The Development of Medical Device : X- Ray

Belinda Pingguan, Juliana Basheer Biomedical Engineering Program, University Of Malaya

CONTENTS

Conception of IdeasInvention Process and Clinical PrototypingRefinement and EnhancementOutcome Limitation

CONTENTS

Conception of IdeasInvention Process and Clinical PrototypingRefinement and EnhancementOutcome Limitation

Conception of Ideas

X-rays were accidentally discovered by Dr.Willem Roentgen in late 1895, in Wurtzburg, Germany.

Dr Williem Roentgen

Conceptions of Ideas-cont Roentgen was carrying out

experiments with a Crookes tube, a fairly common research apparatus of the time.

As Roentgen applied large voltages to the device to study the behaviour of electrons emitted from the metal, he noticed that a piece of phosphorus material, situated elsewhere in the room, glowed!

Conception of Ideas-cont He tried to block the

emissions by covering the tube first by a piece of cardboard and then by a piece of wood only to find that the phosphorus still glowed.

He also noticed that when he held his hand between the tube and the phosphorus, the light given off seemed to present an image of his hand.

Conception of Ideas-cont To convince himself

he wasn't going crazy, Roentgen recorded such images on pieces of film thus obtaining the first x-ray images of human anatomy.

Mrs. Roentgen’s hand- the very first x-ray of human

CONTENTS

Conception of IdeasInvention Process and Clinical PrototypingRefinement and EnhancementOutcome Limitation

Invention Process and Clinical Prototyping

Simons was the first to start to design x-ray tube

This tube is equipped with a disk-shaped cathode of molybdenum and a magnesium target.

It is evacuated to a barometric pressure of .0001 millimeters of mercury.

The over-all length of the tube is about seven inches.

X-ray tube designed and constructed by Simons

Invention Process and Clinical Prototyping

Circuit diagram of Simon's X-ray apparatus

Invention Process and Clinical Prototyping

The source of high voltage for Simon's X-ray machine

CONTENTS

Conception of IdeasInvention Process and Clinical PrototypingRefinement and EnhancementOutcome Limitation

Refinement and Enhancement

Currently most diagnostic (such as chest and mammographic i.e. breast imaging) radiographic systems in clinical use are based on a phosphor screen.

Phosphor screen emits light in response to x-rays absorption. The resulting optical image is conventionally used to expose a photographic film as shown above.

This method is referred to as film-screen radiography and has been used since the discovery of x-rays 100 years ago.

Digital Radiography In recent years there has been

considerable research effort in finding digital alternatives to film-screen radiography.

Digital x-ray imaging refers to methods in which the image information is represented as a matrix of numbers whose value corresponds to the x-ray transmission.

An example of digital image would be a computer scanned version of a film image.

Digital Radiography-cont In general, a digital detector would

absorb x-rays and produce an electric signal, either directly or indirectly via multiple stages, as the output.

The electric signal can then be assigned numerical, i.e. digital, values according to its amplitude and these numbers can be stored in an 2-dimensional array to be displayed as an image on the computer screen.

Digital Radiography-cont Once in digital format

images can be stored and transferred as data files.

Digital imaging would potentially also allow improved image quality

In addition, digital images can be displayed on a computer monitor, their appearance can be altered via image processing and computer software can be use to aid disease diagnosis.

An example of digital

radiography

Flouroscopy Fluoroscopy refers to real-time imaging carried out to observe motion within the body. Procedures where fluoroscopy is used include the barium swallow and the barium enema carried out to study the intestine.

II of Flouroscopy

Fluroscopy - Cont Fluoroscopic imaging of the blood

vessels, angiography, involves a contrast agent injected into the vessel to increase its x-ray absorption and thus its contrast in the x-ray image.

Computed Tomography Scanner

Newer non-invasive perspectives in CT imaging e.g. angiography of aorta/arteries in mid-brain with an excellent vascular enhancement due to bright vascular opacification.

Computed Tomography-cont

Ct Scanner also provide premier image quality for quicker diagnosis. The most patient friendly CT scanning technique available (entire liver or lung exam in single breath-hold). It also provide maximum patient comfort due to minimum scanning time and low X-ray radiation for patient safety.

Mammography Mammography is a radiographic

examination specially designed for detecting breast pathology. Recent interest in breast imaging has be fostered by the realization that approximately 1 out of 9 women will develop breast cancer over a lifetime.

Early x-ray mammography was done with nonscreen, direct exposure film. These images exhibited low contrast , required high radiation doses and yielded poor diagnostic quality.

Mammography-cont The new version

optimises X-ray dose and image quality.Determines the optimum degree of compression needed to produce uniform tautness, based on individual breast characteristics. Stereotactic biopsy are also attachment with the advancement. It also provide maximum patient comfort and low scanning time.

CONTENTSConception of IdeasInvention Process and Clinical PrototypingRefinement and EnhancementOutcome Limitation

Outcome Limitation Much work has been done to

optimize film-screen radiography, but it still has shortcomings in image quality, dose efficiency as well as practicality.

Many of these limitations arise from the fact that the film is used both as x-ray detection, and image recording and storage medium.

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