Saving Your Body (Ergonomic Design Considerations)

Eliot Siegel, M.D.Chief Imaging VA Maryland Healthcare SystemProfessor and Vice Chair University of Maryland School of Medicine Dept. Diagnostic RadiologyImaging Informatics National Cancer Institute

Introduction to Radiology Reading Room Ergonomics

• There has never been a more critical need for improved radiology reading room ergonomics than today

• Volume and complexity of studies is at an all time high

• Increasing numbers of radiologists are complaining of repetitive motion disorders, eye strain, neck pain, that in many cases are impairing their work and home activities

Ergonomic Model for Radiology?

Introduction

• Surprisingly little research in this area in diagnostic radiology

• This was the inspiration for our ergonomic “Radiology Reading Room of the Future” project

Baltimore VA Medical Baltimore VA Medical CenterCenter

PACS has been in operation more PACS has been in operation more than 14 yearsthan 14 yearsRadiologists reading Radiologists reading ““softsoft--copycopy”” using using computer workstations for 13 computer workstations for 13 ½½ yearsyearsHave had more experience with poor Have had more experience with poor reading room design for PACS than reading room design for PACS than any other facilityany other facilityInitial experience has allowed us to Initial experience has allowed us to share with others how share with others how notnot to design a to design a filmless reading roomfilmless reading room

The ChallengeThe Challenge

Completely redesign the old reading room Completely redesign the old reading room (approx. 23 x 23 feet or 532 sq. ft) to create:(approx. 23 x 23 feet or 532 sq. ft) to create:

Ergonomically optimized productive and low stress Ergonomically optimized productive and low stress environment for 5 radiology workstations (10 x 10 ft environment for 5 radiology workstations (10 x 10 ft space per reading area)space per reading area)Create an environment that allows the radiologists to Create an environment that allows the radiologists to collaborate easily yet minimizes distractionscollaborate easily yet minimizes distractionsCreate showcase for ergonomic room designCreate showcase for ergonomic room designCreate Create ““laboratorylaboratory””/research environment for study of /research environment for study of physical and cognitive ergonomic factorsphysical and cognitive ergonomic factors

Charette ProcessCharette ProcessConcentrated effort to solve an architectural problem

•Listen

•Envision

•Draw

Charette Process: Experts From Across the Country

MD’s: Eliot Siegel, Bruce Reiner, David Channin, Khan Siddiqui, David Weiss, Steve Horii

GE Project system engineer (Mark Morita), GE lighting, GE Acoustics, Environments Group (Schultz et al)

Ken Johnson

Charette Process

Room Layout

Single unpartitioned space was adequate in a film based environment because:

Film room next door would bring a cart with studies to be readNo partitions or special lighting requirements because conventional light boxes are sufficiently bright that glare is not a major problemThought we needed space for large number of clinicians who would review imaging studies

Room Layout SolutionRoom Layout Solution

Best solution for us was to create custom Best solution for us was to create custom spaces using partitions in shared reading spaces using partitions in shared reading room to encourage collaboration with room to encourage collaboration with other radiologists and cliniciansother radiologists and clinicians

Room design should allow radiologist can go Room design should allow radiologist can go into either into either ““independent studyindependent study”” when when necessary and collaboration mode when necessary and collaboration mode when requiredrequired

Initial Proposed Reading Room Plan Initial Proposed Reading Room Plan –– 532 Square Feet532 Square Feet Radiologists Thought Too Much Like Traditional OfficesRadiologists Thought Too Much Like Traditional Offices

Final Design: Hybrid of Final Design: Hybrid of ““CubiclesCubicles”” and Offices and Offices Maximizes FlexibilityMaximizes Flexibility

Each Room with Unique Ergonomic Approach Each Room with Unique Ergonomic Approach

MRI Scanning Room

Answer is dependent upon many variables.No one solution is best for everyone.

What is the best design for you?

Key factors to take into consideration:• Traffic flow (e.g. Teaching institution

different from private practice)• Number or radiologists• Areas where they work and/or have offices• Existing conditions and workflow• Available space and funding

Main RadiologyDepartment

Link to MOB

Start @1,000’ Height to Understand Existing ConditionsCourtesy: Kenneth Johnson and Associates, Inc

500’ View of Existing Conditions: All Persons Flow Past Secretary

Conclusions from initial assessment:1. Impossible to install 8 reading stations within Film Library2. Installing PACS Reading Rooms within existing offices.3. Rooms 4, 5 and 6 are very cramped.

Rad.

Admin .

Chair .

Sec’y .

Film Library1

54

6

2

3 7 8

Majority Of Studies Are Read Within Main Department• 1 – 6 double as offices, 7 and 8 shared by others, 9 is ED viewer

• Overall workflow within area is excellent

9

To gain consensus for design of individual PACS reading stations, a mockup was created involving radiologists, IT director and administration.

Mockup Actual Outcome

Room LightingRoom Lighting

Room LightingRoom Lighting

We have found subWe have found sub--optimal monitor optimal monitor brightness resulted in:brightness resulted in:

Increased radiology reading times Increased radiology reading times (radiologists are less productive)(radiologists are less productive)Decreased radiologist accuracyDecreased radiologist accuracyIncreased radiologist fatigueIncreased radiologist fatigueWill discuss in more detail in image Will discuss in more detail in image perception refresher courseperception refresher course

Interpretation AccuracyInterpretation Accuracy ““Clinically Significant FindingsClinically Significant Findings””

85%79%

74%

0%

20%

40%

60%

80%

100%

OffHalf OnOn

Overhead Fluorescent Lights in Overhead Fluorescent Lights in Old Reading RoomOld Reading Room

Controlled by on/off switchControlled by on/off switchSource of monitor glare and ambient lightSource of monitor glare and ambient lightNo dimmable controls or task lightingNo dimmable controls or task lightingSource of Source of luminance imbalanceluminance imbalance

Solution: Luminance Solution: Luminance BalanceBalance

Contrast discrimination is optimal when Contrast discrimination is optimal when levels of ambient light and computer levels of ambient light and computer monitor display are of similar intensitymonitor display are of similar intensity

Monitor luminance initially between 50 and 65 Monitor luminance initially between 50 and 65 ft. lamberts (under 200 cd/mft. lamberts (under 200 cd/m22) in 1993; we) in 1993; we’’ve ve migrating to LCD monitorsmigrating to LCD monitors

400 to 500 cd/m400 to 500 cd/m2 2 probably better for typical probably better for typical lighting conditions and brighter monitors improve lighting conditions and brighter monitors improve ability to perceive more shades of contrastability to perceive more shades of contrast

Past Mistakes: FatiguePast Mistakes: Fatigue

Upon transition to PACS, there was overall Upon transition to PACS, there was overall improvement in radiologist productivity by improvement in radiologist productivity by more than 40%more than 40%However, this was accompanied by However, this was accompanied by increasing complaints of fatigue and increasing complaints of fatigue and eyestrain using the computer workstationseyestrain using the computer workstations

Past Mistakes: FatiguePast Mistakes: Fatigue

Increased radiologist fatigue was felt to be Increased radiologist fatigue was felt to be multifactorial:multifactorial:

Decreased monitor brightnessDecreased monitor brightnessMonitor flickerMonitor flickerSmall cursor sizeSmall cursor sizeActive role required for image manipulationActive role required for image manipulation

Ambient room lightAmbient room light

Visual Fatigue and EyestrainVisual Fatigue and Eyestrain

Increased myopization found in Video Display Increased myopization found in Video Display Terminal operators working in excess of 4 hours Terminal operators working in excess of 4 hours per dayper dayEnvironmental factors with highest correlation Environmental factors with highest correlation with eye discomfortwith eye discomfort

Ambient lightAmbient lightMonitor luminanceMonitor luminance(Gobba et al. Int. Arch. Occup. Environ. Health 1988; (Gobba et al. Int. Arch. Occup. Environ. Health 1988; 60:8160:81--87)87)

Minimizing EyestrainMinimizing Eyestrain

Resting point of vergenceResting point of vergence (RPV)(RPV)Distance at which eyes converge (relax) in total Distance at which eyes converge (relax) in total darknessdarknessIt is typically about 45It is typically about 45”” when looking straight ahead when looking straight ahead and 35and 35”” with a 30 degree downward gaze anglewith a 30 degree downward gaze angleThe farther away from the monitor, the less eyestrainThe farther away from the monitor, the less eyestrainDistance from screen to eyes should be at least 25 Distance from screen to eyes should be at least 25 inchesinches (preferably greater)(preferably greater)http://www.officehttp://www.office--ergo.com/viewing.htmergo.com/viewing.htm

20/20/20 Rule:20/20/20 Rule:Every 20 minutes look 20 feet away for 20 secondsEvery 20 minutes look 20 feet away for 20 seconds

Lighting Lighting RecommendationsRecommendations

Dimmable controls and individual task lighting Dimmable controls and individual task lighting are preferred to allow are preferred to allow maximal flexibilitymaximal flexibility

New radiology room has PC controlled and New radiology room has PC controlled and programmable lighting programmable lighting

We use We use blueblue background light with a blue shade background light with a blue shade for the walls because it has been shown to have for the walls because it has been shown to have favorable effect on visual acuity and minimizes favorable effect on visual acuity and minimizes stressstress

Environmental ControlsEnvironmental Controls

Challenge: Ventilation and Challenge: Ventilation and HeatHeat

Old Radiologist reading room currently has Old Radiologist reading room currently has no controls for temperature, ventilation, or no controls for temperature, ventilation, or powerpowerNew room includes workstations with New room includes workstations with individual controls for each workstation individual controls for each workstation useruser

Temperature/Ventilation Temperature/Ventilation RecommendationsRecommendations

Provide individual controls for Provide individual controls for temperature/ventilation at each temperature/ventilation at each workstationworkstationSwitch from CRT to LCD monitors to Switch from CRT to LCD monitors to decrease heat dissipationdecrease heat dissipation

Carnegie Mellon Intelligent WorkplacIndividual

EnvironmentalControls

Ventilation and Temperature Controls: Ventilation and Temperature Controls: New Radiology Reading RoomNew Radiology Reading Room

Lack of Integration of Lack of Integration of Information SystemsInformation Systems

Previously information Previously information systems such as the systems such as the dictation system, PACS dictation system, PACS workstation, and workstation, and electronic medical electronic medical record (including erecord (including e--mail, Internet and mail, Internet and Office Suite), phone Office Suite), phone were separate unitswere separate units

Integration: SolutionIntegration: Solution

These functions These functions including speech including speech recognition should be recognition should be integrated into a integrated into a single computer single computer workstationworkstation

Acoustics

NoiseNoise

We did not consider noise at all in We did not consider noise at all in the design of old the reading roomthe design of old the reading roomIt was a major factor in the new It was a major factor in the new reading room especially due to reading room especially due to concerns about speech recognition concerns about speech recognition and proximity to the MRI scannerand proximity to the MRI scanner

Acoustics in Old Reading RoomAcoustics in Old Reading Room

Background noise from multiple sourcesBackground noise from multiple sourcesNo acoustic dampening devices/materialsNo acoustic dampening devices/materialsPotential impediment with migration to Potential impediment with migration to speech recognitionspeech recognition

Noise in Old RoomNoise in Old RoomComputer workstations generate a good deal of Computer workstations generate a good deal of noisenoiseRadiologists dictating or talking on the phone, or Radiologists dictating or talking on the phone, or clinicians discussing cases with radiologists or clinicians discussing cases with radiologists or other clinicians can also create a distraction to other clinicians can also create a distraction to the others in the roomthe others in the room

Acoustics in New Acoustics in New Reading RoomReading Room

The new reading room has sound absorbing The new reading room has sound absorbing materials and acoustic panelingmaterials and acoustic panelingA sound masking system generates A sound masking system generates ““noisenoise”” in in the general frequency range of human voice the general frequency range of human voice (also works to attenuate MRI scanning noise)(also works to attenuate MRI scanning noise)

Music and NoiseMusic and Noise

Music or white noise may have a positive impact Music or white noise may have a positive impact on productivity and may reduce fatigueon productivity and may reduce fatigue

One room has focused One room has focused ““beambeam”” of directed sound to of directed sound to allow radiologist to enjoy music/sounds without allow radiologist to enjoy music/sounds without disturbing othersdisturbing others

Impact of Ambient Noise on Impact of Ambient Noise on Speech Recognition AccuracySpeech Recognition Accuracy

Reading Room Furniture Reading Room Furniture including Tables, Chairs, etc.including Tables, Chairs, etc.

WorkstationsWorkstations

SeatingSeating

Furniture Ergonomics Furniture Ergonomics Issues in Old RoomIssues in Old Room

Lack of adjustable keyboards/monitorsLack of adjustable keyboards/monitorsLimited adjustability of chairs with lack of Limited adjustability of chairs with lack of lumbar supportlumbar supportImproper ergonomics results in:Improper ergonomics results in:

Eye strainEye strainFatigueFatigueLow back painLow back painOccupational repetitive stress disordersOccupational repetitive stress disorders

ErgonomicsErgonomics

Occupational repetitive stress disorders Occupational repetitive stress disorders well described in computerwell described in computer--related related workersworkersTwo common types of upper extremity Two common types of upper extremity compressive neuropathiescompressive neuropathies

Carpal tunnel syndrome (median nerve)Carpal tunnel syndrome (median nerve)Cubital tunnel syndrome (ulnar nerve)Cubital tunnel syndrome (ulnar nerve)

ErgonomicsErgonomics

Upper extremity compressive neuropathies Upper extremity compressive neuropathies in radiologists practicing in an academic in radiologists practicing in an academic filmless departmentfilmless department

4 cases of cubital tunnel syndrome4 cases of cubital tunnel syndrome1 case of carpal tunnel syndrome1 case of carpal tunnel syndrome(Reuss et al. ARRS 2001)(Reuss et al. ARRS 2001)

Ergonomics Ergonomics RecommendationsRecommendations

Chairs Chairs –– should have adjustable should have adjustable height/armrests with lumbar supportheight/armrests with lumbar supportKeyboards Keyboards –– should be adjustable in should be adjustable in height/position with keyboard traysheight/position with keyboard trays(Lincoln et al. Am J Prev Med 2000;18:37(Lincoln et al. Am J Prev Med 2000;18:37-- 50)50)

Ergonomics: AdjustabilityErgonomics: AdjustabilityErgonomics: AdjustabilityOptimal Viewing Distance = 24” to 36”

OptimalViewing Angle = 100 to 200

Position Monitor & Body Within Optimum ParametersPosition Monitor & Body Within Optimum Parameters

AdjustableAdjustableKeyboard Keyboard TrayTray& Monitor & Monitor BaseBase

Input DevicesInput Devices

Want to reduce stress while maximizing Want to reduce stress while maximizing efficiency for interpretation of imaging efficiency for interpretation of imaging studiesstudies

Methods and MaterialsMethods and Materials

Conventional 2 button mouseConventional 2 button mouse

Methods and MaterialsMethods and Materials

Game controllerGame controller

Methods and MaterialsMethods and Materials

Roller Mouse ProRoller Mouse Pro

Methods and MaterialsMethods and Materials

Up to 3 training cases were provided per device Up to 3 training cases were provided per device for each userfor each userEach device was programmed and mouse and Each device was programmed and mouse and keyboard shortcuts were mappedkeyboard shortcuts were mappedStandard instructional handouts were also Standard instructional handouts were also providedprovided

Function MappingFunction Mapping

Accuracy Accuracy –– Renal length measurementRenal length measurement

100.2 100.1 100.6 101.7103.7

101.9

50

60

70

80

90

100

110

120

Right Left

Conventional MouseGame PadRoller Mouse

p=0.987 p=0.794

mm

Interpretation TimeInterpretation Time

445.1 464.4

306

0

50

100

150

200

250

300

350

400

450

500

Interpretation Time

Conventional MouseGame PadRoller Mouse

Seco

nds

p=<0.001

Reading Spaces Swapped Out Over Reading Spaces Swapped Out Over Time Over TimeTime Over Time

Most Complex First to GoMost Complex First to Go

Poetic Technology

Miscellaneous Features of New Miscellaneous Features of New RoomRoom

Scented candles to appeal to the sense of Scented candles to appeal to the sense of smell which is increasingly recognized by smell which is increasingly recognized by retail stores and hotels and others as retail stores and hotels and others as being important to promote calm and being important to promote calm and pleasant feelingspleasant feelings

Meditation/Hypnotherapy RoomMeditation/Hypnotherapy Room

Productivity Productivity Improvement??Improvement??

Personalized SpacesPersonalized Spaces

Although radiologist workstations are Although radiologist workstations are shared would like to personalize the space shared would like to personalize the space (digital photographs in display), light and (digital photographs in display), light and furniture settings customized for user, furniture settings customized for user, dashboard on PC optimized for user dashboard on PC optimized for user preferences (e.g. stock market ticker, child preferences (e.g. stock market ticker, child care web cam, etc.)care web cam, etc.)

PrivacyPrivacy

Radiologists should be able to work in Radiologists should be able to work in environment that is open and that invites environment that is open and that invites collaboration yet be able to maintain collaboration yet be able to maintain privacy when appropriateprivacy when appropriateComputer controlled LCD privacy glassComputer controlled LCD privacy glass

ConclusionConclusionRadiologists are increasingly exposed to Radiologists are increasingly exposed to occupational stress especially as a result occupational stress especially as a result of the transition to the use of computer of the transition to the use of computer workstations from reading environments workstations from reading environments designed for filmdesigned for filmOur experience suggests that relatively Our experience suggests that relatively small investments in time and money can small investments in time and money can result in major reductions in stress and result in major reductions in stress and improvements in productivity and even improvements in productivity and even accuracyaccuracy

Reading Room and Reading Room and ErgonomicsErgonomics

Eliot Siegel, M.D.Eliot Siegel, M.D.Chief Imaging VA Maryland Healthcare SystemChief Imaging VA Maryland Healthcare SystemProfessor and Vice Chair University of Maryland Professor and Vice Chair University of Maryland School of Medicine Dept. Diagnostic RadiologySchool of Medicine Dept. Diagnostic RadiologyImaging Informatics National Cancer InstituteImaging Informatics National Cancer Institute