Tracheal tube

In 1871 , Frederick Trendelendurg describes a tube that was inserted into the
Trachea through a tracheal cannula . The tube had a small , thick-walled , LowVolume inflatable rubber cuff.
In 1880 William McEwen describes , a Glasgow surgeon , the use of ETT past
blind to relieve into the trachea through the mouth and the airway obstruction
and anesthesia.
In 1893 , Eisenmenger in Vienna describes the first endotracheal tube with an inflatable
Cuff at high volume. The intra- cuff pressure may be estimated by scanning the
great driver tube.
In 1910 , Dorrance describes a tube similar to those inflatable cuff
today .
Described Guedel and Waters , 1928 A cuffed endotracheal tubes designed for closed
Circuits intratracheal administration of anesthesia using carbon dioxide
Absorption technique . This tube was similar to the tube Dorrance . He had a thin
Rubber sleeve is connected to the tube. When deflated rubber sleeve is in folds close
in the catheter wall . These tubes have been shown effective in the prevention of aspiration
and sealing the trachea.
In 1943 , Macintosh describes a tube with a self - inflating cuff Mushin created .
This ease cuff controlled ventilation for thoracic anesthesia. Holes were cut
in the tube under the cap , the cap and inflated only during inspiration. However,
Holes are sometimes blocked by mucus plugs.
Although the first endotracheal tubes tied was described in 1893, not handcuffs
Tubes were in common use until 1950. In 1952 , during the polio
Epidemic were used balloon catheter . After this experience, he has the standard
Clinical application of handcuffs tubes during anesthesia practice. The use of non - Cuff
Tubes is now a more common practice in pediatric anesthesia.
The first pipes were made ​​of red rubber with rigid thick-walled cuffs. High collar and
Tracheal pressure were required to have an effective tracheal seal . this
Tubes were associated with major complications from the pressure
exerted on the wall of the trachea. These complications include erosion distal trachea.
A better understanding of the pathology associated cap led to an improved design
Wrists and techniques to limit the intra - cuff pressure . the introduction
Disposable plastic tubes was an important development that has largely moved
Rubber hoses .
The risk of cross contamination and toxins that are released by the red rubber tube ,

supports the tendency to use plastic pipes. In addition, rubber hoses
deteriorated autoclaved and were more resistant to breakage, pushing
the tube against the wall of the trachea.

Saline solution

Saline was believed to have originated in the blue Indian cholera pandemic that swept Europe in 1831. William Brooke O'Shaughnessy , a recent graduate of the Faculty of Medicine of Edinburgh , suggested in an article in the medical journal The Lancet to inject cholera patients with highly oxygenated to treat the " universal stagnation of the venous system salts and rapid cessation of arterialization of blood " seen in severely dehydrated cholera patients . He found his treatment harmless in dogs, and his proposal was quickly adopted by the physician Thomas Latta in treating cholera patients to beneficial effect. In the following decades , variations and alternatives to Latta solutions have been tested and used in the treatment of cholera patients. These solutions contain a range of concentrations of chloride, sodium hydroxide , potassium carbonate, and phosphate . The breakthrough in achieving physiological concentrations was accomplished by Ringer in 1831 , when he determined the optimal salt concentrations to maintain the contractility of frog heart muscle tissue. Normal saline is considered a descendant of pre -Ringer solutions , ring findings have not been widely adopted and used until decades later . The term " normal saline " itself seems to have little historical basis , except for Hartog Jakob Hamburger 1882-1883 in vitro studies of the lysis of red blood cells that incorrectly suggested that 0.9% was the salt concentration in human blood (instead of 0.6 % , the actual concentration) .

Pen needles

Insulin and other injectable drugs are generally administered with pens drug delivery . Pens are one of the simplest and most dynamic in the administration of insulin and other injectable drug . The medicament is either a pen or a disposable cartridge for use with a reusable pen . The user generally grants pen needle dials a dose , then injects the drug under the skin. Very popular for over 20 years in Europe, the use of injection pens and pen needles spread rapidly in the United States for the treatment of diabetes and other non -diabetic drugs.
As technology advances and competition , driving the desire for more comfortable and effective injections , the design of the pen needle and its parts has become increasingly important. Among the most advanced projects of the pen needle proactively address the ease of use, the injection rate , ergonomic handling, injection depth control and accuracy, and the safe use of transportation available .

Sphygmomanometers history

Sphygmomanometers 

the Sphygmograph, a device that was attached to the forearm and recorded arteial pulsations on an external graph, was deverloped in 1855 by Karl Vierordt. A host of other sphygmometers, devices that externally measured arterial pressure by directly compressing the radial artery, followed though the end of the century and beyond. SR von Basch introduced the rubber, hollow ball filled with water or mercury to obstruct the artery, and combined this with an aneroid manometer in 1880. The mercury sphygmomanometer, a sphygmometer with a separate compression device for the arm, was introduced by Scipione Riva-Rocci in 1896. Independently, in 1897, Hill and Barnard introduced a similar device with and aneriod manometer.

In 1905, Nikoli Korotkoff was the first to suggest listening to artery sounds while using a stethoscope, which by then was nearly a century old. This ausclutatory method was more reliable than palpation in identifying the diastilic pressure.

Thermometer history

In 1654, Ferdinando II de Medici crafted first thermometer by by used seal tube partially filled with alcohol and a reservoir bulb, thereby eliminating the interference of barometric pressure common inprevious models.
Daniel Gabriel Fahrenheit produced a thermometer by using mercury in 1724 and established the fahrenheit scale. Because of mercury's high coeffecient of expansion, the results were highly reproducble. Eightteen years later, Arders Celsius proposed that a scles of zero degrees (melting point of water) to 100 degrees (boiling point) was more practical. Both scales are still used today, as is the original mercury sealed-glass thermometer.
Dr James Currie popularized the use of these glass thermometer for the measurement of patient temperatuer towards the end of the 18th century. He pratised in Liverpool from 1780 to 1805, published his findings and theories, and corresponded with the leading scientists of the day.

Stethoscope

The stethoscope is an acoustic medical device for auscultation, or listening to the intenal sounds of body. It is used to listen to lung and heart sound. When combination with a sphygmomanometer. It can listen to bloodflow in arteries and veins. "Mechanic's stethoscopes" are used to  listen intenal sound made by machines, such as automobile engine.
The stethoscope was invented in France in 1816 by René Laennec the Necker-Enfants Malades Hospital in Paris. It consisted of a wooden tube and was monaural. His device was similar to the common ear trumpet, a historical form of hearing aid indeed, his invention was almost indistinguishable in structure and function from the trumpet, which was commonly called a "microphone".
In 1851, Arthur Leared invented a binaural stethoscope, and in 1852 George Cammann perfected the design of the instrument for commercial production, which has become the standard ever since. Cammann also authored a major treatise on diagnosis by auscultation, which the refined binaural stethoscope made possible. By 1873, there were descriptions of a differential stethoscope that could connect to slightly different locations to create a slight stereo effect, though this did not become a standard tool in clinical practice.

Syringes history

Syringes history
Syringe is  "an instrument such as a hypodermic syringe,
or a rubber ball with a slender nozzle for use in drawing or injecting fluids, cleansing wounds,
etc." In Roman times,  nasal syringes had an other metal case with a tow or flax plunger. In the 17th, English syringes were made from pewter or silver. The barrel and head were 20 cm long. reccomment to rectal ro vaginal use.
John Moyle (1693) used wine in an ear syringe and Dominique Anel developed a suction syringe
to used for infected wounds. Larger syringes were used for irrigation. Almost all structures,
including the lachrymal duct, were cannulated. In the mid of 19th. century a small syringe was
developed. It had a screw arrangement, which permitted the release of a single drop.
The first syringe patents by John and Frederick Weiss were taken out in 1824 and 1851
respectively. A stomach pump was patented by John Read (1760–1847). Read’s enema syringe
was made of brass and had ivory attachments.

19th.century novels suggest that the enema was taking a place in the lives of the healthy as
well as the ill. There was an ingenious and wide variety of apparatus. Maw’s catalogue of
1868 offered 39 varieties of equipment for colonic irrigation, made of every material, and
some were extensively decorated. The smaller ones were made of brass, pewter, or glass,
with a rubber or twine bound plunger. A silk covered rubber tube was supplied with an ivory
plug for rectal irrigation or a rubber covered brass tube for the vagina. Larger varieties had
an independent reservoir and worked as a brass pump. One introduced in 1830 was sold as
“Maw’s Domestic Medical Machine”.