It was 1 a.m. and the medical ward was quiet. In a few seconds, the peaceful environment was filled with excitement and despair. A man is brought to me with chest pain, blurred vision and disorientation. I recorded his blood pressure with my aneroid sphygmomanometer, and it was over 200 with 130 millimeters of mercury (mmHg). A frank hypertensive crisis was putting her life at risk. If it was not corroborated by the manometer reading and timely treatment, the person could have organ damage and die.
Every medical student knows that their bedside equipment will always be a stethoscope and a sphygmomanometer. It is something that every physician in a healthcare role carries with pride.
I love to see the movement of the needle, dancing on a scale ranging from 20 to 300 mmHg. It is an instrument of technological precision with a very interesting history in its origins. It is the part of the sphygmomanometer that lasts the longest and reflects a person's blood pressure.
Through the movement of its needle, it displays the systolic and diastolic pressure figures, to indicate the pressure exerted by the heart on the blood flowing through the arteries.
The hoses and the fabric cuff are the weak part of this equipment. A manometer can lose its calibration settings, but if we take care of it, it can last for many years.
When you touch it, you feel the weight of the well-designed metal with that mastery of its creators, something that is no longer seen in many modern equipment, where the digital is imposed, and plastic cases of transitory duration are the generality.
At home, I treasure gauges that existed before my parents had children. I have been able to rescue some of them, and today I present them to you in this post, along with others.
Accoson brand manometer:
Founded in 1859 in Clerkenwell (London) by Alfred Charles Cossor, a glassblower. In 1904, Accoson manufactured its first manometer with built-in glass.
Macro photo of air flow control valve
Tycos brand manometer:
Their origin comes from Dr. Rogers Tycos. Manufactured from 1917 to 1935. Manufactured in Rochester, New York and other places in USA.
This certified and registration numbered manometer was used by my father in his medical practice. It has its needle in a reddish color, to make a nice contrast with the black lettering on the dial.
Others:
Japanese KTK manometer:
They are a key part of an autonomous diving equipment or Scuba. Its function is to let us know, the pressure of the breathing mixture that is remaining inside the cylinders, during the diving activity. Cylinders that are filled to average pressures of 200 bars or 2900.75 PSI.
They can measure pressure on their scale in both bar or kilograms per square inch (Kg/in2) and PSI or pounds per square inch (lb/in2).
1 bar equals 1 atmosphere (1 atm) or 14.5 PSI or 760 mmHg, equal to 10 meters depth in salt water m.c.a..
In the photo, you can see that they have a red color zone, between 0 to 50 BAR or 0 to 725,189 PSI. It is a mark used internationally. It alerts us that it is necessary to ascend to surface, when in use, the reserve air that remains in the tank. If you consume this remaining breathing mixture, whether compressed air or other mixtures, and you are at a certain depth, you will be left without breathing and may suffer a dysbaric diving pathology that can lead to death.
Cylinders filled with medical oxygen must also have a pressure gauge. Only these are manufactured to the most stringent specifications. They must not contain or be in contact with any type of grease to avoid deflagration.
This is a manometer of prestige and history, the Dräger brand, based in Lübeck (Germany),
Founded in 1889 by Johann Heinrich Dräger, and cementing its success through a family business, which knew how to achieve safety and medical technology at levels of excellence.
This manometer was a gift I received from two technicians working in electromedicine, while I was president of the National Medical Commission of the Cuban Federation of Underwater Activities, for 9 years.
I used it frequently, in sporting events and freediving training.
Friends, every day, we wander through life, not realizing that we are under the influence of physical laws that are always present. One of them is environmental pressure. It affects all beings that inhabit our planet, without distinction of species, and we can measure with these instruments, the pressure exerted at different levels.
Today I showed you my collection of pressure gauges, and the reason for my motivation for them; but above all, because they are measuring instruments that save lives.
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Own photos. Camera: Panasonic Lumix model DMC-ZS100
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Text by Andrés Brunet
@abrunet