Standards for Accessible Medical Diagnostic Equipment

Transfer Examples

[Video: 30 second video showing a woman transferring from her wheelchair to an exam table with no 

assistance, a woman transfer from an exam table to her wheelchair with minimal assistance and a young 

man being transferred from his wheelchair to an exam table.]

Transfer Surface Size

[Photo: Slide contains two illustration, one of an exam table with the transfer surface highlighted 

showing 30 inches wide minimum and 15 inches deep minimum and the other of an exam chair with the 

transfer surface highlighted showing 21 inches wide minumim and 15 inches deep minimum.]

M301.2.2 Size

M302.2.2 Size

Two distinct requirements for each equipment category – difference as proposed is width

M301 Diagnostic Equipment Used by Patients in Supine, Prone, or Side-Lying Position

[Photos: Slide contains two photographs, one of the Access Board Executive Director and Board 

Members looking at imaging equipment and the other of an exam table.]

May not have back support.

ANSI/AAMI HE75

[Photo: Picture showing the cover of ANSI/AAMI HE75:2009 Human factors engineering design of 

medical devices document.]

16.4.7 Contact surfaces

e) The support surface should be wide enough to enhance patient safety and comfort.

“For platforms on which patients lie down, patients should be able to roll to a side or prone 

position with minimal need to lift and shift their center of gravity. For example, a standard 

exam table is approximately 27 inches wide and a bariatric table is approximately 30 to 32 

inches wide, but a wider surface makes repositioning easier to accomplish.”

30” wide min. and 15”deep min.

[Photo: Illustration of the lower end of an exam table with the transfer surface highlighted showing 30 

inches wide minimum and 15 inches deep minimum.]

Width is based on comments by the Disability Rights Education and Defense Fund (DREDF) in 

response to DOJ’s ANPRM on equipment and furniture.

Generally consistent with the dimensions for rectangular seats in roll-in showers in the 2004 

ADA and ABA Accessibility Guidelines.

30” wide min. and 15”deep min. 

[Photo: Slide contains three illustrations of figures from the ADA/ABA Guidelines; figure 608.2.2 which 

depicts the standard roll-in type shower compartment with size and clearance measurements, figure 

610.3 (a) which depicts the 3 inch maximum distance allowed between the shower compartment entry 

and the shower seat and figure 610.3.1 which depicts the required size and location of the rectangular 

shower within the shower compartment.]

Seat sizes in widths of 26”, 28” and 30” for minimum size shower – 14.5” and 15” deep.

M302 Diagnostic Equipment Used by Patients in Seated Position
[Photos: Slide contains two illustrations. One is a photograph of an exam chair with headrest, armrests 

and footrest. The other Illustration is of person transferring from wheelchair onto an exam chair. This 

illustration is taken from the “Example Applications of the Proposed Medical Diagnostic Equipment 

Accessibility Standards” document.]

Differences from “tables”.

21” wide min. and 15”deep min. 

[Photo: llustration of an exam chair with the transfer surface highlighted showing 21 inches wide 

minimum and 15 inches deep minimum. ]

Width is based on the ideal chair width recommended in Architectural Graphic Standards for 

auditorium seating. 

Depth is generally consistent with the dimension for rectangular seats in roll-in showers in the 

2004 ADA and ABA Accessibility.

Transfer Surface Research 

• No research directly addresses

• Do have sources of anthropometric data

Anthropometric Data 

[Photo: Illustration of Anthropometric data from Dreyfuss, The Measure of Man & Woman showing seat 

depth for different size adults.]

Concerns about 15” min. depth:

The Measure of Man & Woman (Henry Dreyfuss Associates, 2002)

Seat Depth:

16 inches – all adults

20 inches max. – for lounge or leisure or tall adults

Anthropometric Data 

[Photo: Midmark illustration showing a 50 percentile male transferred onto an exam chair with the a 

transfer surface of 30 inches wide and 15 inches deep.]

Concerns about 30” min. width:

Distance required to reach supports

Reference to 50th percentile male from The Measure of Man & Woman (Henry Dreyfuss 

Associates)

Anthropometric Data

[Photo: Midmark illustration showing a 50 percentile male transferred onto an exam chair with the a 

transfer surface of 30 inches wide and 15 inches deep. The 30 by 15 inch transfer surface is highlighted 

in purple with a 28 inch wide highlight superimposed over it.]

Concerns about 30” min. width:

28” minimum width proposed

Reference to 50th percentile female from The Measure of Man & Woman (Henry Dreyfuss 

Associates)

Anthropometric Data

[Photo: An illustration of a page taken from “The Rules of Work” by Author Dan MacLeod showing a

table giving anthropometric data for male and female adults.]

29” min. width proposed
21” seat width plus 8” for 2 hands

The Rules of Work (Author Dan MacLeod , 2000)

95th Percentile Male:

Hand Breath – 3.9 inches

Hip Breath – 16.1 inches

16.1 + 2 x 3.9 = 23.9

Note differences from female

Anthropometric Data

[Photos: Slide contains two illustrations. One is an illustration showing measurements for a 90 

percentile man. The other Illustration shows measurements for the hand of a 90 percentile man.]

The Measure of Man & Woman

95th Percentile Male:

Hip Sit – 16.9 inches

99th Percentile Male:

Hand Width – 4.6 inches

16.9 + 2 x 4.6 = 26.1

Anthropometric Data

[Photo: An illustration of a page taken from the Wheeled Mobility Anthropometry Project showing clear 

floor space requirements.]

www.udeworld.com/anthropometrics.

Wheeled Mobility Anthropometry Project:

• Anthropometric data on people who use mobility devices

• Includes many relevant dimensions

• More detailed presentation following

No Heading

[Photo: Illustration showing both the forward and side views of a person seated in a wheelchair.]

Dimensions Analyzed

A: Thigh breadth bi-lateral

B: Bi-deltoid (Shoulder) breadth

C: Posterior seat to popliteal length

D: Seat depth

No Heading

[Photo: Illustration of a box-plot showing the distribution for thigh breadth stratified by gender and 

mobility device type. The horizontal line splitting the box depicts the median, the box length represents 

the inter-quartile (25th – 75th percentile) range, and the whiskers represent the minimum and 

maximum values. Extreme values are shown as dots and asterisks. The red dotted lines depict the 

observed range of 95th percentile values across sub-groups.]

No Heading

[Photo: Illustration of a box-plot showing the distribution for shoulder breadth stratified by gender and 

mobility device type. The horizontal line splitting the box depicts the median, the box length represents 

the inter-quartile (25th – 75th percentile) range, and the whiskers represent the minimum and 

maximum values. Extreme values are shown as dots and asterisks. The red dotted lines depict the 

observed range of 95th percentile values across sub-groups.]
No Heading

[Photo: Illustration of a box-plot showing the distribution for approximate buttock-popliteal length 

stratified by gender and mobility device type. The horizontal line splitting the box depicts the median, 

the box length represents the inter-quartile (25th – 75th percentile) range, and the whiskers represent 

the minimum and maximum values. Extreme values are shown as dots and asterisks. The red dotted 

lines depict the observed range of 95th percentile values across sub-groups.]

No Heading

[Photo: Box-plot showing the distribution for approximate wheelchair seat depth stratified by gender 

and mobility device type. The horizontal line splitting the box depicts the median, the box length 

represents the inter-quartile (25th – 75th percentile) range, and the whiskers represent the minimum 

and maximum values. Extreme values are shown as dots and asterisks. The red dotted lines depict the 

observed range of 95th percentile values across sub-groups.]

IDeA Center Memo Conclusions

1. Proposed minimum width of 30 in. provides sufficient space for almost all individuals in sample 

based on static measurements. Could be reduced to 28” and still accommodate 95%.

2. Width of 30” would also accommodate the shoulder breadth of most individuals. Reducing 

width to 28” would still accommodate 95% of sample.

3. Increasing minimum width is recommended for individuals that are morbidly obese and/or use 

bariatric wheelchairs if also a priority. Reference maximum values recorded for thigh and 

shoulder breadth.

4. Depth of 15” for a seating surface found suitable based on median values of buttock-popliteal 

length and wheelchair seat depths.

5. Results reflect static anthropometry measurements and are a starting point. User testing is 

recommended for arriving at more accurate transfer surface dimensions and design.

Considerations 

• What Data sets to use?

• What gender and percentile would be a good benchmark?

• How much to extrapolate from “static” anthropometric dimensions?

• Balance between the use of different equipment features?

• Multiple recommendations?