Medical Design project of Design & Engineering course. Autumn semester 2013/2014

1. 2014
Moving Patients!
Creating smoother transitions for immobile patients in the hospital
Kirill Andreitšuk
Fabien Bernard
Mart Kekišev
Patrick Mallon
Kerstin Oppe

3. Contents
profiles!
general brief!
regionaal haigla!
personas!
problem definition!
market research!
design brief!
concept sketches!
concept development!
concept selection!
prototyping & testing!
user feed back!
final design!
technical drawings
01!
02!
03!
05!
06!
07!
09!
10!
11!
12!
19!
22!
23!
25

4. Kerstin Oppe !
BA interior architecture & furniture design
kerstin.oppe@artun.ee
Patrick Mallon!
Bachelors of Architecture
pjmallon.blogspot.com
pjmallon@gmail.com
Fabien Bernard!
MEng of Mechanical Engineering, Design & Ergonomics
www.linkedin.com/pub/fabien-bernard/5b/57a/a33
fabien.bernard83@gmail.com
fabien.bernard@utbm.fr
Mart Kekišev!
Bachelors of metal art and design
artkek.carbonmade.com
mart.kek@gmail.com
!
!
Kirill Andreitšuk!
BSc (Bachelor in Science) in Mechanical Engineering, TUT,
Production Engineering and Product Development
k.andreitshuk@hotmail.com
2014!
01

5. GeneralBrief
The aim of the project is to understand and test how design can be used to bring forward a better
medical care in the hospital by approaching two subjects: patient safety and patient dignity
Patient
dignity
Patient
safety
Hospital environments are designed from
functional aspects to offer better treatment and
care. At the same time patients’ needs and
expectations for privacy, personal dignity and
comfort have received little to no attention.
Human beings make mistakes mainly
because the systems, tasks and processes
they work in are poorly designed. Mistakes in
hospital care are not unusual and could have
very serious effects.
The aim of the project is to make patients’ hospital
experience better by helping them feel less
vulnerable and more dignified in order to improve
the quality of care.
The aim of the project is to reduce number of
errors within hospital care, make them easier
to discover when they do happen and reduce
the harmful effects of errors that do occur.
!
work structure
01
research
02
concept generation
03
problem definition
04
embodiment design and prototyping
05
testing with patients
02

6. regionaal haigla
every workday…!
3700 employees will come to work!
1500 outpatient contact, incl. 250 emergencies!
100-300 hospital admission/discharges!
800-1000 patients treated as inpatients!
up to 200 operations performed
main !
entrance
Average patient staying time in the hospital: 5 days
ward floor plan
03

7. Students of TUT Design and
Engineering M.Sc. were invited
to under take observational
re s e a rc h a t P e r h H o s p i t a l
between the 19th and 23rd of
September 2013 in the aims of to
improving the areas of patient
safety & dignity.
hospital vision:
To be a recognised medical
centre in Europe
hospital mission:
To assure medical security to
the Estonian population and
health care system as a multiprofiled hospital providing acute
care. To be in the forefront in
teaching, scientific and
developmental work in medicine
and health care
After attending a lecture given by
the head surgeon we were
informed that one of the biggest
problems at the hospital was the
continual need to move patients
in and out of their beds and the
difficulty in lifting them of the
ambulance stretcher.
04

8. personas
We took our 2 personas from both ends of the process – a patient and a nurse. An important aspect
of this was to consider the behaviour and safety issues for both the performer and the passenger.
Patient – Heli 71
Nurse – Kristel 28
Heli was taken to the hospital because of
the severity of her joint pain. It has made
her very hard and painful to move from
her hips and legs. She is also in the
hospital to get chemo therapy. This has
made her a longer resident in the hospital.
Above all, she misses being outdoors to
see the sun and get fresh air instead of
being in the ward all day with closed
windows.
Kristel is a new worker in the hospital
and thus is just getting to know the
systems of that hospital. Her
assignments are helping the ward with
transporting patients from bed to
wheelchair and back and transporting
them to necessary locations.
Issues
Issues
Regardless of her good general health,
she has a high risk of back injury,
because the lifting and moving of
patients is done while her muscles are
not warmed up to be resistant for
strain. In these cases, it is quite easy
to hurt herself while lifting a patient in
a slightly wrong position. She would
normally require the help of a bigger
and stronger male ward assistant, but
he is not always available. Because of
this her shift at work is physically
exhausting.
what does she need?
05
We want to make her work in the
hospital safer. Our goal is to change the
heavy lifting of patients in a way that
it becomes effortless for her and
removes the most obvious possibilities
for her to hurt herself. This way, her
work will be easier and she will be less
tired at the end of the shift.
Currently she is transported around the
hospital on her bed. The bed needs two
assistants to move and takes a long time
to navigate the big thing in the hallways.
Putting her into a wheelchair is not an
option due to her incapability of moving
herself. She weighs about 90 kilos and
would need 2 assistants to get her to move
into the wheelchair.
What does she need?
We want her transport around the hospital
not to need two assistants and for the
whole process to be less space demanding.
In addition to that, her capability of
having progress in healing in any way is
clearly dependent on her getting daily
fresh air and sun, because it is healthy and
it makes her happy. Right now, that is not
possible, as it is not safe for her nor the
nurses to lift her into a wheelchair, and a
bed can not be transported outside. Our
goal is to make it possible for her.

9. problem definition
To explore current methods, cultures & technologies surrounding the lifting/moving of
patients in the hospital, to identify inefficiencies and to propose creative solutions.
?
“Patients are on average
moved 4-5 times a day”
Jüri Tera, MD, FACS
chief Oncological and General Surgical Centre
The need for patient-lifting equipment has grown in
recent years. “What is happening nationally is that
patients are getting older, sicker and heavier
Joan Forte, interim director of nursing at Stanford Hospital & Clinics
patient journeys
immobile
patient
examination
room
washing &
showering
procedures
&
operations
WC
“In a 2001 survey of some 5,000
nurses, 40 percent said they had
been injured on the job, and 60
percent cited disabling back
injuries as one of the culprits.”
American Nurses Association
patient
lounge
Outside
partially
mobile
patient
06

10. mobile patient lift
static patient lift
chair bed
bed chair
Sliding devices
07

11. market research
Research was conducted to determine the existence
of products that moved patients in and out of their
beds and around the hospital.!
!
An abundance of technological solutions were found
to exist, ranging from engineering marvels such as a
lifting robot donning a friendly bear exterior to a
simple draw sheet that is placed underneath
patients.!
!
massage chair
Some of the devices on the market hinted possible
dignity issues, (as what healthy individual is used to
being hung in a bag)!
!
Other observations included the apparently
awkward merging of technologies. A bed that could
transform into unlikely chair, and a chair that could
transform into an uncomfortable narrow bed, both
provided useful guidance to design a product that
was built from scratch for a specific purpose.!
!
The products which impressed us most were the
draw sheet, for its ease of operation and minimal
movement required of the patient, and other devices
which aided the sliding motion such as a hover mat.
We decided that this sliding motion would become a
core of our design.!
barbers chair
!
Additional inspiration was also sought from other
more static equipment, (massage chair, barber
chair) as they provided some of the most ergonomic
and smooth transitions. The obvious weight needed
to ground these contraptions provided early
concerns to whether we could engineer something
that was comfortable, safe and still light enough to
move around the hospital.!
!
Getting hands on with developing designs at
university (see below) provided useful insights, but
also reminded us that certain mechanisms were
protected under copyright.!
chair research
08

12. Design Brief
Making the transportation of patients throughout the hospital safer for nurses and more
comfortable for patients by improving the movement of the patients in and out of their ward bed.
concept
Reducing physical stress for
nurses & patients
With emphasis on the swiftness
& simplicity of the action
No forced movement
required by the patient.
To t r a n s f o r m t h e
transport from bed to
wheelchair safer for
patients and staff by
providing a device that
demands no forced
movements from the
patient and minimal
stress on the ward
assistant.
b2b - identified problems:
Aim of the research: !
To explore current methods, cultures & technologies
surrounding the lifting/moving of patients in the hospital,
to identify inefficiencies and to propose creative solutions.
!
!
!
!
!
•
•
(b2w) + (w2b) Bed to Wheelchair :
The moving of conscious mobility impaired patients from
their beds to wheelchair.
b2w - identified problems:
•
High numbers of staff required
•
High tech mechanical solutions
•
•
•
(b2b) Bed to Bed :
From the ambulance bed to the hospital/ examination bed
in accident and emergency scenarios.
•
•
•
Research for the moving of patients has been divided into
two main topics of enquiry:
!
!
!
!
!
Low tech lifting/moving solutions require many trained
staff
A degree of human error present and therefore patient
pain
09
•
High level of risk to patient due to lack
of information on the nature of injury.
!
!
!
!
!
!
High levels of Physical strength required
High number of staff required
High degree of training required
High level of risk of injury to both patient
and carers
High level of pain for the patient
Current technologies prohibitively
expensive and only designed for one
use

13. concept sketches
Strong arm
There was always the danger of creating an over
engineered mechanical monstrosity lightness of touch
was crucial
fabric + rollers + static frame
t
in
o
tp
vo
pi
searching forr a pivot point
a
o
f
ng
i
ch
r
ea
s
It was established early
on that piston
technology was a sure
way to make our
product unnecessarily
expensive and they
were consciously left as
a last option.
10

14. concept development
Most of the concept development
focused on how many pivot points were
necessary and where to place them.
!
We established from physical experience
that a 90 degree lifting motion from the
waist was uncomfortable for the patient,
as the head moved such a long distance
!
Wheel designs were considered of
secondary importance to transition
movement and were designed at a later
stage
11

15. concept selection
Stress deformation and technical details
General mathematical information!
In order to anticipate all necessary
equations for each prototype,
standard equations have been used.
!
Gravity Center!
All CAD model are integrated in a 3D
space, that is why, the gravity center
is considered according to the axles
X, Y and Z.
Prototype 1!
To simplify our mathematical model,
wheels and the brake system has not
been modelled. The main static part is the
support of the three pistons (and as well,
of the wheels).
!
1) First solution, Static deformation (only
in elastic area) in 90° wheelchair
position.Modelled by Catia (with Manikin
for having a real size in close relationship
with standard data) Mathematical model
and Stress deformation in mm (Von Mises
criteria) by Ansys
!
Safety coefficient: 2
Maximal weight of patient: 150 kg
Maximal load applied for this test: 3000 N
Materiel used: Aluminium
With
!
i = the name of the part
m = weight of the part
v = volume of the part
=density
This data is important for the
mechanical aspect but also for the
ergonomics aspect. Here, the human
characteristics is essential. In this
case, the mass ratio of the human
body has to be known.
12

16. 2) Second solution, Static deformation
(only in elastic area) in 130° wheelchair
position. Modelled by Catia (with Manikin
for having a real size in close relationship
with standard data) Mathematical model
and Stress deformation in mm (Von Mises
criteria) by Ansys
So:
!
Safety coefficient: 2
Maximal weight of patient: 150 kg
Maximal load applied for this test: 3000 N
-Leg part= 210N
-Seat part= 2500N
-Back part= 290N
Materiel used: Aluminium
With:
F=m.g
!
(g=9,81 m/s²)
Safety coefficient: 2
So:
For dimensioning the size of the pistons,
the system is simplified into 3 parts.
With: a=AB=300mm=0,3m
b=BC=460mm=0,46m
c=CD=950mm=0,95m
!
It is expected to find the Moment Force
(N/m) on the points A, B, C and D.
Immediately, the Moment Force in B is
equivalent to 0 because it is fix (this
mechanism turns around this point).
!
13
Conclusion!
In mechanics field, this solution works.
So, the dimensioning of these three
pistons, and the elbow part seems to
be a good mechanical solution. The
patient will have three possibilities:
!
-bed position
-wheel chair position (90°)
-Transition position (here, team has
decided to test a 130° angle (90+40)).
!
For the medical staff, the brake system
can be control by the treadle or the
hand system. The hydraulics system is
sufficient and gives an easily help
system to manipulate the patient with a
very effort.

17. Prototype 2
!
As it is precised before in this report,
the solution with piston has to replace
by a solution working only with human
force. With this condition, two others
idea and prototype has been imagined
and designed.
!
The prototype 2 looks like the prototype
1 but without non-automatic piston
(system cheaper, cleaner and with less
maintenance). Additionally, it works
with the famous rule of “the lever arm”
reducing the human force and allowing
to move a heavy patient. The following
pictures show an overview and the
autonomous pistons. The front wheels
are not represented to simplify the finite
elements analysis.
This following picture shows the human
weight repartition for each part (feet,
legs, seat, back and head).
The FEA has been carried out but with
the same structure, the deformation is
low and the system stays in the
medical standard. Some parts have
been removed and optimised.
!
Conclusion!
This solution could be interesting
because it gives the same
characteristics than before, but only
manually. It will be more simple to make
it and during the using, the nurse or the
patient will not have any problem for
use it.
14

18. Prototype 3!
This new prototype is radically different.
The size is the same but the
mechanism is different and also
adapted for the human force. It works
with a classic lever arm but with two
translations (explained afterward).
The following picture shows the
mechanism with two Translation/rotation
which are in close relation with the
central pivot.
!
The seat can rotate between 0° and
21,6° corresponding on the
comfortable standards. This solution is
autonomous, in other words, the
mechanism allow to control every part
by one part.
!
If the leg part (pink part) moves, the
seat part (blue part) and the back part
(green part) will move automatically.
But here, the green part will be the
point control and the motion of the blue
part and the pink part will be control by
this way.
This following picture shows the human
weight repartition for each part (feet,
legs, seat, back and head).
15

19. To control the motion!
This mechanism is interesting because
it could control by one point. Indeed,
with two translation/rotation and three
rotations, every parts is linked between
them. The motion of the Back part will
cause the motion of the seat part and
the leg part.
With the standards, we can take a
spring with k=20,01N/mm
!
!
1. By springs!
To control the motion, it is decided to
add two springs for both links
“translation/rotation”, so 4 springs in
total.
!
!
!
!
Determination of the Spring size:
It is remembered:
So:
2. By piston
!
This technical solution seems better
and mainly safer. We propose to
add one or two pistons on the back
part. It will be linked between the
top of the back part and the frame.
It will be a double acting and it will
give a safety condition for the
transition motion between the chair
and the bed position.
!
This characteristic is given by:
One piston version:
By safety, for both it will be chosen 20
N/mm
So:
With F=2310N
P=10 Bar=1N/mm²
!
To select the piston, we need the radius:
It will be necessary to use a piston
with a radius of 15,3mm and a
pressure of 10 Bar.
16

20. Locking part!
In order to lock our system in wheelchair position, we
have chosen the same mechanism used in a bus (for
example) with the elbow support. The following picture
shows you the principe between 0° and 180° but with
our system, it will work only between 0° and 21,6°.
general conclusion
As it was explained previously, the
prototype 3 has been chosen for few
reasons.
!
-the mechanism and the kinematic are
not the most simple but the system
uses only one piston (or two, depends
on the space available).
!
-the reduction of the help systems (like
piston, electric devices etc) allows to
keep the light weight.
!
-the reduction of the pneumatic or
hydraulic system is in correlation with
the hospital environment
!
!
-the cost of the maintenance will be
low
-the production will be simple because
it limits the waste of material and the
shape is classic (weld system).
!
Ergonomics
This part is essential, again more in a hospital
environment. Take in consideration the human factor
allows to optimize the system during the designing and
the virtual production.
This system is thought to optimize the comfort of the
patient, the medical staff but as well for the hospital
environment with the dimension of the room, the corridor
and every displacements.
!
Bed position!
The medical staff can move and walk without any
difficulty and the patient has enough place on the bed to
feel comfortable.
17
-the ergonomics part has been
optimize for the patient, medical staff
but for the hospital environment as
well.

21. Free wheely
1st iteration
18

22. prototyping & testing
Aluminium was our preferred material, but steel is much easier to weld
Lifting motion
its possible to go from flat to sitting to flat with very little effort while laying on it
19

23. prototyping & testing
proof of concept
The form is slightly suggestive of a capable four legged animal
connection details
20

24. Second iteration
the system appears ready for the patient to be slid over the support rails
simplified joints and locking mechanism on the proof of concept prototype
The handle now visible beneath the plywood
21

25. user feedback
lessons learned
Things we learned from prototyping
No major systems were changed, for
the main concept of the mechanism
worked in practice. The prototype was
made of the joints we had on the spot
and could make up ourselves, but in
the real life, some simple additions like
ball bearings on the frame rolls will
make it move considerably swifter with
l e s s f r i c t i o n w h e n m o v e d f ro m
horizontal to seat position.
behavioural changes
What was beautiful in our discoveries
is how the wheely lifts the patient eye
height up to almost a regular persons
shoulder. This changes the whole
experience of being transported
around and interacting to people. The
patient is no longer at hip height, as
they would be in a bed or a wheelchair,
but at a more accessible height that
other people can more easily
communicate with. The behavioural
change is evident from the early test..
22

26. The perfect ward assistant
Free wheely works in conjunction with a draw mat, or other patient sliding device, to efficiently
slide a patient from the lying position on bed to Free wheely, once there the nurse can release the
locks and the patient will be smoothly assume a commanding upright position ready to be moved
around the hospital in comfort. Once there the process is reversed to complete a safe transition.
23

27. Lifting patients using the Free wheely to the sitting position
(and visa versa) requires almost no effort from the nurses or
patients and wheeling it around is just like any other device
or baby stroller. Using this device, a patient who may have
had to stay in their beds can now be easily transported
around the hospital and possibly even outside to benefit
from the healing benefits of fresh air and sunshine.
Free wheely
cushioned seat, faux leather
potential !
IV drip post add on
leg rest support fixed !
to the frame for stability
nurse handle
patient hand rest,!
thermo treated oak veneers
24

28. 1
237
110°
116°
1970
105°
247
1429
3
2
46
78
684
Preliminary Drawing - Not Issued for production
588
25
46
68 °
ISO drawing method "E"
Department of Mechanical Enginnering
Drawn:
K. Andreitshuk
Supervisor
Date
13.01.2014
Tallinn University of Technology
Sheet
1/1
Mass (Item)
30,382 kg
47,079 kg
7,488 kg
Quantity
1
1
1
Scale Weight
1 : 10 84,9 kg
FW0001.GA
Free Wheelie General Arrangement
Drawing Number
Title
Tolerance
u.o.n. ISO 2786-mK
Title
Vertical Position (1:20)
Sitting Position (1:20)
Item Number
Document Number
1
FW0001.0001
Frame
2
FW0001.0003
Slider
3
FW0001.0002
Handle
Material:
1061
155
°

29. 26
1
570
2
25
25
3
110°
25
84,5
62
25
84,5
4
116°
25
1970
25
1770
105°
234,5
184
78
8
7
155
°
101
880
198
5
25
175
30
44
53
10
9
Quantity
1
1
ABS Plastic, high impact
Steel, structural
Acrylic, high impact grade
SKF Bearing Unit
Shaft
Bracket
SYK-20-TF
FW0001.0003.06
FW0001.0003.01
Bolt
DIN933 A2 M10x25
Material:
7
8
9
10
Department of Mechanical Enginnering
K. Andreitshuk
Drawn:
Supervisor
13.01.2014
Date
Tallinn University of Technology
Sheet
1/1
1
Assembly
FW0001.0003.03
6
ISO drawing method "E"
3
ABS Plastic, high impact
Head Plate
FW0001.0003.08
5
FW0001.0003
Free Wheelie Slider
Drawing Number
Title
Tolerance
u.o.n. ISO 2786-mK
2
Scale Weight
1 : 10 47,1 kg
1
6
ABS Plastic, high impact
Torso Plate
FW.0001.0003.05
4
A2
1
ABS Plastic, high impact
Shit Plate
Hip Plate
FW0001.0003.07
Assembly
Hinge
FW0001.0003.04
2
3
1
8
Material
ABS Plastic, medium impact
Title
Foot Plate
Document Number
FW0001.0003.02
1
Item Number
Preliminary Drawing - Not Issued for production
6
220
136
130
40
1477
659

30. 27
5
4
2
578
67
120°
256
7
8
A
A
SECTION A-A
10
674
574
11
6
u.o.n. Butt
3
2
2
a3
445
Main Beam
Title
3
Shim
Right Holder
Left Holder
Bolt
Mid Holder
Handle Holder
Material:
6
7
8
9
10
11
ISO drawing method "E"
Castor
5
Mid Beam
Small Leg
2
4
Big Leg
1
Item Number
223
306
266
178
77
Drawn:
K. Andreitshuk
welds Supervisor
Date
13.01.2014
Tallinn University of Technology
Preliminary Drawing - Not Issued for production
Department of Mechanical Enginnering
u.o.n. Corner welds -
120
°
244,5
60
B
9
1
,5
243
S355J2R
A2
S355J2R
S355J2R
Plastic
AISI316
AISI316
AISI316
AISI316
AISI316
Sheet
1/1
2
32
2
2
4
4
2
2
2
2
Quantity
2
Scale Weight
1 : 10 30,4 kg
FW0001.0001
Free Wheelie Frame
Drawing Number
Title
10
213
Material
117
50
FW0001.0001.02
S355J2R
Tolerance
u.o.n. ISO 2786-mK
FW0001.0001.05
DIN933 A2 M10x25
FW0001.0001.03
FW0001.0001.06
Tente D150
FW0001.0001.07
Tube 50x50x2
FW0001.0001.08
FW0001.0001.01
FW0001.0001.04
Document Number
VIEW B
234
419
428

31. 28
3
a3
u.o.n. Butt
1
2
2
2
a3
FW0001.0002.01
3
ISO drawing method "E"
Fw0001.0002.03
2
Material:
FW0001.0002.02
Document Number
50
1
Item Number
500
Drawn:
K. Andreitshuk
welds Supervisor
Date
13.01.2014
Tallinn University of Technology
Preliminary Drawing - Not Issued for production
Department of Mechanical Enginnering
u.o.n. Corner welds -
SECTION A-A
a3
653
574
474
20
20
Sheet
1/1
Axis
Grip
Beam
A
A
S355J2R
S355J2R
AISI316
FW0001.0002
Free Wheelie Handle
Drawing Number
Title
1
1
2
Quantity
Scale Weight
7,5 kg
1:5
Material
Tolerance
u.o.n. ISO 2786-mK
Title

32. aitäh