Measurement
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Well when we talk about measurements in our curriculum here, the very first class we take that is a basic laboratory experience class, we immediately tell our students that the most important thing that they are going to learn to do is to make measurements Because we’re using the measurements to make reagents So we talk about measurements like volumetric and mass and how important it is to be able to do accurate measurements so that the reagents they make are of the highest quality, they are the best they can do No matter how crazy good your lab skills are, if you start out with a bad reagent, your results will always be bad. So the most important thing is get the reagent right first and then everything else will fall into place Well in the healthcare world, measurements is literally a life and death type of experience and you know everything from, we take care of folks from you know, even before they’re born, the pregnant woman all the way through the end of life care. And all through that, you know measurements are something that all health care professionals are gonna have to be aware of and not just aware of but be very able to do very precise calculations Because it has to do with giving medications, it has to do with giving treatments it has to do with giving oxygen therapy, it has to do with just some basic things like height and weight, blood pressure measurements things that we’re all familiar with if you’ve ever been to a healthcare provider’s office before But the world of measurement is just a universe we live in and breathe in everyday in health technologies. Well it’s important for anyone to learn about measurement, that if you think about just in daily life you go go to the gas station and you’re given a price per gallon, you go to the grocery store and you look at nutritional information and they tell you the number of servings and the for instance, sodium content per serving or the fat per serving and so any of this deals with measurements Now specifically for science students, that science is very quantitative that you’re dealing with numbers throughout the entire duration of whatever you’re doing in science And it’s part of the communication, that if in terms of measurement, not only is the value important, the units important but how you actually got those values, what tools did you use, and so on it makes the communication easier if we have this sort-of universal base language that we can all rely on Well, in our department, the Biotechnology department, our students are trying to train, many of them to get jobs right out of the 2 year program, so a lot of the things they might be expected to do in a laboratory deals with measurements. So knowing how to use the balances, knowing how to measure volume, knowing how to do significant figures and understanding the quality of your measurements all goes in to that. Basically it comes down to not having to repeat experiments often. If you’re in a situation where it’s a medical situation it could also be something where the health of somebody could depend on So it all depends on what kind of work you’re doing I think it’s important to remember when you think about healthcare you think about oxygen therapy. Every time you see something on TV and someone is really sick, how do they mimic it? They mimic it by putting a little nasal canula in their nose and oh my gosh, the patient’s really sick. It’s commonplace now, when you go into the hospital, everyone receives oxygen. But what people don’t remember is that oxygen is a drug and like any other drug it does have side effects And so particularly, you know, not only with adults but with particularly with babies, which is my specialty there can be dramatic sideeffects from too much or too little oxygen, so obviously if there’s too little oxygen, we’ll give them oxygen but we also don’t want to give them too much oxygen. Various types of lung disease, problems all throughout the body can be affected by too much oxygen. We’ve documented this, this is a tried and true thing over time, it’s well documented. Well routinely we will do volumetric measurements. We do mass measurements, ok? We also are doing a lot of things where we’re reading and analyzing using machines. So we’re doing a lot of measurements with very small volumes, working with our DNAs, working with our initial protein concetrations, we’re looking into microliters and micrograms and so we have to learn how to use the metric system way down at some of its lowest values. Well, routinely in the healthcare field, we deal a lot with medications and when you deal with medications you’re usually dealing with some sort of syringe and knowing how to calibrate and draw up accurately medications in a syringe. Um, also there’ll be fluids the different types of fluids we have come in liter bags or this one is a 250 mL or a fourth of a liter bag But there’s also weight and height. Particularly when we’re weighing premature newborns, that’s all done in gram weight. Not in pounds and ounces like when a newborn baby comes into the world and it’s 8 pounds 12 ounces. With our little premature babies, we have to measure them because they’re so small in gram weight. And so, it’s just across the board, it’s every way you can do a measurement on a human system. Or a human chemistry level even. Deciliters, millimeters, those sort of things go into calculations when you’re looking at blood studies and that sort-of thing. So it’s across the board of how we use these kind of conversions Well the big three that most labs will do commonly are temperature measurements, mass, or weight and also volume. Commonly solids are weighed and liquids are dispensed by volume. So those are the three and then there’s a wide range of other measurements that are done depending on the situation, but those three are the big ones. Usually pH, weight and volume, especially small volume. That’s what we basically concentrate on in our labs. Well, universally, of course, universally means globally, that is the system that’s most conmonly used, it’s the one that is most consistent, it’s easiest to use, when you talk about the logic that goes into how units are determined as compared to the English system. We know that in our world we’re going to be dealing with other scientists and they’re gonna be using the same system we are. We convert between the metric system all the time. Good examples are, and these are ones I really work with on students in the basic lab techniques class Converting between milliliter and microliter, when a paper or some protocol tells you that you need to add 0.5 mL, and you’re using a micropippeter, it’s just something that you need to be able to do is to say how many microliters that is. Same with weight, if you’re supposed to add 250 milligrams and your scale is measuring in grams, then you need to be able to convert those numbers back and forth so that you can actually use the equipment. One of the advantages of the metric system is that it’s based on a factor of ten. So the units often have prefixes that are, a power of ten or multiple powers of ten. And it’s very easy to go from say a small unit to a larger unit by multiplying by the right number of factors of ten. But very frequently we need to use a larger number or a smaller number and then we have to do conversions very frequently. They’re important because if you convert in the wrong direction you may be saying or reporting that something is bigger than it really is or smaller than it really is. So being able to do a conversion accurately is an important skill. I was thinking of some of the mistakes that have been dealt, that have happened because of measurement Usually with conversion, it’s not the measurement technique itself but the conversion technique That there’s the famous incident of the probe being sent to Mars Where they had the thrust that was calculated that needed to be figured out was done based upon one system of units and the computer was based a different system of units. There’s another famous incident with a Canadian aircraft, the Gimli Glider, that where they had just officially converted from one system of units to another, they calculated the how fuel they needed based in one system of units and filled up based on that but didn’t have enough jet fuel to make it halfway to their desination. Fortunately no one was hurt, that eventually the pilots were able to put the glider down. It’s part of that common language of just because you see a number, doesn’t automatically immediately mean what you think it means. The proper technique does two things. One, it will make it very clear what units we’ve used But also it makes the measurements that you’re talking about that much more accurate. If you know how to use for instance a Vernier Caliper, then later if you’re talking used a Vernier Caliper and it came out to be 5 mm, well then that right there is indicating you don’t know what you’re talking about, because at least I have never seen one that goes that far, or that large of a measurement. But if you’re using a Vernier Caliper then everyone else, if you’re using it properly then everyone else knows OK, I’ve used it before, I know what he’s done, I know the accuracy of that. And again, it’s part of the communication of the ideas. In Science, especially Physics, which is more my field, that the precision and the accuracy of language is very particular and it is just part of the common language that is basically understood all over the world. The consequences are that it goes back to what we started with and that is that the reagents aren’t going to be any good. You’re not going to be able to meet the needs that you’ve set forth for your experimental system. Uh, yeah, that’s it. Well, I mean, I don’t think I can overstate this enough, it truly can be life or death, it truly can be. I mean, in the way of giving medications Particularly when you talk about the most vulnerables like our children. Children dosage, you know because it’s so much predicated on their weight, you’re going to give X amount of medication based on their weight. If my order is three tenths of a millileter and I don’t see the decimal there and I go give 3 milliliters. Then I, then possibly that could have devastating effects, giving that kind of incorrect dosage, so it is absolutely critical to be precise, to know how to do these accurate conversions because truly it is, it can be life and death.

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