Conference PaperPDF Available

Ergonomic Bed to reduce bedsores for bedridden patient

Authors:
International Conference on Ergonomics and Human Factors, HWWE 2011 2009
ERGONOMIC BED TO REDUCE BED
SORES OF BEDRIDDEN PATIENTS
M. L. Chanpur 1 and Dr. (Mrs.) N.R. Rajhans 2
1 College of Engineering, Pune, India
Email: mohan.chanpur@gmail.com
2 College of Engineering, Pune, India
Email: hod.prod@coep.ac.in
Abstract Bed Sores / Pressure Sores / Decubitus
Ulcers are areas of damage to the Skin underlying
tissues ultimately resulting in ulceration. A bedsore
most commonly occurs over bony areas. They are
very difficult to treat, extremely painful and even life
threatening in extreme cases. The main causes of bed
sores are pressure, friction, shear; also some factors
like impaired mobility, sensory impairment and
temperature are the risk factors of developing ulcers.
General practice of curing / treatment of the bed sore
is dressing the wound properly and changing the
position of bedridden patients; such as patients with
back injuries, paralyzed patients, aged patients who
are immobilized (either can not move or are not
allowed to move).
Air and water mattresses are commonly used for
prevention of pressure sores. But it does not serve
the purpose of curing the sores. These mattresses are
difficult and costly to maintain and suggested not to
be reused, to avoid infections.
The problem of bed sores can thus be addressed by
designing a bed for immobilized patients. The main
cause of bed sores is the generation of pressure
points at different locations according to the position
of bones. The research work is an attempt towards
identifying pressure areas and reducing these
pressures by designing the mattress. The study is
focused on collecting the data for identifying different
pressure area with the help of questions asked to the
doctors and nursing care unit. The data thus collected
is analyzed to find which most prone areas in the
body to PU are.
Index Terms Pressure Ulcer, bedridden patients,
comfort of patient, mattress.
I. INTRODUCTION
Pressure Ulcer (PU) is usually developed over a
bony prominence as a result of pressure and by
other factors like shear stress and/or friction [1].
Major contributing factors include immobilization.
The damage may occur in as little time as 12 hours
of pressure, but it might not be noticed until days
later when the skin begins to break down. Pressure
ulcers represent a major burden of sickness and
reduced quality of life for patients. Advancing age is
associated with an increase in cardiovascular and
neurological disease, and changes to the resilience
and elasticity of the skin. Individuals over 65 years
of age are at greater risk than the general
population of developing pressure ulcers. Effective
ulcer prevention and early detection will greatly
reduce patient’s suffering / discomfort. Strong
motivation for this work comes from the growing
shortage of trained health care providers and the
ever-increasing cost of health care. In 2000, the
shortage of nurses was estimated at 6%. This
shortage is expected to grow to 20% by 2015 and, if
not addressed, to 29% by 2020 [2].
To alleviate the interface pressure, care givers
need to regularly (every two hours is often
recommended) turn the patient. Practically this is
not possible due to shortages of resources. One
preventative approach has been through the
improvement of clinical support surfaces (i.e. beds,
tables, stretchers, chairs, etc.) that minimize
external forces on a patient’s body. Pressure
mapping mats is used for measurement of high
pressure on the body. While collecting the data of
different surfaces, the boundary conditions of test
have practical importance. The interface pressure
data are collected with the object in the supine
position, using a sample size.
II. LITERATURE SURVEY
Patients comfort is one position is an important
aspect as compared to the extraordinary features in
bed. Peter Buckle [3] in his test asked the subject to
rate the level of comfort on 1-10 scale. Here, the
comfort can not be defined, it varies with human
being. But by carrying out questionnaire based on
the scale one came come to some average value.
PU can be prevented by studying the blood
reheology but it is a difficult task. PU will develop at
a maximum pressure area at the specific tissue and
it depends on physical properties of the tissue and
the blood flow through it, as well as the time of
exposure. The weight of the body pushes against a
bony area to cut off the blood and O2 to the area.
Therefore Alvin H. Sacks [4] developed the equation
of pressure as Ps = f (ρ, Q, E, T). Interface pressure
involves mapping using sensors to quantify the
pressure between two contacting objects, such as a
person and their support surface. It is commonly
used by clinicians and by researchers investigating
the surface, risk factors for ulceration and ulcer pre-
vention protocols [5], [6]. Fredrick Shelton [7] com-
International Conference on Ergonomics and Human Factors, HWWE 2011 2009
pared different surfaces for elderly people (65-70
years) mannequins with Tekson 5315 system in
his test. The sacrum, hips, spine, elbow, ears,
shoulders, toes and heels are areas that can break
down if a point is kept in one position for a long pe-
riod of time.
Figure 1. Shows the major areas of PU in supine position.
III. METHODOLOGY
A. Subjects:
Subjects from the age group 60 70 years
participated in the experiment. All the subjects were
male to minimize anthropometric differences with
different disorders. Supine position is selected for
collecting the interface pressure of body in lying
condition.
B. Environment:
For this study static conditions were being
considered. Experiment is carried on the objective
questionnaires. In objective questionnaire comfort of
patient is considered. From literature survey four
points indentified for data collection.
Questionnaire:
1. Which are the areas in body that are more
prone to PU?
2. Which type of bed is used to prevent PU?
3. Which mattresses is use for bed bound
patients?
4. What difficult nursing care unit face while
handling bed bound patients on water
beds?
5. Is it necessary to move the body of bed
bound patient, if yes then what is the
frequency of moving them?
6. What problem patients face in the standard
or special beds in hospital on part of their
comfort?
7. What is the difference between young age
bedridden patient and old age bedridden
patient?
8. What provision is taken to heal the PU on
Sacrum or on buttocks?
9. Which is the most vulnerable area of PU?
10. Do you think is there any improvement re-
quired in the present beds used for bedrid-
den patients?
TABLE I.
QUESTIONNAIRE ANSWERS
Q.
No
Doctors
Nursing Care Unit
1.
sacrum, Ischium,
hips, spine, elbows,
ears, shoulders i.e.
scapula, toes and
heels are more
prone to PU
Sacrum, Ischium and Shoul-
ders.
2.
Specialized Turning
beds
Automated Turning beds
3.
Water Beds, and Air
mattresses.
Water Beds, and Air mat-
tresses.
4.
Water beds are not
stable due to water
hence while moving
the patient’s body will
have friction with the
bed and ultimately it
will generate the
ulcers.
Very difficult and two person
will be required to move the
patient.
5.
Yes as per the condi-
tion of the patient.
For every 2 4 hours
time schedule.
Yes after every 2 hours.
6.
Can not sleep in one
position more than an
hour.
Shoulder area and buttocks
are most of the region where
the patient feels uncomforta-
ble.
7.
Skin layer between
and of young age
patient thick as com-
pared to old age
bedridden patient.
Skin of old age patient is soft
bed sheet for them should be
wrinkle free.
8.
Ultra violet technique,
Dressing, and nurs-
ing care.
Dressing, and properly fol-
lowing the schedule to turn-
ing the patients.
9.
Ischium and sacrum.
Lower back and buttock and
the shoulder.
10.
Yes, mattresses
which can generate
less pressure on the
bony areas on body
in lye down condition
for hours.
Yes, it should comfortable to
handle the patient.
C. Summary:
10 doctors and 5 nursing care unit people were
asked questions. Analysis of this data is divided into
two parts doctors and nursing care is related to the
subjects comfort.
TABLE II.
SHOWS THE DATA FOR THE AREA ON THE BODY MOST
PRONE TO THE PU AND THE LESS COMFORTABLE IN
LYING CONDITION ON THE STANDARD MATTRESSES IN
THE HOSPITALS.
QN
Point
Number of
doctors
Number of Nursing
Care people
1
Sacrum
10
5
Heels
4
0
Scapula
10
5
Head
5
1
6
Buttock
10
5
Shoulder
10
4
Head Elevation
6
3
Heels
4
0
Statistics in the table shows that the Shoulder
area and lower back and buttock area have
maximum chances of formation PU. The patients
International Conference on Ergonomics and Human Factors, HWWE 2011 2009
found them uncomfortable in the same area of PU
for when they are lying on the bed.
D. Discussion:
The back of head, ears and heel is the region
where the weight of the body is less therefore the
chances of PU formation is least over there. Water
beds and air bed requires maintenance and the cost
of the maintenance is very much high. Handling the
patient on water bed and air mattress is difficult.
CONCLUSION
With the help of questionnaire it can be
concluded that the mattresses which are presently
used in hospitals are need to be improved. The
major position of PU area is defined. In Future
scope the pressure mapping of subjects in the lie
down condition will give exact pressure point on the
body. Anthropometric data of 5th and 95th percentile
male will help in the designing and manufacturing
the mattresses and the bed.
REFERENCES
[1] National Pressure Ulcer Advisory Panel:
http://www.npuap.org/pr2.htm
[2] US Department of Health and Human Services,” Pro-
jected Supply Demand and Shortage of Registered
Nurses:2000-2020.”http://www.ahcancal.org/research
data/staffing /Documents/Registered Nurse Supply
Demand.pdf, July, 2002.
[3] Peter Buckle and Avalino Fernandes (1996) Mattress
Evaluation -assessment of contact pressure, comfort
and discomfort. In Applied Ergonomics Vol 29, No.1,
pp. 35 39.
[4] Alvin H. Sacks (1989) Can pressure sores be
prevented? In IEEE Engineering in Medicine and
Biology Society 11th International Conference 1479.
[5] Inhyuk Moon (2005) Control of Air cell mattress for
preventing pressure ulcer based on approximate an-
thropometric model. In Proceeding of the 2005 IEEE,
9th International Conference on Rehabilitation Robot-
ics, USA.
[6] John G. Webster (1989) A pressure mat for
preventing pressure sores. In IEEE Engineering in
Medicine and Biology Society 11th International
Conference 1479.
[7] Frederick Shelton (1997) Full body interface
pressure testing as a method for performance
evaluation of clinical support surface. In Applied
Ergonomics Vol 29, No.6, pp. 491 497.
Article
Proper ventilation is a critical consideration for the comfort of hospitalized patients. Dry skin, skin rashes, weariness, poor sleep, and other concerns caused by insufficient ventilation can all be avoided with proper ventilation. Air-Ventilated Air Beds are used to supply air to the major parts of the patient’s body. This air bed is constructed in such a way that air is circulated con-tinually throughout the body of the hospitalized patient. It is especially beneficial for people who are bedridden and need to spend a significant amount of time in bed due to illness. Exces-sive heat generated between the bed and the patient is perhaps the common cause of bedsores. Sweating is the leading cause of bedsores. Air ventilation is included in the system to prevent sweating and reduce the incidences of bedsores. Dual compressors, rubber tubes, flow control valves, and anti-decubitus mattresses are among the components used. The rubber tubes are used to ventilate the space between the body of the patient and the upper surface of the air bed. Above the mattress, the rubber tube mesh is positioned. The air is first compressed in two compressors before passing through the distribution manifold and through the meshing. The tubes are altered by drilling holes at certain intervals. The air from the compressor is circulated through the pipes before passing through the openings in the pipes. The unrestricted passage of compressed air via a capillary tube lowers the temperature of the air. The air exhausted through the capillary tubes maintains the patient’s body temperature stable for a while before lowering it. The air is ventilated throughout the bed in this manner. Bedsore can be avoided by reduction of sweat by using the air in close contact with the patient.
Conference Paper
Using a 0.4-mm thick Interlink conductive polymer pressure sensor, the pressure distribution under the buttocks was measured. The measured pressures under the ischial tuberosities were much higher when the subject was seated on a table than when seated on a cushion. A pressure mat incorporating an array of these sensors, to be placed under any bony protuberance, is proposed. When the pressure-time profile of any sensor exceeds safe limits, an alarm would be provided to the patient or caregiver. It is believed that this pressure mat could reduce the incidence of pressure sores in the spinal-cord injured, in the elderly, and in the operating room
Article
The ergonomic evaluation of mattresses is largely ignored in the current literature. This is somewhat surprising given their importance and the length of time spent using them. This study considers some ergonomic aspects of their design, including body contact pressure and subjective ratings of comfort. Subjects (12 females) found all of the mattresses tested to be significantly more comfortable than an incompressible wooden reference surface. However, no significant differences were found between mattress types, which included orthopaedic and normal designs. Analysis of body contact pressures (measured at the shoulder, elbow, hip, knee and ankle) found few significant differences between experimental conditions. It is argued that limitations in the methodology may not take account of the change in surface area and anatomical sites of contact under different conditions of mattress compressibility. No significant associations were found between comfort ratings and peak body contact pressures. It seems likely that subjective ratings of mattress comfort are dependent on a wider set of factors than contact pressure alone, a finding reported elsewhere in studies of seating.
Article
A method for evaluating the performance of clinical support surfaces is required by designers in their efforts to produce better clinical support surfaces that will reduce the incidence of pressure ulcers. In this study, a Pressure Index (P(index)) is defined which is derived from an analytical equation used to evaluate the average interface pressure, the peak pressure, the magnitude of the peak pressure, and the number of peak pressures on the entire body. The type of subjects needed to represent a population of users as well as the head of bed elevations necessary to simulate clinical applications were integrated with the P(index) to create a single-value mean pressure index which can be used to evaluate any type of surface. To determine the accuracy and repeatability of the mean pressure index, three surfaces (a standard hospital innerspring, a replacement foam mattress, and a low-airloss surface) were tested and evaluated using this method. The low airloss performed the best and the standard innerspring clearly performed the worst (p < 0.0001). The method appeared to accurately and reproducibly predict the relative performance of the three surfaces in reducing pressure.
Conference Paper
Air mattress is now used widely to prevent the pressure ulcer by reducing the localized pressure peaks. In this paper an air-cell mattress and its pressure control method based on an approximate anthropometric model are presented. The air-cell mattress has eighteen cylindrical air cells made of porous material allowing air leakage to contribute in reducing the development of pressure ulcer by lowering the pressure peak, temperature and humidity. To determine an optimal air-cell pressure appropriate for each user, we divide the parts of the body into four sections such as head, trunk, hip, and leg. Then, the pressure of each section is independently calculated from the weight of each part based on the individual body height and weight and the approximate anthropometric model. Air supply system for the air-cell mattress is implemented by using four electronic solenoid valves and an air compressor, and it is driven by a real-time micro-controller. The experimental results for seven subjects shows that the proposed air-cell mattress is effective for the prevention of the pressure ulcer.
Can pressure sores be prevented?
  • Alvin H Sacks
Alvin H. Sacks (1989) Can pressure sores be prevented? In IEEE Engineering in Medicine and Biology Society 11 th International Conference –1479.