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Moving Patients!Creating smoother transitions for immobile patients in the hospital
Kirill Andreitšuk Fabien Bernard Mart Kekišev Patrick Mallon Kerstin Oppe
2014
Contents
01!02!03!05!06!07!09!10!11!12!19!22!23!25
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
Kerstin Oppe !BA interior architecture & furniture design [email protected]
Patrick Mallon!Bachelors of Architecture pjmallon.blogspot.com [email protected]
Fabien Bernard!MEng of Mechanical Engineering, Design & Ergonomics www.linkedin.com/pub/fabien-bernard/5b/57a/a33 [email protected] [email protected]
2014!
Kirill Andreitšuk!BSc (Bachelor in Science) in Mechanical Engineering, TUT, Production Engineering and Product Development [email protected]
Mart Kekišev!Bachelors of metal art and design artkek.carbonmade.com [email protected] !!
01
GeneralBrief
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.
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.
Patient dignity
Patient safety
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
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 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.
concept generation
problem definition
embodiment design and prototyping
testing with patients
research01
02
03
04
05
work structure
02
regionaal haigla
main !entrance
03
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
ward floor plan
Average patient staying time in the hospital: 5 days
04
To be a recognised medical centre in Europe
To assure medical security to the Estonian population and health care system as a multi-profiled hospital providing acute care. To be in the forefront in t e a c h i n g , s c i e n t i fi c a n d developmental work in medicine and health care
hospital mission:
hospital vision:
Students of TUT Design and Engineering M.Sc. were invited to under take observat ional research at Perh Hospi ta l between the 19th and 23rd of September 2013 in the aims of to improving the areas of patient safety & dignity.
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.
personasWe 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.
Nurse – Kristel 28
Kristel is a new worker in the hospital and thus is just getting to know the sy s tems o f tha t hosp i ta l . Her assignments are helping the ward with transporting patients from bed to wheelchair and back and transporting them to necessary locations.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?
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.
Patient – Heli 71
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. Issues 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.05
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.
immobile patient
partially mobile patient
procedures &
operationsWC
examination room
washing & showering
Outside
patient lounge
patient journeys
06
“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
“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
Sliding devices
mobile patient lift
07
static patient lift
chair bedbed chair
market research
barbers chair
massage chair
08
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.!!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.!!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
Design BriefMaking 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.
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.
conceptReducing physical stress for nurses & patients
09
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. !!Research for the moving of patients has been divided into two main topics of enquiry: !(b2b) Bed to Bed : From the ambulance bed to the hospital/ examination bed in accident and emergency scenarios. !!(b2w) + (w2b) Bed to Wheelchair : The moving of conscious mobility impaired patients from their beds to wheelchair.
With emphasis on the swiftness & simplicity of the action
No forced movement required by the patient.
b2b - identified problems: !• 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
b2w - identified problems: !• High numbers of staff required !• High tech mechanical solutions !• Low tech lifting/moving solutions require many trained
staff !• A degree of human error present and therefore patient
pain
fabric + rollers + static frame
10
concept sketches
Strong arm
searching for a pivot point
There was always the danger of creating an over engineered mechanical monstrosity lightness of touch was crucial
searching for a pivot point
It was established early o n t h a t p i s t o n technology was a sure w a y t o m a k e o u r product unnecessarily expensive and they were consciously left as a last option.
concept development
11
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
concept selectionStress 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.
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.
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
12
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 !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
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). !
With: F=m.g (g=9,81 m/s²) !Safety coefficient: 2
So:
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.
13
So:
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 b e c a u s e i t g i v e s t h e s a m e 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.
This following picture shows the human weight repartition for each part (feet, legs, seat, back and head).
14
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.
Prototype 3!This new prototype is radically different. The s ize i s the same bu t 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 2 1 , 6 ° c o r r e s p o n d i n g o n t h e 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
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. !1. By springs!!To control the motion, it is decided to add two springs for both l inks “translation/rotation”, so 4 springs in total. !Determination of the Spring size: !!It is remembered: !So:
By safety, for both it will be chosen 20 N/mm
With the standards, we can take a spring with k=20,01N/mm
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:
16
One piston version:
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.
17
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°.
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.
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). !-the ergonomics part has been optimize for the patient, medical staff but for the hospital environment as well.
general conclusion
18
Free wheely1st iteration
prototyping & testing
Lifting motion
19
its possible to go from flat to sitting to flat with very little effort while laying on it
Aluminium was our preferred material, but steel is much easier to weld
prototyping & testing
proof of concept
connection details
20
The form is slightly suggestive of a capable four legged animal
Second iterationthe system appears ready for the patient to be slid over the support rails
21
simplified joints and locking mechanism on the proof of concept prototype
The handle now visible beneath the plywood
22
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 less f r ict ion when moved f rom horizontal to seat position.
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 o ther peop le can more eas i l y communicate with. The behavioural change is evident from the early test..
lessons learned
behavioural changes
user feedback
23
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.
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
24
nurse handle
potential !IV drip post add on
cushioned seat, faux leather
patient hand rest,!thermo treated oak veneers
leg rest support fixed !to the frame for stability
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