INTRODUCTION TO CHEM

1. INTRODUCTION TO CHEM/PHYSICS OF ANESTHESIA Review of Measurements Review of Chemistry Basics Review of the Basics of Physics Fluids Solubility Gas Laws Vaporization Acid Bases and Buffers Sine Waves Electricity

2. Mathematical Review What is Physics Review of Basic Math Measurement and Significant Calculations Estimation Accuracy and Precision Si Density Specific Gravity

3. Order of Operation Addition Subtraction Multiplication Division You need to do multiplication and division before addition and subtraction

4. X = 12 + 3 x 10 X = 12 = 30 X = 42

5. Algebra Unknown quantity Convert equation into some form of x If the variable is multiplied by some number you need to divide both sides of the equation by that number If the variable is divided by some number you need to multiply both sides of the equation by that number Addition and substraction the same rule applies

6. 12X = =180 X = 15

7. Square Roots

8. Exponentials Shorthand for the number of times a quantity is multiplied Volume = 1cm x 1cm x 1cm Volume 1 x 1 x 1 = cm x cm x cm 1 x 1 x 1 =1 1cm�

9. Logarithms Logarithms are mixed up exponents.

10. Scientific Notation The use of exponents for handling very large numbers. A number multiplied by the power of ten. How many places you have to move the decimal point so that one digit remains to the left of the decimal point. 11,000,000 = 1.1 x 107 0.00000000045 = 4.5 x 10 -9

11. Estiminations How many piano tuners are there in Chicago?

12. Graphing The value of x changes in a predictable way in response to changes in the value of some other variable

13. Accuracy and Precision Accuracy The agreement between experimental data and the true value Precision Is agreement between replicate measurement

14. It is important that the pulse oximeter gives consistent readings If the readings are different every time you will lose confidence in the patients condition

15. Si metric system The metric system consists of a base unit and a prefix multiplier Base unit = length, mass or volume Prefix = multipliers increase or decrease the size of the base unit

16. Session 2 Review of Chemistry

17. State of Matter Five states

18. Atomic Structure

19. molecules Made up of atoms of or different elements

20. Vanderwaals Forces Two molecules on collision course Closer accelerate toward one another Initial collision molecule adopts new straight course As temperature increases number of collisions increase

21. Isotopes Different atomic weights caused by gain or loss of atoms � different physical properties

22. Avogadro Avogadro's Number, 6.022 x 1023

23. Periodic table

24. Chemical bonding

25. Chemical bonding NaCl

26. Covalent bond Covalent bonds form when atoms share electrons. Since electrons move very fast they can be shared, effectively filling or emptying the outer shells of the atoms involved in the bond. Such bonds are referred to as electron-sharing bonds. An analogy can be made to child custody: the children are like electrons, and tend to spend some time with one parent and the rest of their time with the other parent. In a covalent bond, the electron clouds surrounding the atomic nuclei overlap.

29. Covalent Bond

30. 

31. Chemical reaction Combustion

32. Carbon Dioxide Absorber Reaction of CO2 in Soda Line CO2 + H2O H2CO3 H2CO3 + 2NaOH Na2CO3 + 2H2O + heat Na2CO3 + Ca(OH)2 CaCO3 + NaOH

33. Valence a measure of the number of chemical bonds formed by the atoms of a given element. The concept was developed in the middle of the nineteenth century in an attempt to rationalize the formulae of different chemical compounds.

34. Radical

35. Radical Group of Atoms Hydroxyl l (-OH) Phosphate (PO4.2) Ammonium (NH4) Bicarbonate (HCO3) Sulfate (SO) Nitrate (NO3) Carbonate l (CO3)

36. Organic Chemistry

37. Names Ethane 2 Carbons Propane 3 Carbons Butane 4 Carbons Pentane 5 Carbons Hexane 6 Carbons Heptane 7 Carbons Octane 8 Carbons nonane 9 Carbons Decane 10 Carbons

38. The next most complex hydrocarbon structure is called ethane CH3CH3

39. Alkane Each bond is accounted for by an individual atom Remove a H substance become a radical Methane CH4 Methy CH3 Radicals are named by converting ANC to YL Methane to Methyl Propane to Propl

40. Complex Organic Compounds Branch chain alkanes (named for longest continued chain) Name, position on chain begins at either end of longest chain Primary, Secondary and tertiary are used to differentiate forms of the same compound Atom groups may be indicated by a prefix. Numbers denote position When identical groups are located on the same carbon the main chain number are supplied for each group Last portion of the compound name will be the main chain alkane

41. Alkenes and Alkynes Alkenes Have a general formula C2H2

42. Isomers

43. Stereoisomers Identical structural formula but different in their spatial arrangement Optical Oeometric

44. Optical Isomers When the groups attached to the carbon atom differ from one another Cause a bending (rotation) of light passing through the substance�s vertical axis. Light polarized to the right produces a dextro isomer, when light is polarized left the levo isomer is formed Mirror images Mixed racemic

45. Oeometric Isomers Two carbon atoms joined by a double bond

46. Class Divisions of Organic Compounds Alcohol

47. Class Divisions of Organic Compounds Alcohols Primary Secondary Tertiary

48. Class Divisions of Organic Compounds Halogen Aldehydes

49. Class Divisions of Organic Compounds Ketone

50. Class Divisions of Organic Compounds Esters

51. Class Divisions of Organic Compounds Amino acid

52. Class Divisions of Organic Compounds Amine

53. Class Divisions of Organic Compounds Amide Amide synthesis

54. Class Divisions of Organic Compounds Thio Compounds

55. Class Divisions of Organic Compounds Organic Acids (COOH)

56. Class Divisions of Organic Compounds Quaternary Base Formed from Ammonium hydroxide

57. Class Divisions of Organic Compounds C6H6

58. Class Divisions of Organic Compounds Ethyl ether Dimethyl ether Diethyl ether isoflurane

59. Class Divisions of Organic Compounds Polynuclear Aromatic Structure

60. Session 3 Review of Physics

61. CAUSES OF MOTION Newton�s First Law Newton�s Second Law Newton�s Third Law Vectors Gravity Frictional Forces

62. MOTION SPEED VELOCITY ACCELERATION

63. Reduction Valves

65. Resistance Resistance = pressure drop/flow Pressure drop along a tube which results fluid flow

66. Pumps Heart Apply and learn most laws of Physic Flow Force

67. Work Work Work done on an object is the force times the distance moved W =Fs

68. Energy Capacity for doing work Cannot be lost but converted

69. Law of Conservation of Energy Energy can neither be created or destroyed through it can be transformed from one form to another

70. Power RATE OF DOING WORK Differential of work Similar to velocity (distance :velocity) Units of power are watts

71. Machine DEVICE FOR MULTIPLYING FORCE Does not supply energy Mechanical advantage = force output/force input

72. Heat and Temperature Temperature is a measurement of the tendency to gain or loose heat Heat is energy which can be transferred

73. First Law of Thermodynamics

74. Stress Force on a given area Stress = force/area

75. Thermal Expansion An increase in heat will cause an object to expand Expansion is constant for a given material Expansion is constant in all directions

76. Thermometry Liquid expansion Thermometers Bimetallic Strip Thermometer Thermocouples Thermistors Radiation Thermometry

77. HEAT Calorie is the unit of measurement Calorie is the heat required to raise 1g of water 1o C

78. Heat Capacity Heat required to raise the temperature of a given material HEAT Capacity = Mass x Specific heat

79. Specific Heat The amount of heat required to raise the temperature of 1kg of a substance by 1oC Specific heat of gas<<<<<specific heat of corresponding liquid

80. Effects of heat Heat of crystallization Latent heat of fusion Latent heat of vaporization

81. Factors that affect the rate of change of heat of an object Heat Capacity (inv proportional) Temperature gradient (dir proportional) Surface area (dir proportional) Forced convection(dir proportional)

82. Heat Transfer Convection 30% Conduction 20% Radiation 40% Evaporation 10%

83. Convection Heat transfer caused by the movement of a liquid or gas natural forced

84. Conduction Transfer of heat by the direct interaction of molecules in a hot area with molecules in a cooler area Does not involved motion of the body thermal conductivity of material is a measure of efficiency Rate of heat loss = (wall area)(thermal conductivity wall thickness

85. Radiation All bodies absorb or emit electromagnetic radiation including thermal or infrared radiation Stefan-Bolzman - Total emmissive power

86. Evaporization Heat lost through respiration

87. Body Temperature Average body temperature Core temperature 37C Skin temperature 34C Average Temp 36C 0.66 x core temperature + 0.34 x ave skin temp 2/3 Core 1/3 Shell

88. Session 4 Fluids

89. Pressure P = f/a P = pressure f = force a = area Pressure is inversely proportional to the cross section of the radius

90. Pascal�s Principal When an external pressure is applied to confined fluid, it is transmitted unchanged to every point within the fluid

91. Pressure is inversely proportional to the cross section of the radius

92. Buoyancy buoyancy is the upward force on an object produced by the surrounding liquid or gas in which it is fully or partially immersed, due to the pressure difference of the fluid between the top and bottom of the object.

93. Archimedes Principles An object immersed either totally or partially in a fluid feels a buoyant force equal to the weight of the fluid displaced

94. Hydrodynamics Moving fluids Flow Rates The volume of fluid passing a particular point per unit time Velocity

95. Bernoulli Law states that the pressure of a fluid varies inversely with speed, an increase in speed producing a decrease in pressure (such as a drop in hydraulic pressure as the fluid speeds up flowing through a constriction in a pipe) and vice versa

96. Venturi Tube Flowmeter

97. Venturi cont The Venturi effect is the fluid pressure that results when an incompressible fluid flows through a constricted section of pipe.

98. Surface Tension The force per unit length acting across any line in the surface and tending to pull the surface apart across the lines Temperature

99. Surface Tension

100. Viscosity A measure of the resistance of a fluid to deform under shear stress. It is commonly perceived as "thickness", or resistance to pouring.

101. Laminar Flow When a fluid streams through a tube, the particles comprising the fluid

102. Poiseuille�s Law Poiseulle determined that the laminar flow rate of an incompressible fluid along a pipe is proportional to the fourth power of the pipe's radius. To test his idea, we'll show that you need sixteen tubes to pass as much water as one tube twice their diameter.

103. Reynolds Number For a given liquid and tube there is a critical flow rate above which the flow will become turbulent Proportional to viscosity Inversely Proportional to density Inversely proportional to the radius of tube

104. Turbulence

105. Session 5 Solubility

106. Density Density= Mass/Volume

107. Absolute humidity refers to the mass of water in a particular volume of air

108. Specific Gravity Specific Gravity = density of substance/density of water

109. Diffusion Process by which the molecules of a substance transfer through a layer or area such as the surface of a solution Diffusion can still take place without a membrane or gas-liquid barrier Process of molecular intermingling Molecular movement and should not be confused with movement in bulk, for which some external force like gravity must apply

110. Gas diffusion

111. Solubility Henry�s Law Temperature effect Coefficient of solubility Bunsen Solubility Ostwald�s Solubility Coefficient Meyer Overton Fick Graham

112. Osmosis

113. Osmotic Pressure Inversely proportional to the volume of the solution Proportional to absolute temperature PV =nRT

114. Solubility Applications Oxygen Therapy Oxygen therapy for abdominal distention Air Embolism Diffusion Hypoxia Inhalation of gas mixtures at positive pressure

115. Solubility Coefficient

116. Relative Humidity Relative humidity is defined as the ratio of the partial pressure of water vapor in a gaseous mixture of air and water to the saturated vapor pressure of water at a given temperature. That is, a ratio of how much energy has been used to free water from liquid to vapor form to how much energy is left

117. Session 6 Gas Laws

119. Gas Laws Boyle�s Charles Dalton�s Henry�s Graham�s Gay-Lussacs Ideal Ficks

120. BOYLES V/T=CONSTANT P1V1 = P2V2

121. Boyles law

122. Charles Law V1 / T1 = V2 / T2

123. Charles / Guy Lussacs

124. Daltons Law P =P1 + P2 + P3

125. Henrys Law The amount of a non reacting gas which dissolves in liquid is directly proportional to the partial pressure of the gas, provided the temperature remains constant

126. 

127. Ficks Law Fick's First Law is used in steady state diffusion, i.e., when the concentration within the diffusion volume does not change with respect to time (Jin=Jout).

128. Ideal Gas Law PV = nRT P = pressure V = volume n = Mass or number of gas molecules R = gas constant (8.317J / mole K) T= absolute temperature

129. Joule-Thompson Effect is a process in which the temperature of a real gas is either decreased or increased by letting the gas expand freely at constant enthalpy (which means that no heat is transferred to or from the gas, and no external work is extracted).

130. Adiabatic Compression Compression in which no heat is added to or subtracted from the air and the internal energy of the air is increased by an amount equivalent to the external work done on the air. The increase in temperature of the air during adiabatic compression tends to increase the pressure on account of the decrease in volume alone; therefore, the pressure during adiabatic compression rises faster than the volume diminishes

131. Remembering Gas Laws

132. Law of La Place

133. Tension and Pressure Relations for Soap Bubbles

134. Tension and Pressure Relations for Surfactant Deficient Alveoli (ARDS)

135. La Place

136. Applications of Gas Laws

137. Session 7 Vaporization

138. Vaporization Vapor pressure Boiling point Concentration of gases Specific heat Thermal conductivity

139. Heat of Fusion The energy required to change a gram of a substance from the solid to the liquid state without changing its temperature is commonly called it's "heat of fusion". This energy breaks down the solid bonds, but leaves a significant amount of energy associated with the intermolecular forces of the liquid state.

140. Heat of Vaporization The energy required to change a gram of a liquid into the gaseous state at the boiling point is called the "heat of vaporization". This energy breaks down the intermolecular attractive forces, and also must provide the energy necessary to expand the gas (the PDV work). For an ideal gas , there is no longer any potential energy associated with intermolecular forces. So the internal energy is entirely in the molecular kinetic energy. The final energy is depicted here as being in translational kinetic energy, which is not strictly true. There is also some vibrational and rotational energy.

141. Saturated Vapor Pressure The process of evaporation in a closed container will proceed until there are as many molecules returning to the liquid as there are escaping. At this point the vapor is said to be saturated, and the pressure of that vapor (usually expressed in mmHg) is called the saturated vapor pressure. Since the molecular kinetic energy is greater at higher temperature, more molecules can escape the surface and the saturated vapor pressure is correspondingly higher. If the liquid is open to the air, then the vapor pressure is seen as a partial pressure along with the other constituents of the air. The temperature at which the vapor pressure is equal to the atmospheric pressure is called the boiling point.

142. Evaporation Ordinary evaporation is a surface phenomenon - some molecules have enough kinetic energy to escape. If the container is closed, an equilibrium is reached where an equal number of molecules return to the surface. The pressure of this equilibrium is called the saturation vapor pressure. In order to evaporate, a mass of water must collect the large heat of vaporization, so evaporation is a potent cooling mechanism. Evaporation heat loss is a major climatic factor and is crucial in the cooling of the human body

143. Evaporation vs Boiling

144. Boiling Point The boiling point is defined as the temperature at which the saturated vapor pressure of a liquid is equal to the surrounding atmospheric pressure. For water, the vapor pressure reaches the standard sea level atmospheric pressure of 760 mmHg at 100�C. Since the vapor pressure increases with temperature, it follows that for pressure greater than 760 mmHg (e.g., in a pressure cooker), the boiling point is above 100�C and for pressure less than 760 mmHg (e.g., at altitudes above sea level), the boiling point will be lower than 100�C. As long as a vessel of water is boiling at 760 mmHg, it will remain at 100�C until the phase change is complete. Rapidly boiling water is not at a higher temperature than slowly boiling water. The stability of the boiling point makes it a convenient calibration temperature for temperature scales.

145. Vaporization Vapor Pressures at 200C Isoflurane 239mmHg Enflurane 175mmHg Halothane 243mmHg Desflurane 669mmHg Sevofurane

146. Calculating Volumes of Vapor Formed in Vaporizers Volume Vaporized Vp (vapor pressure) = Total Gas Flow Patm (atmosphere pressure) (Vp/760mmhg)(carrier Flow) volume vaporized = -------------------------------------- 1- (Vp/760mmhg (239/760)(200) (.31)(200ml/min) VV = ------------------- = ---------------------- = 91ml/min 1 - (329/760) (.69)

147. Generic Vaporizer Schematic

148. Humidity Humidity is the amount of water vapor in an air sample There are three different ways to measure humidity: absolute humidity relative humidity, specific humidity.

149. Specific Humidity Specific Humidity is the ratio of water vapor to air (dry air plus water vapor) in a particular volume of air.

150. Session 8 Acid Base Buffers

151. Chemical Equilibria Starting materials products Starting materials combine to give products break down into starting materials. These two processes occur simultaneously

152. Le Chatelier Principle Equilibrium is a good thing and nature strives to attain and/ or maintain equilibrium

153. changing concentration If you add products the equilibrium will shift toward reactants. If you remove products the equilibrium will shift towards the product. Hb + 4O2 Hb(O2)4 Lungs oxygen concentration is high increased oxygen concertration is added to the material equilibrium shifts towards the product ( oxyhemoglobin) trying to undo the increased oxxygen Cells the oxygen is low the system precieves this as removing reactant equilibrium shift towards the material trying to replace the missing reactant oxygen Therefore hemoglobin loads up on oxygen in the lungs and dumps oxygen into the cells

154. changing temperature Exothermic reaction evolve energy from the system Endothermic reactions absorb energy from the system Therefore: increase in temperature favors endothermic process

155. Changing volume and pressure Changing volume and/or pressure only impacts equilibrium reactions when at least one reactants or products is a gas ( solids and liquids are not compressable) With respect to hemoglobin when the partial pressure of oxygen is increased equilibrium shifts right ( why giving pure oxygen results in a greater oxygen saturation in the blood)

156. Acid and Bases Acid donates a hydrogen ion to a base Base accepts a hydrogen ion from an acid

157. Acid Base Pairs HCL H+ + CL- The H+ ion is a proton Chloride ion has special relationship with HCL If the reaction ran in reverse the chloride ion would pick up the hydrogen ion. If the chloride ion took a hydrogen ion that would mean if was acting as a base. Therefore: Chloride is the conjugate base of HCL and HCL is the conjugate acid to chloride They are conjugate acid-base pairs

158. Conjugate Acid and Bases

159. acid conjugate base of acid HCL + H2O CL + H3O+ base conjugate acid of base

160. Strong acid When a strong acid dissolves in water it essentially 100% ionized. That means essentially all of the molecules dissociate into ions. The reaction is not an equilibrating process, so all of the starting materials are converted into product. HCL + H2O H3O + CL-

161. Common Strong Acids

162. Strong Bases Bases accept hydrogen ions the strongest possible base is the hydroxide ion OH A strong base ionizes 100% produces the OH- ion NaOH Na+ + OH-

163. Strong bases

164. Weak Acids Weak acids are able to donate hydrogen ions to bases but are less determined to do so than strong acids When weak acid dissolves in water establishes dynamic equilibrium between molecular form and ionized form HC2H3O2 H+ + C2H3O2- acetic acid in water

165. Weak Acids (notice that ions can behave as acids as well as molecular compounds)

166. Weak bases Weak bases do not completely ionize in water When weak bases dissolve in water it establishes a dynamic equilibrium between the molecular form and the ionized form NH3 + H2O NH4+ + OH-

167. Weak bases

168. Polyprotic acids Diprotic acid has more than one hydrogen ion to donate H2CO3 carbonic acid Tripotic Acid has three hydrogen ions to donate H3PO4 phosphoric acid

169. pH pH= -log[H+]

170. Buffers The buffer in a solution resists changes in pH Buffer contains contain weak acid and conjugate base

171. Ka Negative log of Ka is pKa The concentration of the base is greater than the concentration of the weak acid Therefore the pH is on the basic side of the pKa

172. pKa (weak acids and weak bases) Weak acids become more unionized as ph decreases pKa of a weak acid is the pH at which 50% of the weak acid is ionized and 50% is unionized pKa is different for different weak acids unionized pH 1 7.4 8.5 14 pKa

173. ionized 1 3.5 7.4 14 pH pKa pH pH The higher the pKa of a weak acid the greater the amount of drug that is unionized at physiologic pH

174. Weak bases A weak base is more unionized as th ph increases The pKa of a weak base is the pH at which 50% of the weak base is in ionized and 50% ins unionized The pKa is different for different weak bases A given weak base may have any pKa however the pKa is constant for a given weak base

175. Weak bases ionized 1 7.4 9.1 14 pH pH pKa pH unionized 1 4.5 7.4 14 pH pKa pH pH

176. Session 9 Sine wave

177. Biological Potentials Cell Membrane Hydrophobic interior Protein and carbohydrate exterior Change in ion charges Sodium pump

178. ECG Resting membrane potential is about 90mV Rapid loss occurs prior to conduction Depolorization Sodium ions move in Potassium ions move out Repolorization Opposite on transfer brings membrane back to negative Active transport

179. ECG cont 1-2 mV Signals pass through muscle and skin and spread outward P wave represents atrial depolorization (wave repolorization is hidden in the QRS) QRS Ventricular depolorization T wave ventricular repolorization The larger the muscle the more voltage required and the greater the deflection

180. EMG Shorter duration 5-10mS Repolarizes very quickly Do not depolorize in wave like fashion

181. EEG Appearance is important Slow low frequency cerebral hypoxia Anesthesia depth is indicated by a decreasing frequency and amplitude

182. Electrodes Used to pick up biological electrical potentials directly at the skin Skin surface Moisture Electrical impedance

183. Amplifiers Measure differences between two sources Resistance may vary Drift Range of frequencies is relative constant bandwidth Ratio of voltage to output Gain measured in decibels

184. Electrical potential initiators Defibrillators Nerve stimulators Pacemakers Pain stimulators ECT

185. Sine Waves

186. Cathode Ray Tube CRT Today�s method of recording Biological Potentials An electron beam passes through two deflecting devices, one is deflected horizontally (x axis) the othee vertically (y axis). When the beam strikes a fluorescent screen a tracing is produced The electron beam has negligible inertia therefore: you get a very high frequency response

187. Concept of sine waves Biological processes occur in a repetitive pattern A sine produces this pattern

188. Sine waves cont Angle A has a different value at each moment because the crank is rotating at a constant rate. D on the vertical axis shows the angle of A corresponding to the different times along the hortizontal axis

189. Wave Length The distance between any two corresponding points in successive cycles (the distance between 2 peaks or troughts) Horizontal axia

190. Amplitude Maximum displacement of the wave from horizontal axis

191. Frequency Number of cycles which occur in 1 sec. Cycles per second are called Hertz (Hz)

192. Period of wave motion The time taken for one complete cycle to occur The reciprocal of frequency T=1/f

193. Velocity of a wave in motion Velocity = frequency x wavelength

194. waves Different waves have different velocities If the velocity is fixed-then the frequency and wavelength are inter-related The higher the frequency the shorter the wave length and vice versa

195. Sound Waves

196. Sound waves cont Sound waves of different frequencies are picked up by the ear as changes in pitch Sound waves with high frequency, short wave length = high pitch note Sound wave with a low frequency, long wave length =low pitch

197. Sound waves cont Sound waves are regions of higher and low pressure in the air and travel at a fixed velocity. As the object producing sound mover closer to you, each high pressure region becomes closer to the previous one and the wave length becomes shorter. You pick up this frequency as a higher pitch. Vice versa Doppler effect

198. Sound waves cont ultra sonic detectors Ultrasonic waves are beamed along an artery and the red blood cells reflect these high frequency sounds waves. The movement of the RBC�s give a Doppler change in frequency

199. Sound waves cont When sound wave and other waves reach a boundary between two different substances, part of the wave is transmitted and part is reflected. Sound waves- the difference in the density between the two the two materials determine how much of the wave tis transmitted and how much is reflected.

200. Sound waves cont If an ultra sound transducer is used, the wave must pass between air (low density) and a solid structure (high density) the signal can be attenuated Gel reduces density

201. Sound waves cont Ultrasound waves can also be used to form images of body structures become the wave are reflected off boundaries and interfaces between substances of different densities.

202. Sine waves The addition of whole range sine waves, each with different frequencies, may result in quite a complex wave form. The range is important in the design and use of monitoring equipment. Wave forms can be produced by addin appropriate sine waves

203. Fourier Analysis Mathematical process of analyzing complex patterns into a series of simple sine wave patterns. .5Hz Frequency range 100Hz Wave patterns that have sharp spikes have high frequencies, smooth rounded waves have a more limited range of frequencies

204. Light Waves

205. Light waves cont Light wave motion with high frequency and short wave length = blue Color spectrum Light wave motion with lower frequency and longer wavelength = red

206. Light waves cont Visible light is a small part of the electromagnetic spectrum and includes Radio waves Infrared waves Infrared radiation Gamma and X-rays Visible light Visible and infrared

207. Light waves cont Ultrasound have a limit to the power which can be absorbed by tissue with harm. Absorbed power raises temperature Cavitations

208. The relationship between absorbance and transmittance is illustrated in the following diagram:

209. The amount of radiation absorbed may be measured in a number of ways: Transmittance, T = P / P0% Transmittance, %T = 100 T Absorbance, A�=�log10 P0 /�PA�=�log10 1�/�T A�=�log10 100�/�%TA�=�2�-�log10 %T�

210. Section 10 Electricity

211. Basic Principles of Electricity Fundamental force of nature Electrical force is the force between two objects on their charge Charge is a basic property of two of the elementary particles (protons and electrons) Electrical force can be attraction or repulsion The force is inversely proportional to the square of the distance between the objects

212. Basic principles cont Ohms Law (electrons to pass through their conduction band with very little effort) V = I + R V = electromotive force I = current R = resistance

213. Basic principles cont DC = electron flow is always in the same direction

214. Basic principles cont AC = electron flow reverses direction at regular intervals

215. Basic principles cont Capacitance = measure of the ability of object to hold charge

216. Basic principles cont Inductance = is the magnetic field induced around the wire when electron flow is in the wire

217. Basic principles cont Impedance (Z) = forces that oppose electron movement in an AC circuit. ( a more complicated form of resistance that includes capacitance and inductance.

218. Basic principles cont Series circuits = current flows through each object one after another

219. Basic principles cont Parallel = current divides every time it come to a junction different currents flow through the different objects

220. Basic principles cont Grounding Electrical power Grounded Ungrounded Electrical equipment

221. Basic principles cont ungrounded power

222. Basic principles cont grounded power

223. Basic principles cont Conductors

224. Basic principles cont Insulator a substance in which a charge cannot easily move

225. Basic principles cont Semiconductor material whose conduction charges as a result of an external force Thermistor as temp increases resistance decreases Photodector switch Diode Transistor

226. Basic principles cont Static electricity ( rubbing amber against material can lead to a transfer of electrons, so that one will have an excess of the and the other a deficit)

227. Basic principles cont Ampere (unit of current) electromagnetic force 6.24 x 10 to the 18 electrons per minute

228. Electrical Hazards in the OR Whenever an individual contacts an external source of electricity Shock is possible

229. Electrical Hazards in the OR Sources of electroshock Macroshock > 1 mA Microshock < 1 mA Conducting fluids Electrosurgery

230. Electrical Hazards in the OR Macroshock sources Severity depends on the amount and duration of current flow Occur when patient becomes the conduit through which current flows toward ground Isolated system in the OR provides significant protection from macroshock

231. Electrical Hazards in the OR Microshock sources Pacer wires Swan Ganz catheter CVP catheter Leakage* *partially ungrounded power source

232. Electrical Hazards in the OR Current can interfere with signal from ECG and other monitors If electrode is applied incorrectly a defective wire current will seek the path of least resistance Patient ECG or temperature probe

233. Electrical Hazards in the OR (LIM) Isolation power system provides an ungrounded electrical service for various applications within a hospital. These isolation power systems remain in operation in the event of a single line-to-ground fault situation. The system also eliminate the danger of an electric shock to patients who may be more susceptible to leakage current.

234. Electrical Hazards in the OR (LIM)

235. Electrical Hazards in the OR Summary All electrical equipment must undergo preventative maintenance, service and inspection Protect patients from contact with �earth�

236. Electrical Hazards in the OR summary Water on floor is dangerous Protect susceptible patients Uses common sense Be vigilant

237. Final Exam MAY