An endoscope is an inspection instrument composed of image sensor, optical lens, light source and mechanical device, which is used to look deep into the body by way of openings such as the mouth or anus. A typical endoscope applies several modern technologies including

optics Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultrav ...

, ergonomics,

precision mechanics Precision mechanics (also "fine mechanics") is an engineering discipline that deals with the design and construction of smaller precision machines, often including measuring and control mechanisms of different kinds. The study may be further defin ...

electronics The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification ...

, and

software engineering Software engineering is a systematic engineering approach to software development. A software engineer is a person who applies the principles of software engineering to design, develop, maintain, test, and evaluate computer software. The term '' ...

. With an endoscope, it is possible to observe lesions that cannot be detected by

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

, making it useful in

medical diagnosis Medical diagnosis (abbreviated Dx, Dx, or Ds) is the process of determining which disease or condition explains a person's symptoms and signs. It is most often referred to as diagnosis with the medical context being implicit. The information r ...

. Endoscopes use tubes which are only a few millimeters thick to transfer illumination in one direction and high-resolution images in real time in the other direction, resulting in minimally invasive surgeries. It is used to examine the internal organs like the throat or

esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...

. Specialized instruments are named after their target organ. Examples include the

cystoscope Cystoscopy is endoscopy of the urinary bladder via the urethra. It is carried out with a cystoscope. The urethra is the tube that carries urine from the bladder to the outside of the body. The cystoscope has lenses like a telescope or microscop ...

(bladder), nephroscope (kidney),

bronchoscope Bronchoscopy is an endoscopic technique of visualizing the inside of the airways for diagnostic and therapeutic purposes. An instrument (bronchoscope) is inserted into the airways, usually through the nose or mouth, or occasionally through a trac ...

( bronchus), arthroscope (joints) and colonoscope (colon), and laparoscope (

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the to ...

pelvis The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

). They can be used to examine visually and diagnose, or assist in surgery such as an arthroscopy.

Etymology

"Endo-" is a scientific Latin prefix derived from ancient Greek ἐνδο- (endo-) meaning "within", and "-scope" comes from the modern Latin "-scopium", from the Greek σκοπεῖν (skopein) meaning to "look at" or "to examine".

History

The first endoscope was developed in 1806 by German

physician A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...

Philipp Bozzini Philipp Bozzini (May 25, 1773 – April 4, 1809) was born in Mainz, Germany. On June 12, 1797 he was awarded the degree of doctor of medicine. From 1804 onwards, Bozzini devoted himself virtually completely to develop his instrument, Lichtleiter ...

with his introduction of a "Lichtleiter" (light conductor) "for the examinations of the canals and cavities of the human body". However, the College of Physicians in Vienna disapproved of such curiosity. The first effective open-tube endoscope was developed by French physician

Antonin Jean Desormeaux Antonin Jean Desormeaux (25 December 1815 – October 1894) was a 19th-century French physician and inventor who has been called the "father of endoscopy", because he made significant improvements to the early endoscope and was the first to succ ...

. He was also the first one to use an endoscope in a successful operation. After the invention of

Thomas Edison Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation, mass communication, sound recording, and motion pictures. These inventi ...

, the use of electric light was a major step in the improvement of endoscope. The first such lights were external although sufficiently capable of illumination to allow cystoscopy, hysteroscopy and sigmoidoscopy as well as examination of the nasal (and later thoracic) cavities as was being performed routinely in human patients by

Sir Francis Cruise Francis Xavier Richard Cruise (3 December 1834 – 26 February 1912) was a notable 19th-century Irish surgeon and urologist best known for inventing an endoscope and using it successfully in surgery in 1865.Mater Misericordiae Hospital in Dublin, Ireland. Later, smaller bulbs became available making internal light possible, for instance in a hysteroscope by Charles David in 1908.

Hans Christian Jacobaeus Hans Christian Jacobaeus (29 May 1879 – 29 October 1937) was a Swedish internist born in Skarhult. In 1916 he became a professor at the Karolinska Institutet in Stockholm. From 1925 until his death in 1937, he was a member of the Nobe ...

has been given credit for the first large published series of endoscopic explorations of the abdomen and the thorax with laparoscop (1912) and thoracoscope (1910) although the first reported thoracoscopic examination in a human was also by Cruise. Laparoscope was used in the diagnosis of

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it i ...

and gallbladder disease by Heinz Kalk in the 1930s. Hope reported in 1937 on the use of laparoscopy to diagnose

ectopic pregnancy Ectopic pregnancy is a complication of pregnancy in which the embryo attaches outside the uterus. Signs and symptoms classically include abdominal pain and vaginal bleeding, but fewer than 50 percent of affected women have both of these symptom ...

. In 1944,

Raoul Palmer Raoul Albert Charles Palmer FRCOG (29 August 1904, Paris – 5 July 1985), known as A.C. Palmer, was a French gynecologist and pioneer in gynecologic laparoscopy. Palmer was born in Paris. His parents, Fritjof Palmer and Signe, née Garling, were ...

placed his patients in the Trendelenburg position after gaseous distention of the abdomen and thus was able to reliably perform

gynecologic Gynaecology or gynecology (see spelling differences) is the area of medicine that involves the treatment of women's diseases, especially those of the reproductive organs. It is often paired with the field of obstetrics, forming the combined area ...

laparoscope. Georg Wolf, a Berlin manufacturer of rigid endoscopes established in 1906, produced the Sussmann flexible gastroscope in 1911.

Karl Storz Karl may refer to: People * Karl (given name), including a list of people and characters with the name * Karl der Große, commonly known in English as Charlemagne * Karl Marx, German philosopher and political writer * Karl of Austria, last Austrian ...

began producing instruments for

ENT Ents are a species of beings in J. R. R. Tolkien's fantasy world Middle-earth who closely resemble trees; their leader is Treebeard of Fangorn forest. Their name is derived from an Old English word for giant. The Ents appear in ''The Lor ...

specialists in 1945 through his company,

Karl Storz GmbH Karl Storz SE & Co. KG is a German medical device company that manufactures and sells endoscopes and surgical instruments. It was founded in Tuttlingen by Dr. Karl Storz in 1945. The company is privately owned; Storz' daughter, Sybill, took over ru ...

Fiber optics

Basil Hirschowitz Basil Isaac Hirschowitz (29 May 1925 – 19 January 2013) was an academic gastroenterologist from the University of Alabama at Birmingham (UAB) best known in the field for having invented an improved optical fiber which allowed the creation of ...

, Larry Curtiss, and Wilbur Peters invented the first fiber optic endoscope in 1957. Earlier in the 1950s Harold Hopkins had designed a "fibroscope" consisting of a bundle of flexible glass fibres able to coherently transmit an image. This proved useful both medically and industrially, and subsequent research led to further improvements in image quality. The previous practice of a small filament lamp on the tip of the endoscope had left the choice of either viewing in a dim red light or increasing the light output – which carried the risk of burning the inside of the patient. Alongside the advances to the optics, the ability to 'steer' the tip was developed, as well as innovations in remotely operated surgical instruments contained within the body of the endoscope itself. This was the beginning of "key-hole surgery" as we know it today.

Rod-lens endoscopes

There were physical limits to the image quality of a fibroscope. A bundle of say 50,000 fibers gives effectively only a 50,000-pixel image, and continued flexing from use breaks fibers and so progressively loses pixels. Eventually so many are lost that the whole bundle must be replaced (at considerable expense). Harold Hopkins realised that any further optical improvement would require a different approach. Previous rigid endoscopes suffered from low light transmittance and poor image quality. The surgical requirement of passing surgical tools as well as the illumination system within the endoscope's tube which itself is limited in dimensions by the human body left very little room for the imaging optics. The tiny lenses of a conventional system required supporting rings that would obscure the bulk of the lens' area. They were also hard to manufacture and assemble and optically nearly useless. The elegant solution that Hopkins invented was to fill the air-spaces between the 'little lenses' with rods of glass. These rods fitted exactly the endoscope's tube making them self-aligning and requiring of no other support. They were much easier to handle and utilised the maximum possible diameter available. With the appropriate curvature and coatings to the rod ends and optimal choices of glass-types, all calculated and specified by Hopkins, the image quality was transformed even with tubes of only 1mm in diameter. With a high quality 'telescope' of such small diameter the tools and illumination system could be comfortably housed within an outer tube. Once again it, was Karl Storz who produced the first of these new endoscopes as part of a long and productive partnership between the two men. Whilst there are regions of the body that will always require flexible endoscopes (principally the gastrointestinal tract), the rigid rod-lens endoscopes have such exceptional performance that they are still the preferred instrument and have enabled modern key-hole surgery. (Harold Hopkins was recognized and honoured for his advancement of medical-optic by the medical community worldwide. It formed a major part of the citation when he was awarded the Rumford Medal by the Royal Society in 1984.)

Composition

A typical endoscope is composed of following parts: * A rigid or flexible tube as a body. * A light transmission system that illuminates the object to be inpsected. For the light source, it is usually located outside the scope body. * A lens system that transmits the image from the objective lens to the observer, usually a relay lens system in the case of a rigid endoscope or a bundle of optical fibers in the case of a fiberoptic endoscope. * An eyepiece which transmits the image to the screen in order to capture it. However, modern

videoscope A flexible Videoscope or Video Borescope is an advanced type of borescope that houses a very small image sensor embedded into the tip of the scope. The video image is relayed from the distal tip and focusable lens assembly back to the display vi ...

s require no eyepiece. * An additional channel for medical instruments or manipulators (only for a multi-function endoscope, see below in "Classification”). Besides, patients undergoing endoscopy procedure may be offered

sedation Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure. Examples of drugs which can be used for sedation include isoflurane, diethyl ether, ...

in to avoid discomfort. Laparoscopic stomach surgery

Clinical application

Endoscopes may be used to investigate symptoms in the

digestive system The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller compone ...

including

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of th ...

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenter ...

abdominal pain Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues. Common causes of pain in the abdomen include gastroenteritis and irritable bowel syndrome. About 15% of people have a m ...

, difficulty swallowing, and gastrointestinal bleeding. It is also used in diagnosis, most commonly by performing a biopsy to check for conditions such as

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, t ...

, bleeding,

inflammation Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molec ...

, and cancers of the digestive system. The procedure may also be used for treatment such as

cauterization Cauterization (or cauterisation, or cautery) is a medical practice or technique of burning a part of a body to remove or close off a part of it. It destroys some tissue in an attempt to mitigate bleeding and damage, remove an undesired growth, or ...

of a bleeding vessel, widening a narrow esophagus, clipping off a polyp or removing a foreign object. Health care workers can use endoscopes to review the following body parts: * The

gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...

: **

Esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...

: chronic

esophagitis Esophagitis, also spelled oesophagitis, is a disease characterized by inflammation of the esophagus. The esophagus is a tube composed of a mucosal lining, and longitudinal and circular smooth muscle fibers. It connects the pharynx to the stomach; ...

esophageal varices Esophageal varices are extremely dilated sub-mucosal veins in the lower third of the esophagus. They are most often a consequence of portal hypertension, commonly due to cirrhosis. People with esophageal varices have a strong tendency to develop s ...

, esophageal hiatal hernia, esophageal

leiomyoma A leiomyoma, also known as a fibroid, is a benign smooth muscle tumor that very rarely becomes cancer (0.1%). They can occur in any organ, but the most common forms occur in the uterus, small bowel, and the esophagus. Polycythemia may occur due t ...

esophageal cancer Esophageal cancer is cancer arising from the esophagus—the food pipe that runs between the throat and the stomach. Symptoms often include difficulty in swallowing and weight loss. Other symptoms may include pain when swallowing, a hoarse voi ...

, cardiac cancer, etc. ** Stomach and

duodenum The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear, and the terms anterior intestine or proximal intestine m ...

: chronic gastritis,

gastric ulcer Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines i ...

, benign

gastric tumor Tumors of the Stomach Tumors of the stomach are known as gastric tumors, and can be either benign or malignant (gastric cancer). These tumors arise from the cells of the gastric mucosa which lines the stomach. Typically, most gastric tumors are c ...

gastric cancer Stomach cancer, also known as gastric cancer, is a cancer that develops from the lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a number of subtypes, including gastric adenocarcinomas. Lym ...

duodenal ulcer Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines i ...

, duodenal

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

. **

Small intestine The small intestine or small bowel is an organ (anatomy), organ in the human gastrointestinal tract, gastrointestinal tract where most of the #Absorption, absorption of nutrients from food takes place. It lies between the stomach and large intes ...

: small intestine

neoplasm A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

smooth muscle Smooth muscle is an involuntary non- striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit ...

tumors,

sarcoma A sarcoma is a malignant tumor, a type of cancer that arises from transformed cells of mesenchymal ( connective tissue) origin. Connective tissue is a broad term that includes bone, cartilage, fat, vascular, or hematopoietic tissues, and sar ...

s, polyps,

lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include en ...

, etc. **

Large intestine The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces before bein ...

: nonspecific ulcerative colitis,

Crohn's disease Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, abdominal distensi ...

, chronic colitis,

colonic polyps A colorectal polyp is a polyp (fleshy growth) occurring on the lining of the colon or rectum. Untreated colorectal polyps can develop into colorectal cancer. Colorectal polyps are often classified by their behaviour (i.e. benign vs. malignant) o ...

colorectal cancer Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel ...

, etc. * The

pancreas The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an ...

and

biliary tract The biliary tract, (biliary tree or biliary system) refers to the liver, gallbladder and bile ducts, and how they work together to make, store and secrete bile. Bile consists of water, electrolytes, bile acids, cholesterol, phospholipids and ...

: **

pancreatic cancer Pancreatic cancer arises when cells in the pancreas, a glandular organ behind the stomach, begin to multiply out of control and form a mass. These cancerous cells have the ability to invade other parts of the body. A number of types of pancr ...

, cholangitis,

cholangiocarcinoma Cholangiocarcinoma, also known as bile duct cancer, is a type of cancer that forms in the bile ducts. Symptoms of cholangiocarcinoma may include abdominal pain, yellowish skin, weight loss, generalized itching, and fever. Light colored stoo ...

, etc. * The laparoscopy: ** liver disease, biliary disease, etc. * The

respiratory tract The respiratory tract is the subdivision of the respiratory system involved with the process of respiration in mammals. The respiratory tract is lined with respiratory epithelium as respiratory mucosa. Air is breathed in through the nose to ...

: **

lung cancer Lung cancer, also known as lung carcinoma (since about 98–99% of all lung cancers are carcinomas), is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. Lung carcinomas derive from transformed, mali ...

, transbronchoscopy lung biopsy, selective

bronchography Bronchography is a radiological technique, which involves x-raying the respiratory tree after coating the airways with contrast. Bronchography is rarely performed, as it has been made obsolete with improvements in computed tomography and bronchos ...

, etc. * The urinary tract: ** cystitis,

bladder The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine en ...

conjugation, bladder tumor, renal

tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, ...

, renal stones, renal tumors, congenital malformations of ureter,

ureteral stones The ureters are tubes made of smooth muscle that propel urine from the kidneys to the urinary bladder. In a human adult, the ureters are usually long and around in diameter. The ureter is lined by urothelial cells, a type of transitional epi ...

, ureteral tumors, etc. * The ear,

nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passe ...

and throat: ** Ear: tympanitis, inner ear deformity, etc. ** Nose: rhinitis, nasal polyp, etc. ** Throat: retropharyngeal abscess, specific infection, etc.

Classification

There are many different types of endoscopes for medical examination, so are their classification methods. Generally speaking, the following three classifications are more common: * According to functions of the endoscope: ** single-function endoscope: A single-function endoscope refers to an observation mirror that only has an optical system with it. ** multi-function endoscope: For a multi-functional endoscope, in addition to the function of observation, it also has at least one working channel like lighting, surgery, flushing and other functions. * According to detection areas reached by the endoscope: ** enteroscope ** otoscope ** colonoscope **

rhinoscope A Rhinoscope (or Nasoscope) is a thin, tube-like instrument used to examine the inside of the nose. A rhinoscope has a light and a lens for viewing and may have a tool to remove tissue. Types Rhinoscopy is performed by two procedures. * Anterio ...

** arthroscope ** laparoscope ** etc. * According to rigidity of the endoscope: ** rigid endoscope: A rigid endoscope is a

prismatic An optical prism is a transparent optical element with flat, polished surfaces that are designed to refract light. At least one surface must be angled — elements with two parallel surfaces are ''not'' prisms. The most familiar type of optical ...

optical system with advantages of clear imaging, multiple working channels and multiple viewpoints. ** flexible endoscope: A flexible endoscope is an optical-fiber-based system. Notable features of a flexible endoscope include that the lens can be manipulated by the operator to change direction, but the imaging quality is not as good as a rigid one.

Recent developments

* Robot assisted surgery CapsuleEndoscope

With the development and application of robotic systems, especially surgical robotics, remote surgery has been introduced, in which the surgeon could be at a site far away from the patient. The first remote surgery was called the Lindbergh Operation. And a wireless oesophageal pH measuring devices can now be placed endoscopically, to record ph trends in an area remotely. * Endoscopy VR simulators

Virtual reality Virtual reality (VR) is a simulated experience that employs pose tracking and 3D near-eye displays to give the user an immersive feel of a virtual world. Applications of virtual reality include entertainment (particularly video games), edu ...

simulators are being developed for training doctors on various endoscopy skills. * Disposable endoscopy Disposable endoscopy is an emerging category of endoscopic instruments. Recent developments have allowed the manufacture of endoscopes inexpensive enough to be used on a single patient only. It is meeting a growing demand to lessen the risk of cross contamination and hospital acquired diseases. A European consortium of the SME is working on the DUET (disposable use of endoscopy tool) project to build a disposable endoscope. * Capsule endoscopy Capsule endoscopes are pill-sized imaging devices that are swallowed by a patient and then record images of the gastrointestinal tract as they pass through naturally. Images are typically retrieved via wireless data transfer to an external receiver. *

Augmented reality Augmented reality (AR) is an interactive experience that combines the real world and computer-generated content. The content can span multiple sensory modalities, including visual, auditory, haptic, somatosensory and olfactory. AR can be de ...

The endoscopic images can be combined with other image sources to provide the surgeon with additional information. For instance, the position of an

anatomical Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having it ...

structure or tumor might be shown in the endoscopic video. * Image enhancement Emerging endoscope technologies measure additional properties of light such as optical polarization, optical phase, and additional wavelengths of light to improve contrast. Endoscope,_USB,_2015-05-30

Non-medical Use

* Industrial endoscopic

nondestructive testing Nondestructive testing (NDT) is any of a wide group of analysis techniques used in science and technology industry to evaluate the properties of a material, component or system without causing damage. The terms nondestructive examination (NDE), n ...

technology The above is mainly about the application of endoscopes in medical inspection. In fact, endoscopes are also widely used in industrial field, especially in non-destructive testing and hole exploration. If internal visual inspection of pipes, boilers, cylinders, motors, reactors, heat exchangers, turbines, and other products with narrow, inaccessible cavities and/or channels is to be performed, then the endoscope is an important, if not an indispensable instrument.

References

{{Reflist * Medical devices

Etymology

History

Fiber optics

Rod-lens endoscopes

Composition

Clinical application

Classification

Recent developments

Non-medical Use

See also

References