WHAT IS BIOMEDICAL ENGINEERING,SPECIALITY AREAS AND CAREER OPPURTUNITIES

Bio Medical Engineering:

Bio Medical Engineering combines Engineering expertise with medical needs for the enhancement of health care. It is a branch of Engineering in which knowledge and skills are developed and applied to design and solve problems in biology and medicine. Students choose Bio Medical Engineering to be service to people; for the excitement of working with living systems; and to apply advanced technology to the complex problems of medical care. The Bio Medical Engineer is a health care professional, a group that includes Physicians, Nurses and Technicians. Bio Medical Engineer may be called upon to design instruments and devices, to bring together knowledge from many sources to develop new procedures or carry out research to acquire knowledge needed to solve new problems.

Specific Activities :

Example of work done by Bio Medical Engineer include:

•       Designing and constructing cardiac pace makers, defibrillators, artificial kidneys, and blood oxygenates, hearts, blood vessels, joints, arms and legs.
•       Designing computer systems to monitor patients during surgery or in intensive care, or to monitor healthy persons in UN usual environments, such as Astronauts in Space or under water divers at great depth.
•       Designing and building sensors to measure blood chemistry, such as potassium, sodium, O2, CO2 and pH.
•       Designing instruments and devices for therapeutic uses, such as laser system for eye surgery or a device for automated delivery of insulin.
•       Devoicing strategies for clinical decision making based on expert system and artificial intelligence, such as computer based systems for selecting seat cushions for paralyze patients or for, managing the care of patients with severe burns or for diagnostic diseases.
•       Designing clinical laboratories and other units within the hospital and health care delivery system that utilize advances technologies. Examples would be a computerized analyzer for blood samples, ambulance for use in rural areas or a cardiac catheterization laboratory.
•       Designing, building and investigating the medical imaging systems based on X – rays (Computer Assisted Tomography), Isotopes (Position Emission Tomography), Magnetic Fields (Magnetic Resonance Imaging), Ultrasound or newer modalities.
•       Constructing and implementing mathematical / computer models of physiological systems.
•       Designing and constructing bio – materials and determining the mechanical, transport, and biocompatibility properties of implant able artificial materials.
•       Implementing new diagnostic procedures, especially those requiring engineering analysis to determine parameters that are not directly accessible to measurements, such as in the lungs or heart.
•       Investigating the Bio – Mechanics of injury and wound healing.

Specialty Areas :

Some of the well-established area within the field of Bio Medical Engineering is:

1. Bio – Instrumentation.

2. Bio – Mechanics.

3. Bio – Materials.

4. System Physiology.

5. Clinical Engineering.

6. Rehabilitation Engineering.

7. Genetic Engineering.

8. Bio Medical Electronics.

9. Robotics.


Bio Medical Engineers are employed in industry, in hospital, in research facilities of educational and medical institutions, in teaching and in government regulatory agencies. They often serve a co coordinating or interfacing functions, using their back ground in both the engineering and medical fields. In industry, they may create designs where an in depth understanding of living systems and of technology essential. They may be involved in performance testing of new or proposed products. Government positions often involve product testing and safety, as well as establishing safety standards for devices. In the hospital, the Bio Medical Engineer may provide advice on the selection and use of medical equipment, as well as supervising its performance testing and maintenance. They may also build customized devices for special health care or research needs. In research institutions, Bio Medical Engineer supervised laboratories and equipments, and participates in or directs research activities in collaboration with other researchers with such backgrounds as medicine, physiology and nursing.

Some Bio Medical Engineers are technical advisor for marketing department of companies. Some Bio Medical Engineers also have advanced training in other fields. E.g. Many Bio Medical Engineer may also have M.D. Degree, thereby combining and understanding of advances technology with direct patient care and clinical research.

Career Preparation :

The Bio Medical Engineer should plan first and foremost to be a good engineer. Beyond this, he or she should have a working understanding of life sciences systems and terminology. Good communication skills are also important, because the Bio Medical Engineer provide a link among professionals with medical, technical and other backgrounds.

Career Opportunities :

1. Hospitals:

Diagnosis, Patient Care monitoring systems, orthopedics and artificial limb designing, EEG, EMG, ECG. X – Rays, Ultrasound Laboratories.

2. Pharmaceutical Companies:

Research, Development and production of drugs, techniques and devices.

3. Surgical Equipment Manufacturer.

4. Bio Medical / Bio Technology / Laboratory equipments suppliers.

5. Universities.

Teaching, Research etc.

6. Research in various areas:

Instrumentation, diagnostic and theraputic devices, artificial organs, medical information system.

APPLICATIONS OF GAMMA CAMERA

APPLICATIONS OF GAMMA CAMERA:
GAMMA CAMERA used to locate cancerous tumours, minor bone fractures, abnormal functioning of organs and other medical problems .Iodine-131 is used to detect thyroid (a gland that absorbs Iodine) problems. Technetium-99 is used to find tumours in the body. Gamma rays do not ionise cells inside the body so no damage is caused.

•    Bone scan.
•    Myocardial Perfusion
•    Lung scan.
•    Kidney function.
•    Thyroid uptake.
•    Whole body scan.

SCAN IMAGES OF GAMMA CAMERA MACHINE:

 

WHOLE BODY SCAN

  

KIDNEY SCAN

RENAL SCAN

WORKING OF GAMMA CAMERA

WORKING OF GAMMA CAMERA:
A gamma camera is an medical imaging device, most commonly used as a imaging device in nuclear medicine. It produces images of the distribution of gamma rays emitted by metastable radionuclides (isotopes), also called metastable nuclear isomers. A gamma ray comprises gamma photons, which are high energetic photons (at least 5000 times those of visible light). They are produced from sub-atomic particle interaction, such as electron-positron annihilation and radioactive decay. (Annihilation is the collision of a positron with an electron, followed by vanishing of both. Two (sometimes more) (gamma) photons are produced moving in almost opposite directions.) A radionuclide can also produce subatomic particles (which give ionization). Excited metastable isomers de-excite with sending a gamma photon mostly within much les than one picosecond, but some isomers are far much slower. These are for example the Technetium isomers 99mTc (here indicated without atom number; m indicates metastable; half-life 6.01 hours) and 95mTc (half-life of 61 days) are used in medical and industrial applications.
A gamma camera is a complex device consisting of one or more detectors mounted on a gantry. It is connected to an acquisition system for operating the camera and for storing the images. The system counts gamma photons that are absorbed by a crystal in the camera, usually a large flat crystal of NaI with thallium doping in a light-sealed housing. The crystal scintillates in response to incident gamma radiation: when a gamma photon knocks an electron loose from an iodine atom in the crystal, a faint flash of light is produced when the electron again finds a minimal energy state. The initial phenomenon of the excited electron is similar to the photoelectric effect (an electron hitting an atom, with as a result the emission of another electron and back-scatter of the electron with a lower speed) and (particularly with gamma rays) the Compton effect. This is generally an electron hitting an atom, with as a result the emission of a photon and back-scatter of the electron with a lower speed. So actual it is fluorescence, but here for impinging gamma rays. The flash of light must be detected. Photomultiplier tubes (extremely sensitive detectors of UV, near-IR and visible light) behind the crystal detect the fluorescent flashes and a computer sums the fluorescent counts. The computer in turn constructs and displays a two dimensional image of the relative spatial count density on a monitor. This image then reflects the distribution and relative concentration of radioactive tracer elements present in the organs and tissues imaged.

GAMMA CAMERA MACHINE (2)

COMPONENTS OF GAMA CAMERA:

2) SCINTILLATION DETECTOR [NaI(Tl)]:
 The radiation coming from the collimator is received by the crystals to be converted into light photons. NaI(Tl) crystal with 1.25cm thick x 30-50 cm in diameter.Thinner crystal is preferred for Anger camera in order to get better intrinsic resolution therefore better image.

 

3)  PHOTOMULTIPLIER TUBES (PMT's): 

  At the face of the PMT is a photocathode which converts the light photons into electrons. PM tubes (37,61,75 or 91, round, hexagonal or square shapes) arranged in hexagonal pattern, Then the electrons get amplified during the passage through many dynodes. This process is repeated for each electron. The final large cluster of electrons is collected at the anode in order to convert them into electrical signals. Part of the signal processing circuitry (preamplifier, pulse height analyzers, amplifier, pulse pile-up rejection etc.) is attached to each PM tube and sealed in a light-tight protective housing.

SCHEMATIC DIAGRAM OF PMT

 

GROUP OF PMT's IN HEAD OF GAMMA CAMERA

4) PRE-AMPLIFIER:
Preamps attach above the PMT.The amount of charge given by PMT is very small. Even though we have used a sophisticated photodetector like a PMT we still end up with quite a small electrical signal.A very sensitive amplifier is therefore needed to amplify this signal. This type of amplifier is generally called a pre-amplifier.

5)  Position logic circuit:
Using resistive-coupled network to provide positional information from outputs of photomultiplier tubes .

6) Computer:
This works to process the incoming data to be finally displayed as a readable image for diagnosis. Images can be stored also.

GAMMA CAMERA MACHINE (1)

GAMMA CAMERA:
Gamma camera is considered as one of the most important devices used in the field of nuclear medicine. It works to produce functional images of the body part which play a major role in the diagnostic process.

 GAMMA CAMERA MACHIINE

RADIO PHARMACEUTICAL USED:
Patient is injected with a certain substance called "radio pharmaceutical".

COMPONENT OF GAMMA CAMERA:
This radio pharmaceutical interacts with the patient target organ resulting in gamma rays production. The emitted gamma rays are detected by the gamma camera passing through its components. These components are:
•    Collimator
•    NaI(Tl) crystal
•    Light Guide (optical coupling)
•    PM-Tube array
•    Pre-amplifier
•    Position logic circuits (differential&addition etc.)
•    Amplifier (gain control etc)
•    Pulse height analyzer
•    Display (Cathode Ray Tube etc).

EXPLAINATION OF COMPONENTS:

1)    COLLIMATOR:
Made of a large number of small holes drilled in a plate of lead. The holes accept only the gamma rays that are traveling along their direction, while the angled ones get absorbed by the lead. It comes with different types.

 

STRUCTURE OF COLLIMATOR

 

HOW COLLIMATOR WORK