Biomedical

Electronics » Biomedical

The objective of this laboratory is to study the different electronic circuits that are commonly used in the clinic practice by means of propaedeutic and advanced modules. It is part of the TIME boards system, with the same hardware, but aimed at those who want to deepen the biomedical field. It has been designed by De Lorenzo to train engineers for the development of the equipment and technicians for its operation and its maintenance. The basic topics are: transducers, amplifiers, filters and pulse conversion and the application ones ranging from ECG/EEG/EMG to blood pressure monitoring passing through magnetotherapy and laser therapy. A fault simulator, for troubleshooting, is provided for all of them and they can be interfaced to personal computer through a CAI software. This lab is complete with power supplies with or without interface to PC and virtual instrumentation. It is recommended for high schools and first years of university.

Products Details

TRANSDUCERS

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

DL 3155BIO1

AMPLIFIERS

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.
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:
• 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

DL 3155BIO2

FILTERS

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.
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:
• 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

DL 3155BIO3

PULSE CONVERSION

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.
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:
• 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

DL 3155BIO4

ECG – EEG - EMG

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).
ECGSIMULATOR 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.
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.

DL 3155BIO5

PULSE RATE

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.
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:
• 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

DL 3155BIO6

TEMPERATURE AND RESPIRATION

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.

DL 3155BIO7

GALVANIC SKIN RESISTANCE

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.
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:
• 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

DL 3155BIO8

AUDIOMETER

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
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.

DL 3155BIO9

T.E.N.S.

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 longlasting 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
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.

DL 3155BIO10

MAGNETOTHERAPY

Low frequency and low intensity magnetic fields and high frequency electromagnetic 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.

DL 3155BIO11

ELECTROSTIMULATION

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
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.

DL 3155BIO12

LASER THERAPY

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.

DL 3155BIO13

IONOPHORESIS

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
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.

DL 3155BIO14

ULTRASOUND THERAPY

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
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.

DL 3155BIO15

BLOOD PRESSURE MONITORING

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
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.

DL 3155BIO16

BASE FRAME WITH POWER SUPPLY AND INTERFACE TO PC AND VIRTUAL INSTRUMENTATION

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

DL 3155AL2RM

BASE FRAME WITH POWER SUPPLY AND INTERFACE TO PC

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.

DL 3155AL2

Download Area

ProductsCodeCatalogueTender specsManuals SimpleVideo
TRANSDUCERSDL 3155BIO1
AMPLIFIERSDL 3155BIO2
FILTERSDL 3155BIO3
PULSE CONVERSION INDICATORDL 3155BIO4
ECG - EEG - EMGDL 3155BIO5
PULSE RATEDL 3155BIO6
TEMPERATURE AND RESPIRATIONDL 3155BIO7
GALVANIC SKIN RESISTANCEDL 3155BIO8
AUDIOMETERDL 3155BIO9
T.E.N.S.DL 3155BIO10
MAGNETOTHERAPYDL 3155BIO11
ELECTROSTIMULATIONDL 3155BIO12
LASER-THERAPYDL 3155BIO13
IONOPHORESISDL 3155BIO14
ULTRASOUND THERAPYDL 3155BIO15
BLOOD PRESSURE MONITORINGDL 3155BIO16
POWER SUPPLY WITH INTERFACE TO PC AND VIRTUAL INSTRUMENTATIONDL 3155AL2RM