human factors (hf) and nocturnal home hemodialysis (nhd) draft michael mendelson, d.d.s., m.s....
Post on 15-Jan-2016
224 views
TRANSCRIPT
Human Factors (HF) and Human Factors (HF) and Nocturnal Home Nocturnal Home Hemodialysis (NHD)Hemodialysis (NHD)
Human Factors (HF) and Human Factors (HF) and Nocturnal Home Nocturnal Home Hemodialysis (NHD)Hemodialysis (NHD)
DraftDraft
Michael Mendelson, D.D.S., M.S.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
TopicsTopics
Introduction to human factors (HF)Magnitude of medical error-caused adverse incidentsHF methodsNocturnal home hemodialysis challenges and observationsHuman Factors Branch Recommendations for premarket submissions
3
General Definition of Human Factors (HF)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
4
General Definition of ErrorGeneral 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
5
Magnitude of the Problem of Medical ErrorMagnitude of the Problem of Medical Error
Errors during hospital treatment result in 120,000 deaths each year – roughly equivalent to a jumbo jet’s 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
6
Safe & effective
Unsafe orineffective(Use Error)
Use Environment• Light, Noise• Distraction• Motion/Vibration
Device User• Knowledge• Abilities• Expectations• Limitations
Device• Operational requirements, procedures• Device complexity• Specific user interface characteristics
Use
HF Considerations
DeviceUse
7
Increased Patient Safety through USABILITY (“User Friendliness”) of the Use Interface
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
8
Two Key Human Factors (HF) MessagesTwo 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 can’t OVERCOME a flawed design.
9
Some Important Principles of Good Design (modified from The Design of Everyday Things, Donald Norman)
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 Don’t be arbitrary, be consistent Simplify tasks Use appropriate constraints Design for error
10
MAKE THINGS VISIBLE: This PCA pump fails.MAKE THINGS VISIBLE: This PCA pump fails.
Obradovich and Woods (1996)
11
Obradovich and Woods (1996)
12
Some Important Principles of Good Design (The Design of Everyday Things, Donald Norman)
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 Don’t be arbitrary, be consistent Simplify tasks Use appropriate constraints Design for error
13
Some Important Principles of Good Design (The Design of Everyday Things, Donald Norman)
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?” Don’t be arbitrary, be consistent Simplify tasks Use appropriate constraints Design for error
14
Some Important Principles of Good Design (modified from The Design of Everyday Things, Donald Norman)
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 Don’t 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)
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 Don’t be arbitrary, be consistent Simplify tasks (e.g., reduce programming
steps) Use appropriate constraints Design for error
16
SAFE
Lead Wires with ProtectedPins and Correct Connections
UNSAFE
Lead Wires with UnprotectedPins and Incorrect Connections
Protected Pins
Protected Pins
ElectrodeLead Wires
PatientCable
PowerCord
Monitor
Use only lead wires that have protected pins. Protected pins can not accidentally be plugged into power cords or electrical outlets.
From Patient
UnprotectedPins
From Patient
UnprotectedPins
Power Cord orExtension Cord
APPROPRIATECONSTRAINTS
FDA, Dec. 28, 1993
17
Some Important Principles of Good Design (The Design of Everyday Things, Donald Norman)
Some Important Principles of Good Design (The Design of Everyday Things, Donald Norman)
Make things visible Communicate clearly Provide correct and natural mappings Don’t be arbitrary, be consistent Simplify tasks Use appropriate constraints Design for error: (e.g., require
confirmation of critical actions)
18
Human Factors (HF): Critical in Nocturnal Home HemodialysisHuman 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)
*D’Amico&Bazzi, Home Hemodialysis, in Replaplacement of Renal Function by Dialysis, 1989, page 694
19
Clinical Incidents: Potential Nocturnal Home Issues?Clinical Incidents: Potential Nocturnal Home Issues?
Hazards always exist. Documented clinical post-market risks and adverse incidents (errors):
Midtreatment shutdown without warning =>clot/embolism risk
*ECRI Healthcare Product Comparison System, Sept. 2004; page 6
20
Clinical Incidents: Potential Nocturnal Home Issues? (continued)
Clinical Incidents: Potential Nocturnal Home Issues? (continued)
For 3 fault codes which indicate need for manual adjustment of transmembrane pressure (TMP) => not actually controllable. Recall. Solution: labeling *
If unit plugged into receptacle without ground fault circuit interrupter (GFCI) – with certain other conditions => overheating. Recall. Solution: labeling *
*ECRI Healthcare Product Comparison System, Sept. 2004; page 10 (HDA A5092, A5624)
21
Nocturnal Home Hemodialysis User NeedsNocturnal 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”)
22
Nocturnal Home Hemodialysis User Needs (continued)
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
23
Nocturnal Home Hemodialysis User Needs (continued)
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.
24
Nocturnal Home Hemodialysis User Needs (continued)
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.
25
Nocturnal Home Hemodialysis User Needs (continued)
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
26
Design of Hemodialysis Systems Requires Human Factors Engineering (HFE)
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
27
Introducing Human Factors (HF) Into Design: How Early?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.
28
Productdevelopment
Productmarketing
Productrelease
Breakevenpoint
Time
Cu
mu
lati
ve s
av
ing
s
0
a b
c
Early Introduction of Human Factors to Medical Device Design
29
ConceptPhase
DesignInput
DesignOutput Verification Validation
Literature
Complaints
Observation
Interviews
Tasks
Users
UseEnvironment
Standards &Guidelines
Drawings
Mockups
ComputerPrototypes
ExpertEvaluation
RapidPrototyping
Usability/HF Testing
ProductionUnits
Usability/HF Testing
PerformStudies &Analyses
DevelopRequire-
ments
DevelopSpecs.
Test OutputAgainst
Input
Test AgainstPatient &
UserNeeds
Applying HF is a Process:Human Factors Engineering Applying HF is a Process:Human Factors Engineering
30
Usability Study: Validation of Use InterfaceUsability 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)
31
Clinical Trials and Usability Studies: Complementary
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? ==>
32
Clinical Trials and Usability Studies: Complementary (continued)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
33
Human Factors Interaction:Manufacturer <==> FDAHuman Factors Interaction:Manufacturer <==> FDA
FDA HF Branch emphasizes PROCESS, not specific design features (usually).
Submit comprehensive description of HFE process early to FDA: ODE ==> Human Factors Branch
34
Submit comprehensive description of HFE process early to FDA: ODE ==> Human Factors Branch
Submit comprehensive description of HFE process early to FDA: ODE ==> 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
35
Human Factors Recommendations/Conclusion
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.
36
ADDITIONAL SLIDES FOLLOWADDITIONAL SLIDES FOLLOW
ADDITIONAL SLIDES
37
Sources of Design InputSources 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”)
38
Design Controls: HF implied in the design controls portionof the Quality System Regulation
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)
39
FDA Recognized StandardsFDA Recognized Standards
ANSI/AAMI HE74:2001, HF process standard (FDA-recognized)
ISO 14971:2004, Risk Management ISO/IEC alarm standard 60601-1-8,
1st edition
40
Guidance DocumentsGuidance 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