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

1. BATHROOM IN THE HOSPITAL
Project of Autumn Semester 2013/2014
www.design-engineering.ee

3. CONTENTS
Our team and our tutors 4
Introduction 5
First visit to the hospital 5
Current situation 7
Actions to do in the bathroom 8
First presentation 10
Concepts 11
Ergonomics considerations 16
Materials used 20
Toilet seat 21
Water tap + air dryer 22
Sliding door 23
Concept 3D pictures 24
Rapid prototyping 28
Technical drawings 29
Thank you 30
3

4. OUR TEAM
Helena Veidenbaum
2nd year D&E student
BA interior design
Chen Zhang
2nd year D&E student
BSc industrial design
Pierre Herry
2nd year Ergonomics,
Design & Mechanical
Engineering student,
Erasmus exchange
student
Constant Charveriat
2nd year Mechanical
Engineering and
Design student,
Erasmus exchange
student
Jonas Koch
2nd year Mechanical
Engineering student,
Erasmus exchange
student
OUR TUTORS
Martin Pärn
Estonian Academy of
Arts, head of Design &
Engineering
4
Janno Nõu
teaching assistant,
Designer at Iseasi
Henrik Herranen
Tallinn University of
Technology

5. INTRODUCTION
Our development project this semester is medical design project that is being done in cooperation
with North Estonia Medical Center (Põhja-Eesti Regionaalhaigla) and we are concentrating on the
fields of patient safety and patient dignity. From the field research of observations and interviews
that we carried out in small teams in the hospital, we found several issues that could be improved
both from the patients and nurses point of view.
Our team of 5 students is concentrating on improving bathroom inside the hospital, while giving
more independence to the patients and reducing the workload of the hospital staff (nurses and
ward assistants).
On the following pages of this project report you can read about the development process of our
bathroom project. We hope that dealing with these socially important issues can raise the awareness and importance of the work in this field.
FIRST VISIT TO THE HOSPITAL
On the 17th of September, we met the hospital staff for the first time and we were given a presentation about the hospital and the Estonian health care system. We were informed about the
on-site situation (current construction work taking place) and our attention was drawn on special
features of the North Estonian Medical Center.
On the same, the third week of September, we were meeting in small groups in the hospital where
we went to different departments to get a firsthand experience about life in a hospital and to get
the chance to watch doctors and nurses doing their job. This visit made it also possible to look at
hospital equipment and how the employees use it. Due to the fact that none of us was familiar with
the internal handling and procedures in hospitals before, we had a strong interest in observing
workflows and routine jobs to discover weak points and to identify their causes.
Lots of procedures and local conditions that we found in the hospital attracted our attention. We
found it striking and astonishing that there was very bad lightning in most of the rooms. Due to
that, the blinds had to be opened all day to take care of the patients even though there were constructions going on outside of the building and the workers were working just next to the window.
During the discussions with the nurses we found out that the lighting issue causes lots of problems
if a patient needs to be medicated or treated at night time.
The size of some of the patient rooms was another point that we identified as a week point. The
lack of free floor space created the problem that the bed of the patient who was closer to the door
had to be rolled out of the room before they were able to roll out the second patient, who had to be
rolled out of the room with his/her bed in the first place.
Due to the renovations that were going on in the hospital, lots of boxes and other things were just
standing around in the corridor. All these things were potential tripping hazards for patients as well
as for employees.
We discovered the fact that the alarm system was just displaying the whole room and not the specific patient to be problematic as well. It could be that the nurse or assistant don’t understand 5

6. right away who needs their help and they may loose essential seconds saving someone’s life.
The stand for infusions attracted our attention. We noticed that all the handles were laid out only
for right-handed people which made it awkward for left-handed people to use it.
Also, a lot of nurses had problems using the drug cabinet. The top shelf was hard to reach for
them and due to the fact that lots of liquids were stored there the single shelves were quite heavy.
Once the shelves were pulled out, it tilted down by about 30 degrees to improve reachability. The
problem was that some of the products fell out of the shelf under that angle.
Some of the bathrooms got our attention, because there were no showers inside, which means
patients had to share bathrooms with other rooms (more patients per one shower room). The
washing wheelchair that we saw in the bathroom seemed cold, unfriendly and uncomfortable to
use both for the patient and assistant. By observing, it looked like the chair itsself takes longer
time to wash than the patient.
In summary it can be said that we spent a very interesting day in hospital which helped us a lot for
the rest of this project.
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7. CURRENT SITUATION
We learned about the situation of one ward assistant per 22 patients, so the work of the ward assistant can become complicated very easily.The patients have to wait for the assistant for approximately 10 minutes, whatever their problem or issue may be. And it could be that this issue can’t
wait that long, but it only gets worse. Putting aside the happiness of patients being cured, they still
give away a piece of their pride and dignity while they are feeling helpless along the way in getting
better.
Duties of a ward assistant/helper:
- Bathes, grooms, shaves, dresses, and/or drapes patients to prepare them for surgery, treatment
or examination
- Measures and records intake and output of liquids, takes and records temperature, pulse and
respiration rate, report changes to professional staff (nurses, doctors)
- Gives enemas
- Administers catheterizations and bladder irrigations
- Collects specimens such as urine, feces, or sputum
- Provides patient care by supplying and emptying bed pans, applying dressings and supervising
exercise routines
- Carries meal trays to patients and feeds patients who are unable to feed themselves; collects
food trays after meals
- Lifts patients onto and from bed, transports patients to other areas, such as operating and x-ray
rooms, by rolling bed, or using wheelchair or wheeled stretcher
- Sets up equipment, such as oxygen tents, portable x-ray machines, and overhead irrigation bottles
- Cleans rooms, makes beds and collects soiled linens, change linens
- Bathes deceased patients, accompanies body to morgue, and places personal belongings in
mortuary box
- Works as part of a medical team that examines and treats clinic outpatients
- Provides patients with help while walking, exercising, and moving in and out of the bed
- Turns and repositions bedridden patients, alone or with assistance, to prevent bedsores
- Answers phones and direct visitors
- Delivers messages, documents and specimens
- Explains medical instructions to patients and family members
- Maintains inventory by storing, preparing, sterilizing, and issuing supplies such as dressing packs
and treatment trays
- Performs clerical duties such as processing documents and scheduling appointments
From this (not fully comprehensive) list you can see that all of the assistants, helpers and nurses
are very busy all day long. As we identified the current bathrooms to be something which patients
can’t use without the help of the ward assistant, then we decided to concentrate on re-designing
the bathroom for hospital in a way, which could give more privacy and independence to the patients, so they could use bathroom by themselves and hence feel more dignity in different bathroom related activities. In adition, we would ease and reduce the workload of the hospital staff.
This would hopefully increase the number of active patients who can manage their daily activities
in the bathroom by themselves.
To go further, we indentified different actions which people do in the bathroom, as well as several
types of patients who are using the bathroom and this was the starting point for our project. We
mapped steps in washing hands, taking shower and going to the toilet which is presented in the
schemas on the following pages.
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8. Actions to do in the bathroom:
Showering
Washing
hands
Bio needs
Brushings
teeth
Sampling
Taking
medication
dress up
Extra uses
(phone call)
Paralyzed
people
Can’t
walk
Sick and
weak
people
Wheel
chair
users
Type of
patients
Visually
deficient
Do you need kneel?
Do you need to grab
something to be stable?
Do you need to clean the sit?
Biological needs
(before/after)
Man
Standing
up
Woman
Showering
Siting
vomiting
Pulling the
flush
How?
Alone?
In a wheel chair?
How to lock it?
Automatic?
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Accessibility?

9. Washing hands
Water
T°/
pressure
Reaching
the sink
Turning
on the
light
Get the
soap
Drinking
water ?
Drying
your
hand
TOWEL?
Is it the same than the one for
showering?
Hand
sanitazer
Where is it? Easy to access?
How/where does it dry?
HANDS DRYER?
Turning on the light??
Temperature?
Height (accessibility?)
PAPER?
Easy to pull/ rip?
Trash bin?
Accessibility?
Where do you put your
clothes?
Adjust the T°/ power of the
shower?
Dirty clothes?
Washing difficult areas
(leg back)?
Taking the
shower
undress
Getting
into the
bathroom
Washing
liquid
Bringing
stuff back
to room
Drying
yourself
Puting
your
clothes
Going back
to the
room
How to catch the towel?
How to dry all your body?
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10. FIRST PRESENTATION
On Wednesday, 23rd of October, we met at 10am in the North Estonia Medical Center to give our
first presentation about the bathroom topic we had been dealing with over these last few weeks.
We started off with giving feedback to the hospital equipment where we pointed out that it is hard
for several groups of people to use the bathroom on their own. We found out that a lot of the
equipment was not geared to the target groups and therefore the functionality was not ensured.
That is where we saw our goal right from the beginning. We wanted to design a bathroom that provides patients with more privacy and independence, at the same time we wanted to ease helper’s
and nurse’s job. This goal includes the increased security of the bathroom devices. Summarizing
the above, we wanted to increase the number of active patients allowing them to be independent
without the help of other people. To progress towards that goal, we defined all groups of people
using a hospital bathroom and we defined all activities that are done there. This step helped us to
focus on the functions that we had to focus on. We identified and pointed out weak points in the
existing bathroom.
Subsequently, we presented
additional ideas that we wanted
to integrate into our project as
well, like wheelchair accessible
storage space or sensor controlled lights. We concluded our
presentation by showing our
primary idea on how the bathroom could look like. The top
view of this bathroom is depicted in figure 2.
The idea for this concept was
to integrate foldable walls into
the bathroom that makes it
possible for nurses to enter the
bathroom with a patient’s bed
and therefore reduce patient’s
movement. Special needs like
the turning circle of a wheelchair user were taken into
consideration as well.
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11. CONCEPTS
The idea here is to have three blocks representing the three main functions of the bathroom:
a cleaning part, a toilet part and a storage part. It’s aimed to answer the needs of weak patients or
those unable to move out from their bed by having a mobile bathroom wherever they need,
because this bathroom can move through the whole room. These blocks are independent and can
be moved separately to the bathroom to be cleaned.
Advantages:
- Allow a proximity to the patient’s bed,
easily reachable
- Independent, mobile blocks to organize
the space
- Easy cleaning by moving each one to
the bathroom
Disadvantages:
- Privacy issue if the patient isn’t alone in
the room
- Odor occurring, hygiene problems
- No shower, just basic cleaning
Movable blocks along the wall can be another great feature as it allows the bathroom to be totally
adaptable depending on the patient’s condition.
Advantages:
- Quick space organization
- Customizable environment
Disadvantages:
- Can end up to be an expensive feature
- Can lead to safety issues
11

12. The idea here was to have a direct access from the sleeping room to the bathroom, to ease the
transition between both rooms for the patients. Also, once in the bathroom side, the seat helping
the transition could be the place from where the patient cleanses himself.
Advantages:
- Direct and easy access
- Doesn’t require much effort
Disadvantages:
- Technically complex
- Thus, expensive
- Can create safety issues
- Access for beds / wheelchair users
limited / difficult
Usually, a patient goes to the bathroom for one specific purpose. Here, the different activities in the
bathroom are separated so the patient can choose what he wants to do among the main functions
of a bathroom (shower, wash hands or brush teeth using the sink, going to toilet or using storage
area to put away some of his stuff). Choosing the preferred activity rotates the unit to the required
position.
Advantages:
- Simplification of the uses of the bathroom
- Save space
- New experience
Disadvantages:
- Cleaning
- One activity at once
- Technically complex
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13. To bring an atmosphere reminding the patients something they know well and thus make them feel
comfortable, this idea tries to create a “sauna-like” ambience of a bathroom. A bench (wood imitation) which runs along the walls is equipped with a movable seat. It allows the patient to go easily
from one point of the bathroom to another without standing up.
Advantages:
- Creates a familiar atmosphere (sauna)
- Easy displacement in the bathroom
- Allows the nurse to help efficiently
Disadvantages
- Privacy, everything is connected
- Lack of space adaptation
- Movable seat can be uncomfortable
Helping the process of being washed can be a great feature, especially for people too weak to
wash themselves efficiently without getting overly tired. This idea is about being washed by sitting
comfortably, waiting for the water-shoot to spurt out from the water orifices. The seat is composed
in a net/grid, allowing water to go through in order to clean every part of the patient’s body.
Advantages:
- Comfort, taking a shower without effort
- Adjustable to different heights
- Efficient and relaxing cleaning
Disadvantages:
- Technically complex
- Safety issue (including automatic system
in a very humid environment)
- Cleaning problem
13

14. Creating a bench that would be supporting and helping patients to move autonomously inside the
bathroom by leaning on the bench was other concept idea we had. We imagined to create shower
area with a movable curved shower wall and again sauna and spa references arose. This concept
is wheelchair and walker accessible with flowing smooth surfaces offering enjoyable journey inside
the bathroom. Using wood imitation materials creates special atmosphere that would help patients
in healing processes. Through half-transparent sliding door it is visible if the bathroom is occupied
or not and lights go on and off according to patients’ motions in the bathroom.
14

15. After having all the concept ideas on the table, we decided to pick the last concept idea for further
development. Having sauna-spa references arose for the second time in the concept creation
phase, we figured we should give it a shot. As our main goal was to improve privacy of the patients
who are going to the bathroom by giving them more independency, we found the bench to be useful for them to fill this purpose. Creating the sauna-like bench for patients to lean on while walking around the bathroom was our starting point of creating several 3D models to find out which
shapes, forms and sizes to use. Keywords to describe the concept were the following:
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16. ERGONOMICS CONSIDERATIONS
One of the important features of our project is the toilet seat. It has to be adaptable so everyone
can both easily sit and stand up. Several dimensions have to be taken in account for the seat to
respect ergonomics precepts.
Usually in chairs or toilets design, dimensions are made to accommodate the hypothetical 50th
person. However here, our goal is to make the toilet sit accessible for ideally everyone, especially
in this hospital environment where people suffer from various conditions.
It is chosen to answer the need of the 5th-percentile female to the 95th-percentile male (excluding
the 10th the least “similar” of the population).
The standards are taken from the Belgian population in 2005. It can assimilated to the Estonian
population as it represents a mid / northern European population.
The three main dimensions needed here are the popliteal height (1) to determine the toilet height,
the buttock-popliteal length (2) to determine the toilet depth, and the buttock height (3).
16

17. For more clarity, 1st, 5th,95th, 99th percentiles and the mean values are indicated.
Thus:
- the height in “sit position” has to be adjustable between 399mm & 499mm;
- the height in “stand up position” has to be adjustable between 721mm & 913mm;
- the depth of the seat has be to between 448mm & 545mm.
GAS SPRING SIZING
It’s essential to dimension correctly the gas springs of the toilet seat. Two things must be determined: the stroke length and the strength of the spring.
The pictures above show the system in its two extreme positions.
- The minimum stroke length should be:
385.5 – 311 = 74.5mm minimum for the stroke length of the rod.
Furthermore, the cylinder length can’t exceed 300mm because of assembly issues.
- The strength needed can be calculated thanks to the angle indicated on the pictures. The least
favorable situation for the spring is in “down” position (that’s when it will need to develop the most
strength).
Now let’s consider the majority of people being comprised between 30kg and 130kg. The minimum value has to be taken so the lightest individual one can sit and go down.
30 x 9.81(g) = 295. 30kg is equivalent to a strength of 295N applied vertically.
17

18. Now, using the angle (in the most unfavorable situation):
W the weight, with W = m.g = 295N
R the support reaction (2nd Newton law)
T the effort of the spring
When the patient starts to stand up, the support reaction disappears and has to be compensated
by the effort developed by the spring.
After calculus, T = 157N. There are two springs (for the balance of the system), so one spring
should develop 157/2=78.5N. This is the effort from which a person weighting 30kg (a child basically) will move down when he sits down on the toilet.
Browsing through standards springs from a constructor, it’s possible to select one that fits the
application. Stroke length 145 (we need 74,5 min.), length 383 (we need 385,5 , but the screed
inside the casing can compensate this few millimeters) and strength 100N (we need 78.5 to move
a 30kg patient, 100 would be equivalent to a person of 38kg).
This gas spring is good for the application.
BENCH DIMENSIONING THROUGH STRENGTH OF MATERIALS
As it’s told in the section about the materials, the bench is composed of PVC. PVC
characteristics which are important here are: density: 1.4, Young Modulus: 4.0GPa.
Here is a sample of the bench (300x150x20mm), which represents the surface used
when someone leans on it. The potential maximum weight taken is: 130kg (1300N).
Using a method of finite elements, it’s found by simulation that the flexion of the bench
would be around 15mm at its edge. This is way too much. The effort is not big enough to
lead to plastic deformation yet (Von Mises criteria 12MPa, Young Modulus of PVC 4GPa).
18

19. Conclusion: this could be enhanced by adding some ribs under the bench and reducing the
width of the bench. After a quick study, it is recommended to have a width of 16mm instead of
20mm, and add 5mm width ribs every 200 or 300mm. This helps reducing the flexion when someone leans on the bench, and it reduces the use of material, thus the overall price of the bench.
MATERIALS USED
The shower door is made of glass, which is an amorphous solid material. Glass is a very durable material having high chemical stability and which is therefore resistant against detergents. This ensures that it is very easy and timesaving to clean the shower. Due to the easy
production of different shapes, it is simple and cheap to produce the curved shower door. Depending on the needs, it is possible to produce the door transparent or opaque. The result leads to a high quality impression of the shower door which makes the user feel good.
The upper part of the walls is painted with water resistant paint.
The lower part of the walls of the bathroom are made of ceramics. This possess a wide range
of properties which fit perfectly to this application. Due to the fact that the bathroom is a wet-area application with high air humidity, the porous tiles can absorb moisture which involves health
and safety issues. Ceramic tiles are good chemical resistant, and due to their excellent stain resistance, it is easy to clean and remove any substance on their surface. A further advantage of
ceramic tiles is their high breaking strength which is assessed by how much weight is needed to
cause breakage. All these properties make ceramic tiles the first choice in bathroom applications.
The bench of the bathroom is manufactured of polyvinyl chloride. This particular material is suitable
for this application due to its durability, low density of about 1.4 g/cm3, and its simple and cheap production. Besides that, it is possible to adapt the properties of the material by the addition of additives
like stabilizers or lubricants – to soften it, to color it or to make it longer lasting. Thereby it is possible
to produce a material that is adapted perfectly to the bathroom application. Through the use of these
additives, it is possible to produce the wood imitating optic that will be applicable in the bathroom.
The heat stability of PVC meets the application in the bathroom because the material starts decomposing once it exceeds 140˚C. Its biological and chemical resistance ensures the cleaning friendliness of the bench. At the same time the smooth surface helps because it is hard for bacteria to settle
down. Due to the fact that plastic materials have a low conductivity, less thermal energy is transferred to the body once it is being touched. This fact ensures that it is pleasant to touch the bench.
There are no corrosion problems with plastic which is also important in the moist bathroom area.
19

20. Glass door
Ceramic tiles
Wood imitating PVC
Polymer coatings are new trendy materials used in a large panel of coating applications as gymnasiums, hospital corridors and bathrooms. This material has lot of interesting properties, but it is
also easy to install and clean. We would use this as a floor material. As polymer compound, there
is wide range of available colours to create different atmosphere.
Safety for patients: easier for wheelchair people to go in the bathroom (3 mm thick material); slip
pads barefoot; sealing floor/wall system - waterproof coating; hygiene: SANASOL Surface treatment; rounded corners that makes maintenance and cleaning easier; easy and economical maintenance with brush; sustainable solution: 100% recyclable products; compound to over 50% of
mineral materials or inexhaustible
20

21. TOILET SEAT
The objective is to assist people when they both want to sit on the toilet and stand up once they’re
done. The concept is inspired by a chair developed by the Japanese company Okamura. This
chair helps the user in sitting down and assists him when he wants to stand up.
This can be a great feature for our application since a lot of patients are weak and need to be
helped through the process of going to the toilet.
The concept provides a progressive descent thanks to two gas springs. The system doesn’t require any external energy source (electrical or pneumatic), and is triggered by the patient’s weight.
It is designed to block automatically once it’s in low position, so it doesn’t move while the patient is
sitting. To stand up, the patient just has to push a button to deliver to blocking system, and as he
starts to stand up, the gas springs will gently and progressively help him moving up.
The springs are cased to provide an optimal safety both for the patient and for the system protection. The casing also allows the patient to rest his arms while he sits, in a most comfortable way
as possible. Dimensions are thought to fit more than 95% of the population, including wheelchair
users, through ergonomics and anthropology standards.
21

22. WATER TAP + AIR DRYER
Instead of choosing basic hand dryer that could be cumbersome, noisy and expensive, the Dyson
Airblade Tap was chosen, which optimizes the standard faucet by incorporating a built-in hand
dryer. This system gathers two systems in one, a tap and a hand dryer, both controlled by infrared sensors. A two-in-one solution to washing hands, it ensures that people won’t be lazy when it
comes to accepted hygiene practices. How this system works, is that first, a sensor located in the
main body detects your hand, so lukewarm water will start flowing. When it is finished, two sensors
located on each side of the tap will detect hand’s movements and activate the hand drying system where high-speed cold air blows water off the skin (rather than warming and evaporating it).
With its 1600W motor that blasts out air at 420mph, the Dyson tap can dry hands in about 12
seconds instead of 43 seconds for older versions. Thanks to the addition of HEPA filters, it also
cleans the air before blowing it onto people’s hands, which is more than what regular hand dryers
do. Filters pick up 99,9% of bacteria and viruses in the bathroom air. The unit is 85mm across.
This system is also more economical in the long run (lowest operating cost).
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23. SLIDING DOOR
As it was needed, basic sliding door system was used for the door of the bathroom. Cheap and easy
to install, this system will also allow patients in wheelchair to easily open the door. Divided into two
parts, a rail and a bearing system, this kind of system is mainly built-in in a wall. In that case it was decided just attaching it to the wall. So it is cheaper and the wall does not need to be breaked to install it.
The pictures below shows the all system used and was 3D modelled for our bathroom. The upper part
of the aluminium box shelter the rail, and the right part is here to close and lock the door if needed.
The same system is used for the panel in the shower, little more expensive because of curved system,
it’s water resistant and as easy use to use as the main door. Instead of previously described, a rail
guide system located on the floor will be used. It will help the panel to move and follow its curved path.
To avoid bacteria and humidity, the panel will be located between the wall and the shower seat. More over,
it will be easier for cleaning lady to clean and repairman to have an access on the mechanism if needed.
23

24. View from the door
Left side view
24

25. Left side view
Side view without the shower wall
25

26. Side view
Top view without shower wall
26

27. Top view to the shower wall and seat
Top view with shower wall
27

28. RAPID PROTOTYPING
Parts of 3D printed model of the bathroom
28

29. 1050
750
3020
820
1525
415
600
40
430
600
100
35
200 B
B
100
3200
17
31
3200
Materials
Design & Engineering
Scale: 1:50
Date: 10/01/2014
Observations
Project: Bathroom

30. THANK YOU
Doctors, nurses and assistants of North Estonia Medical Center
Patients with whom we interacted in the hospital
Martin Pärn
Janno Siimar
Henrik Herranen
Janno Nõu
Ahti Põlder from 3D printing studio
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