Stethoscope-2
This early stethoscope belonged to Laennec. (Science Museum, London)
Early stethoscopes
Early flexible tube stethoscopes. Golding Bird's instrument is on the left. The instrument on the right is the stethophone.[1]
Parts of a binaural stethoscope
A Pinard horn used by a U.S. Army Reserve nurse in Uganda
Stethoscope
The stethoscope is a medical device used for auscultation, or listening to internal sounds of an animal or human body.
From Dual Bells to Binaural Brain Science
The evolution of stethoscopes did not just benefit cardiology, but also illuminated human sensory perception. In 1858, Somerville Scott Alison presented his stethophone to the Royal Society, featuring two separate bells to capture audio from different anatomical sites simultaneously. This dual-input design provided researchers with the experimental apparatus needed to conduct foundational studies on binaural hearing, sound localization, and binaural fusion.
From Wikipedia · CC BY-SA 4.0
A French sphygmomanometer used during World War I
BP 138/73 mmHg as result on electronic sphygmomanometer
Aneroid sphygmomanometer with an adult cuff
Aneroid sphygmomanometer dial, bulb, and air valve
Clinical WelchAllyn sphygmomanometer
Medical student taking blood pressure at the brachial artery
Sphygmomanometer
A sphygmomanometer, also known as a blood pressure monitor, is a medical device composed of an inflatable cuff and a manometer used to measure blood pressure.
Acoustic Clues to Diastolic Numbers
Early arterial cuffs could only detect when blood flow ceased entirely, providing systolic data alone. In 1901, Dr. Harvey Cushing modernized and popularized Scipione Riva-Rocci's cuff design within the American medical community. The true breakthrough for complete cardiovascular monitoring occurred in 1905 when Russian physician Nikolai Korotkov identified arterial sounds during deflation. Matching cuff pressure to the disappearance of these Korotkoff sounds enabled physicians to measure diastolic pressure reliably for the first time.
From Wikipedia · CC BY-SA 4.0
NeedleBevels
Syringe on left, hypodermic needle with attached colour coded Luer-Lock connector on right
Hypodermic needle features
Syringe made entirely of glass, similar to the Wood design, except it is etched with volume marks.
A hypodermic needle tip under microscope
Six hypodermic needles on Luer connectors. These needles are normally used with other medical devices, such as a syringe; from top to bottom: 26G × .mw-parser-output .frac{white-space:nowrap}.mw-parser-output .frac .num,.mw-parser-output .frac .den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output .frac .den{vertical-align:sub}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}1⁄2″ (0.45 × 12 mm) (brown)25G × 5⁄8″ (0.5 × 16 mm) (orange)22G × 1+1⁄4″ (0.7 × 30 mm) (black)21G × 1+1⁄2″ (0.8 × 40 mm) (green)20G × 1+1⁄2″ (0.9 × 40 mm) (yellow)19G × 1+1⁄2″ (1.1 × 40 mm) (cream) See also Birmingham gauge.
Hypodermic needle
A hypodermic needle is a very thin, hollow tube with a sharp tip, commonly used with a syringe to inject substances into or extract fluids from the body.
Goose Quills and Animal Bladders in Early Dog Trials
Early experimentation with intravenous delivery relied on crude biological materials long before modern metal and glass instruments existed. In 1656, Christopher Wren carried out the earliest confirmed trials by fashioning syringes from animal bladders and needles from goose quills. He used this apparatus to administer drugs such as opium directly into the veins of dogs. These pioneer experiments sought to prove whether traditional oral medications could function when introduced intravenously.
From Wikipedia · CC BY-SA 4.0
St Jude Medical pacemaker with ruler
An ECG in a person with a single-chamber pacemaker to the atrium. Note the circle around one of the sharp electrical spikes in the position where the P wave would be expected.
ECG rhythm strip of a threshold determination in a patient with a temporary (epicardial) ventricular pacemaker. The epicardial pacemaker leads were placed after the patient collapsed during aortic valve surgery. In the first half of the tracing, pacemaker stimuli at 60 beats per minute result in a wide QRS complex with a right bundle branch block pattern. Progressively weaker pacing stimuli are administered, which results in asystole in the second half of the tracing. At the end of the tracing, distortion results from muscle contractions due to a (short) hypoxic seizure. Because decreased pacemaker stimuli do not result in a ventricular escape rhythm, the patient can be said to be pacemaker-dependent and needs a definitive pacemaker.
Three leads can be seen in this example of a cardiac resynchronization device: a right atrial lead (solid black arrow), a right ventricular lead (dashed black arrow), and a coronary sinus lead (red arrow). The coronary sinus lead wraps around the outside of the left ventricle, enabling pacing of the left ventricle. Note that the right ventricular lead in this case has two thickened aspects that represent conduction coils and that the generator is larger than typical pacemaker generators, demonstrating that this device is both a pacemaker and a cardioverter-defibrillator, capable of delivering electrical shocks for dangerously fast abnormal ventricular rhythms.
Two types of remote monitoring devices used by pacemaker patients
An external Medtronic pacemaker in 1961
Artificial pacemaker
A pacemaker is an implanted medical device that generates electrical pulses to regulate the heart's rhythm and maintain an adequate heart rate.
Mechanical Chest Strikes as Emergency Conduction
Before electrical devices are deployed, rhythmic mechanical force can temporarily substitute for a malfunctioning cardiac conduction system. Striking a patient's sternum with a closed fist from a distance of 20 to 30 cm induces ventricular beats by elevating internal pressure to 10–15 mmHg. This physical maneuver serves as a rudimentary bridging technique until powered instrumentation arrives.
From Wikipedia · CC BY-SA 4.0
Defibrillation Electrode Position
Electrodes on a real body
Self-adhesive electrodes of a defibrillator
A circuit diagram showing the simplest (non-electronically controlled) defibrillator design, depending on the inductor (damping), producing a Lown, Edmark or Gurvich Waveform
State-of-the-art defibrillator (manual)
Implantable cardioverter-defibrillator with its lead (ex vivo)
Defibrillator
Defibrillation is a treatment for life-threatening cardiac arrhythmias that delivers a dose of electric current to the heart to help re-establish normal sinus rhythm.
Power-Cycling Rather Than Jump-Starting
Popular depictions routinely show defibrillators reviving flatlined patients whose hearts have completely stopped. In clinical reality, asystole cannot be restarted with an electric shock, and administering one is only indicated for chaotic rhythms like ventricular fibrillation or pulseless ventricular tachycardia. Defibrillation acts by forcibly depolarizing heart muscle simultaneously to halt chaotic propagation, effectively inducing temporary asystole so the sinoatrial node can re-establish normal rhythm.
From Wikipedia · CC BY-SA 4.0
Pulse oximeter
A pulse oximeter probe applied to a person's finger
Consumer pulse oxymeter
Absorption spectra of oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (Hb) for red and infrared wavelengths
Simplified principle of operation of a transmissive LED pulse oximeter
The inner side of a pulse oximeter
Pulse oximeter
Pulse oximetry is a noninvasive method for monitoring peripheral blood oxygen saturation by passing wavelengths of light through tissue to a photodetector.
Isolating Arterial Pulses from Static Tissue
Standard pulse oximeters isolate arterial blood from surrounding tissues by cycling red (660 nm) and infrared (940 nm) LEDs thirty times per second. By measuring the fluctuating absorbance across a cardiac cycle and subtracting the minimum baseline absorbance, the sensor eliminates optical interference from resting venous blood, bone, and skin. The resulting ratio between the two light signals determines the exact percentage of oxygenated hemoglobin.
From Wikipedia · CC BY-SA 4.0
Blausen 0244 CochlearImplant 01
1994 body-worn Cochlear Spectra processor. Early cochlear implant users utilized body-worn processors like this one.
Cochlear implant recipient utilizing a behind-the-ear processor
Robin Michelson – early creator of the Cochlear Implant
Internal components of a conventional device (not yet implanted)
Cochlear implant
A cochlear implant is a surgically implanted neuroprosthesis that provides sound perception to individuals with moderate-to-profound sensorineural hearing loss.
Space Engineering in the Technical Library
NASA electronics instrumentation engineer Adam Kissiah spent three years researching inner ear mechanisms on his own initiative. Rather than doing aerospace work during his lunch breaks and evenings, he utilized Kennedy Space Center's technical library to develop a cochlear implant design. In 1977, NASA helped Kissiah obtain a patent for his device, which he eventually sold.
From Wikipedia · CC BY-SA 4.0
Hinterkammerlinse 01 (fcm)
A phakic IOL
Before surgery (natural crystalline lens, left). After surgery (implanted PCIOL, right).
An anterior chamber IOL (ACIOL)
A posterior capsular opacity (PCO) around a posterior chamber IOL (as seen on retroillumination in a slit lamp)
Acrylic MICS-IOL in holder
Intraocular lens
An intraocular lens is a lens implanted in the eye, usually as part of a treatment for cataracts or to correct other vision problems such as myopia and hyperopia.
Wartime Cockpit Splinters as Medical Inspiration
Modern intraocular lens surgery traces back to World War II fighter pilots who sustained ocular trauma from shattered airplane canopies. Observing that lodged aircraft windshield fragments caused no foreign body reaction, Sir Harold Ridley deduced that polymethylmethacrylate was completely inert inside ocular tissue. On 29 November 1949, Ridley performed the first successful intraocular lens implantation at St Thomas' Hospital in London using PMMA.
From Wikipedia · CC BY-SA 4.0
Blausen 0034 Angioplasty Stent 01
A balloon-expandable coronary stent on a balloon catheter
Compressed and expanded peripheral artery stents
Example of a ureteral stent used to alleviate hydronephrosis of the kidney
Endoscopic image of a self-expanding metallic stent in an esophagus, used to palliatively treat esophageal cancer
Endoscopic image of a biliary stent seen protruding from the ampulla of Vater at the time of duodenoscopy
Stent
In medicine, a stent is a tube made of a metallic alloy or polymer that is inserted into a vessel or duct to keep the passageway open.
Mechanical Distinction Between Rerouting and Scaffolding
Medical tubes are frequently conflated, but stents and shunts accomplish entirely different tasks despite sharing similar manufacturing materials. A shunt acts as a conduit connecting two previously unconnected anatomical areas to redirect internal fluid flow. In contrast, a stent operates within an existing lumen or duct, functioning purely as a mechanical scaffold to keep an obstructed natural channel open.
From Wikipedia · CC BY-SA 4.0
Iron lung CDC
An iron lung cylinder (black) showing the patient’s head exposed through a sealed opening. The diaphragm (yellow) mechanically extends and retracts, varying the air pressure in the cylinder, causing the patient’s chest to expand (inhaling, top) and contract (exhaling, bottom).
A patient wearing a cuirass respirator
An iron lung from the 1950s in the Gütersloh Town Museum. In Germany, fewer than a dozen of these breathing machines are available to the public.
A Drinker iron lung displayed at the chapel of Netley Hospital, 2018
![Both–Nuffield iron lung display at the Thackray Museum of Medicine, Leeds. Pictures show assembly at the Morris motor works.[35]](https://nwjvzop1xgplmzvt.public.blob.vercel-storage.com/wikifeed/iron-lung/5-28cc10edbd.webp)
Both–Nuffield iron lung display at the Thackray Museum of Medicine, Leeds. Pictures show assembly at the Morris motor works.[35]
Iron lung
An iron lung is a type of negative pressure ventilator that encloses most of a person's body and varies air pressure to stimulate breathing.
Vacuum Cleaner Motors for Gas Poisoning
When Philip Drinker and Louis Agassiz Shaw Jr. developed the first widely used iron lung at Harvard, its initial target was not polio. The machine was originally constructed to treat victims of coal gas poisoning. The mechanical pumping mechanism relied on commonplace household appliances, utilizing air pumps taken from two vacuum cleaners to cycle pressure inside the chamber.
From Wikipedia · CC BY-SA 4.0
Coronary artery bypass surgery Image 657C-PH
Illustration of one typical way that a heart-lung machine may be connected to the veins and arteries near the heart. The three implements on the left represent (from top to bottom) the pump, the oxygenator, and the reservoir.
Perfusionist operating a modern heart lung machine
A heart lung machine used in London's Middlesex Hospital in 1958. Science Museum, London (2008)
Cardiopulmonary bypass machine used at the University of Michigan in the 1960s.
Cardiopulmonary bypass
Cardiopulmonary bypass (CPB), or a heart-lung machine, is an extracorporeal device that temporarily takes over the function of the heart and lungs during open-heart surgery.
Automotive Engineering in the Operating Room
The development of cardiac bypass relied on unusual cross-disciplinary partnerships, including an automotive manufacturer. On July 3, 1952, Forest Dewey Dodrill achieved the first successful mechanical support of left ventricular function using a machine co-developed with General Motors called the Dodrill-GMR. This milestone helped pave the way for John Gibbon and Frank F. Allbritten Jr. to perform the first successful human open heart procedure on May 6, 1953.
From Wikipedia · CC BY-SA 4.0
Infant-Incubator-wBaby-1978-USA
A pediatric nurse checking recently born triplets in an incubator at ECWA Evangel Hospital, Jos, Nigeria
Neonatal intensive-care unit from 1980
A new mother holds her premature baby at Kapiolani Medical Center NICU in Honolulu, Hawaii
An early incubator, 1909.
NICU at Sir Salimullah Medical College Hospital in Dhaka, Bangladesh
Incubator (neonatal)
A neonatal intensive care unit (NICU) is an intensive care unit specializing in the care of ill or premature newborn infants.
From Poultry Incubators to Carnival Sideshows
Modern neonatal incubators trace their lineage directly to agricultural equipment designed for hatching poultry eggs. In 1880, Stephane Tarnier introduced the first closed infant incubator to keep premature newborns warm in Paris. Public awareness and clinical acceptance grew through unorthodox means when Martin Couney exhibited premature infants inside incubators as sideshow attractions at Coney Island and the World's Fair in 1933 and 1939.
From Wikipedia · CC BY-SA 4.0