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manufacture manufacturer maker producer High Blood Pressure
in African Americans Human Blood Pressure Determination by Sphygmomanometry
(booklet) Don't wait for it to happen to you... high blood pressure and stroke
"How Can I Reduce High Blood Pressure?" in Answers By Heart kit (also
in Spanish kit) "What Is High Blood Pressure Medicine?", "Why
Should I Limit Sodium?" and "How Can I Monitor My Weight and Blood
Pressure?" in Answers By Heart kit
Cholesterol, Blood Pressure and Weight Tracker (wallet card) Question When I
go to the doctor's office and they put that cuff thing around my arm to check
my blood pressure, what are they doing? What are they listening for with the
stethoscope? What does "blood pressure" really mean? Answer Your heart
is an amazing pump. It works reliably for decades, and it safely pumps blood
-- one of the trickiest liquids around. In the same way, your blood vessels
are pipes. They take the output from the pump and distribute it throughout the
body. A blood pressure gauge is simply a way to measure the performance of the
pump and the pipes. There are two numbers in a blood pressure reading: systolic
and diastolic. For example, a typical reading might be 120/80. When the doctor
puts the cuff around your arm and pumps it up, what he/she is doing is cutting
off the blood flow with the pressure exerted by the cuff. As the pressure in
the cuff is released, blood starts flowing again and the doctor can hear the
flow in the stethoscope. The number at which blood starts flowing (120) is the
measure of the maximum output pressure of the heart (systolic reading). The
doctor continues releasing the pressure on the cuff and listens until there
is no sound. That number (80) indicates the pressure in the system when the
heart is relaxed (diastolic reading). If the numbers are too high, it means
that the heart is having to work too hard because of restrictions in the pipes.
Certain hormones, like adrenaline (which is released when you are under stress)
cause certain blood vessels to constrict, and this raises your blood pressure
-- if you are under constant stress, your blood pressure goes up, and it means
that your heart has to work too hard. Other things that can increase the blood
pressure include deposits in the pipes and a loss of elasticity as the blood
vessels age. High blood pressure can cause the heart to fail (from working too
hard), or it can cause kidney failure (from too much pressure). Wenzhou Wuzhou
Group Co.,Ltd. is a core enterprises with 20,000 square meters factory building,
concentrate on manufacturing Door Locks, Eyeswear, Lighters, Shoes, Kitchenware,
and Medical Apparatus which are produced by our subsidiary factories Separately.
Our trading devision enjoys 10-year experience in importing and exporting. Your
attention are most welcome and contact us for more details at following address.
The first article in this series described the maintenance of a mercury sphygmomanometer,
this article describes the maintenance of an aneroid blood pressure apparatus.
Aneroid means, in Greek, operating without liquid or containing no fluid. Aneroid
blood pressure gauges are generally smaller than mercury ones but they are easily
damaged and can go out of calibration without detection. A common type of aneroid
apparatus is shown in figure 1. It consists of a dial which normally rises to
300mmHg and a thin brass corrugated bellows inside. There is a shaft which connects
two pins at right angles to each other; one of these rests on the bellows, the
other is inside a concave sided triangle which meshes with a pinion connected
to the dial pointer. A thin coiled spring (known as a hair spring) is also connected
to the pinion and returns the pointer to zero when the pressure is released.
When in use the gauge is connected to a blood pressure cuff around the patient's
arm. As the pressure in the cuff rises, the pin resting on the expanding bellows
is lifted. This movement is transmitted by the other pin which moves the triangle
and therefore the pinion and pointer. This can be seen in figure 2. The following
errors may occur: Leaks in the system. If a leak develops in the system wrap
the cuff around itself and secure the end. Inflate the system to 250mmHg, watch
the pointer. If it slowly drops there is a leak - it is most likely to be in
the cuff or inflation bulb. It is fairly rare for a leak to occur in the gauge
itself. A small pointed brush with soapy water on it will help find the smallest
leak.
Incorrect zero - the gauge does not return to zero after the cuff has been deflated.
On some models, such as the example photographed, there is an adjustment screw
to set the zero point. However using this screw requires the instrument to be
taken out of the case and the screw may be very stiff. The easiest method of
adjusting the zero is by removing the glass from the front of the gauge and
carefully taking off the pointer and replacing it in the correct position The
pointer can usually be taken off using your finger and thumb nails. If this
is not successful find two very small screwdrivers or thin flat pieces of metal
and lever the pointer upwards using one on each side. Calibration check. Every
aneroid blood pressure gauge should be compared with a well-maintained mercury
sphygmomanometer on a regular basis. Connect the gauges together with a plastic
T-piece and connect the third arm to an inflation bulb (figure 3). Inflate the
bulb slowly and note the readings showing on each instrument on a piece of paper
at intervals of say, 20mmHg, starting at 40mmHg and going up to 200mmHg. After
you have finished the test inspect the figures (example shown below) and note
the difference between them. If the readings are within a few millimeters of
mercury throughout the scale this is acceptable for clinical use. In Table 1
the aneroid is reading 10mmHg higher across the scale - this is an example of
a linear error. Table 1: Example of a linear error Mercury Sphyg. (mmHg) Aneroid
Sphyg. (mmHg) Difference (mmHg) 40 50 +10 60 70 +10 80 90 +10 100 110 +10 120
130 +10 In the example shown in Table 2, at low pressures the aneroid sphygmomanometer
reads less than the mercury sphygmomanometer, becomes the same at 80mmHg, and
then reads higher above 80mmHg. This is an example of a non-linear error. Table
2: Example of a non-linear error Mercury Sphyg.(mmHg) Aneroid Sphyg. (mmHg)
Difference (mmHg) 40 20 -20 60 50 -10 80 80 0 100 110 +10 120 140 +20 Correction
of calibration. This is required occasionally, usually as result of the gauge
being dropped. It is best done by someone who has experience of aneroid blood
pressure machines. However, it may be undertaken by carefully following the
instructions below. Each adjustment should be made in very small amounts followed
by a check to assess the effect. Start by making sure the pointer is on the
zero mark. Remove the glass, then carefully remove the pointer and lift off
the dial. You should now see the triangle with concave sides, on one side of
which is a pin. In order to correct a non-linear error bend this pin very slightly
away or towards the side of the triangle, replace the dial and pointer and run
the calibration check again. Repeat this operation until the error has gone.
When correcting a linear error bend this pin very slightly along the line of
the triangle side. Run the calibration check again and keep adjusting until
the error is gone. Broken cover glass. Visit the local watch repairer or make
a glass from a thin plastic sheet. After making the adjustments apply a little
watch oil to the bearing points. A mercury sphygmomanometer is operated by inflating
a rubber cuff placed around a patient's arm until blood flow stops. The cuff
pressure is measured via the mercury column. The figure shows the parts of a
mercury sphygmomanometer. The inflating bulb is used to inflate the cuff. It
contains two one- way valves. Valve A allows air to enter the back of the bulb.
When the bulb is squeezed this valve closes and the air is propelled through
valve B to the cuff. Valve B
