Presentation on theme: "Conversion and Calculations of Healthcare Measurements"— Presentation transcript:
1 Conversion and Calculations of Healthcare Measurements
2 Solution Concentrations Volume of Solutions/Blood Metric UnitsMeasurements are used often in Healthcare.The Clinical laboratory uses measurement in almost all aspects of its operation.Ex.Solution ConcentrationsCell CountsDensity of SpecimensVolume of Solutions/BloodDilutionsTimeTemperatures
3 Which method is best to convert between units? Converting between units can be done in different ways. Initially, students learn to convert units using the ladder method. This method is not appropriate for healthcare. As conversions progress in difficulty, particularly between measurement systems it is best to use the dimensional analysis /proportional relationship method.
4 Scientists and Healthcare Professionals Work in Metric Units Measurements made in the Healthcare Laboratory have a direct impact on the quality of patient care. It can be a matter of determining a diagnosis, follow the course of a disease and prescribing the correct treatment. The measurement must be reliable, accurate, standardized and precise. Measurements in healthcare can mean the difference between life and death.Reinforce the importance of precision and accuracy of measurement in Health Care.
6 Systems of Measurement United StatesEnglish System of Measurement, sometimes called the U.S. customary system. Used in every day life in the U.S. for measurement.English Units for Distance:Inch, feet, yard, mile, etc.Example: How many inches arethere in 12 feet?12 inches (”) =1foot (’)12” * 12’ = 144”
7 English System of Measurement Other common Units in the English System Pound Cups Pint Miles These units are not accurate enough for scientific measurement; hence the most accurat system the metric system is used.
8 Metric SystemUsed internationally by scientists and Healthcare In most countries the metric system is used in everyday The metric system is based on the power of 10, decimal system with a fundamental unit Due to the decimal system very, very small quantities can be measured accurately and easily.
9 Groups of TenThe Metric system is based on Powers of Ten. Ten of one unit equals 1 of the next, and ten of those equals 1 of the next… and so on and so on.Have students come up with a mnemonic to help them remember the powers of 10Example: King Henry Died Basically Drinking Chocolate (Kilo, Hecta, Deca, Basic Unit, Deci, Centi, Milli, Micro, Nano).
11 Measurements of Length Base UnitMeterType of MeasureLengthToolRuler
12 Measurements of MassBase UnitGramType of MeasureMassToolScale
13 Measurements of Volume Base UnitLiterType of MeasureVolumeToolGraduated Cylinder
14 Measurement of Temperature Base UnitDegree CelsiusType of MeasureTemperatureToolThermometer
15 Temperature is not reported in metric or SI units Three ScalesFahrenheitboiling point 212° Ffreezing point 32 ° FUsed in the U.S. for cooking, body temperature and weatherCelsiusboiling point 100° Cfreezing point 0° CUsed for making most scientific temperature measurements. Most countries other than the US use the Celsius scale for everyday temp.KelvinThe Kelvin scale is a scientific scale for the temperature above absolute zero (0 K, °C). The difference in scales is
17 Conversion of Temperature If someone says that the temperature will be 303 K today, how can you express that temperature in °C and °F? Try to SolveTo convert from Kelvin to Celsius: TC = TK - 273To convert from Celsius to Fahrenheit: TF = 9/5(TC) + 32
18 Conversion of Temperature If someone says that the temperature will be 303 K today, how can you express that temperature in °C and °F?To convert from Kelvin to Celsius: TC = TK TC = TC = 30°CTo convert from Celsius to Fahrenheit: TF = 9/5(TC) TF = 9/5(30) TF = 86°FTemperature Conversion Answer30°C, 86°F
19 International System of Units Standardize scientific measurements worldwideIn the U.S. SI units are mandated in all federal agenciesSI units are derived from the metric system are based on seven fundamental units.
20 Again the Fundamental Units of the Metric System are… Different units are used to measure different things. Length – Meters Mass – Grams Volume – Liters Density – Mass/Volume Also part of the Metric System: Temperature - Celsius
21 Common Basic Units in Healthcare Liter Meter Gram In the laboratory it is more common to measure smaller units than the basic units.
22 Metric System uses Power of 10 Prefixes are added to the base unit (ex. liter,meter or gram) to indicate larger or smaller units.
23 cm=centimeter cc=cubic cm milli- m thousandth 1/1000 = 0.001 10-3 mega-Mmillion1,000,000106kilo-kthousand1,000103kilogramsdeci-dtenth1/10 = 0.110-1dm3=litercenti-chundredth1/100 = 0.0110-2cm=centimeter cc=cubic cmmilli-mthousandth1/1000 = 0.00110-3mg=milligram mL=millilitermicro-millionth1/1,000,000 =10-6µg=microgramnano-nbillionth1/1,000,000,000 =10-9nm=nanometersExamplesMetric facts: 1 cubic centimeter = 1 milliliter (1 cc=1mL) Liter = 1 cubic decimeter = 1,000 cubic centimeters = 1,000 milliliters Lower case “m” stands for meter or “milli”. Capital “L” for liter.
24 Unit PrefixesSimply add a prefix to the unit to show the quantity, size or value in powers of tenUnits Larger than the base:deca = 10 xhecto = 100 xkilo = 1,000 xUnits Smaller than the base:deci = .1 xcenti = .01 xmilli = .001 x
25 What to do to solve metric conversions problems? Identify what you are asked. Write down what is given or known. Look for relationships between knowns and unknowns (use charts, equations). Rearrange the equation to solve for the unknown. Do the computations, cancel the units, check for reasonable answers.
26 Steps of Dimensional Analysis Start with what value is known, proceed to the unknown.Starting point = the number and unit provided by the questionFinal destination = the units desired after convertingDraw the dimensional lines (count the “jumps”).Insert the unit relationships.Cancel the units.Do the math, include units in answer.
27 Dimensional jumps between prefixes How many jumps between deci and giga 10-1 x 10 9 = 10 jumps (9-(-1) =10)For the next few slides instructs students to identify the known and unknown and set up a proportional relationship, using both the chart and dimensional jump methods. Demonstrate both methods to the students.
28 Write the KNOWN, identify the UNKNOWN. EX. How many km is 582 mm ?582mm = ______km
29 Draw the # of dimensional “jumps” EX. How many km is 582 mm ?582 mm2 x_____ x_____x_____x_____x_____x_____
30 Using the dimensional jump method 582 mm x_____ x_____x_____x_____x_____x___
31 *Units leftover SHOULD be units of Cancel Units582mmxmmcmdmmdkmhmkm*Units leftover SHOULD be units ofUNKNOWN
32 Insert Relationships (Prefixes from the known to the unknown) How many km is 582 mm ?582 mm x_.1cm_ x_____x_____x_____x_____x_____.1dm.1m.1dkm.1hm.1km1 dm1 mm1cm1m1dkm1hm
36 Convert 21 mg per liter (21 g/L) to grams per 100 cc Starting amountequalequalequalEnd Amount21 mg Liter0.001 milli1L 1000cc= g cc
37 Conversion of Metric Units to Metric Units The ratio and proportion procedures is probably the most useful way to convert one unit of measure to anotherEx.How many milligrams equal 0.025g?The unknown ratio is 0.025g to “x” mg.Make a ratio:0.025g/x mg = 1g/1,000mgx= X 1,000x = 25 mgHence 25mg = g