Medical Instrumentation

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1 Medical Instrumentation
Application and Design, 4th Edition John Wiley and Sons Ltd, Feb 2009, Pages: 713 Basic Concepts of Medical Instrumentation Basic Sensors and Principles Amplifiers and Signal Processing The Origin of Biopotentials Biopotential Electrodes Biopotential Amplifiers Blood Pressure and Sound Measurement of Flow and Volume of Blood Measurements of the Respiratory System Chemical Biosensors Clinical Laboratory Instrumentation Medical Imaging Systems Therapeutic and Prosthetic Devices Electrical Safety

2 Biyomedikal enstrümantasyon 2013 – 2014 Güz yarıyılı
Başarı Değerlendirme Ölçütleri Önceki dönemlerden başarısız olan öğrencilerin devam mecburiyeti vardır. Derslere devam MADDE 25 –(1) Ders, uygulama ve laboratuvarlara en az %70 oranında devam şartı vardır. Bu şartı sağlamayan öğrenciler, o dersten başarısız sayılır. (2) (Değişik: RG-10/12/ ) Tekrarlanan derslerde, önceki dönemde devam şartı yerine getirilmişse, verilen ödev, proje ve benzeri görevler yerine getirilmek ve ara sınavlara girilmek kaydıyla dersin öğretim elemanınca devam koşulu aranmayabilir. DEVAM KOŞULU ARANACAKTIR. Derse %70 devam, her ders denetlenecektir. Kısa sınav 1  %5  ( 14 Kasım2013) Ödev 1  %5  ( 21 Kasım 2013) Nefes alma kapasitesi ve hızı, ölçme yöntemi ve devresi Vize sınavı  %15  (Kasım son haftası içinde 2013) Kısa sınav 2  %5  (19 Aralık 2013) Ödev 2  %5  (9 Ocak 2014) Kan şekeri ölçme yöntemi ve devresi Öğrenci tarafından tutulan ders notlarının değerlendirilmesi  %15 (9 Ocak 2014) Final sınavı             %50 ( Ocak 2014) Ödev formatı : kapak sayfası + 5…10 sayfa konu + 1 sayfa sizin kendi yorumunuz Ödev sayfaları dosya içine yada poşet içine konulmadan sadece sol orta kenardan 2 adet tel zımba ile birleştirilecektir. Ödev ve ders notu gecikmelerinde  -1puan/gün uygulanacaktır.

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13 A 100mA

14 Ödevler: Bioelektrik empedans tanımı, ölçmeleri, dijital terazide vücudun yağ, su değerlerinin belirlenmesi Thermocouples Thermistor Resistance Temperature Detector Infrared Thermometers Pressure Transducers Load Cells Strain Gage Flowmeters pH Measurement Level Measurement 4 Kasım 2011 28 Ekim 2011

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33 cardiac cycle Systole Diastole pressure volume flow

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36 Elektrik akımı ve geriliminin insan için zararlı, öldürücü olma değerlerini, frekans özelliklerini de göz önüne alarak anlatın.(%20) Duyarlık elemanlarımızın cevaplarının zaman göre çıkışlarının: (giriş çıkış arasındaki gecikme var/yok, gecikmenin türü) zero-order (%5) firs-order (%5) second-order (%5) olma özelliklerini anlatın. EKG işaretlerinin algılanmasını, elde edilen işaretin genlik ve frekans özelliklerini, şeklini ve anlamlarını anlatın. (%20) Kan basıncını (mekanik-analog) ölçme yöntemini (ölçülen değerlerin anlamlarını belirterek) anlatın. (%15) Bioelektrik empedans tanımı, ölçmeleri, dijital terazide vücudun yağ, su değerlerinin belirlenmesi anlatın. (%20) Sadece üst tarafından erişilebilen 10 m derinlikte bir havuzunun içindeki suyun seviyesiini en güvenli şekilde ölçmek, ve display etmek için gerekli farklı iki sistemi tasarlayı, çizin, anlatın. Öneri-1(%5), Öneri-2(%5),

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40 Miniature Wireless Pulse Oximeter
CMS-P PC Based Pulse Oximeter

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42 Pulse oximetry 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.

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61 Ödevler: Bioelektrik empedans tanımı, ölçmeleri, dijital terazide vücudun yağ, su değerlerinin belirlenmesi Thermocouples Thermistor Resistance Temperature Detector Infrared Thermometers Pressure Transducers Load Cells Strain Gage Flowmeters pH Measurement Level Measurement

62 this multimeter may also be known as a volt-ohm-milliammeter
this multimeter may also be known as a volt-ohm-milliammeter

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65 Digital Capacitance Meter
                                                                        (1) Each units are: t seconds, R ohms, C farad and epsilon is a Napier's number (approx. 2.72). When VC reaches VC1, the time t1 can be expressed in following formure.                                                                                       (2) This means that the t1 is proportional to C. Thus the capacitance can be calcurated from charge time and any other fixed parameters.

66 Displacement, Location, or Position Sensors

67 Displacement, Location, or Position Sensors

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69 FREQUENCY MEASUREMENTS
ANALOG FREQUENCY MEASUREMENTS

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71 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.

72 This 1-kHz linear-scale analog frequency meter circuit uses the 555 as a pulse counter

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74 DEFIBRILLATORS

75 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 INSTRUMENTATION

76 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

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78 Energy limits A.C. defibrillator 0.25 sec × 230 volts × (I Amps) = 450 watts-sec. Required required I = 7.5Amps. But preferable 0.01 sec. Pulses. Then I = 450/(230 × 0.01) = 175 A. This is too much to be supplied by household mains.

79 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 1. External 400J (7 kV). 4. Charging time constant of 4 seconds M Ω × 16 μF 2. (charging resistor) Takes about 16 secs. to charge to 4 kV.

80 CAPACITIVE-DISCHARGE DC DEFIBRILLATORS
MEDICAL INSTRUMENTATION Application and Design FOURTH EDITION John G. Webster, Editor CAPACITIVE-DISCHARGE DC DEFIBRILLATORS A short high-amplitude defibrillation pulse can be obtained by using the capacitive-discharge circuit shown in Figure 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.

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82 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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84 Fast charging — less than 3 seconds to 150J and less than 5 seconds to 270J

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88 Principles of Bioelectrical Impedance Analysis

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90 A method which involves the measurement of bioelectrical
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. FFM was assessed by hydrodensitometry and ranged from 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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93 Uroflowmetry http://www.digitimer.com/urodynamics/urodynamics.htm
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. Tepe idrar akım hızı erkeklerde 20 ml/sn, kadınlarda ise 25 ml/sn üstünde normal oalrak kabul edilir

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95 Turbine Flowmeters for Liquid Measurement

96 Peak-Flow Metre (Nefes ölçüm testi)

97 Peak-Flow Metre (Nefes ölçüm testi)

98 Breath Alcohol Tester

99 MQ303A is semiconductor sensor is for Alcohol detection,
Alcohol Tester Sensor MQ303A is semiconductor sensor is for Alcohol detection, Model No. MQ303A Sensor Type Semiconductor Standard Encapsulation Metal Detection Gas Alcohol Concentration ppm Alcohol Standard Circuit Conditions Heater Voltage V H 0.9V ± 0.1V AC or DC Loop Voltage Vc ≤6V DC Load Resistance R L Adjustable Heater Resistance R H 4.5W ± 0.5 W(Room Tem.) Heater Current IH 120±20mA Heater Power PH ≤ 140 mW Character Sensor Consumption PS ≤10 mW Sensing Resistance Rs 4KΩ-400KΩ(in air) Sensitivity S Rs(in air)/Rs(125ppm Alcohol)≥3 Slope α 0.50 ± 0.15(R300ppm/R100ppm Alcohol) Condition Tem. Humidity 20°C±2°C;65%±5%RH Standard test circuit Vc:3.0 V±0.1 V DC; VH: 0.9 V±0.1 V DC Preheat time Over 48 hours

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102 Digital Blood Pressure Meter