Health: 5 commonly used medical instruments and their history

Reneacute Laennec stumbled upon the design of the stethoscope while treating a female patient in 1816 at the NeckerEnfants Malades Hospital in ParisAccording to Laennecs own account the young woman in question seemed to be suffering from what he described as symptoms of diseased heart Unable to use the regular method of diagnosis in such a case as the common method of putting the ear to the chest would be inapplicable in the case of the patients age and gender Reneacute Laennec recollected a simple and wellknown fact in acoustics the great distinctness with which we hear the scratch of a pin at one end of a piece of wood on applying our ear to the other He rolled up a piece of paper into a cylinder and applied one end of it to the region of the heart and the other to his ear and was pleased to hear the action of the heart distinctlyA stethoscope Pic for representational purposesReneacute Laennec PicYouTubeLaennec built his first stethoscope as a 25 cm by 25 cm hollow wooden cylinder which he later refined to comprise three detachable parts His clinical work allowed him to follow chest patients from bedside to the autopsy table He was therefore able to correlate sounds captured by his new instruments with specific pathological changes in the chest in effect pioneering a new noninvasive diagnostic tool Laennec was the first to classify and discuss the terms rales rhonchi crepitance and egophony ndash terms that doctors now use on a daily basis during physical exams and diagnosesReneacute Laennecs stethoscope PicYouTubeAfter Laennec Irish physician Arthur Leared invented the modern binaural stethoscope with two ear pieces in 1851 and George Cammann perfected the design of the instrument for commercial production in 1852 which has become the standard ever sinceThe stethoscope an acoustic medical device is used to listen to lung and heart sounds intestines blood flow in arteries and veinsA look atother medical instruments commonly used today in medicineSphygmomanometer The sphygmomanometer also known as a blood pressure meter or blood pressure gauge was invented by Samuel Siegfried Karl Ritter von Basch in 1881 A more simplified and easily usable version by introduced by Scipione RivaRocci and the device was modernised and popularised within the medical community by Harvey Cushing in 1901A sphygmomanometer Picture for representational purposesA sphygmomanometer is a medical instrument that measures blood pressure It consists of an inflatable cuff a measuring unit the mercury manometer or aneroid gauge and a mechanism for inflation which may be a manually operated bulb and valve or a pump operated electrically The usual unit of measurement of blood pressure is millimeters of mercury mmHg as measured directly by a manual sphygmomanometer It is always used in conjunction with a means to determine at what pressure blood flow is just starting and at what pressure it is unimpededBy observing the mercury in the column while releasing the air pressure with a control valve one can read the values of the blood pressure in mm Hg The peak pressure in the arteries during the cardiac cycle is the systolic pressure and the lowest pressure at the resting phase of the cardiac cycle is the diastolic pressure Measurement of the blood pressure is carried out in the diagnosis and treatment of hypertension high blood pressure and in many other healthcare scenariosTypesManual sphygmomanometers Used by trained practitioners it is possible to obtain a basic reading through palpation alone but this only yields the systolic pressure Manual sphygmomanometers require a stethoscope for auscultation ie listening to the internal sounds of the bodyMercury sphygmomanometers These sphygmomanometers measure blood pressure by observing the height of a column of mercury once made errors of calibration cannot occur They are often required in clinical trials of pharmaceuticals and for clinical evaluations of determining blood pressure for highrisk patients including pregnant women due to their high accuracyAneroid sphygmomanometers These sphygmomanometers are mechanical ones with a dial and require calibration checks unlike mercury manometers They are inexpensive and considered safer than the mercury based ones but are less accurate A major cause of departure from calibration is mechanical jarring Aneroids mounted on walls or stands are not susceptible to this particular problemDigital sphygmomanometers These instruments use measurements and electronic calculations rather than auscultation and are easy to operate without training and can be used in noisy environments Most instruments also display pulse rate Digital instruments may use a cuff placed in order of accuracy and inverse order of portability and convenience around the upper arm the wrist or a finger Some instruments claim also to measure arterial stiffness and irregular heartbeat However such machines are not recommended for regular users as machines that claim to have 3 per cent accuracy rate are usually inaccurate to over 7 per cent and even provided two different readings when checked at the same timeTuning fork This instrument was the invention of British musician John Shore It is generally used by doctors to test for deafness and to categorize it Tuning forks usually C512 are used by medical practitioners to assess a patients hearing This is most commonly done with two exams called the Weber test and Rinne test respectively Lowerpitched ones usually C128 are also used to check vibration sense as part of the examination of the peripheral nervous systemA couple of tuning forks Picture for representational purposesThe Weber test named after Ernst Heinrich Weber is a quick screening test for hearing It can detect unilateral onesided conductive hearing loss middle ear hearing loss and unilateral sensorineural hearing loss inner ear hearing lossThe Rinne test named after German otologist Heinrich Adolf Rinne is primarily for evaluating loss of hearing in one ear and compares perception of sounds transmitted by air conduction to those transmitted by bone conduction through the mastoid Thus one can quickly screen for the presence of conductive hearing loss Ophthalmoscope An ophthalmoscope is done as part of an eye examination also known as an ophthalmoscopy or a fundoscopy and may be done as part of a routine physical examination It is crucial in determining the health of the retina and the vitreous humor Although Charles Babbage is partially credited for its invention in 1847 Hermann von Helmholtzs 1851 reinvention enabled the usefulness of the ophthalmoscope to the medical professionAn ophthalmoscope in use during an ophthalmoscopy Picture for representational purposesThe instrument was later made into a handheld device with concave mirror by Greek ophthalmologist Andreas Anagnostakis during his training in France Francis A Welch and William Noah Allyn invented the worlds first handheld direct illuminating ophthalmoscope in 1915TypesThere are two types of ophthalmoscopes namelyDirect ophthalmoscope Commonly used during routine medical checkups its the size of a small flashlight with several lenses that can magnify upto 15 timesIndirect ophthalmoscope It can be either monocular or binocular and is used for peripheral viewing of the retina Consisting of a light attached to a headband a small handheld lens it provides a wider view of the inside of the eye and thus enables a better view of the fundus even if the lens is clouded by cataractsOphthalmoscopy enables the detection and evaluation of symptoms of various retinal vascular diseases or eye diseases such as glaucoma Disorders like intracranial pressure hydrocephalus benign intracranial hypertension and even brain tumours can be discovered through this method if symptoms like headaches swollen optic discs or papilledema are detected during the ophthalmoscopyOtoscope Also known as an auriscope it is a medical device used to screen for illness during regular checkups and also to investigate ear symptoms An otoscope potentially gives a view of the ear canal and tympanic membrane or eardrum Since the eardrum is the border separating the external ear canal from the middle ear its characteristics can be indicative of various diseases of the middle ear space Diseases which may be diagnosed by an otoscope include otitis media and otitis externa infection of the middle and outer parts of the ear respectivelyA doctor examines a patients ear using an otoscope Picture for representational purposesOtoscopes are also frequently used for examining patients noses avoiding the need for a separate nasal speculum and with the speculum removed upper throats Many otoscopes used in doctors offices are wallmounted while others are portable Wallmounted otoscopes are attached by a flexible power cord to a base which serves to hold the otoscope when its not in use and also serves as a source of electric power being plugged into an electric outlet Portable models are powered by batteries in the handle these batteries are usually rechargeable and can be recharged from a base unitThe most commonly used otoscopesthose used in emergency rooms pediatric offices general practice and by internists are monocular devices They provide only a two dimensional view of the ear canal its contents and usually at least a portion of the eardrum depending on what is within the ear canal and its status