Digital Human Modeling

Vincent G. Duffy, Ph.D.Associate Professor

Regenstrief Center for Healthcare Engineering

School of Industrial Engineering and Department of Agricultural &

Biological EngineeringPurdue University

Lecture 17 & 18Thursday, 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)

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…

Brief Research Background

Perception-based safety design

through evaluations of the impact of perception & decisions on safety

I.3

(Wickens, Lee, Liu & Gordon-Becker 2004)

(Computers in Industry, 2003,

Duffy, Wu & Ng)

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

1st Generation DHM: Empirically Driven

Originating with Computer-Aided Ergonomics & Safety (CAES)

Education & Research

Courses, Students Students, Projects

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

New

OldReal-time analysis; Motion capture; Virtual-view; Real wheelchair (Ch.1-upper left) (Ch.2-upper right) (Ch.3-lower left) (Ch.4-lower right)

Advanced 1st Generation DHM: Verification & Validation

Virtual Interactive Safety Design

New

Old

Advanced 1st Generation DHM: Verification & Validation

Dynamic Aspects of Work

Moving Beyond Original Assumptions

US Army-TACOM funded validation, dynamic aspects and cognitive model integration with Virtual Soldier Research (Mississippi State & U..Iowa)

Classification of risk using motion capture (Cappelli & Duffy, 2005; 2006)

Virtual prototypes: limitations & challenges in simulation & validation

60/749,553 provisional patent application & SAE 2006-01-1060 (Duffy, et al. 2005).

3rd Generation DHM: Integrating the Cognitive Models

Virtual prototypes: limitations & challenges in simulation & validation

Trade-offs in virtual & real prototyping

When product or process When product or process requires more interactivity requires less interactivity

Full Prototype Full Simulation Virtual environment for design iterations (Duffy, 2004)

It was proposed that:

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)DHM

Opportunities

Needs

Current Limitations

Capabilities

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

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.

DHM in Healthcare Engineering

Simulations & Prescriptive Medicine

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.

DHM in Healthcare Engineering

Real Robotic Surgery Available - Laporoscopic

Intuitive’s DaVinci – need training alternatives & lower cost solutions

Toward Minimally Invasive Tele-robot/Augmented Simulation

Simulations & Training for Surgeons

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

Bringing the DHM Research Community Together

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

Occupational Ergonomics Applications for DHM

In Summary

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 generationb. two parts, including a visualization and some math and/or science in the backgroundc. three parts, including a cognitive modeld. my first Jacke. none of the above

Occupational Ergonomics Applications for DHM

In Summary

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 generationb. two parts, including a visualization and some math and/or science in the backgroundc. three parts, including a cognitive modeld. my first Jacke. none of the above

Answer: b

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

2. A cognitive model for DHM may be based on which of the following:

a. Wickens Information Processing modelb. A robotc. healthcare engineeringd. all of the abovee. none of the above

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

2. A cognitive model for DHM may be based on which of the following:

a. Wickens Information Processing modelb. A robotc. healthcare engineeringd. all of the abovee. none of the above

Answer: a

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

3. Second generation models are:

a. empirically drivenb. computationally drivenc. always focused on verification and validationd. all of the abovee. none of the above

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

3. Second generation models are:

a. empirically drivenb. computationally drivenc. always focused on verification and validationd. all of the abovee. none of the above

Answer: b

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

4. First generation DHM are:

a. empirically drivenb. more focused on validation and verificationc. usually incorporate the physical aspects of workd. all of the abovee. none of the above

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

4. First generation DHM are:

a. empirically drivenb. more focused on validation and verificationc. usually incorporate the physical aspects of workd. all of the abovee. none of the above

Answer: d

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

5. Jack software:

a. enables analysis of computer generated workstations b. is available to Purdue students through all ITaP labs, and at homec. includes analyses related to RULA, NIOSH Lift, Comfort, Snook Tables, Postural Analysis & Energy Expenditured. all of the abovee. none of the above

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

5. Jack software:

a. enables analysis of computer generated workstations b. is available to Purdue students through all ITaP labs, and at homec. includes analyses related to RULA, NIOSH Lift, Comfort, Snook Tables, Postural Analysis & Energy Expenditured. all of the abovee. none of the above

Answer: d

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

6. The human-system interface design for complex products can highlight

a. current capabilities in cognitive modelsb. the need for more 1st generation models c. current limitations in DHMd. all of the abovee. none of the above

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

6. The human-system interface design for complex products can highlight

a. current capabilities in cognitive modelsb. the need for more 1st generation models c. current limitations in DHMd. all of the abovee. none of the above

Answer: c

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

7. Motion capture systems enable:

a. new models without old assumptionsb. integration with CAEc. data related to Velocities, Accelerations, Angular Velocities and Angular Accelerationsd. all of the abovee. none of the above

Occupational Ergonomics Applications for DHM

In Summary

Review questions:

7. Motion capture systems enable:

a. new models without old assumptionsb. integration with CAEc. data related to Velocities, Accelerations, Angular Velocities & Angular Accelerationsd. all of the abovee. none of the above

Answer: d

Occupational Ergonomics Applications for DHM

In Summary