Human Factors (HF) and Nocturnal Home Hemodialysis (NHD)

1
Human Factors (HF) and Nocturnal Home
Hemodialysis (NHD)

• Draft
• Michael Mendelson, D.D.S., M.S.
• Biomedical Engineer, Director Health Promotion
  Officer
• Human Factors Science and Engineering Branch
• Division of Device User Programs
• Office of Communication, Education, and Radiation
  Control
• Center for Devices and Radiological Health
• June 8, 2005

2
Topics

• Introduction to human factors (HF)
• Magnitude of medical error-caused adverse
  incidents
• HF methods
• Nocturnal home hemodialysis challenges and
  observations
• Human Factors Branch Recommendations for
  premarket submissions

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General Definition of Human Factors (HF)

• Human Factors discovers and applies information
  about human behavior, abilities, limitations, and
  other characteristics to the design of tools,
  machines, systems, tasks, jobs and environments
  for productive, safe, comfortable, and effective
  human use.
• -- Alphonse Chapanis 1985
• Sanders McCormick, Human Factors in
  Engineering and Design., McGraw-Hill, Inc., 1987
  page 5

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General Definition of Error

• Human error is an inappropriate or undesirable
  human decision or behavior that reduces, or has
  the potential for reducing, effectiveness,
  safety, or system performance.
• Sanders McCormick, Human Factors in
  Engineering and Design., McGraw-Hill, Inc., 1987
  page 607

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Magnitude of the Problem of Medical Error
Errors during hospital treatment result in
120,000 deaths each year roughly equivalent to
a jumbo jets crashing each day. (Leape, Harvard
School of Public Health) At least 44,000
people,and perhaps as many as 98,000 people,die
in hospitals each year as a result of medical
errors that could have been prevented(To Err is
Human Building a Safer Health System Institute
of Medicine / National Academy of Sciences, 1999)
Photo courtesy of Boeing
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HF Considerations
Use

• Use Environment
• Light, Noise
• Distraction
• Motion/Vibration

Safe effective

• Device User
• Knowledge
• Abilities
• Expectations
• Limitations

Device Use
Unsafe or ineffective(Use Error)

• Device
• Operational requirements, procedures
• Device complexity
• Specific user interface characteristics

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Increased Patient Safety through USABILITY (User
Friendliness) of the Use Interface

• Intuitive operation
• Clear displays
• Safe and simple-to-use controls
• Positive and safe connections
• Effective alarms
• Clear and effective and labeling
• Safe and simple installation, repair,
  maintenance, and disposal

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Two Key Human Factors (HF) Messages

• A poorly designed device use interface can
  needlessly permit and even induce error.
• Warnings and instructions in the operating manual
  (and even on the device) may help but they cant
  OVERCOME a flawed design.

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Some Important Principles of Good Design
(modified from The Design of Everyday Things,
Donald Norman)

• Make things visible
• Communicate clearly
• Provide correct and natural mappings
• Dont be arbitrary, be consistent
• Simplify tasks
• Use appropriate constraints
• Design for error

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MAKE THINGS VISIBLE This PCA pump fails.
Obradovich and Woods (1996)
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Obradovich and Woods (1996)
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Some Important Principles of Good Design (The
Design of Everyday Things, Donald Norman)

• Make things visible
• Communicate clearly (e.g., mode/system status)
• Provide correct and natural mappings
• Dont be arbitrary, be consistent
• Simplify tasks
• Use appropriate constraints
• Design for error

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Some Important Principles of Good Design (The
Design of Everyday Things, Donald Norman)

• Make things visible
• Communicate clearly
• Provide correct and natural mappings What is
  this switch for?
• Dont be arbitrary, be consistent
• Simplify tasks
• Use appropriate constraints
• Design for error

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Some Important Principles of Good Design
(modified from The Design of Everyday Things,
Donald Norman)

• Make things visible
• Communicate clearly
• Provide correct and natural mappings
• Dont be arbitrary, be consistent e.g., valve
  conventions
• Simplify tasks
• Use appropriate constraints
• Design for error

15
Some Important Principles of Good Design
(modified from The Design of Everyday Things,
Donald Norman)

• Make things visible
• Communicate clearly
• Provide correct and natural mappings
• Dont be arbitrary, be consistent
• Simplify tasks (e.g., reduce programming steps)
• Use appropriate constraints
• Design for error

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APPROPRIATE CONSTRAINTS
FDA, Dec. 28, 1993
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Some Important Principles of Good Design (The
Design of Everyday Things, Donald Norman)

• Make things visible
• Communicate clearly
• Provide correct and natural mappings
• Dont be arbitrary, be consistent
• Simplify tasks
• Use appropriate constraints
• Design for error (e.g., require confirmation of
  critical actions)

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Human Factors (HF) Critical in Nocturnal Home
Hemodialysis

• Users
• Lack of on-site staff and supplies
• Variable level of education
• Medically compromised vision, touch, memory
• Language and cultural diversity
• Healthy-patient selection responsibile for home
  safety level

• Environment
• Family responsibilities, children, pets
• Stress
• Physical (placement, voltage/grounding,
  temperature, humidity, dust)
• DAmicoBazzi, Home Hemodialysis, in
  Replaplacement of Renal Function by Dialysis,
  1989, page 694

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Clinical Incidents Potential Nocturnal Home
Issues?

• Hazards always exist. Documented clinical
  post-market risks and adverse incidents (errors)
• Midtreatment shutdown without warning
  gtclot/embolism risk
• ECRI Healthcare Product Comparison System, Sept.
  2004 page 6

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Clinical Incidents Potential Nocturnal Home
Issues? (continued)

• For 3 fault codes which indicate need for manual
  adjustment of transmembrane pressure (TMP) gt not
  actually controllable. Recall. Solution labeling
  
• If unit plugged into receptacle without ground
  fault circuit interrupter (GFCI) with certain
  other conditions gt overheating. Recall.
  Solution labeling
• ECRI Healthcare Product Comparison System, Sept.
  2004 page 10 (HDA A5092, A5624)

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Nocturnal Home Hemodialysis User Needs

• Simplify setup minimize requirements for strict
  hygiene where possible.
• Minimize burden on training. Consider periodic
  retraining.
• Minimize dependence on bulky labeling. Use
• On-screen help/voice prompts (Wizards)
• Quick Guides (laminated cards, cheat sheets)

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Nocturnal Home Hemodialysis User Needs (continued)

• Monitor supplies and preparation of prescribed
  dialysate
• Ensure simple set up operation, and adjustment.
• Ensure safety of consumables possible
  after-market consumables lacking OEM safety
  features? (e.g., after-market infusion pump
  tubing sets lethal outcome)
• Need for priming blood lines, knowing symptoms of
  air embolism, how to respond

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Nocturnal Home Hemodialysis User Needs (continued)

• Potential interrupted treatment Ability to
  detect and respond?
• Allow flexible installation various viewing
  angles.
• Allow for physical impairment (ESRD
  co-morbidities).
• Consider touch screen and no cryptic error codes.

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Nocturnal Home Hemodialysis User Needs (continued)

• Consider progressive disclosure of information
  for range of user abilities and wants.
• Facilitate detection of bleeding enuresis pads,
  moisture detectors, effective needle dislodgement
  alarm (single needle?).
• Patient abilities may be lowest at start of
  session.

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Nocturnal Home Hemodialysis User Needs (continued)

• Consider tricky power-interruption scenarios
  (error-codes, default settings)
• Design in virtual guardrails.
• Allow for compromised nocturnal response to
  alarms

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Design of Hemodialysis Systems Requires Human
Factors Engineering (HFE)

• The Quality System Regulation HF implied in
  Design Controls Section (21 CFR 820.30)
• Manufacturer
• Must address the intended use
• Must address the needs of the user and patient
• Shall include testing under actual or simulated
  use conditions

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Introducing Human Factors (HF) Into Design How
Early?

• 510(k)/PMA submission is too late
• Pre IDE/IDE submission is late
• The concept stage is ideal.
• User needs designed in.
• Early HF design changes fast and economical.
• Fewer slapped-on warnings and bulky manuals.
• User acceptance and product life increased.
• Industry estimate 3 return on 1 HF investment.

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Early Introduction of Human Factors to Medical
Device Design
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Applying HF is a ProcessHuman Factors
Engineering
Concept Phase
Design Input
Design Output
Verification
Validation
Perform Studies Analyses
Develop Require- ments
Develop Specs.
Test Output Against Input
Test Against Patient User Needs
Tasks Users Use Environment Standards
Guidelines
Literature Complaints Observation Interviews
Drawings Mockups Computer Prototypes
Expert Evaluation Rapid Prototyping Usability/HF
Testing
Production Units Usability/HF Testing
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Usability Study Validation of Use Interface

• Most visible human factors step
• Actual production units
• Prospective users
• Realistic environment
• Test user in critical functions (from hazard
  analysis, literature, other reports)
• Objective measures not preferences (e.g.,
  time, error rate, physiological stress)

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Clinical Trials and Usability Studies
Complementary

• Usability Studies demonstrate low risk of
  dangerous use error where, when, and how device
  is used by typical users. (usually a simulation)
• Clinical trials demonstrate safety and
  effectiveness where, when, and how used exactly
  as directed.
• Demonstrate usability before clinical trials!
  Why? gt

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Clinical Trials and Usability Studies
Complementary (continued)

• Clinical trials not usually representative users
• Clinical trials cannot impose hazardous
  scenarios
• Clinical trials usability measurement can be
  intrusive
• Clinical trials too late for HF design
  improvements

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Human Factors InteractionManufacturer ltgt FDA

• FDA HF Branch emphasizes PROCESS, not specific
  design features (usually).
• Submit comprehensive description of HFE process
  early to FDA ODE gt Human Factors Branch

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Submit comprehensive description of HFE process
early to FDA ODE gt Human Factors Branch

• Concepts
• Design input sources
• Describe testing
• Include hazard analysis
• Standards and guidance used

• Submit all labeling
• Describe training
• Include usability study and report
• Identify discovered usability problems and
  describe solution

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Human Factors Recommendations/Conclusion

• Begin comprehensive Human Factors Engineering
  (HFE) process at concept stage.
• Assume significant patient/user and environmental
  compromises.
• Minimize burden on training and paper
  instructions.
• Ensure comprehensive patient/user support from
  manufacturer or value-added retailer.
• Encourage postmarket feedback from users.
• Engage FDA early.

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ADDITIONAL SLIDES FOLLOW

• ADDITIONAL SLIDES ?

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Sources of Design Input

• User input, other devices, environment
• General HF design conventions, knowledge
  (heuristics)
• Standards (including HF, risk, alarms)
• FDA HF Guidance documents (Web www.fda.gov/cdrh
  Topic Index Human Factors)

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Design Controls HF implied in the design
controls portionof the Quality System Regulation

• Design input Paragraph 820.30 (c)
• Design verification Paragraph 820.30 (f)
• Design validation Paragraph 820.30 (g)

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FDA Recognized Standards

• ANSI/AAMI HE742001, HF process standard
  (FDA-recognized)
• ISO 149712004, Risk Management
• ISO/IEC alarm standard 60601-1-8, 1st edition

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Guidance Documents

• Device Use Safety Incorporating Human Factors in
  Risk Management
• Do It By Design an Introduction to Human Factors
  in Medical Devices
• Guidance on Medical Device Labeling
• (Web www.fda.gov/cdrh Topic Index Human
  Factors).
• HF guidance integrated into FDA software guidance
  documents and specific device guidance