Fibre Optics and Endoscopes
By Aditya
Introduction
Fibre Optics
Fibre optics are thin rods of high quality glass. When Light gradually passes through the fibre it attenuates(gets thinner). This is expressed as db/km(decibels per kilometer). As the picture 2 below shows, fibre optics have what is called Total internal reflection. Total internal reflection is where Light bounces of the edge of a material and goes inwards to the next edge where it bounces off again. No refraction occurs in this process so the light doesn't bend. In other words, light goes through a dense transparent material and instead of refracting, reflects of the base of the material. A fibre optic is made of 3 concentric layers which are called as the core, cladding and coating. This big image on the bottom shows as how a fibre optic would look like on the inside. The core is where the light is transmitted (passed through) and is made from silica. The cladding is where the light is passed in such a way that it creates Total Internal Reflection. The coating is the outer layer of the Fibre optic which protects the cladding from any environmental damage or any damage. There are two types of Fibre Optics: Multimode Fibre, Singlemode Fibre. Multimode fibre is where the light bounces/creates Total Internal Reflection because the light follow different paths known as modes. Picture 2 is an example of Multimode Fibre. Another example is the picture 3 . There is also Singlemode fibre. An example of that and explanation is in picture 1.
Fibre Optics are also used in Cables for electronics such as Television. There are different types of fibre optic cables which are similar to the fibre optic glass: Single way cable and multiway cable. More is explained in the image below the fibre optic glass images.
How an optic fibre looks like
Fibre optic cables
Endoscopes
An endoscope is a type of a fibre optic. it is a long flexible tube that has light go through it at one end and a video camera at the other end. An example of an endoscope is shown here on the right.The video camera shows an image on a television set up next to it where the doctor can see the patient's internal organs. This is called endoscopy. It is used by doctors and is demonstrated to students who want to learn medicine and diseases. It is mainly used for cancer. There are various types of endoscopes for various reasons. Some examples are the following: colonoscopes (which are used to examine your large intestine), Gastroscopes (which are used to examine your oesophagus and stomach), bronchoscopes (which are used to examine the lungs and the airways), arthroscope (which are used to examine the joints in you body) and there are many more for various uses. In endoscopy, the doctor will usually put the endoscope through, the mouth, the throat or through a small cut in the skin cut by the doctors (which is known as a keyhole surgery). Normally endoscopy is done when the patient is unconscious so the doctors give a local anesthetic (a medicine that numbs an area of the body making forcing the patient to lay unconscious) so that the patient can’t feel anything when they put an endoscope through your skin. Endoscopy normally takes 60minutes depending on what the endoscope is being used for. Endoscopy doesn’t take a very long time so patients don’t have to stay overnight at a hospital. There are various reasons why endoscopes/endoscopy is used for such as: Endoscopy to confirm a diagnosis, Endoscopy and biopsies, Endoscope use in surgery.
Endoscopy to confirm a diagnosis
Endoscopy are used to diagnose illness in anyone. Endoscopy is carried out to determine the degree of problem that the patient has so the doctor can suggest the best diagnosis to treat the patient. For example, an endoscopy is normally used when the patient has issues such as Breathing disorders, Internal Bleeding, Stomach Ulcer etc.
Endoscopy and biopsies
Endoscopies are also commonly used for the diagnosis of Cancer. This is where biopsies comes in. Biopsies is taking samples of tissues in the body and determining whether they are cancer tissues or not. Endoscopy and biopsies is only used for cancer related issues. The American Society for Gastrointestinal Endoscopy stated that colonoscopes are the most effective endoscopes for the screening of collateral cancer.
Endoscope use in surgery
For surgical reasons, more modified endoscopes are used for situations such as removing particular objects from the lungs or the intestines. There is also the fact of removing the gallbladder. The gallbladder is a small organ under the liver which stores excess bile or digestive juices which is used later on for meals. But sometimes it has to be removed because it can cause gallstones which a stone formations inside the gallbladder which can cause nausea, diarrhea etc. Gallstones can range in various different sizes. A laparoscope is used to remove the gallbladder.
How does endoscopy work
The patient swallows a capsule which is wirelessly connected to the specific endoscope’s camera. As it goes through the body, whatever part the doctors want to diagnose, it will take the pictures of that and wirelessly send it to a computer which once there, the pictures will be downloaded by the doctor and then inspected. But before any of this happens, the patient has to take a fast/fasts overnight. Then once they reach the doctors, the equipment that contains a belt and a battery and a data recorder. Then, leads will have to be hooked up the abdomen. This is painless and perforated(makes a hole in) the skin. Then the patient has to swallow the capsule. Normally this will last 7~8 hours before the equipment is removed from the patient’s body.
Conclusion
To conclude, FIbre optics are a major convenience for the doctors because it helps them to know what to do when diagnosing a patient. There are a lot of advantages. For example, fibre optics have an advantage of weighing less. Compared to copper conductors, they weigh 10~15 times less, easy to install and require less duct space, produce less radiation when turned on/installed and many more things. There are also a lot of advantages for endoscopes for example, one big one is that endoscopy is never painful only in some cases people will feel a mild discomfort, similar to indigestion or having a sore throat, it is very useful to doctors because of the video camera they can easily look inside a patient’s body without having to do painful work. But on the other hand, there are some disadvantages of optical fibre. For example the price. Even though the materials that are used to make the optical fibre are cheap, the optical fibre itself is very expensive compared to copper. Then there is the fragility. Optical fibres are even more fragile than electrical wires. The there is the opaqueness. When you expose optical fibres to radiation. it will immediately become opaque and not let light through and so the whole optical fibre will not work. Rest assure, I think that fibre optics is the best thing that could ever be made in history for doctors as they don’t have to worry about the diagnosis or get anything wrong whenever a patient has a disease. They can simply use the endoscope and treat the patient easily.