertex, etc.) in the environment to measure to measure between?
The measuring tool inside of Santos® Pro/Lite can be used to measure from markers, objects, and/or avatars to other markers and objects. Markers can be placed anywhere in the environment, but can also be placed on the normal, corners or the vertex of any object for a more precise measurement. Markers can also be placed on the ground for height measurements. The tool provides visual green and red lines and threshold marks to see if any measurements are above or below the threshold.
Can individual segments be scaled on the human model?
Every connection between each joint can be adjusted by the end user.
Technical Capabilities – Zone Differentiation
If a zone differentiation volume (trade-off analysis) calculation (based on the settings in a currently loaded project) is running in the background, will any change to the currently loaded project affect the zone diff calculations running in the background?
No. Batch zone diff “jobs” are based on the current project settings but then spun off into a separate threaded operation. This means that any changes to the main software never get sent down to the batch job once the batch job is started and the zone diff batcher never comes back to the main code to check values.
I have an issue where the zone diff window will not display even when using all recommended ways to recover an out-of-screen window and re-installing santos Pro software repeatedly.
Switching between multi-monitor and single-monitor display settings if one of the windows is located on the display that is no longer present can cause the issue you are describing. Please try the following and let us know if these steps address the issue you are experiencing:
- Quit Santos Pro (critical 1st step)
- Locate the file, layout.config, which can be found in your \Documents\SHI\Santos directory
- Delete layout.config
- These first 3 steps are critical because the layout.config file is updated with the current (potentially problematic) window settings when you exit the application
- If the layout.config file does not exist when Santos Pro is restarted (this is what we want to happen to address this issue), the software writes out the default factory windows layout settings and uses those on startup
- Restart Santos Pro
I have a question relating to the output of the posture analyzer visualization tool and the colors/graduation of Zone-differentiation study. As the zone-diff and the posture analyzer are results of, or driven by, the posture performance measure settings, is there a correlation between the two?
The output of the Zone Differentiation Analysis takes into consideration all current settings, including the human performance measures and constraints in the predictive model, the size of the target avatar, the avatar’s range of motion and strength, collision and vision requirements, and the need to remain in balance relative to the external forces currently defined, just to name a few.
The values in the Posture Analyzer window provide insight into specific human performance measures for any currently exhibited behavior which may have been predicted, or created by manually manipulating the individual joints, or even taken as a one moment in time from a motion capture study. While the zone differentiation results include the effect the human performance measures have on any predicted behavior there is no unique correlation between the values shown in the posture analyzer window and any given zone differentiation result.
There are post-processing capabilities that allow you to extract samples from an existing zone differentiation analysis based on the mean or n standard deviations from the mean. This may be useful depending on your evaluation goals.
Technical Capabilities – Posturing Santos and Adding Equipment
What are the different methods for posturing the human? How is each used?
There are several different methods for creating the human postures, including joint manipulation; manually editing the avatar’s pose joint by joint, using the Santos predictive models to predict physical behavior based on the avatar constraints/set-up); using previously saved poses; and more.
Can the human brace themselves?
The user can define reaction forces to represent the displacement of weight.
Can the human automatically grasp objects in the environment?
Yes, as shown in this grasp predication demonstration video.
How does the user input forces and apply them to the avatar?
Using the “Point Load” tool users can apply any number of external forces and change the direction and magnitude of the force as well as which joint the force is applied to.
Our students are using Santos Lite and we’re not sure how to “encourage” the model to predict a reasonable posture for grasping a box on the floor without access to the ZMP constraint (not available in Lite).
We created a video demonstrating this. Watch it now on the SantosHuman YouTube Channel.
The other thing you may wish to consider is that, currently, our digital human characters don’t have brains, which is to say that learning better behaviors is not an option.
Some of the things we naturally do correctly, we do because it’s natural to our joints, muscles, strength, etc. Other things which we do naturally are not the best way to do things (like lifting a box, holding a rifle, ballet, or swinging a golf club), and we have to learn to do that kind of stuff differently, contrary to what our bodies want to do. To address the fact that humans learn behaviors, we imposed a means of gravitating towards (a now understood to be poorly named) neutral posture. By default, the neutral posture is standing upright with the weight evenly distributed between the two legs. But any saved posture or an avatar’s current joint settings can be used as a neutral posture—Like, a saved posture that represents the “correct” way to lift a box to minimize exposure to risk of injury.
You can create your own, obviously, but somewhere within the posture library, there is a folder that contains a bunch of pre-defined postures. One of them looks like someone trying to lift a box. If you drag and drop this (or any other posture) onto the target avatar; right-click on the avatar; and then select the “set current posture as neutral posture” option from the pop-up menu, all predictions going forward (until you reset or change the neutral posture) will try to gravitate towards that posture. In this way, we provide the avatar with a way to “learn” behaviors that reflect a better or more correct way to do things.
Can Santos evaluations include the effect of wearing gloves on task completion?
We can include gloves in several ways.
- Visuals: All Santos warfighter avatars have been created/rigged with gloves, but this provides a visual effect only and does not consider the effect wearing gloves have on task completion. However…
- Collision: We can overestimate the size of the hand to subjectively reflect the additional space required to do tasks while wearing gloves.
- Finger Range of Motion: The technology to predict change in range of motion to the fingers based on glove material bunching based on its warp, weft, and stiction does not exist in a robust, commercially available form in any digital human model. However, we can modify the range of motion of the fingers to not exceed some known effect based on real-world experiments done with the targeted gloves.
- Physics: Likewise (see above), there is no robust, commercially available means of predicting the finger force required to overcome glove material bunching in any digital human model. However, there are some tools available that can extrapolate finger force based on grasp requirements, and these can certainly be used to compare finger force requirements with the force a finger is likely able to produce.
Compared to the 3DSSPP programming we currently utilize, can Santos provide a balance assessment (Center of Pressure of the human and its base of support) based on the posture that is created and forces applied? Does it also allow for forces to be applied to various locations of the body other than at the hands?
Yes, Santos Lite includes the ZMP viewer, which stands for Zero Moment Point. Similar to the 3DSPP capability, the ZMP viewer shows a projection of the center of pressure onto the base of support. The location of the center of pressure can be altered by updating point loads (i.e., hand forces) acting on the body (or by updating the posture). Point loads can be applied to the hand, or to other body locations as necessary.
In Santo Pro, there is Carpal Tunnel Analyzer in Visualizer list. Please introduce this and the research/textbook this part analysis refers to.
References for the Carpal Tunnel Risk Calculator Follow:
Occhipinti E (1998). “OCRA: a concise index for the assessment of exposure to
repetitive movements of the upper limbs.” Ergonomics, 41(9): 1290-312.
Colombini D (1998). “An observational method for classifying exposure to repetitive
movements of the upper limbs.” Ergonomics, 41(9): 1261-89.
Borg, Gunnar. “Psychophysical scaling with applications in physical work and the
perception of exertion.” Scand J Work Environ Health. 16.1 (1990): 55-8.
Please note that this is a direct implementation of existing work by the researchers listed above at the request of one of our clients. Once implemented, we had hoped there would be a means of gleaning the inputs directly from the digital human model, but this did not turn out to be the case. It remains within the Santos Pro capabilities as a stand-alone calculator whose implementation was validated by Sandalwood Engineering & Ergonomics in 2009.
Technical Capabilities – Importing and Exporting Data
In general, what can I save and export from Santos?
You can export avatars, objects, analysis information, marker information/locations, and joint information (length, rotation, and weights).
How is external geometry imported into a Santos session managed?
A user can import geometry by going to the File Tab and clicking on “Import” or “Import as Sub-Models” or “Import as Hierarchy.” The geometry is then imported after selecting which unit system the geometry was designed in. The geometry can then be moved, rotated, and scaled inside of the program.
Various attributes can be viewed throughout the sequencing of events, but can that data be collated and presented as a graph using a time axis? For example, is it possible to provide values for lower back/neck strain in an instance of time and cumulative strain over a sequence of events?
Currently, we have provided the ability to export Spine Shear (Anterior/Posterior, Medio-Lateral) and Spine Compression data over time as well as joint angle, joint velocity, joint acceleration, joint torque, and joint torque as a percentage of maximum torque – all over time. If there are specific data-over-time evaluations you wish to have access to, we would be happy to work with you to incorporate those.
After creating a task sequence involving the setup of collision surfaces, anchor points, etc., can an alternative avatar be applied to the ‘scene’ and the task sequence easily re-evaluated without manipulation?
All the elements used to predict any given key moment in a sequence can be exported and re-imported back onto other avatars to assist in recreating the sequence. Some minor alterations can be required depending on the task requirements and the difference in avatar size, but you do not have to recreate the sequence from scratch for each avatar used.
Can the SantosHuman software can be integrated in CAD software like CATIA V5?
CAD geometry from any source can be easily imported into the Santos environment and we can also export geometry in formats that can be imported into any CAD environment.
Can a user export the created mannequin from Santos into another modeling program such as SketchUp?
Importing Sketch Up Geometry Into Santos:
The following video demonstrations were created for one of our clients many years ago. They both cover the same basic material. The first one is fairly short. The other one is a bit more in-depth.
Exporting the Avatar to Other Design Environments:
Santos Pro and Lite provide the ability to export an avatar’s mesh as an OBJ file to capture the current pose. Obviously, the avatar functionality within a Santos product, including the ability to manipulate the joints, would not be included. Once exported, converting the OBJ file to any other format with Okino Polytrans (the converter our in-house services team uses) is easy to do and the following links will take you directly to a 2-part series available on the SantosHuman YouTube Channel on this topic:
Also, please note that there will likely be differences in scale between geometry imported/exported between Santos and Sketch Up (or any other design environment). Sometimes this is just a matter of selecting the correct units within the import dialog. In other cases, a scale conversion factor must be determined between the environments. This is normal and just means that the geometry may come into Sketch Up very large or very small. The correct scale conversion factor can be determined quickly and easily. We are happy to help with this if required.
Which 3D file formats can be imported into the software?
We have worked with Okino to develop a process that allows 3D geometry to be imported from just about any source. There is a 2-part video series (see links below) on the SantosHuman YouTube Channel on the process we have been using for many years. It works very well with all file formats encountered.
Which 3D file formats and video formats can be exported from the software?
See above and note there are a few 3D geometry formats that contain proprietary attributes that can only be provided by the native design environment. However, there are always formats that can be exported for import back into whatever design environment your team is using.
Santos products do not export video. Screen capture capabilities like Camtasia are quite good. All videos on the SantosHuman YouTube Channel were created using Camtasia, which is easy to use and relatively inexpensive.
We are looking at how adjustable the mannequins are, specifically the ability to dress them in protective/custom clothing and attach multiple pieces of equipment before animating and running tests.
Santos Pro has an extensive ergonomic assessment toolset that includes the usual suspects but also includes access to the most accurate and extensively validated method of predicting exposure to risk of injury for arm-related tasks available today. You can read more about that capability using the following links:
Arm Force Field Product Sheet PDF
Arm Force Field in University of Iowa News
As for Santos Digital Human Character Adjustability, the ability to alter a Santos avatar to meet target anthropometric boundary characteristics is possible through a variety of methods, including referencing the ANSUR II and NHANES anthropometric databases. Other adjustable parameters include strength, range of motion of any joint, weight, and age (as it relates to strength).
Can end-users import and use clothing made of flexible fabrics?
The ability for an end-user to import geometry representing articles of clothing made of flexible fabric (a HAZMAT suit, for example) and then drape that fabric onto a digital human character and have it move and bend with the motion of the limbs, torso, and other body parts is a very specific capability. With few exceptions, this capability is primarily available in high-end 3D animation environments used to create the types of computer graphics seen in block-buster action films or 3D animated movies from Pixar, Disney, ILM, etc. In fact, outside of a few niche-market products focused solely on the garment-design industry, these types of cloth simulation capabilities have not been successfully implemented in any commercially available human simulation product.
That said, digital human characters can be created with clothing designed to move as expected, but the clothing has to be “rigged” for that type of movement; is not “simulated”; nor does it affect the digital human character’s ability to complete tasks. There are digital human characters within our flagship products that have been “rigged” with clothing as described.
Can end-users import and attach equipment to the avatars?
Yes, this is easy to do in our products in a variety of ways. And as long as the equipment can be assumed to be relatively inflexible, the “attached” equipment will apply additional weight, restrict range of motion, and have an effect on the digital human character’s ability to complete tasks.
Can Santos Import Custom 3D Environments?
Importing 3D geometry is easy to do from any source. It does not matter whether that geometry represents tools, equipment, vehicles, or environments.
I would like to manipulate specific portions of the imported geometry. After importing the .obj file, I do not have access to the list of nodes in the imported geometry—it just appears as one object rather than a collection of objects that can be manipulated individually. Is there a way to access the list of nodes in the imported geometry?
Until we come up with an efficient way to handle the extensive hierarchies that are often included in CAD geometry files, the current workaround is to save the subassemblies you wish to interact with separately from the rest of the model as individual OBJ files. Once this is done, all associated OBJ files can be imported at once by selecting multiple files from the import browser. Once imported, interactive hierarchies can be created using the PICK PARENT command from the pop-up menu that appears when right-clicking on an object or the OBJECT -> PICK PARENT command from the main menu.
Note that there are two methods of picking available from the TOOLBOX. The default option with the single arrow always selects the top node of any given hierarchy regardless of what is selected when geometry is picked from within the 3D View window. The other picking option, the one with 2 arrows (one smaller than the other), allows subassemblies to be selected within the 3D View window.
Also, regardless of which 3D view picking option is selected, subassemblies can always be selected from within a hierarchy from the EXPERT PANE.
Technical Capabilities – Arm Force Field
What is the meaning of arm force field_max acceptable effort (%)? For example, when the frequency or the duration of one cycle increased, the % will drop, what does this mean?
Regarding Maximum Acceptable Effort: Please use the following link to review the SantosHuman YouTube Channel video guide on using the Arm Force Field Plug-In.
Does the Arm Force Field Method take gravity into consideration AND does it consider how gravity affects the ability of the arms to do tasks if the torso is bent?
According to Dr. Jim Potvin, developer of Arm Force Field method:
We collected data with the trunk upright. However, we wanted to be able to apply it to all trunk postures. So, we estimated how much gravity would have contributed to the manual arm strengths and subtracted that effect. So, in essence, we are estimating the strengths in zero gravity. Then, depending on the posture and force direction, we (1) estimate the manual arm strength, (2) estimate any potential contribution of gravity and add or subtract that from the 0G MAS to get the MAS in a gravitational field.
For example, if you have your hand out in front of the shoulder with an upright trunk, gravity will increase the force your muscles can cause to push down but will subtract from how much your hand can push up. That is all accounted for.
Is the MAE frequency correction include with the AFF module?
Yes, this is included inside of the tool.
For arm force field, I noticed there is “Max Acceptable Effort (%)” in inputs area, can you further explain what this means?
When using the default configuration (i.e., not changing any of the inputs) the maximum acceptable effort will be 100%. The default input settings assume that the simulated task is performed one time (i.e., a one-time maximum capability). If the inputs are changed to reflect a task that is performed more than one time per day, the maximum acceptable effort will be scaled down from 100% to reflect that one cannot work at their maximum during repetitive work. The scaling factor is described in Potvin 2012: (https://pubmed.ncbi.nlm.nih.gov/22624285/).
In my understanding, the estimate arm force is based on single motion/load. What if one wants to learn the combinative effort/result/impact to subject’s arm(s) from a series of motions/postures? I notice that by using sequencer to predict motions, may give the live data, but not sure if it can also provide a summarized impact, or “average” result.
The ability to calculate a multi-task composite risk score based on more than one posture is a pressing challenge in the ergonomics field. Techniques are emerging in the peer-reviewed literature, like the RCRA method, and we are working to build these techniques into the list of available Santos Visualizers.
Technical Capabilities – Joint Torque Visualizer
What does the color code of joint ROM and joint torque mean? I was wondering if the different color means only the percentage of an angle or torque, or it indicates more information, such as, if a torque shows dark orange, it means less than 75% sample population can safety perform this task, or if it colored red, means contain risk of developing MSD on certain joint/body part that needs immediate attention.
The color coding is consistent with the typical approach used, moving from green to yellow/orange to red. In terms of strength (joint torque), typically below 75% would be green, above would be red, and there would be a narrow transition area in between that is yellow/orange.
The easiest way currently available within Santos Pro and Lite to assess risk of injury associated with repetitive tasks involving the use of the arms is through the Arm Force Field Plug-In. Professor Steven Fischer, Kinesiology at the University of Waterloo, provided a brief overview of this capability on the SantosHuman YouTube Channel which you can watch here:
This PDF on the Arm Force Field Plug-In includes further details this capability.
Sources for the joint ROM?
Default range-of-motion limits are based on a combination of 3 different anthropometric datasets. Using the information obtained from the literature, we worked closely with experts in human anatomy, physical therapy, and sports medicine to transform readily available data to the Santos structure. Of course, new datasets are easily substituted in the Santos system.
The end-user has the ability to modify the default range of motion limits.
Efforts to provide the end-user with the ability to select between the competing literature models has been reviewed and we look forward to working with partners interested in implementing the approach.
How does the ROM compare to your competitors?
We have not compared our RoM to our competitors. Ours is a predictive model and intended to simulate human physical behavior and performance. Our digital human characters possess 109 predicted degrees of freedom. There are likely differences between a predictive digital human model and those with joints that can only be manually manipulated into postures.
Can the joint ROM be edited?
Yes, the user can manually edit all the joint ranges of motion for each of the avatars.
Using the Joint Torque Visualizer tool in Santos Lite, I noticed that the ankle torques, especially eversion/inversion, always seem to be well over the limit, even for a neutral posture. Is this expected behavior?
Because ankle torque depends on the force acting on the foot and the center of pressure (COP) where that force is being applied, it may be possible that the approximated COP is more toward the toes (mass is more towards the toes). This would cause ankle torques to be higher than what might be expected. However, in reality, a worker might actually have their body weight more directly under their heels, which means that the actual ankle torque would be lower.
Most likely, depending on how the ground reaction force is applied to the body, it is possible that the ankle joint torques are overestimated in the model, which is typical in digital human models in general, but also generally ignored as work-related ankle injury due to overuse is uncommon. The Ergonomics/Kinesiology experts that have consulted with us have indicated that there is no data is suggesting ankle injury is common, this common overestimation of ankle torque seems acceptable in the industry.
Is it possible to export the Joint ROM visualizer data in the same way as the Joint torque visualizer export?
Yes. Please use the following steps to save the active avatar’s range of motion to a generic text file and then import the contents of the text file into Excel:
- Select the avatar whose current joint angles and joint angle range of motion limits you wish to import into Excel (or any other spreadsheet application)
- Select the JOINT LIMITS tab from the CONTEXT window (WINDOWS -> CONTEXT WINDOW -> JOINT LIMITS)
- Select the TO CLIPBOARD option that appears at the bottom of the JOINT LIMITS window.
- Open Excel
- Type CTRL-V or use the EDIT->PASTE command
You should now see the joint names, the joint description, the current joint angle, and the range of motion limits within the Excel application.
Do the coefficients to equations (torque curves) affect the torque calculations?
No. The factors that affect torque calculations include:
- Joint angle
- Link length (segment) weight
- External forces
Can the user change the min and max torque values?
Yes, but only fixed values in the interface via the expert pane. Coefficients cannot be changed as they have no real-world equivalent. But users can select gender and percentile.
Are fixed torque values the same for male and female?
Where are the fixed torque values stored?
In the SAVTR file. Here is what is going on behind the scenes in the torque visualizer. Some confusion could have stemmed from this bug.
- The torque acting on each joint is calculated — this value is only dependent on the avatar weight, segment (weight of link – forearm, lower leg etc.), any external loads, joint angle. It has to be calculated for each and every joint, even if we are not displaying all joints
- The joint torque calculation is not dependent on the strength coefficients. Only the min and max torque values.
- The strength coefficients are coefficients used for a complex trigonometric and logarithmic template equation (something like aLog Q + b Cos^2 Q…)
- The strength coefficients come from Laura’s research and are regression-based equations. They are not changeable by the user.
- Since they are regression equations, the net effect of a user changing the coefficient values is only to change the fitting of a curve. (R square value). There is nothing corresponding to the coefficients in the physical world. Hence, for the strength curve option, users don’t have the ability to change anything with regard to the avatar other than percentile in the Santos interface. If a new set of equations becomes available, it has to be added in the code since it also needs a new template for equations.
- There is also an option in Santos Pro to use fixed min and max torques. It is called “fixed” because unlike the min and max from the torque curves, the value does not change based on the avatar joint angles. These fixed values are based on literature. In Santos software, they are the same for male and female avatars and read from the savtr file. This fixed upper and lower limit is user changeable via the expert pane.
We have a question about avatar posturing. When reviewing Joint ROM, the shoulder joint is going outside it set limits. Should this be happening?
Please note that when the parameter UseCoupledJointLimits is ON, this overrides the Joint Range of Motion (RoM) limitations for the shoulder and clavicle joints when necessary. In most cases, this option provides more realistic predicted results and why the option is ON (True) by default.
In situations where end-users wish to strictly enforce RoM limitations for the shoulder and clavicle, the option can be turned OFF as follows:
- Select the avatar
- Open the Expert Pane window (WINDOWS -> EXPERT PANE)
- Expand the ANTHROPOMETRY tab located at the top of the Expert Pane window
- Double-Click on the UseCoupledJointLimits parameter (the second to the last option in the Anthropometry tab) to toggle it ON or OFF (True or False, respectively)
We are about to start a project where we want to use Santos to evaluate steering and pedal force requirements. Steering forces seem doable with the Arm Force Field (AFF) Plug-In, but we only have information on max torque at the ankle/knee joints. Any ideas how we can use other information to convey to your client?
A quick google scholar search highlights a number of studies that provide reference on suggested upper (max) limits for pedal force requirements (often based on 5th percentile ankle strength as measured from a given population). The joint torque visualizer could be used along with a point load on the foot to determine the maximum point load that would be possible based on a 5th percentile population.
Based on a cursory review of the literature, fewer papers seem to consider how pedal forces might need to be further reduced to consider frequency of use of sustained used. To consider frequency of use, you could estimate the duty cycle for pedal use (based on how many pedal presses will occur in a given time, how long is each press sustained, and what the given time is), and then use Potvin’s Duty Cycle Equation to manually determine what % of maximum strength would be acceptable (referred to as MAE and Maximum Acceptable Effort). You could use Santos in a trade-off analysis approach to iterate the point load representing the pedal force until the ankle torque (expressed as a percentage based on female strength) was equivalent to the MAE calculated by the equation.
Here is a link to a conference paper that has applied this approach, but based on the use of 3DSSPP.
Potvin’s DC equation paper can be found here. This is effectively the same thing that happens within the Arm Force Field visualizer, but we apply it based on ankle strength instead of manual arm strength.
Alternately, you could consider this challenge from the perspective of static endurance, which can be done manually or using the static endurance visualizer available in Pro. You could use the equations published by Laura Frey-Law (see Table 2), to estimate the endurance time, based on the ankle torque required to sustain the pedal press. Using a trade-off analysis approach, you can vary the pedal force in Santos to explore how pedal force affects ankle torque as a percentage of strength, and then, in turn, use the updated ankle torque (as a percentage of strength) in the Frey-Law equation to update the estimated endurance time.
Technical Capabilities – Obstacle and Collision Avoidance
When predicting behaviors, can the avatars avoid collisions?
Yes. This is demonstrated in the Santos Master Class video on Collision Avoidance.
You demonstrated the ability to recognise obstacles. Can other avatars also be used as obstacles? i.e., will an avatar avoid collisions with another avatar?
This is not currently an option.
Does the avatar always look straight ahead, or can eyes be manipulated to change the look direction without turning the head?
We have 2 vision objective functions, which are demonstrated towards the end of the Santos Master Class video on obstacle avoidance (see link below). One of the objective functions seeks to aim the head directly at a vision target. The other allows the range of motion of the eyes to be included.
Santos® Master Class Series: 002 – Avoiding Collisions & Vision Obstructions
In ergonomics, the obstacle avoidance feature is so important that, to avoid various obstacles/confined spaces, the user starts and maintains awkward postures which often can be recognized as root causes. However, in Santos Lite, the obstacle avoidance function is hidden. Why is this?
Currently, there are no plans to provide the suite of capabilities that would be required to include obstacle avoidance within Santos Lite. It would be impossible to do so while also meeting the affordability goals for why Santos Lite was created. (See Santos Lite FAQ above.)
Santos Lite was created at the request of Prof. Jim Potvin and Prof. Nick La Delfa to provide ergonomic and kinesiology professionals operating as independent contractors with a solution to a very serious problem within a budget-friendly package. Learn more about this solution.
In contrast, Santos Pro was created from the ground up to provide a foundational human-centric design platform that can perform fast-forward, market acceptance litmus tests at any stage within existing design processes.
If you and your teams have only intermittent requirements for capabilities that go beyond Santos Lite and investing in Santos Pro is not currently an option, you may wish to consider SHI’s services group (Santos Solutions) on a project-by-project basis.
Technical Capabilities – Motion Capture and Animation
What animation tools are available in Santos Pro?
Santos products are not “animation” environments the way that Autodesk products like Maya or 3D Studio Max are animation environments. Our products do, however, provide the ability to simulate motion through interpolation between sets of key static poses, and this works very well for most work-related tasks.
Are there any studies or literature that compare Santos predictions of limb motion/kinematics to mocap data?
While Santos technologies include the ability to use motion capture data from any motion capture system that can output C3D data (as demonstrated in several videos on the SantosHuman YouTube Channel), Santos Pro is not a motion capture system. Rather, it is a foundational platform for human-centric design that includes support for motion capture input.
That said, recent work completed for one of the world’s largest defense contractors has led to capabilities that allow virtual accelerometers to be attached to our digital human characters. This virtual accelerometer data can then be exported from Santos Pro just as if the original motion capture session had included them. We are not experts in motion capture, but we think this new capability could be leveraged to export virtual motion capture data for any motion generated within Santos Pro.
Have studies been conducted to compare Santos generated motion with motion capture?
All of our predictive models are validated with motion capture, and much of this validation work and the methods by which it is done has been published. See the following links to download those publications:
With regards to studies that have used Santos technologies to drive applications designed for muscle force simulations like OpenSim, download this zipped file.
Technical Capabilities – Authoring Capabilities
What primitive objects can be authored in Santos, e.g. spheres, cylinders, rectangles?
A library of primitive objects is available to the users. This includes spheres, cylinders, rectangles, cones, and more.
Can primitive objects be exported into an assembly hierarchy?
Primitive objects can be parented to or made children of other primitive objects and/or imported objects. The children of the parent object will export with the parent if the option (Export with hierarchy) in the Exporting Window has been checked.
Can the primitives be scaled more precisely than is shown in the Santos experience, i.e. other than grabbing and dragging the slider bar?
Yes, the “Object Scale Tool” is available to set the width, height, and depth of any object in the currently set units. The Santos software units (metric or English) can also be set by the user.
Technical Capabilities – File Management
How are ‘studies’ managed?
The Santos Application starts with a fresh project every time a user opens up the program. Users can save, re-open, and share a file to continue working on a project. The Santos project file (.sproj and .sprojx) can be saved anywhere on the user’s computer. The file type .sproj will save all of the Santos details but will call in the file name of any geometry imported into the environment. The file type .sprojx will save all of the Santos details and the geometry details. These files can be shared to a new computer without losing any details.
How are ‘studies’ updated? I want to change a piece of geometry, update a posture, update a force, etc.
After reopening a saved file, the user can import a new piece of geometry into the program, adjust any posture and add new forces at any time. The user can also save the Santos files to a new project name. Saving both the original project and the updated project allows the user to go back after adjusting any project details.
In general, how do I set up and prepare my file management system to efficiently create and save individual studies and/or multiple what-if scenarios?
There are a couple different options for sharing, analyzing, and saving files. See previous FAQ (above this one) for saving options for project files. The user can also save off Avatar predicted physical behaviors and reload them onto a new avatar or share to a new computer. If the user continues to set up a similar project, the user can create a template file with the project details already set-up. The analysis windows contain export options in order to reimport the data into Excel, which creates an easy way for the user to compare different postures, scenarios, forces, etc.
Technical Capabilities – Anthropometric Databases and Human Scaling
I need to provide the anthro measures and database sources for Santos, Sophia, others. I can partially view dimensions measurements on Santos so I was wondering if you could provide a txt or csv file of the anthro for each avatar and the source of it.
The avatars available in Santos are all based on scans from actual humans (not estimated from a database). If he is able to provide the stature for each avatar, you could quickly evaluate how each avatar fits into the percentiles of relevant databases (i.e., NHANES, ANSUR II, etc.).
Whatever the original subject’s anthropometry and morphology were at the time of the body scan is what was used to create the Santos avatar. We do provide the ability to adjust anthropometry of any targeted avatar. If you select one of our avatars from the library, it is as if you’ve selected an actual person off the street. This approach was taken because of a report done by the Air Force Research Lab in the early 2000’s that argued that since there are no people who have the measurements of a 50th percentile male (for example), it is better to use actual case studies for design purposes. All of our funding partners agreed with this, and that is the approach we have always taken.
I have gone through a lot of the publicly available technical resources that states that the anthro of Santos is based on the FAA’s GEBOD. Is that no longer true for segment dimensions? Has it become more of a modified approach?
GEBOD is used to take an overall body weight and distribute it amongst the various parts of the body. We do this because when we predict dynamic movement, inertia of all the parts of the body play a key role in the calculations for the solution. Since it is very difficult to find people willing to be chopped up into bits so that their various body parts can be weighed while still wet, GEBOD provides a literature-based method that can be used to approximate these.
I see ISO 3411 and NASA 3000 as options in the “Link Length” tab of the context window in Santos.
In the latest version of Santos Pro and Lite, the ANSUR II and NHANES databases have been implemented in the anthro scaling capabilities.
What energy expenditure equations are used?
American Industrial Hygiene Association (AIHA). The energy consumed is based on experimental field studies. In Santos, it is not based on any avatar joint energy expenditure. Only the joint angles and distances that are then used as input for formulas recommended by AIHA. The formulas used can be found in this PDF file.
Spine Shear and Compression – is this more comparable to the calculations coming from Jack or WATBAK since it is measured at L4/L5 instead of L5/S1 like UM3DSSPP?
Our models use the L4/L5 and builds upon WATBAK, but efforts were included to extend this capability into a 3D solution which was guided by USCAR and validated by a group of ergonomists at Sandalwood.
Is Static Fatigue in Santos equivalent to Rhomert?
Sort of. More specifically, we updated Rhomert’s Static Fatigue Models (Curves) based on large meta-analysis. Hundreds of data points were pulled from an extensive literature review in order to create the following Joint-specific models:
- General (all joints)
- Determined that power equations were better than exponential equations
- New analytical fatigue model was developed to predict changes in peak torque over time
- A previous fatigue model was advanced to allow for sub-maximal contractions
- Utilizes % of Max effort at the joint level instead of at the muscle fiber level (using 3-D Strength Surfaces)
- Validated against static fatigue data (see above)
- Optimized model parameter values (fatigue and recovery rates) for each specific joint region (above)
- Model is able to predict endurance time, decay in peak force, and force recovery and rest allowance
- Model can predict fatigue from static, intermittent and dynamic contractions
Ongoing and future efforts include:
- Meta-analysis of intermittent static fatigue data to develop 3-D Rhomert Curves
- Endurance time as a function of task intensity and duty cycle
- Validate analytical fatigue model for intermittent tasks using Meta-analysis described above
- Validate dynamic contractions
I am applying reaction forces for a tightly constrained seated avatar. Can you tell me more about the Static Fatigue visualizer and how it represents the impact on the human?
The static fatigue visualizer estimates the amount of time that a given joint could sustain the simulated task-focused behavior, often referred to as an endurance limit. For example, think of holding a soup can in each hand, then extending your arms out beside you into a “T.” The endurance limit is the duration of time that you could last before you had to lower your arms down to rest. The predicted static fatigue/endurance limit for each joint depends on the torque at each joint, which depends on the forces and posture. Changing the postural requirements or the reaction force requirements will change the static fatigue/endurance limits in the visualizer.
Please note that the static fatigue visualizer is limited to estimating endurance limits for static postures that are maintained for 60 minutes or less.
To interpret the data, users often find it helpful to first find the “weakest link,” or the joint with the lowest endurance limit. If the simulated task-focused behavior is expected to be held for a duration that is less than the shortest static fatigue/endurance limit, the task could be deemed acceptable (from a static fatigue perspective). If the simulated task-focused behavior is expected to last for a duration that is longer than the shortest static fatigue endurance limit, the task may need to be redesigned (reaction force requirements reduced, or postural requirements altered).
Musculoskeletal Effort, Musculoskeletal Joint Displacement, Musculoskeletal Discomfort, Musculoskeletal Potential Energy – Please explain these tools.
These are considered performance measures rather than tools. They are what our posture prediction algorithm uses, with additional parameters, to determine a predicted behavior.
Our joint displacement optimization function attempts to minimize the displacement of joints from their respective neutral positions.
Our discomfort optimization functions strive to minimize the moments created within the muscles while avoiding reaching maximum or minimum rotation within the joints.
Our potential energy performance measures seek to minimize the total change in potential energy.
Carpal Tunnel Risk Indicator – Is this the P. Keir carpal tunnel pressure risk assessment tool?
The Santos® Carpal Tunnel Risk Calculator uses the Occupational Repetitive Actions (OCRA) analysis (E. Occhipinti).
Systematic Workload Estimator, Zero Moment Point Evaluator – Please explain these tools.
The Systematic Workload Estimator has been replaced with the Energy Expenditure tool.
ZMP tool (Zero Moment Point) calculates the avatar’s area for balance while standing a flat surface with both feet on the ground.
Can Santos create kinetic simulations? Can the human be kinetic? Can other geometry be kinetic?
Yes, the human can be kinetic and other geometry can be kinetic.
Technical Capabilities -Santos Pro Security
Would the software enable users to look at data moving across the network traffic (i.e., packet capturing), identify assets (hardware/software) on the GDMS network or scan for vulnerabilities? If so, could it be set up in a way that doesn’t do that?
No. None of the Santos-related products “need” to be connected to the network to run for node-locked licenses. For floating licenses, some server is required to host the licenses, but network access can be restricted to a LAN by hosting the license server locally. We set this up for a lot of our clients so it’s a well-defined process and, of course, we can assist as needed. However, if the license server is not local, then network access would be required.
Would the software be used to externally transfer GDMS or customer data to a non-GD organization? If so, could it be set up in a way that doesn’t do that?
No data leaves the host machine through the Santos software, with the exception of licensing information for floating licenses, which would obviously need to be provided to some license server, somewhere. Again, the license server can be local, in network, or externally hosted, whichever is the best fit for your IT requirements.
Does the software allow a non-GDMS entity to take control of a GDMS computing device (regardless of location) or does the software provide remote desktop/virtual machine capability?
No, it does not.
Our resources include videos that show how Santos technologies can assist you in human-centric trade-off analyses. The software’s ease of use and ability to predict human behavior places powerful, valid human body simulation software in your hands. Please watch these videos and let us know if you have questions about human body simulation software.
For tutorial videos and more, browse our YouTube playlists.