Medical Equipments and machines

From Out to In , X-Ray is watching you

===============================

The first X-ray machines revealed shadows on the lungs, fractures in bones, and inflammation of

arthritic joints. Later, readiopaque substances, which are deliberately introduced into the body to

absorb X-rays, were developed to make readiographs (X-ray photographs) of soft tissues possible.

Barium meals are ingested to reveal gastric ulcers, and dyes are injected to image the heart and kidneys.

Many choices to select

=====================

Today, advanced machines called computer-tomography (CT) scanners use multiple X-ray

beams to build up detailed cross-sectional images of the body. Ct scans clearly show the

structure of all tissue and bone, greatly enhancing diagnosis and treatment.

Radiography

===============

An x-ray tube projects a beam of X-rays through a body and onto a film where it makes a radiograph. The beam, which passes through a variable-sized aperture onto the body, is absorbed according to the density of the internal tissues. Bones absorb more of the X-ray beam than muscles, lungs, or other tissues and show up as light areas on the radiograph.

Computed tomography

====================

A computer-tomography (CT) scanner projects a series of thin X-ray beams from different angles as

its drum rotates through a 360-degree circle around a patient's body. A detectors opposite the tube

send signals to a computer, which synthesizes the many views into one cross-sectional digital picture,

showing a slice of the body. A 3-D accumulation of different slices allows entire organs to be viewed .

MRI and PET scanning

====================

Modern medical-imaging techniques allow doctors to look inside the human body with

far more detail than that offered by X-rays. Techniques such as magnetic resonance

imaging (MRI) and positron-emission tomography (PET) scanning image soft tissue

inside the body and even chemical changes in tissues carrying out certain functions.

Together , these techniques are revolutionizing many aspects of diagnosis treatment ,

and research.

How an MRI scanner works

========================

The humans body is a packed with hydrogen atoms, each of which acts like a tiny magnet. Normally, these atoms are randomly aligned , so the body has no net magnetic field. An MRI scanner forces all the hydrogen atoms to align and then probes the body with radio waves to "see the density of hydrogen in different areas".

How PET scanning works

======================

Positron-emission tomography (PET) scanning maps the function of the body's organs and

tissues by detecting the amount of metabolic or chemical activity in a particular part of the

body. A small amount of a tracer substance, typically radioactive glucose, is introduced into

the body. Glucose tracer molecules are "labeled" with radioactive fluorine atoms. The tracer

becomes concentrated in those regions of the body that are most active and need most glucose.

Radiation from the decay of tracer molecules is then mapped by a ring-shaped array of detectors.

Endoscopic surgery

===================

Endoscopic surgery is a revolutionary procedure in which surgeons operate without making large

incisions. It relies on the use of an endoscope, a viewing tube that is inserted through a tiny incision

or a natural body opening such as the mouth, through which small surgical instruments may be

passed. Endoscopic surgery produces less scarring than open surgery, is quicker, and reduces

healing time.

Surgical endoscope handset :

--------------------------------------------

The surgeon uses control wheels on the handset to maneuver the endoscope inside the body. The

handset also has controls for delivering air and water to the endoscope tip and for removing waste

by suction. The handset is linked to the video monitor.

Endoscopic instruments

=====================

Specialized surgical tools controlled by a cable are passed down the endoscope to enable

the surgeon to operate inside the body. Forceps are used for holding and removing body

parts undergoing surgery. An electromagnetic wire loop can sever or seal tissue using a

high-frequency electric current. Biopsy forceps remove small tissue samples, and cytology

brushes scrape cells from tissue surfaces. These samples can then be tested for infection

or disease. Other instruments include laser attachments, which are used in many operations

to cut or seal tissue and to stop bleeding. Today, endoscopic surgery has replaced traditional

open surgery for many operations.

Endoscope tube

===============

Inside the tube are channels that house control wires and bundles of optical fibers.

These light-transmitting glass fibers, as thin as human hair, both illuminate the inside

of the body and transmit images. Other channels carry air, water, and a range of surgical

instruments to the operation site.



Endoscopic Machine

======================

Endoscope are given different names according to the body part being viewed.

For example,

a laparoscope is used for operations on the abdomen,

a bronchoscope for the the windpipe and lungs, and

an arthroscope for joints.

The endoscope is commonly used as a diagnostic tool, but an examination with an endoscope

will often be the precursor to endoscopic surgery. Imaging technology enables surgeons to identify

precisely the areas requiring surgery before operating. Instruments and laser attachments passed

down the endoscope can cut tissue, drain fluid, destroy diseased cells, and seal wounds.

Ultrasound

===========

Sound at frequencies above the upper limit of human hearing (by convention , 20 kHz ) is called

ultrasound waves transport energy and can be reflected, refracted (bent), and focused. These

properties are exploited in numerous applications, such as sonar. In medicine, ultrasound is used

in a range of diagnostic and treatment procedures, from prenatal imaging to destruction of kidney

stones.



Ultrasound scanning

=====================

An ultrasound machine consists of a scanner head, which is both the source and receiver, a computer,

and a display unit. Piezoelectric transducers in the scanner head vibrate under an applied voltage ,

generating ultrasound. A computer controls the voltage applied, regulating and focusing the ultrasonic

pulses. The pulses travel at different speeds through different tissues and organs, and are partially

reflected as they cross boundaries between them. Returning echoes are received by the transducers,

causing them to vibrate and produce a voltage. A computer analyzes the strength and delay of the echo

signal and constructs an image on a monitor screen.

Prenatal scanning

================

Ultrasound scanning is relatively simple, inexpensive, and safe. Since no radioactivity or

electromagnetic radiation is involved, the technique is suitable for scanning a fetus and is

a routine diagnostic procedure during pregnancy. Prenatal ultrasound is used to measure

fetal growth, to check for multiple pregnancies, and to screen for abnormalities such as

spina bifida and Down's syndrome.

Shock wave lithotripsy

====================

Some people are prone to developing hard masses called stones in their urinary system.

Small stones can pass out of the body, but large stones traditionally needed surgical removal.

Today, a non-invasive procedure called lithotripsy makes such surgery unnecessary. During

lithotripsy, the patient lies still on a treatment table and the kidney stone is located using X-rays,

or, less commonly, low-intensity ultrasound. High-intensity ultrasonic shock waves from an

external source are then focused onto the stone, crumbling it into fine particles that can pass out

of the body with urine.