BIO307- Bioengineering principles FALL 2016 Lecture 8a Bioinstrumentation(Chapter 11) Lecturer: Jasmin Sutkovic 15.12.2016

Introduction Hospital operating rooms, emergency rooms, and doctors’ offices each contain an array of instruments used to measure and record a patient’s vital signs such as temperature, blood pressure, pulse, and oxygen saturation! The medical device industry—the constellation of large and small companies that design, manufacture, and sell medical devices and instruments—is one of the largest and most rapidly growing sectors of the U.S. economy.

Next generation instruments Makes the procedures quicker ! More efficient ! Lab on chip devices ?! Microarray analysis chip

Overview of measurement systems Most instrumentation systems contain common elements, which are present regardless of the parameter being measured! INPUT and OUTPUT The part of the instrument that detects the input is called a sensor. The sensor converts the input parameter into a signal, usually an electrical voltage, which varies in a predictable and reliable way with changes in the input parameter

Types of sensors

Measurement of body temperature High body temperature one of the first indicators for abnormal conditions. The normal body temperature is 98.6◦F (or 37◦C), although normal temperature varies somewhat from person to person. Usually, a temperature above 99.5◦F (or 37.5◦C) is a sign of an underlying illness or infection (or a child who needs to stay home from school) Hyperthermia, or elevated body temperature, can also occur as a result of prolonged exercise or exposure to excessive heat.

Temperature units 0° C = 273,15 K 0° C = 32F 0 °F = -17.77778 °C T(°C) = (T(°F) - 32) × 5/9

Core body temperature Actual core body temperature can be measured directly by using catheters to place temperature sensors into deep body compartments, such as the pulmonary artery. Placement of a catheter—a long, thin tube made of a biocompatible, flexible material, usually some kind of plastic—is accomplished by a procedure called a catheterization

Catheterization By this procedure, the tip of the catheter can be precisely placed in the heart, or into the lumen of vessels near the heart! This measurement is the most accurate reflection of the core body temperature. However, catheterization is invasive, expensive, and risky. Therefore, other methods, such as the glass thermometer, are used for routine temperature measurements.

Glass thermometer

Usage of Mercury glass thermometer However, their use in medicine is becoming increasingly rare. Mercury is highly toxic to the nervous system, and many countries ban their use in medical applications; manufacturers have replaced mercury with liquid alloys of gallium, indium, and galinstan

We cont next time…