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Basic Concepts of Medical Instrumentation
Basic Sensors and Principles
Amplifiers and Signal Processing
The Origin of Biopotentials
Measurements of the Respiratory System
Chemical Biosensors
Laboratuvar Deneyleri
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cardiac cycle
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Elektrik akm ve geriliminin insan için zararl, öldürücü olma deerlerini, frekans özelliklerini de göz önüne alarak anlatn.(%20)
Duyarlk elemanlarmzn cevaplarnn zaman göre çklarnn: (giri çk arasndaki gecikme var/yok, gecikmenin türü)
zero-order (%5)
firs-order (%5)
EKG iaretlerinin alglanmasn, elde edilen iaretin genlik ve frekans özelliklerini, eklini ve anlamlarn anlatn. (%20)
Kan basncn (mekanik-analog) ölçme yöntemini (ölçülen deerlerin anlamlarn belirterek) anlatn. (%15)
Bioelektrik empedans tanm, ölçmeleri, dijital terazide vücudun ya, su deerlerinin belirlenmesi anlatn. (%20)
Sadece üst tarafndan eriilebilen 10 m derinlikte bir havuzunun içindeki suyun seviyesiini en güvenli ekilde ölçmek, ve display etmek için gerekli farkl iki sistemi tasarlay, çizin, anlatn. Öneri-1(%5), Öneri-2(%5),
Prof.Dr.Sezgin ALSAN 2014 Biyomedikal Enstrümantasyon
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The sensor used in this board is TCRT1000, which is a reflective optical sensor with both the infrared light emitter and phototransistor placed side by side and are enclosed inside a leaded package so that there is minimum effect of surrounding visible light. The circuit diagram below shows the external biasing circuit for the TCRT1000 sensor. Pulling the Enable pin high will turn the IR emitter LED on and activate the sensor. A fingertip placed over the sensor will act as a reflector of the incident light. The amount of light reflected back from the fingertip is monitored by the phototransistor.
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The probe contains two high intensity, monochromatic, light- emitting diodes, one emitting red light (660 nm) and the second infrared (940 nm) on one side and a photodetector on the other to measure the amount of light transmitted through the finger.
Pulse oximetry
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This audio frequency meter uses 555 IC as a monostable multivibrator (one-shoot trigger). A monostable multivibrator can act as a frequency-to-voltage converter because it produce a fixed pulse width, with the repetition rate/density is proportional to the triggering input frequency. Here is the circuit’s schematic diagram:
For resistor R1, because it set the measurement range, it’s better to use a rotary switch to select different values for different ranges. For the ampere meter, you can use both analog or digital ampere meter. A cheap dual-slope ADC digital meter is suitable because its averaging characteristic, but a fast digital multimeter can also be used although it may show some uncertainty because of their fast sampling.
Prof.Dr.Sezgin ALSAN 2014 Biyomedikal Enstrümantasyon
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Prof.Dr.Sezgin ALSAN 2014 Biyomedikal Enstrümantasyon
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For this example, the discharge is underdamped (biphasic, also referred to as a Gurvich
waveform) when the patient resistance is less than about 56Ω because
Rpatient+Rinductor=56Ω+10Ω=66Ω<Rcritical=67Ω
In this case, the waveform is underdamped and produces a biphasic (oscillating) waveform.
If the patient impedance is higher than 67Ω, the waveform is overdamped (monophasic,
also referred to as an Edmark waveform). In this case the inductor slows the rate of rise of the discharge current, reduces the maximum voltage applied to the patient, and shapes
the waveform to produce a damped sinusoidal waveform. The current delivered to the
patient gradually rises to a rounded peak and drops back to zero. The discharge current
pulse duration is about 2.5L1/C1, about 2.5 to 3.5ms for most defibrillators.
DESIGN AND DEVELOPMENT
OF MEDICAL ELECTRONIC
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Figure 8.32 Schematic diagram of a damped sinusoidal waveform defibrillator capable of delivering energies of up to 320 J into a 50-Ω
patient load through a 5-ms Edmark (monophasic) waveform. Charge pushbutton SW2 energizes high-voltage transformer T1. C1 is charged through the high-voltage rectifier network D1–D4 and R1. Meter M1 is calibrated to yield an estimate of energy (in joules) delivered to the patient, assuming a load impedance of 50Ω. Defibrillation energy is delivered to the patient by simultaneously pressing on pushbuttons SW3 and SW4, which energize relay K1, which is used to transfer the defibrillation charge from capacitor C1 to the patient via pulse shaping inductor L1. R4 and R5 discharge C1 if the defibrillation buttons are depressed without a suitable load across the paddle electrodes or the
Prof.Dr.Sezgin ALSAN 2014 Biyomedikal Enstrümantasyon
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Required required
I = 7.5Amps.
Then I = 450/(230 × 0.01) = 175 A.
This is too much to be supplied by household mains.
Prof.Dr.Sezgin ALSAN 2014 Biyomedikal Enstrümantasyon
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DC Defibrillation (Fig. 12.10b)
1. Safety housings for electrodes–capacitor discharges only when the electrodes are making
firm contact with the heart or chest wall.
2. Two set of electrodes - not interchangeable sockets
1. Internal 50–72 J (5–3 kV)
3. Meter indicates Joules
4. Charging time constant of 4 seconds
1. 0.25 M Ω × 16 μF
2. (charging resistor)
Prof.Dr.Sezgin ALSAN 2014 Biyomedikal Enstrümantasyon
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CAPACITIVE-DISCHARGE DC DEFIBRILLATORS
A short high-amplitude defibrillation pulse can be obtained by using the
capacitive-discharge circuit shown in Figure 13.10. In this case, a half-wave rectifier driven by a step-up transformer is used to charge the capacitor C. A good rule of thumb is to keep charging time under 10 s.
MEDICAL INSTRUMENTATION Application and Design
FOURTH EDITION John G. Webster, Editor
Prof.Dr.Sezgin ALSAN 2014 Biyomedikal Enstrümantasyon
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When external electrodes are used, energies as high as 400 J may be
required.
The energy stored in the capacitor is given by the well-known
equation
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Prof.Dr.Sezgin ALSAN 2014 Biyomedikal Enstrümantasyon
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resistive impedance (R) for the estimation
of human body composition is described.
This method is based upon the principle that the electrical
conductivity of the fat-free tissue mass (FFM) is far greater than
that of fat.
Using an electrical impedance plethysmograph with a four electrode
arrangement that introduces a painless signal (800 A at 50 kHz)
into the body.
from 44.6-98. 1 kg.
Total body water (TBW) determined by D2O dilution and total body
potassium (TBK) from whole body counting were 50.6 ± 10.3 L and
167.5 ± 38.1 g, respectively.
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Tepe idrar akm hz erkeklerde 20 ml/sn, kadnlarda ise 25 ml/sn üstünde normal oalrak kabul edilir
Uroflowmetry
The SEDIA F1 Flowmeter provides you with a convenient, cost effective and easy to use solution for portable uroflowmetry. Communication between the flow meter and your computer is via Bluetooth connection. The SEDIA software is easily installed on your Windows PC, allowing you to print reports from your own printer.
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Loop Voltage
Standard test circuit
Vc:3.0 V±0.1 V DC; VH: 0.9 V±0.1 V DC
Preheat time
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Prof.Dr.Sezgin ALSAN 2014 Biyomedikal Enstrümantasyon
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TERM
  BRM
DÖNÜÜM
ESK
YEN
AKTVTE
Becquerel (Bq); 1 parçalanma/1 saniye
1Ci=3.7x1010 Bq 1 Ci=37GBq
IINLANMA DOZU
Röntgen (R) ; normal hava artlarnda (00C ve 760 mm Hg basnc) havann 1kg’nda 2.58x10-4 Coulomb’luk elektrik yükü deerinde (+) ve (-) iyonlar oluturan X veya g radyasyonu miktardr.
Coulomb / kilogram (C/kg) ; normal hava artlarnda havann 1 kg’nda 1 Coulomb’luk elektrik yükü deerinde (+) ve (-) iyonlar oluturan X veya g radyasyonu miktardr.
1C/kg=3876 R1R=2.58x10-4 C/kg
SOURULMU DOZ
radiation oz (rad); nlanan maddenin 1 kg’nda 10-2 Joule’lük enerji sourulmas meydana getiren herhangi bir radyasyon miktardr.
Gray (Gy) ; nlanan maddenin 1 kg’nda 1 Joule’lük enerji sourulmas meydana getiren herhangi bir radyasyon miktardr.
1Gy=100rad 1rad=0.01 Gy
DOZ EDEER
röntgen equivalent man (); 1 Röntgenlik X veya n ile ayn biyolojik etkiyi oluturan herhangi bir radyasyon miktardr. rem=(rad)x(WR)*
Sievert (Sv) ; 1 Gy’lik X ve g n ile ayn biyolojik etkiyi meydana getiren herhangi bir radyasyon miktardr. Sv= (Gy)x(WR)*
1Sv=100 rem 1rem=0.01Sv
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Prof.Dr.Sezgin ALSAN Nuclear Instrumentation
Normal background radiation varies from place to place but delivers a dose equivalent in the vicinity of 2.4  mSv /year, or about 0.3 µSv/h.
The international limit for radiation exposure for nuclear workers is 20 mSv per year, averaged over five years, with a limit of 50 mSv in any one year, however for workers performing emergency services EPA guidance on dose limits is 100 mSv when "protecting valuable property" and 250 mSv when the activity is "life saving or protection of large populations. A 250 mSv dose is estimated to increase one's lifetime risk of developing fatal cancer from about 20% to about 21%, and chronic exposure of 100 mSv per year is the "lowest level at which any increase in cancer is clearly evident," according to the International Commission on Radiological Protection . Symptoms of radiation poisoning typically emerge with a 1000 mSv total dose over a day.
Prof.Dr.Sezgin ALSAN 2014 Biyomedikal Enstrümantasyon
Baz radyolojik tetkikler sonucu, ülke seviyelerine ve yaplan tetkiklere göre, hastalarn maruz kald etkin dozlar.
TETKKLER
Seviye 1*
Seviye 2**
Seviye 3-4***
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