Digital Human Modeling
Vincent G. Duffy, Ph.D.
Associate Professor
Regenstrief Center for Healthcare
Engineering
School of Industrial Engineering
and Department of Agricultural &
Biological Engineering
Purdue University
Lecture 17 & 18
Thursday, March 29 & Tuesday April 3,
2007
Overview
Defining DHM
Brief Research Background
1st Generation DHM: Empirically Driven
Education & Original DHM Research
Advanced 1st Generation DHM: Verification & Validation
2nd Generation DHM: Computationally Driven
Moving Beyond Original Assumptions
3rd Generation DHM: Integrating the Cognitive Models
Opportunities for DHM Research
DHM in Healthcare Engineering
Bringing the DHM Research Community Together
Defining DHM
Digital human models (DHM)
– digital representation of the human inserted into a simulation or
virtual environment to facilitate prediction of safety and/or
performance
– Includes a visualization and math/science in background
Enables engineers
– to incorporate ergonomics and human factors engineering
principles earlier in the design process (Duffy, 2004; Chaffin, 2005)
New concepts such as ‘Virtual Build’ using DHM
– Eliminating need for prototyping
– Facilitated by motion capture
– See Brazier, et al. (2003), Li et al. (2004) at Applied Ergonomics, Wu
et al. (2005) SAE-DHM
– Providing real cost savings
• $8.8 Million avoided in injury costs
– Brazier, et al. (2003)
Perception-based safety design
I.3
Brief Research Background
Leading to DHM
Perception-based safety design applies fundamentals of human factors
& ergonomics toward improved product and process design in various
application domains including manufacturing, automotive, military and
healthcare…
through evaluations of the
impact of perception
& decisions on safety
(Wickens, Lee, Liu & GordonBecker 2004)
(Computers in Industry, 2003,
Duffy, Wu & Ng)
Originating with Computer-Aided Ergonomics & Safety
(CAES)
1st Generation DHM: Empirically Driven
Du, et al. (HAAMAHA 2005) used a
NIOSH Lifting Equation, Static
Strength Prediction - Postural
Evaluation; Rapid upper limb
assessment; Energy expenditure;
Borg’s Rating of Perceived Exertion
Chaffin,1999; NIOSH,1994;
McAtamney, 1993; De Luca, 1997;
Marras, 1990;Garg 1978; Borg, 1982
Courses, Students Students, Projects
Education & Research
IE 590D Applied Ergonomics
– 30 students – many currently in industry registered
through engineering professional education
IE 656 Digital Human Modeling: Research Seminar
- 12 Graduate & Undergraduate Students currently
IE 486 Work Analysis & Design II
– 80 students each semester
Virtual Interactive Safety Design
Advanced 1st Generation DHM: Verification & Validation
New
Real-time analysis; Motion capture;
Old
(Ch.1-upper left)
(Ch.2-upper right)
Virtual-view;
(Ch.3-lower left)
Real wheelchair
(Ch.4-lower right)
Virtual Interactive Safety Design
Advanced 1st Generation DHM: Verification & Validation
New
Old
Dynamic Aspects of Work
Moving Beyond Original Assumptions
Classification of risk using motion capture
(Cappelli & Duffy, 2005; 2006)
US Army-TACOM funded validation, dynamic aspects and cognitive model
integration with Virtual Soldier Research (Mississippi State & U..Iowa)
Virtual prototypes: limitations & challenges
in simulation & validation
3rd Generation DHM: Integrating the Cognitive Models
60/749,553 provisional patent
application & SAE 2006-01-1060
(Duffy, et al. 2005).
Virtual prototypes: limitations & challenges
in simulation & validation
Trade-offs in virtual & real prototyping
It was proposed that:
When product or process
requires more interactivity
Full Prototype
When product or process
requires less interactivity
Full Simulation
Virtual environment for design iterations (Duffy, 2004)
DHM: Opportunities for Research
Origins: automotive, aerospace, military
Current capabilities: engineering science, math &
computing
Needs: health systems, rehabilitation engineering
Current limitations: cross-disciplinary research
–
–
–
–
Needs driving emerging DHM
Identify foundations, fundamentals
Develop evaluation methods
analysis tools & applications
Engineering research:
increased by more than
$1B in the past four years
(ASEE, 2005)
Needs
DHM
Opportunities
Capabilities
Current
Limitations
Opportunities for DHM:
Computational Modeling & Visualization
Open loop vs. Closed loop
-Closed loop- Device driven – eg. Biomedical Additional or Open effected
by environment: human factors, HCI & ergonomics must be considered
Data abounds in the health care industry and inexpensive
sensors make more data easily accessible
-Better methods are needed to effectively apply engineering principles to
healthcare delivery (open loop) in a systematic way
-Application of traditional OR techniques may not be sufficient due to
inherent non-linearities that make models with simplifying assumptions
difficult to validate
Opportunities for DHM:
Computational Modeling & Visualization
Open loop vs. Closed loop
-Closed loop- Device driven – eg. Biomedical Additional or Open effected
by environment: human factors, HCI & ergonomics must be considered
Data abounds in the health care industry and inexpensive
sensors make more data easily accessible
-Better methods are needed to effectively apply engineering principles to
healthcare delivery (open loop) in a systematic way
-Application of traditional OR techniques may not be sufficient due to
inherent non-linearities that make models with simplifying assumptions
difficult to validate
Computing infrastructure initiatives at the national level may
bring additional support for applying more computing intensive models.
National attention has been brought to issues such as patient safety
and the rising costs of healthcare that may encourage a willing
partnership between engineering and the medical community for data
gathering and model validation.
Simulations & Training for Nurses: RCHE On-campus Visit
DHM in Healthcare Engineering
DNP & Research Staff in the
Center for Nursing Education
-Sim-Man -later to include Sim-Baby & Sim-Child
using Health Fund Grant
- Lifelike heart and lung sounds, arterial
waveforms, pulses, and responds physiologically
to treatment.
- Can be programmed to cough, talk, moan, and
respond to care while students monitor, analyze,
and react.
Simulations & Prescriptive Medicine
DHM in Healthcare Engineering
There is a need for applying
related computational
modeling methods to
prescriptive medicine,
according to
recommendations from the
National Academies
Institute of Medicine's
forthcoming report that was
recently presented to the
Scientific Advisory
Committee on Infant Mortality.
Simulations & Training for Surgeons
Toward Minimally Invasive Tele-robot/Augmented Simulation
Real Robotic Surgery Available - Laporoscopic
Intuitive’s DaVinci – need training alternatives
& lower cost solutions
Bringing the DHM Research Community Together
Supplementing SAE-DHM efforts through
- ERCIM Digital Patient Working Group
- 1st ICDHM at HCII 2007
- Handbook of Digital Human Modeling
- 2nd AE 2008
- HFES HPM-TG
Including
Digital Visible Human
ICPT- Visualization,
Perceptualization & Data Rendering
In Summary
Occupational Ergonomics Applications for DHM
Through DHM, various industries can bring occupational
ergonomics earlier in design
For addressing, particularly the science of work
New DHM consider the changing nature of work
Examples of interest internationally (eg. Digital Visible Human)
Collaborating Centers and Academic Units at Purdue include:
IE, RCHE, ABE, AMC, PLM, NEXTRANS, SoS, ICPT, ME, AAE,
CE, Health Sciences, Envision Center, Center for Aging, Center
for Nursing Education.
with future applications especially in services industries such as: Healthcare, Energy,
Logistics & Transportation Safety
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
1. A digital human model has which of the following:
a. one part, and it is difficult to tell whether it is first, second or third generation
b. two parts, including a visualization and some math and/or science in the
background
c. three parts, including a cognitive model
d. my first Jack
e. none of the above
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
1. A digital human model has which of the following:
a. one part, and it is difficult to tell whether it is first, second or third generation
b. two parts, including a visualization and some math and/or science in the
background
c. three parts, including a cognitive model
d. my first Jack
e. none of the above
Answer: b
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
2. A cognitive model for DHM may be based on which of the following:
a. Wickens Information Processing model
b. A robot
c. healthcare engineering
d. all of the above
e. none of the above
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
2. A cognitive model for DHM may be based on which of the following:
a. Wickens Information Processing model
b. A robot
c. healthcare engineering
d. all of the above
e. none of the above
Answer: a
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
3. Second generation models are:
a. empirically driven
b. computationally driven
c. always focused on verification and validation
d. all of the above
e. none of the above
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
3. Second generation models are:
a. empirically driven
b. computationally driven
c. always focused on verification and validation
d. all of the above
e. none of the above
Answer: b
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
4. First generation DHM are:
a. empirically driven
b. more focused on validation and verification
c. usually incorporate the physical aspects of work
d. all of the above
e. none of the above
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
4. First generation DHM are:
a. empirically driven
b. more focused on validation and verification
c. usually incorporate the physical aspects of work
d. all of the above
e. none of the above
Answer: d
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
5. Jack software:
a. enables analysis of computer generated workstations
b. is available to Purdue students through all ITaP labs, and at home
c. includes analyses related to RULA, NIOSH Lift, Comfort, Snook Tables, Postural
Analysis & Energy Expenditure
d. all of the above
e. none of the above
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
5. Jack software:
a. enables analysis of computer generated workstations
b. is available to Purdue students through all ITaP labs, and at home
c. includes analyses related to RULA, NIOSH Lift, Comfort, Snook Tables, Postural
Analysis & Energy Expenditure
d. all of the above
e. none of the above
Answer: d
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
6. The human-system interface design for complex products can highlight
a. current capabilities in cognitive models
b. the need for more 1st generation models
c. current limitations in DHM
d. all of the above
e. none of the above
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
6. The human-system interface design for complex products can highlight
a. current capabilities in cognitive models
b. the need for more 1st generation models
c. current limitations in DHM
d. all of the above
e. none of the above
Answer: c
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
7. Motion capture systems enable:
a. new models without old assumptions
b. integration with CAE
c. data related to Velocities, Accelerations, Angular Velocities and Angular
Accelerations
d. all of the above
e. none of the above
In Summary
Occupational Ergonomics Applications for DHM
Review questions:
7. Motion capture systems enable:
a. new models without old assumptions
b. integration with CAE
c. data related to Velocities, Accelerations, Angular Velocities & Angular
Accelerations
d. all of the above
e. none of the above
Answer: d