Lecture 1 Technological Principles of Medical Instrumentation 6 October University Faculty of Applied Medical Sciences Department of Biomedical equipment and systems Technological Principles of Medical Instrumentation By Dr. Eng. Hani Kasban Mahmoud 2017 Lecture 1

Introduction to medical instrumentation systems Lecture 1 Introduction to medical instrumentation systems Author : Dr. Eng. Hani Kasban A. Mahmoud / 2017

Bielectronic system Author : Dr. Eng. Hani Kasban A. Mahmoud / 2017

Instrumentation System A Measuring system is required to compare a quantity with a standard or to provide an output that can be related to the quantity being measured The quantity to be measured is detected by an input transducer or sensor. The detected quantity may be converted to a mechanical or electrical form of energy Display Recorder Signal conditioner Measurand Sensor Input Output

Introduction to Bioelectronics Measured biomaterials Revision (Biology) Measured biomaterials Cells Cells are the basic building blocks of all living things. Proteins Proteins are one of the building blocks of body tissue, and can also serve as a fuel source. Enzymes Large molecules that speed up the chemical reactions inside cells. type of protein, Author : Dr. Eng. Hani Kasban A. Mahmoud / 2017

Introduction to Bioelectronics Measured biomaterials Revision (Biology) Measured biomaterials Deoxyribonucleic Acid (DNA)

Introduction to Bioelectronics Measured biomaterials Revision (Biology) Measured biomaterials The neuron (nerve cell) is the fundamental unit of the nervous system. The basic purpose of a neuron is to receive incoming information and, based upon that information, send a signal to other neurons, muscles, or glands. Neurons are designed to rapidly send signals across physiologically long distances. They do this using electrical signals called nerve impulses or action potentials .

Introduction to Bioelectronics Measured biomaterials Revision (Biology) Measured biomaterials Receptor Receptor is a protein-molecule that receives chemical-signals from outside a cell. When such chemical-signals bind to a receptor, they cause some form of cellular/tissue-response Author : Dr. Eng. Hani Kasban A. Mahmoud / 2017

Introduction to Bioelectronics Revision (Electronics) Electronic-Components Author : Dr. Eng. Hani Kasban A. Mahmoud / 2017

Introduction to Bioelectronics Revision (Electronics) Measured Quantities Series Parallel Current Voltage VS = V1 + V2 + V3 VS = V1 = V2 = V3 Resistance RS = R1+ R2 + R3 Power PS = P1 + P2 + P3 Author : Dr. Eng. Hani Kasban A. Mahmoud / 2017

Equivalent circuit for describing the electrostatic interference. Author : Dr. Eng. Hani Kasban A. Mahmoud / 2017

Bioelectronics Applications Author : Dr. Eng. Hani Kasban A. Mahmoud / 2017

FUNCTION OF INSTRUMENTS Thermometer Indication E.C.G. Recording Bio Monitor Monitoring Computer Data Logging Blood Analysir Analysis Dialysis

1.1 - RANGE Significant factors in measurements The range of an instrument is generally considered to include all the levels of input amplitude & frequency over which the device is expected to operate. The objective is to provide an instrument that will give a usable reading from the smallest expected value of the variable or parameter being measured to the largest.

1.2 – SENSITIVITY Significant factors in measurements The sensitivity of an instrument determines how small a variation of a variable or parameter can be really reliably measured. Significant factors in measurements

1.3 – LINEARITY Significant factors in measurements The degree to which variations in the output of an instrument follow input variations is referred to as the linearity of the device. Significant factors in measurements

1.4 – HYSTERESIS Significant factors in measurements It is a characteristic of some instruments where by a given value of the measured variable results in a different reading when reached in an ascending direction from that obtained when it is reached in a descending direction .

1.5 - FREQUENCY RESPONSE The frequency response of an instrument in its variation in sensitivity over the frequency range of the measurement. It is important to display a wave shape that is a faithful reproduction of the original physiological signal. Significant factors in measurements

Significant factors in measurements 1.6 – ACCURACY It is a measure of systemic error. Errors can occur in a multitude of ways. Although not always present simultaneously, the following errors should be considered. 1. Errors due to tolerances of electronic components. 2. Mechanical errors in meter movements. 3. Component errors due to drift or temperature variations. 4. Errors due to poor frequency response. 5. Errors due to change in atmospheric pressure or temperature. Reading errors due to parallel inadequate illuminations or excessively wide ink traces on a pen recording. Two additional sources of Errors are Correct instrument zeroing or making correct baseline. The effect of the instrument on the parameter to be measured & vice versa. ( Specially in measurements in living organism )

1.7 - SIGNAL TO NOICE RATIO It is important that the signal to – noise ratio be high as possible. Significant factors in measurements

1.8 – STABILITY Significant factors in measurements In control engineering, Stability is the ability of a system to resume a steady state conditions following a disturbance at the input rather than be driven into uncontrollable oscillation. Significant factors in measurements

Significant factors in measurements 1.9 - ISOLATION Electrical Isolation is to be made for avoiding interference between different instruments used simultaneously. It can be achieved by using magnetic or optional coupling technique or using radio tetermetry. Telemetry is also used where movement of the person or animal to be measured.

1.10 – SIMPLICITY All systems & instruments should be as simple as possible to eliminate the chance of component or human error.

BASIC OBJECTIVES OF THE INSTRUMENTATION 1. Information Gathering 2. Diagnosis 3. Evaluation 4. Monitoring 5. Control

Bio – Medical instrumentation can generally be classified into two major types : 1. Clinical Instrumentation . 2.Research Instrumentation.

Many thanks Dr. Eng. Hani Kasban Questions?????