Results

Since LifeMOD/BodySIM™ runs through ADAMS/View, the user has access to the full range of A/View data extraction methods.

In addition to the ADAMS/View tools, LifeMOD/BodySIM provides a special results panel to display body segment motion, and joint, tissue and contact data in X-Y plot. It is also controls the animation of the model.

While an animation runs, dynamic plots simultaneously display the model's internal reactions and the effects on the external environment.

The camera viewing angles, lighting, and path tracing are all additional features used to examine the performance of the model. Movie AVI files may be automatically created from the animations.

The panel can also turn on/off the muscle graphics scaling feature.

Sections:

• Structure of the Results Panels
• Animating the Model
• Plotting Data for the Model
• Calculating Specific Results for the Model

Structure of the Results Panel

Figure 1 displays the general results panel. Sub-menus for animation, data display, and data calculation are available. This panel specifies the default analysis to be animated, plotted, and calculated in the event that more than one simulation needs to be run and compared. The panel also allows the user to switch to the results window and create and delete results pages.

Figure 1: General results panel with functions available for plotting, animation and calculation.

Animating the Model

Results ->Animation

Figure 2 displays the general animation panel, which controls the animation of the model using many ADAMS/View features. At any time all of the features of ADAMS/View may be used to animate the model, however, the BodySIM panel itself contains the more commonly used animation functions. At the top of the panel are the animation controls.

Separate simulation cases may be superimposed over each other by checking Compare Cases and entering the names of the results files in Figure 2.

Figure 2: Animation panel

The camera, or viewpoint, may be fixed to a marker on the model, which allows the user to easily follow the movement of models that must travel a distance in a simulation. The rotations may be fixed to the camera as well. Trace markers may be utilized to trace a path in space. This feature is convenient for observing motion trajectories (Figure 3). Another feature for observing motion trajectories is to turn on the trail frames (Figure 4).

Figure 3: Example of plotting a trajectory with a trace marker

Figure 4: Example of plotting a trajectory trail frames

Figure 5 displays the graphics-scaling section of the animation panel. In this section, the user may turn on scaling joint-and-muscle graphics. Scaling can be confined to a local level by scaling a particular muscle, or it may occur on a global level. Either scaling option is achieved by scaling a particular muscle with consideration for the relative magnitude of the muscle or set of muscles in the simulation.

Figure 5: Dynamic scaling section of the animation panel

To create scaling muscle graphics, be sure to turn on either the muscle graphics or the joint graphics using the LifeMOD Display Tools panel. Then select either joints/tissues global/local and the light bulb in Figure 5. LifeMOD/BodySIM™ then calculates all the scaling functions for the entire simulation. The model is then animated using either the Play button at the top of the Results->Animation panel or by using the ADAMS/View animation tools. Figure 6 displays a sequence of scaling muscles (see Muscle Relocation Tutorial) and Figure 7 (see Lifting Tutorial) displays a sequence of scaling joints.

The animation speed is slightly slower than normal animation speed when the scaling graphics are turned on. This is due to the increased overhead of the changing graphics. For smoother animations, AVI files may be created and replayed. To create these files, select the Record button on the ADAMS/View animation tools.

Figure 6: Three animation frames displaying scaling muscle graphics

Figure 7: Three animation frames displaying scaling joint graphics

Plotting Data for the Model

Figure 8 displays the data display section of the results panel. With this panel, data for body motion, soft tissues, joints, disks, forces and contact forces may be plotted. Data may be plotted in the results window or in a strip chart. The "Strip Chart Display" can be used to create a strip chart which can be viewed with the animation (see Rehabilitation Machine tutorial). Use the Plot Curve button to plot the curve. If "New Plot" is not checked the curve will be overlayed over the preexisting curve on the plot. When creating a full plot, the user has the option to specify the title, subtitle and legend. In addition, the data may be filtered using a Butterworth filter.

Figure 8: Panel used to plot model data

Data Type -> Body Motion

Figure 9 displays the data panel set up to display body motion. Data for CM_Position, CM_Velocity, CM_ Acceleration, CM_Angular_Velocity and CM_Angular_Acceleration are the characteristics available for each body segment in the model.

Figure 9: Panel used to plot body motion data

Data Type -> Joints

Figure 10 displays the data panel set up for joint data-plotting. Joint force, torque, angle and servo error (the difference between the desired angle and the actual simulation angle) can be plotted in each of the sagittal, transverse and frontal planes of the human model.

Figure 10: Panel used to plot data for the joints

Data Type -> Disks

Figure 11 displays the panel set up to plot data for the disks in the model. Disk force and torque may be displayed in the AP shear, ML shear, compression and magnitude.

Figure 11: Panel used to plot data for the disks

Data Type -> Soft Tissues

Figure 12 displays the display panel set up to display data for the soft tissues in the model. Tension, contraction, and activation data are available.

Figure 12: Panel used to plot data for the soft tissues

Data Type -> Contacts

Figure 13 displays the panel that allows data-plotting for the contact forces in the model. The X, Y, Z and magnitude components are available through this function.

Figure 13: Panel used to plot the contact data

Calculating Specific Results for the Model

Through the results panel, specific results, such as Head Injury Criteria (HIC) and Neck Injury Criteria (NIC) may be also be calculated. These data results are used to asses injury propensity for both the head and neck based on common formulas.

Injury Criteria -> Head (HIC)

Figure 14 displays the panel and formula used to calculate the head injury criteria. In most cases, the acceleration results are plotted in the plotting window using the tools in the panel. A beginning time, t1, is specified and the t2 is generated from the delta t, or change in tme. According to most experts, the maximum delta that allows this formula to be effective is 0.036 seconds. After specifying this data the HIC value is generated and displayed on the panel.

Figure 14: Panel used to calculate the head injury criteria (HIC).

Injury Criteria -> Neck (NIC)

Figure 15 displays the panel and formula used to calculate the neck injury criteria. In most cases, the acceleration results are plotted in the plotting window using the tools in the panel. The plot helps the user visualize the data needed to select the time, t, to calculate the NIC. After the appropriate values have been entered, NIC value is generated and displayed on the panel.

Figure 15: Panel used to calculate the neck injury criteria (NIC).