biomedical engineering - de lorenzo group€¦ · biomedical engineering is a new sector of science...

BIOMEDICAL ENGINEERING

index

INTRODUCTION BIOMEDICAL INSTRUMENTATION SCOPE OF THE LABORATORY: OBJECTIVES PROFILE OF THE COURSE MANUALS AND SOFTWARE

POWER SUPPLIES BASE FRAME WITH POWER SUPPLY, INTERFACE TO PC AND VIRTUAL INSTRUMENTATION DL 3155AL2RM BASE FRAME WITH POWER SUPPLY AND INTERFACE TO PC DL 3155AL2

SOFTWARE

CAI SOFTWARE DL NAV LABORATORY MANAGEMENT SOFTWARE DL LAB

MODULES TRANSDUCERS DL 3155BIO1 AMPLIFIERS DL 3155BIO2 FILTERS DL 3155BIO3 PULSE CONVERSION DL 3155BIO4 ECG – EEG - EMG DL 3155BIO5 PULSE RATE DL 3155BIO6 TEMPERATURE AND RESPIRATION DL 3155BIO7 GALVANIC SKIN RESISTANCE DL 3155BIO8 AUDIOMETER DL 3155BIO9 T.E.N.S. DL 3155BIO10 MAGNETOTHERAPY DL 3155BIO11 ELECTROSTIMULATION DL 3155BIO12 LASER THERAPY DL 3155BIO13 IONOPHORESIS DL 3155BIO14 ULTRASOUND THERAPY DL 3155BIO15 BLOOD PRESSURE MONITORING DL 3155BIO16


INTRODUCTION

The prosperity of a nation is directly proportional to the skills and the education level of its people. In that perspective, De Lorenzo is able to provide a significant contribution in the development and modernization of education and research institutions and to ensure that all client needs are thoroughly analysed by our project development team. Established in 1951, De Lorenzo is the oldest Italian leading manufacturer of educational equipment. Nowadays, with a huge number of products and laboratories installed world-wide, De Lorenzo is continuing its tradition of being fully devoted to solve teaching and learning problems for its customers in technical universities, polytechnics, technical and vocational schools, education centres, teacher training centres, etc. in all of the above areas. With this catalogue, De Lorenzo wants to introduce a new laboratory that has been conceived for the specific purpose of training biomedical engineers and biomedical laboratory technicians. Biomedical Engineering is a new sector of Science and Technology and the objective of the laboratory is to create engineers that are able to operate in the biomedical industrial field, for the design and manufacturing of biomedical equipment, or in the public and private structures, for the maintenance and repair of the same type of products. Once again, here, in De Lorenzo, we are ready to help in developing new knowledge, skills and technologies and to meet the demands for a continuously changing industrial environment.

Biomedical INSTRUMENTATION The biomedical engineering forms a new discipline, born from the close co-operation between engineering and medical-biological sciences. A definition of bioengineering, among the many possible and equivalent, is the following: the bioengineering is the discipline that uses the methodologies and the technologies that are typical of the engineering in order to understand, determine and try to solve medical-biological problems, through a close co-operation of the experts of the different sectors, that is, engineers and doctors-biologists. The main objective of the biomedical engineering is the development of the necessary instrumentation in different application fields of the medical practice, such as diagnosis, therapy and rehabilitation.


SCOPE OF THE LABORATORY: OBJECTIVES Within the more general environment of the electronic instrumentation, the biomedical instrumentation is characterized by some peculiar elements, that are correlated to the particular field of application, due to the fact that it has to be interfaced to the human body. This laboratory deals with the design and operating principles of the most common biomedical instrumentation in the field of diagnosis, therapy and rehabilitation. The objective is that of studying in detail different circuits that are commonly used in the clinic practice by means of four propaedeutic modules (DL 3155BIO1 through DL 3155BIO4) and twelve application modules (DL 3155BIO5 through DL 3155BIO16). Each module is complete with both a theoretical manual and an operating manual. In the theoretical manual there are the medical-biological bases of the specific application as well as the operating principles and the circuit aspects of the electronic instrument. The operating manual describes a series of exercises that allow both the in depth study of the theory and the hands-on evaluation of the performances of the instrument. Furthermore, a special attention is paid to the problems related to the electrical safety of the patient.

PROFILE OF THE COURSE This laboratory has been designed to train in particular two types of professionals: • Biomedical engineers, that take care of the design and of the development of the equipment. • Biomedical laboratory technicians, that deal with the operation and the maintenance of the

equipment. The course is targeted to provide the following competences: basic knowledge of biological systems and signals; knowledge of the measurement methodologies related to biomedical signals; study of the circuit solutions that are used in the biomedical instruments; acquisition of circuit diagnosis methods for the detection of possible faults and malfunctions.

MANUALS AND SOFTWARE

Each module is provided with a Theoretical Guide and a Practical Guide, strictly interconnected, to allow students a simple and gradual learning and teachers an efficient tool for planning and performing their courses. The Theoretical Guide is divided in Lessons while the Practical Guide contains several exercises with step-by-step procedures and tests for the students. On request, the modules can be supplied together with a CAI software that allows students performing their learning activities through a Personal Computer, without the need for any other on-line documentation. Moreover, the classroom can be provided with a Laboratory Management software, to allow the realization of fully integrated training systems, where all the educational tasks are managed and controlled by the Teacher, from his own work station.


POWER SUPPLIES BASE FRAME WITH POWER

SUPPLY AND INTERFACE TO PC AND VIRTUAL INSTRUMENTATION

DL 3155AL2RM

Power supplies: 0/+15 Vdc, 1 A

0/-15 Vdc, 1 A

+15 Vdc, 1 A

-15 Vdc, 1 A

+5 Vdc, 1 A

-5 Vdc, 1 A

6 – 0 – 6 Vac, 1 A

Virtual instrumentation: Multimeter • 3 and 3/4 digits • dc/ac voltage: 400 mV, 4 V, 40 V, 400 V or Autorange • resistance: 400 Ohm, 4 kOhm, 40 kOhm, 400 kOhm, 40 MOhm • dc/ac current: 200 mA, 8 A Function Generator • sinusoidal, square , triangular, dc • frequency: 0.1 Hz - 200 kHz • output: ± 10 V • attenuator: 0 dB, -10 dB, -20 dB Digital oscilloscope • dual trace oscilloscope • input: dc/ac, 1 MOhm • meas. ranges: 20/50/100/200/500 mV, 1/2/5 V per division • sampling frequency: 100 Hz to 10 MHz Digital Pattern Generator • output rate: from 200ms to 10s • pattern selection: manual or automatic • display: 20 states of the patterns Logic Wave Analyzer • display: 20 states of the inputs

Features: Interface board for connection

to PC.

Robust structure and modern design.

Voltage regulation and protection against over voltage or short circuit.

Complete with a set of connecting cables.

BASE FRAME WITH POWER

SUPPLY AND INTERFACE TO PC

DL 3155AL2

Power supplies: • 0/+15 Vdc, 1 A

• 0/-15 Vdc, 1 A • +15 Vdc, 1 A • -15 Vdc, 1 A • +5 Vdc, 1 A • -5 Vdc, 1 A • 6 – 0 – 6 Vac, 1 A

Features: Interface board for connection

to PC.

Robust structure and modern design.

Voltage regulation and protection against over voltage or short circuit.

• Complete with a set of connecting cables.


SOFTWARE

CAI SOFTWARE

DL NAV

Each board of the system can be supplied complete with a Student Navigator software that allows students to perform their learning activities through a Personal Computer, without the need for any other documentation. Moreover, the Student Navigator is provided with an interface to the Laboratory Management software DL Lab, to allow the realization of fully integrated training systems, where all the educational tasks are managed and controlled by the Teacher, through his own work station.

Features: theoretical subjects through PC

with hyper textual navigation according to the standard World Wide Web Internet method

practical training guided through PC, with test questions and computer control of the answers

fault insertion from PC (or from remote teacher station) and troubleshooting operations with computer control of the answers

use of the computer as a stand-alone work station or integrated in the computer network of the laboratory

LABORATORY MANAGEMENT SOFTWARE

DL LAB

This application allows Teachers a complete management of all the activities inside the Laboratory: • assignment of the lessons that

the students must study • monitoring of the activities of

each student (in/out from the lessons, right or wrong answers, rating, etc.)

• direct communication with each student workstation (sending and receiving messages, fault insertion on the student workstations

• recording of all the students’ activities in a database (Microsoft Access compatible) on the Teacher’s workstation

• processing of the stored data for the control of the individual or group learning level

The DL LAB software offers a simple and effective user interface (similar to Explorer in Windows) that allows teacher to move among students, lessons, faults and results in the same way he is used to explore the computer resources.

Features: • unlimited number of classes

(one database for each class) • unlimited number of students

per class • maximum number of work

stations connected at the same time: 256

• 32 bit operating systems • user interface similar to

Windows Explorer • control of the Students’ access

through Username and Pass- word

• assignment of the lessons to study, insertion of the faults, access control

• communication with the students and message exchange

visualization of every activity performed by the students

complete list of all the on-line lessons and faults

results of each student in the last performed lesson: details relevant to each question, average rating, time

results of class performance

export of the results in ASCII format


THE MODULES

TRANSDUCERS

DL 3155BIO1

This block deals with biomedical sensors and transducers. The classification criterion that has been used in this course for the sensors and the transducers is based on their physical operation principle. Resistive, optical or photoelectrical sensors and transducers, used in the temperature data and optical signals acquisition, are studied in this board.

This board does not substitute the medical device under study. The results of the experiments have no medical value. They are just for demonstration purposes.

Theoretical topics: The bio-engineering and the

biomedical instrumentation

Biomedical signals

Measurement systems of biomedical signals

Characteristics of the transducers

The temperature sensors

The optical and opto-electronic sensors

Circuit blocks: Temperature sensors

°C/°F converter

U/f transducer

Photodiode

Phototransistor

Optocoupler

AMPLIFIERS

DL 3155BIO2

The electrical signal, generated by sensors, is usually at a low level of amplitude and power, so that it is necessary to amplify it before its transfer, further analogue or digital processing and visualization. In this course we will study the characteristics of the pre-amplifiers and amplifiers for the processing of biomedical signals.


Theoretical topics: Inverting and non inverting

configuration of an OP. AMP. at low and high voltage gain

Differential Amplifier: differential gain and frequency function

Study of the input and output impedances

Pre-amplifiers

Differential amplifier for the instrumentation

Circuit blocks: Amplification of biomedical signals

The ideal operational amplifiers

The real operational amplifiers

Preamplifier and main amplifier

Evaluation of the CMRR


FILTERS

DL 3155BIO3

In this course we will study the devices that allow the passage of biomedical signals with given characteristics, while attenuating those that do not comply with the required parameters.


Theoretical topics: Filtering of the biomedical signals

Types and characteristics of the filters

Main configurations of the 1st and 2nd order filters

Active LP, HP and KHN filters

Filters applications in the biomedical instrumentation

Notch filter

Filters used in the measurement of the EEG and of the EMG

Circuit blocks: Low-Pass

Band-Pass

High-Pass

Notch

Band-Stop

PULSE CONVERSION

DL 3155BIO4

The events monitoring systems such as the frequency of the cardiac pulsations, the breathing frequency, etc., require that an analogue signal be converted to pulses and visualized on a display in order to be measured. In this course students will study some circuits for analogue to pulse conversion, sound indicator and analogue frequency meter.


Theoretical topics: Role of the analogue-pulsed

conversion

Different types of pulse generators

Description of a conversion block

Role of the audio and visual signaling

Description of a visual signalling block

Description of an audio signaling block

Different types of visual and audio indicators

Role of the measurement of the frequency

Instruments for the measurement of the frequency for biomedical applications

Difference between analogue and digital meters

Circuit blocks: Circuit for the conversion of an

analogue signal to a pulse signal

Measurement of the frequency of a periodical signal

Evaluation of the average cardiac frequency


ECG – EEG - EMG

DL 3155BIO5


The bio-electrical potentials are currently recorded as a routine in several specialities of the modern clinical practice. Such potentials are the result of an electrochemical activity of a class of cells, named excitable cells, that form the nervous, muscular and glandular tissues. The measurement of the bioelectrical phenomena is, therefore, used to learn the electrochemical activity of such tissues. The most widely used bioelectrical signals, such as the electrocardiogram, the electroencephalogram and the electromiogram, have a very low amplitude and are generated by sources that have a high internal impedance. In this course we will study first of all the general specifications of the systems for the measurement of bioelectrical signals and subsequently the characteristics of some special systems. This course comprises a further instrument, the ECG SIMULATOR, which is mandatory to provide power supply to the circuit and provides a simulated ECG signal for performing experimental activity.

Theoretical topics: The bio-potentials and their

measurement

The heart and the measurement of its electrical activity

The muscles and the measurement of their electrical activity

The brain and the measurement of its electrical activity

Circuit blocks: Electrocardiograph: to record the

potentials that are generated on the surface of the body during the process of stimulating the cardiac musculature

Electroencephalograph: to record the cerebral electrical activity

Electromiograph: to record the electrical activity of the muscles and of the relevant nervous fibres

ECG SIMULATOR This is an external block which is provided together with DL 3155BIO5. ECG-SIMULATOR provides the power supply to the ECG-EEG-EMG panel in order to meet the requirements for patient safety. Moreover a simulated ECG signal is generated with amplitude of 4 mV pp. ECG signals are available with two frequency rates, such as 60 or 120 bpm (beats per minute). ECG-SIMULATOR is mandatory when an actual ECG measurement is performed on a patient. In fact the external block provides a multiple switching which permits to select the correct LEAD when electrodes are placed on the patient. A calibration fixed level of 1 mV can be selected to perform ECG calibration.


PULSE RATE

DL 3155BIO6

At every heartbeat the arterial blood pressure raises (systolic period) and the dimension of the tips of the fingers slightly increases, while the higher oxygenation causes the decrease of the optical density of the skin tissue. During the cardiac relaxation period (diastolic period) the pressure decreases, the density increases and the physical dimension of the tips of the fingers decreases. Since these cyclical variations follow the cardiac rhythm, they can be used to measure the frequency of the peripheral pulsations.


Theoretical topics: Concept of cardiac rhythm and

typical values, in different subjects and in different conditions of the subject

Measurement of the cardiac frequency

The use of optical sensors

Comparator with hysteresis for the processing of the signal provided by the optical sensor

PLL, frequency dividers, PIC and their role in the measurement and visualization of the cardiac rhythm

Circuit blocks: Recordings of the peripheral

pulsations in a finger

Effects of breathing and exercising on the frequency of the pulsations

Effects of the temperature on the measurement of the frequency of the pulsations

TEMPERATURE AND

RESPIRATION

DL 3155BIO7

The temperature of the body is mainly regulated by the hypothalamus. This region of the brain regulates the homeostatic mechanism that promotes both the production and the loss of heat. In spite of the changes in the environmental conditions, the hypothalamus keeps constant the internal temperature. Moreover, the external temperature of the skin is controlled by both the hypothalamus and the thermal sensors that cause both the afflux of blood to the skin and the perspiration. The breathing system transfers the oxygen to the blood and expels the carbon dioxide in the atmosphere. The breathing frequency can be calculated by measuring the expansion or the contraction of the chest and also by measuring the movement of air that enters and exits from one nostril.

Theoretical topics: Anatomy of the respiratory airways

or tracts

Measurement of the body temperature

Temperature sensors

Temperature meter

Measurement of the respiratory frequency

Circuit blocks: Variation of the temperatures on

the surface of the body

Advantages of the use of the electronic instrumentation with respect to the classic mercury thermometers for the measurement of the temperature

Main functions of the breathing system

Breathing frequency while relaxing and while exercising This board does not substitute the medical device under study. The results of the experiments have no medical value. They are just for demonstration purposes.


GALVANIC SKIN RESISTANCE

DL 3155BIO8

At the passage of an electrical current, the skin shows a resistance that is normally within the 100 kOhm to 1 MOhm range. Such resistance decreases during periods of emotional stress. The changes of the resistance are particularly significant on the palm of the hands and on the plant of the feet. Moreover, the surface of the skin shows an electrical potential, that can reach up to 50mV and that can equally be influenced by emotional states.


Theoretical topics: Galvanic resistance of the skin

The function of the different skin layers

The electric characteristic of the skin

Behaviour of the human body at the passage of an electric current

Different types of measurements

Measurement of the resistance and of the potential

Visual and audio signaling

Circuit blocks: Variation of the resistance in direct

current of the skin with relation to humidity

Recording of the changes of the galvanic resistance of the skin due to emotional or physical stimuli

Typical circuit that is used in the monitoring of the GSR

AUDIOMETER

DL 3155BIO9

The audiometer is used in the medical field to measure the threshold of hearing sounds. An audio signal generator generates all the frequencies between 20 Hz and 25 kHz. The patient, through a headset, checks the level of sensitivity in his ears.

Theoretical topics: Biophysics of sounds

Physiology of the auditory system: perception, transmission and conduction of the sound

Diagnosis and evaluation of the acoustic deficit

Audiometer

Circuit blocks: Typical circuit of an audiometer

Graphical visualization of the hearing sensitivity of a patient in the whole frequency range



T.E.N.S.

DL 3155BIO10

T.E.N.S., or Transcutaneous Electrical Nerves Stimulation, is a particular low frequency wave form that, once applied through electrodes in the area of the cutaneous projection of the pain (triggers area), allows an almost immediate and long-lasting reduction of the painful sensibility. For this reason it is an effective, safe and innocuous therapy for the treatment of all the muscle and skeleton pains, neuralgias, rheumatic pains, articular pains, headaches, lumbar pains, sciatic pains and other affections.

Theoretical topics: T.E.N.S. technology

Physical principles

The importance of the frequency of the pulses

Gate control theory

Theory of releasing the endorphins

Applications for T.E.N.S.

Circuit blocks: Mechanism through which electrical

pulses are able to perform an analgesic effect

Typical circuit that is used in the transcutaneous electrical nervous stimulation


MAGNETOTHERAPY

DL 3155BIO11

Low frequency and low intensity magnetic fields and high frequency electro-magnetic fields, where the magnetic component is almost equal to the electrical component, act on the whole body through an effect of substitution or activation of the missing electrical currents. Consequently, they cause a fast regeneration of the bony and cutaneous tissues and considerably increase the immune defenses of the body.

Theoretical topics: Outline of electromagnetism

The electromagnetism in the medical practice

The magnetotherapy

Equipment for magnetotherapy Circuit blocks: Main functions of the magneto therapy

Typical circuit of a magneto therapy This board does not substitute the medical device under study. The results of the experiments have no medical value. They are just for demonstration purposes.


ELECTROSTIMULATION

DL 3155BIO12

The electro stimulation, or the involuntary muscular contraction that is caused by electrical pulses, is a practice used both in rehabilitation and in sport or fitness. It causes selective muscular contractions, more powerful and extended than those that are possible through voluntary efforts; it allows, without physical efforts, amazing results such as the increase of the tone and of the volume of the muscles; it increases the metabolism of the fats with consequent reduction of the adipose zones; it tones up the muscles and it progressively reactivates the functionalities of limbs that need re-education.

Theoretical topics: Biomedical techniques for the

electrostimulation

The electrostimulation for passive gymnastics

The electrostimulator

Circuit blocks: Main therapeutical effects in sport

and beauty fields

Typical circuit that is used in electro stimulation


LASER THERAPY

DL 3155BIO13

I.R. is a beam of non visible, unidirectional and monochromatic light (since it is emitted in the infrared band) that transfers remarkable amounts of energy represented by photons. This radiation does not produce heat, it does not alter the tissues and it is not felt by the patient that is under therapy. It performs an anti-inflammatory and revitalizing action.

Theoretical topics: Introduction to the Laser

Features of the Laser

Nd:YAG Laser

CO2 Laser

Semiconductor Laser

Circuit blocks: Main applications of the laser

therapy

Typical circuit of an IR laser This board does not substitute the medical device under study. The results of the experiments have no medical value. They are just for demonstration purposes.


IONOPHORESIS

DL 3155BIO14

The ionophoresis is a technique that allows the substances in ionic form to penetrate from the surface of the skin to the deeper layers through a current. These substances, named active principles, of different dimensions and molecular weights, become extremely effective because they act inside the skin tissues at higher concentrations.

Theoretical topics: Leduc experiment

Physical-chemical bases

Therapeutic effects

Application methods

Circuit blocks: Main therapeutic effects

Typical circuit that is used in the ionophoresis


ULTRASOUND THERAPY

DL 3155BIO15

The penetration power of ultrasounds in the tissues of the human body has revolutionized the field of medical diagnostics. This property is successfully used also in physiotherapy, where ultrasounds have demonstrated a remarkable curative validity in several affections, such as arthritis, lumbagos, articular stiffness and many others.

Theoretical topics: Ultrasound

Medical applications of ultrasound

Method of application

Oscillators

Power supply switching

Circuit blocks: Main applications of the ultrasound

therapy

Typical circuit used in ultrasound therapy



BLOOD PRESSURE

MONITORING

DL 3155BIO16

In blood vessels there must be a certain pressure in order that the blood can properly flow. Each heart beat causes a pressure wave that is transferred to the arteries. The upper value (systole) is the maximum pressure that is recorded in the artery in consequence of the heart beat. The lower value (diastole) corresponds to the pressure that we have in the arteries between two heart beats. Therefore, it is necessary to properly evaluate the pressure and its variability through a pressure and heart beat digital meter.

Theoretical topics: The blood pressure

Hypertension

Measuring the blood pressure

The sensors

Circuit blocks: Measurement of the blood

pressure and heart beat

Evaluation of the average cardiac rate

Typical circuit used in blood pressure monitoring


biomedical engineering - de lorenzo group€¦ · biomedical engineering is a new sector of science...

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