Why Is It Vital To Test Vital Signs

Watch our expert biomedical test equipment team for a discussion on patient monitor testing and the critical role it plays in ensuring patient safety.  

This webinar was recorded on March 4. Please note: If you leave this page, you will have to start the video from the beginning.

Video Transcription

- [Katia Katashinskaia] Today we will be, discussing patient monitors. We will go over the application of the medical device itself. We will talk about its purpose in the clinical environment. Then we will discuss the importance of testing patient monitors since, you know, things can and do go wrong sometimes. And after that we'll cover each and every single one of the parameters that patient monitors measure and display.


- [Michael Raiche] Yeah, so to start off, we think it's important to understand what a patient monitor is and why it's such an important medical device. As the definition states, you know, it's a medical device that measures, records and displays human vital signs. We'll go over all those vital signs being measured but they include ECG, respiration, temperature, oxygen saturation, blood pressure, cardiac output. And there are some specific parameters measured in fetal maternal applications. And we'll touch on all of those later. The patient monitor basically allows a physician or a nurse to use those vital signs to do one of two things. One, they could diagnose a patient based off of what they see. And two, they can ensure that a treatment is working as it's intended. Both of these tasks are critical to ensuring patient safety, which is why preventive maintenance of these medical devices is so critical. We need these vital signs to be accurate in order to properly perform, any of those two tasks. So we'll move on to the next slide, where we went over what a patient monitor is and what it does in a general sense. But it's also important to understand the different forms that a patient monitor can take. There are so many ways to mix and match parameters but here's a good general overview of the three main buckets that a patient monitor can fall into. First, there's the basic vital signs monitor. In the U.S. this can be commonly referred to as a nurse on wheels. And this is primarily used on patients whose condition isn't that bad or deteriorated. The vital signs measured here are ECG temperature, blood oxygenation, SpO2, and blood pressure. All these parameters are measured in a noninvasive manner, meaning it doesn't go in the human body. Blood pressure with a cuff temperature with a thermometer that could be oral or dermal, in blood oxygen saturation with a pulse oximeter, that goes on your finger or forehead, or for babies, their toe. There may be some variations here but this is one general bucket of patient monitors. The second bucket is the critical care monitor. These monitors are used in the intensive care unit, the ICU, to treat patients with more deteriorated conditions. Patients that are in a weaker condition, typically need more parameters to be measured. So in addition to everything in the first bucket, you might also see cardiac output or CO, being measured. Blood pressure might not be measured noninvasively with a cuff, but invasively, over the transducer, impossibly from multiple locations in the body. These monitors can do much more than the basic monitor. And in addition to pulse oximetry, they may even add entitle carbon dioxide ETCO2, especially if the patient is ventilated. So, and then there's a third bucket. These are specific kinds of patient monitors used in the pregnancy care or maternity center. The fetal maternal monitor will have special parameters to measure mom and baby in addition to some of the basic vital signs. These may measure noninvasive blood pressure, SpO2, in addition to both fetal and maternal ECG. They may measure intrauterine pressure IUP, to measure the contractions, or toco dynamometer toco, to measure the tension of the abdominal wall which gives an indirect measure of IUP. So those are the three main buckets. And I know that I threw quite a few terms and acronyms at you right now. But rest assured we'll go into more detail as we progress through this webinar. About what you should take from this is that the type of patient, and the patient's condition will dictate what type of monitor is needed, as well as what you might expect to see as you walk into the ICU, versus the emergency department.


- [Katia Katashinskaia] Thank you, Michael. But before we dive into the parameters themselves, now that we're discussing how the importance of patient monitors in a clinical environment and the forms that those patient monitors can take, we need to talk about the importance of making sure that, you know, this very critical medical device, works the way it is supposed to, because sometimes it does not. And the reason when we make this claim is because we'll look at data. And in this case, you know, specifically we'll look at FDA data, and we know that over 400 adverse events are reported to FDA every single year, for NIBP and SpO2 events alone. And, you know, again this data that we're showing here is reported to the FDA which means that this happens, you know, all of this happened in the U.S. only, even though the medical device manufacturer, can be located overseas. But what's important to notice here is that is this is just one country. Now, think about the scale at which all this may happen on the global scale as well. And those are really huge numbers if you think about it. Because, this means that just in the U.S. over 400 monitor parameter failures, get reported, while those monitors are connected to the patient. And our goal here is to prevent all of this from happening by testing patient monitors and making sure that they operate properly. And here also would like to, you know, give a couple of examples of what failures in patient monitor parameters can lead to. And again, this is based on data. And this data particularly is pertained to a non-invasive blood pressure measurement or NIBP. And it says that, in an incorrect reading that overestimates a patient blood pressure by only five millimeters of mercury, leads to inappropriate treatment of that patient, which in turn leads to, adverse drug events from an incorrectly prescribed medication, negative psychological effects of misdiagnosis at that patient and of course, unnecessary cost of such treatment. Another example that, you know, I think this happened last year. This information was reported to the FDA directly. But in this case that was reported, an incorrect NIBP reading. Again, this is NIBP related, almost led to patient's death, because that patient, because of that incorrect reading, who was at the time a stroke patient, did not receive a blockage buster medication, and as a result of that had a cardiac arrest. Luckily for the patient, they were then treated with proper medications. But simply imagine this horrific situation and, you know, this situation is an example of exactly what we must prevent by thoroughly testing patient monitors.


- [Michael Raiche] Yeah, so as promised, we're gonna start digging into some of these parameters that I bombarded you with at the beginning. We'll move one by one to describe what they are, why they're important and how they're measured. And just one thing to add to what Katia just talked about is one of the kind of rules that we like to think about is, you know, after you've done your maintenance, you wanna ensure that you would strap your own mother, family member to that patient monitor and be confident in the way that it performs. Just another kind of sanity check, for making sure you're doing the right work. But, without any further ado, let's get started. And I'll hand it over to Katia to begin.


- [Katia Katashinskaia] Thank you, all right, so the first parameter that we will be discussing today is body temperature. The most correct body temperature measurements are derived from measuring core temperature of a human versus shell or skin temperature that we measure it this days with COVID with all of those infrared and other thermometers. And measuring core temperature is especially critical in the ICU environment. There are actually a few ways to measure and monitor core temperature in the intensive care unit. It can be done using either urinary, nasal or temperatures of the body. Normal body temperature varies by person, age, activity and even time of day. The average normal core body temperature is generally accepted as 98.6 degrees Fahrenheit or 37 Celsius. And you can sort of see in the middle, of this little image that we have on the slide. And any deviation from the normal range of body temperature, is an important clinical indicator for hospital staff, that requires their further investigation. And as you can see on the slide, you know, on this little image, the deep blue and the deep red colors that represent medical emergency conditions, there are not that many degrees apart. Which is why careful and accurate temperature recording is critical. Because hospital staff then relies on all of those observations to make diagnosis and decide on patient treatment. And, you know, statistically speaking, one thing, high frequency of temperature abnormalities in the critical ill patient, and the second thing which is the high correlation between negative outcomes in patients and extremes of temperature. Both of those things suggest that accurate measurement of body temperature is absolutely necessary, to ensure patient safety. Which is why it's so critical, to test the body temperature measurement device on a patient monitor, when it comes to the medical device testing. Next one we have here is the non-invasive blood pressure. And making sure that this device works properly is also absolutely necessary to ensure patient safety and all this talk about why that is. First I would like to begin with kind of like the basic definition of blood pressure and how it is measured. Blood pressure is measured as systolic over diastolic pressure that you can see on the slide. And it is recorded in millimeters of mercury. And systolic pressure is that peak blood pressure when the heart is contracting. Diastolic pressure is the lowest blood pressure when the heart is relaxing and we feel in with blood. Typical adult blood pressure is 120 over 80 millimeters of mercury. So you can see in green on the slide. And even though you can only see kind of like, one of the extremes on the slide, there are actually two of them for blood pressure levels. What's shown here is hypertension or very high blood pressure that puts added stress on the heart. It adds, you know, extra pressure to the vessel balls and it may result in a heart attack or a stroke in a patient. There's also other extreme which is hypotension. Hypotension happens due to inadequate circulation of blood in the body and leads to fainting and dizziness in a patient. There are two main methods of measuring blood pressure noninvasively. The first one is manual something that everyone experiences through in their regular checkups. The other one is actually connecting patients to an NIBP device which is exactly what we'll be discussing today. Normally patient gets connected to an NIBP device when hospital staff needs repeated measurements of their blood pressure. Typically this happens to in a medical procedure like during some surgeries or for continuous monitoring all the patient's state. The way when an NIBP device works is it automatically inflates and deflates the cuff that is placed on the patient, that has been done continually but it is very similar to the manual process of checking blood pressure noninvasively. NIBP machines in general they have a few parameters that can be adjusted by the nurses or other hospital staff. The three main parameters. So, there will be setting the initial inflation pressure, setting an interval for blood pressure monitoring, and last but not least the setting alarms. And setting alarms is actually critical because it is necessary for the staff to check if patient is exhibiting either hypertension that we're just talking about or hypotension, since those are two extremes, it is critical that the hospital staff can promptly react to an indication on one of those conditions happening in the patient. So to sum it up in terms of measurements, in a nutshell we need to check NIBP devices for two things. So first of them is accuracy. Obviously we need to make sure that the blood pressure measurement is being displayed correctly, every single time. And repeatability, that's the every single time component of it. And obviously an alarm check needs to be performed on a device too. And before we move on actually let me ask all of you, what else do you perform, to determine accuracy, of the NIBP device under test? Before we start a poll I'm gonna show the options here. So you can test an NIBP device for accuracy by doing a static pressure test, by doing a dynamic simulator test, or by performing a visual inspection. So those would be the three options. Let me start at the poll. And you will be able to chip the response, that you prefer. I'm not sure what just happened because I think the poll just launched and closed at the same time. Is that what it looks like? Michael, can you,


- [Michael Raiche] The window popped up and then it did go away.


- [Katia Katashinskaia] Oh no, is there a way to relaunch it? Dan do you know that?


- [Dan] No, unfortunately there is not. Let's go and share it, and it look like we had, a higher range going for one of these options.


- [Michael Raiche] Some results are better than none.


- [Katia Katashinskaia] All right, unfortunately only four of attendees were able to vote, which is not ideal. And which is probably why the results are skewed this way. You could also probably use kind of like the, we have this little questions tab where you can add your answer if you would like. I see some answers popping up there. If you would like to take the next maybe 10 seconds to place your vote you will be interesting to discuss what you do in your facility for this other test. I see a lot of responses for dynamic B, B. And this is what the poll is showing too. Thank you very much for your responses. With this I'm gonna move on to, showing what the correct response actually was. Again, we're talking about testing your NIBP device for accuracy. And the correct response here is that you perform the accuracy test, by doing a static pressure test. And I'll explain why. So, the static pressure test is the test that actually is being performed at a difference reference pressure levels statically in a large range of pressure, to make sure that the device actually inflates to a high enough pressure as well. And if it doesn't, there may be a leak in the device. And the causes of that leak could be different. It can be due to a hole in tube. It can be a loose connection. So those need to be properly checked. They need to be are tight. Or there can be a faulty O-ring. So all of those things need to be properly checked and properly tested. And the static pressure test, is the test that you do just the accuracy of your NIBP device. The dynamic simulator test on the other hand is used to assess the repeatability of the NIBP monitor. The way it is being performed it is performed by doing a series of tests and measurements that will evaluate the dynamic functionality of the simulator. So basically you're enabling your simulator to generate a series of equal pressure pulses, and then you see if the results have been consistent and continuous. All right so,


- [Michael Raiche] Yeah so just to reiterate that the static pressure test is the only way to test accuracy. Just applying a single pressure against the NIBP, that the patient monitor and in assessing how accurate it is at displaying that pressure. That's the only way to do accuracy.


- [Katia Katashinskaia] At different levels of pressure but yeah, that's the single. And then repeatability is doing a series, of those pulses. All right, but actually, before we move on to the next parameter, I wanted to briefly mention that if you would like to learn more about NIBP devices and how to test them, our training manager Jerry Sine, did a great webinar just on that. You can find the recording of that webinar on our website. Again, absolutely free, available on demand, for look by medical.com click the knowledge center and click on webinars and there will be an NIBP webinar for you if you would like to dig a little bit deeper on the subject. But here we will move on to the next parameter. And the next parameter here is invasive blood pressure. So, the reason why there are two different ways of measuring blood pressure in the patient is because sometimes clinical staff cannot rely or cannot use the non-invasive methods of monitoring patients' blood pressure. This may actually happen in a variety of different cases. It may happen during certain surgical procedures for example, cardiac surgeries, thoracic surgery, vascular, during transplant surgeries, trauma, airway surgeries and so on and so forth. Like there's actually a quite a wide range of those types of procedures where only invasive methods of blood pressure checking should be used. It is also required when it's important to promptly control blood pressure. Like for example, when a patient has aneurysms or induce hypotension, that could be another case why blood pressure will be taken invasively. So in all of those cases and actually some more that I will mention in a few seconds, hospital staff uses what's called an arterial line, or art-line or a-line, which is basically the invasive blood pressure monitoring system. An art-line or a-line is a thin catheter that you can see on the slide that is inserted into the patient's artery. And the catheter itself is connected to transducer. That's the little thingy in between. It is connected to a transducer by a very steep tubing, that doesn't have any air bubbles or anything like that. That is very important. And then the transducer itself converts one form of energy into another. In this case it converts pressure into electric signals, that are then displayed on the patient monitor. And like I said before, this particular type of blood pressure measurement is most commonly used to monitor a patient's blood pressure directly and accurately, and all those certain pieces that I described, plus it is used to obtain samples over to arterial blood gas analysis or ABGs. And also this comes very convenient to hospital staff when you need to get frequent blood samples from a patient but you don't want the patient to be stuck frequently. So just connecting them to NIBP device as you know, the most convenient way of doing that. And we test NIBP devices for accuracy by simply connecting it to a simulator and checking for correct results on a monitor at different pressure levels.


- [Michael Raiche] All right.


- [Katia Katashinskaia] All right, yep.


- [Michael Raiche] So the next parameter, is oxygen saturation, which is the amount of oxygenated blood volume as a percent of total blood volume. There are invasive methods of testing blood oxygen levels like arterial blood gas ABG, Katia just referenced. And there are also some non-invasive methods like pulse oximetry. For this we're gonna focus on pulse oximetry as it is much more common. And this technology quickly monitors heart and lung function, right? To check that arterial blood is carrying oxygen to the body's cells. That's the main function that you're checking for. Typically a finger or another peripheral part of the body is used to pick up on the pulses of blood from the heart. And the parameter you're actually measuring is referred to as SpO2. Or the saturation of peripheral oxygen. So with that definition, we'll move on to the technology. One important thing to note is that specifically for measuring SpO2, the test device being used is not a simulator, but a functional tester. This language comes from the FDA and it's not a simulator, because it doesn't directly simulate the human body. If this were a test device that was a simulator, it would be a device that would allow light to shine, right through a pulsing medium, that would have to mimic hemoglobin that's oxygenated and be able to oxygenate that hemoglobin at various levels. So you can imagine the difficulty there. A fluke tester pretends in a different way to be a human finger. And it can be programmed to show a range of variables to allow for the most comprehensive testing available. So the way that a pulse oximeter works here in this image, is that the monitor will shine light onto the top of the finger and the tester. This is red and infrared light that's shown in succession, in the tester, which will take the place of the finger in the diagram there, will measure the amount of light coming in, will decide if it's red or infrared. It will then calculate how much light would be shining through an actual finger at those settings. And then it turns on its own LED on the bottom, so that it looks like light actually was shining through the finger. So the actual SpO2 functional testers is pretty complex, and does a lot in a very short period of time. It can adjust for oxygenation level, skin color, finger thickness, and even the type of ambient lighting in the room. And all of this adjusts to make sure that you're getting the right readings so that whatever patient if pulse oximeter is ultimately hooked up to, you get the right reading. And there was actually a recent FDA communication on the effect of these changes on SpO2 readings, which we'll share in the chat. So Dan, if you could post that, that'd be great. And Katia let's move on to Masimo, so,


- [Katia Katashinskaia] There you go.


- [Michael Raiche] Masimo rainbow, is a specific technology on the market that does a bit more than the normal pulse oximeter. So it's worth calling it out. Instead of just red and infrared light, it actually uses multiple wavelengths of light, to acquire additional information. A rainbow can detect percentages of dyshemoglobins. Those are hemoglobins that cannot carry oxygen. Like methemoglobin or carboxyhemoglobin. Masimo is worked with fluke to figure out how to test this technology. It has approved a special cable that interfaces with the fluke biomedical tester. And one other note, just like on NIBP, we have another empower webinar, that goes more in depth on pulse oximetry. Goes to the full period of time and you can refer to the webinar section of our website to learn more if you're interested. So with that we'll move on to capnography. If we think of SpO2 as how much oxygen got into the bloodstream, then entitled CO2 or ETCO2, would be how much waste gas, is leaving the body. This answers the question, is oxygen being metabolized by the body? The human body metabolizes oxygen as shown in the diagram here and I'll walk you quickly through this cycle. It starts with oxygen being inhaled into the body. That oxygen then goes into the lungs, which then allows for the blood to get that oxygen. That blood then reaches the extremities, and basically transfers the oxygen to those cells and takes the deoxygenated blood, back into the lungs where waste gas is then exhaled and the process starts over again. Any changes in patient condition, right? Are gonna be delayed on a pulse oximeter since the blood needs to be pumped from the lung to the heart, to the finger, right? Entitled CO2 can be measured with each breath. And the device that measures this is a capnograph, which can be found in many patient monitors. Normally in that ICU setting. This breath by breath measurement shows how the body is actually metabolizing the oxygen into carbon dioxide. And it's a much more instantaneous measurement. So again, in the image here you'll see that it's hooked up to a patient who's ventilated. So, SpO2 gives you the measurement of how much oxygen is in the blood, and capnography ETCO2 gives you the measure of how that body is metabolizing that oxygen.


- [Katia Katashinskaia] All right, now let's talk ECGs. Electrocardiogram or ECG also known as EKG, is a reading that assesses the size and direction of electrical currents in the human heart. Electrocardiograms are used to detect and survey a really wide variety of heart conditions in the patient. In ICU settings, ECGs are generally used for continuous monitoring of the patient's heart rate and the detection of any potential fatal cardiac abnormalities, such as for example, arrhythmia's. And ECG in fact is considered to be one of the most productive investigations in medicine. Which is why it is essential to ensure the correct performance of your ECG devices. In a nutshell, ECG, isn't a non-invasive procedure. It's a diagnostic medical appliance that is connected to a patient via leads or them electrodes that record the findings in form of wave forms. And for truly effective results, an ECG must be recorded in the most accurate way possible. Generally speaking, there are three methods of placing leads on a patient. There's a three lead, five lead and 12 lead placement with a 12 lead placement being the standard, simply because it provides the most information about the currents in a patient heart. It is good to know now that the OEMs are looking into making 15 and 18 lead placement ECG monitors which will be even more informative. But as of right now, we are, you know, let's take a look at the 12 lead placement. And so, which is something that you can see on the slide here in the image. Even though it is referred to as a 12 lead placement, an ACG only uses 10 electrodes for meetings. So you can see there's four on the limbs and six on kind of like the hard area of a patient. I don't believe that you can see my mouse. I kinda wanted to show a little bit of, you know, why it is called the 12 lead placement but basically it is enabling to see the heart of the patient from 12 different angles, because some of the limb electrodes, like for example right arm, left leg or left leg, left arm, they form pairs and those pairs can look at the heart from an additional angles and right leg is just ground. So a point here is that since it is allowing to see the heart from so many different angles it is critical that all those electrodes, all those leads are tested and verified very thoroughly. It's critical to know that they transmit electrical signals to the monitor correctly and accurately, from all of those angles because some of the hard problems can only be detected from, I don't know, like for example, the pair of left leg and left arm electrodes. Like for example I think the inferior and in fact, is kind of like located on that side of the heart. So yeah, so again, critical to test the ECG devices because if you do not, this will lead to possible misdiagnosis of patient, patient mismanagement, and inappropriate procedures done to patient. And with that, I think we're moving on to the next one. Yep, fetal maternal, Michael.


- [Michael Raiche] Yeah, so this one builds a little bit, on the topic of ECG. Since fetal maternal monitors also need to measure ECG. But they need to be able to measure the heart rhythms of not only the mother, right? But also the much faster heart rates of the baby. So these monitors are, like I said, a grouping of parameters with some specific ones. So these are strapped to the expectant mother, and they're able to measure parameters like ECG and IBP SpO2. So those are kind of the normal as expected except for the fetal heart rates. And then there are two specialized parameters. There's intrauterine pressure IUP, and toco. So, IUP measures the direct pressure inside the uterus. So again, this is touching on the invasive versus non-invasive. And this helps detect contractions, and toco is an indirect measure, right? So that takes the tension of the abdominal wall of the mother and then infers an intrauterine pressure. So, medicine is always moving towards more non-invasive measures. So this is an interesting application of that as well. There are also ultrasound pucks. These ultrasound pucks are attached to the mother, and there's usually a belt and they detect the baby's heartbeat. And these have to be simulated as well. They can be simulated by mechanical fetal heart directly, right? So there's actually a device that we manufacture that simulates the baby's heart right on the puck. And then there's also a method where you can do it through the cable, right? So you can just do an electronic simulation. Ultimately, what these monitors are trying to do are measured the vital signs, of the mother and the child, and they have the added complexity of being able to measure contractions. And then in the last parameter that we wanna touch on today is cardiac output. So in very compromised patients, the heart might not be functioning as it should and it would need closer monitoring. Cardiac output, what it does is it measures the flow of blood through the heart to make sure that the body's getting enough blood. And then some of the other measures like SpO2, measure the oxygenation of that blood. So the real goal is to make sure that the body's getting enough oxygenated blood, through wedgering multiple parameters. The calculation of this has two parts. So one is stroke volume, right? How much blood flows per heartbeat? And then there's heart rate. How often the heartbeats per minute. So to test this in patients, cold water is injected into the vein, and the temperature change is measured, right? So this helps, infer the blood flow per minute in the heart. This parameter is only found in critical care or intensive care units, as it's an invasive procedure. And again, that's something you're gonna find in those critical care or higher end patient monitors. But yeah, that was a brief overview of that. And with that, that's our final parameter. So I'll hand it back to Katia to wrap it up.


- [Katia Katashinskaia] All right, so this was the overview of the eight vital parameters that we need to test on a patient monitor. So with this, we would like to open the floor for the Q and A. So we got a few questions. Oh, and I just pressed, something wrong. We received some questions via the questions tab on go to webinar. If you have not submitted your questions yet, please do so. And we're not gonna move on to the questions that we got. Okay, so the first question is, how do you calibrate your SpO2 simulator?


- [Michael Raiche] Okay, I'll take this one. In terms of calibrating your SpO2 simulator, I just wanna correct the terminology. It's not a simulator, it's a functional tester. And in terms of calibration it's not actually calibrated. It is verified. So what you're doing with your functional tester is you want to make sure, that every year, what's measuring the light and what's admitting the light is functioning the way that it should. Because that's essentially what the functional tester does. So you wanna make sure that the function is verified on a year to year basis. There's nothing to calibrate on it because it does all that calculation in an interpolation inside of it. And yeah, if you wanna dig more into what that math specifically does with our curves and things of that nature, I would urge you to look at the other webinar, because there's a lot of good, helpful information on that.


- [Katia Katashinskaia] All right, so the next question is also related to the SpO2 somewhat. It's the oxygen, type question which is ETCO2 and capnography, are those the same machines?


- [Michael Raiche] Yeah, so ETCO2 is what you measure with a capnometer or a capnograph. So what you're measuring there is the end title CO2 meaning, the CO2 that's exhaled. They're similar but not the same. One is what you're measuring, but what the medical device is. And one is the parameter you're measuring. The capnograph is actually the curve that you're, so you're measuring the parameter, ETCO2. If you measure it on a plot, it's called the capnograph, and then the medical device that's being tested is a capnometer.


- [Katia Katashinskaia] Hope that answers the question. The next one is an NIBP related which is, will the size of the NIBP cuff play a big role on the accuracy of the results of the NIBP? I would say that the placement of the cuff plays a bigger role in the accuracy. Michael if you would like to add anything to it.


- [Michael Raiche] Well also just using the right cuff for the right application is important. 'Cause you do have some for pediatric applications and some for adult. So, in your testing you wanna make sure that you're using the mandrill. So basically the thing that mimics the arm of the patient, you wanna be using the right size there for the cuff that you're using. And like I just said, the placement's important but also the overlap right of the velcro strap can be important as well.


- [Katia Katashinskaia] The next question is, also about placement but this time for the temperature probe. So I would say that the question is where's the recommended placement side for the temperature probe? So there are pitfalls then, you know, the benefits of each single side but it's definitely depends on the clinical condition of the patient and a particular procedure that is being done. So it is up to the hospital staff to decide on, which side to pick in each particular case. The next question is, there's so many. All right so the next one is, why do we need to test all those ECG forms?


- [Michael Raiche] Yes, I'll take that one. The ECG form, what you're trying to do with a patient monitor at the end of the day is make sure that it is ready for another patient. Whatever patient that might be to be hooked up. And Katia talked about it earlier in the webinar in terms of alarms. So, you want to make sure that the patient monitor's able to pick up on someone that is, you know, hyper and hypotensive. You wanna make sure that it's detecting heart rhythms as it should, and communicating that to, the physician or nurse. That you really wanna make sure that it works for any and all patients and any and all conditions. And that's why you're really testing, all these different heart rates to make sure, that the patient monitor is reacting in the way that it should. 'Cause if you miss an alarm and it's not detecting something that it should, that can have really adverse effects on the patient.


- [Katia Katashinskaia] The next question is unusual but it's interesting. So, Michael, why would you say we selected this topic for the webinar today?


- [Michael Raiche] Oh, that is an interesting question. Some people in the audience might feel like patient monitoring and the preventive maintenance attached to it is so common, right? But you know what you've done. You've done it for multiple years, but we have to remember that people are coming into the field every year, right, new people. And we wanna make sure that everyone's brought up to speed, and understands what they're doing. So, this is one of those bread and butter medical devices but it's really important to understand, what you're doing and why you're doing it. So, for some people, this might be an overview. You might've learned something new, and I hope that you did. But yes, we have to make sure that the newest biomeds that are entering the market are educated and prepared to do their jobs.


- [Katia Katashinskaia] Yes, that is absolutely right. And I see that we had get, many related questions about the NIBPs which we have already spoken about. All right, let me see. What else did we get here?


- [Michael Raiche] I see one question on heart rate and how it's measured from UCG.


- [Katia] Oh, good.


- [Michael Raiche] So, we touched on heart rate in a few parameters. And I just wanna kinda call that out. So ECG, it's a wave form, right? So, with each pulse of the heart, you're getting a measurement off of the electrode and you're seeing that. So the heart rate on an ECG is measured peak to peak, right? So that's how ECG is measuring it. We also talked about SpO2. And one measure there is pulse rate, right? It was measuring the pulses of oxygenated blood from the heart. So that's another measure of heart rate. And each of those are used in cardiac output, right? So, you're measuring, well, one is the heart rate, right? And then the other is the stroke volume. So, you can see how all these parameters, play with one another. And when I talked about cardiac output, it really measured. The goal was to see how much oxygenated blood was going, into the body. And you can see how all three of those kind of played together. So, these are all vital signs. They're really important to test. And they do all serve their own individual purposes but together, give you the view of the health of the human body.


- [Katia Katashinskaia] All right, next one is, is SpO2 pinpoint accuracy important? What if readings are one or 2% off?


- [Michael Raiche] Yeah, so this is really up to the manufacturer, right? In terms of service, right? So they're going to say, hey, test this pulse oximeter and make sure that when you put in this reading it's accurate within, plus or minus X percent. So that's ultimately what, biomeds should be following for service. The effect that it has on a patient. I remember Katia saying that, you know, that even the outside temperature can have an effect on temperature. There are multiple things that can have an effect on SpO2. And I touched on a couple of them but skin color, fingernail polish, finger thickness, all of those things can have an effect that creates that plus or minus one or 2%. Is it important? Yeah, it's an important parameter and it helps with diagnosing patients. But one person or a nurse, a physician shouldn't just look at one parameter to make a diagnosis. It should be, all of them in their entirety. So, does the one or 2% make a huge difference? Yes and no. But, it should always be taken into consideration against, or with other parameters.


- [Katia Katashinskaia] All right, let me see what other questions we got there. If you see any Michael, go ahead please.


- [Michael Raiche] That was one that was, the difference between leads and electrodes. So, I think I'll touch on that one real quick. The electrodes are what's actually placed on the body, right? So that's the pad with the adherent adhesive, yeah. And that's really the electrode. And then the lead is what connects the electrode to the patient monitor. So it's the wire, right? So if you think about when you're doing preventive maintenance on a patient monitor you're connecting that lead, to the, in our case, the for example. And that's how you're going to conduct your tests. You're not actually testing the electrode, because it's disposable.


- [Katia Katashinskaia] And by the way, in the meantime, Dan here will copy our emails to the chat box, for everyone. In case we did not answer your question today, please do not hesitate to reach out to Michael or I, and we'll make sure to get your questions answered. I think my email is already in chat, so please feel free to reach out. Let me see if we have other questions.


- [Michael Raiche] Yeah, so there's one that seems to come in from Africa that I think is interesting. And the question is, why aren't simulators and functional test equipment added as essential package, to vital signs equipment during procurement? Here in Africa test equipment and simulators are very rare, and it doesn't make work professional. So for me, I feel like always a good, medical device quality assurance program is key for any hospital. If we think about what we're trying to do here is we're trying to ensure patient safety and operator safety. So, with that, it's always electrical safety, and a functional test. So, I feel like electrical safety is critical to make sure that both patient and operator, are safe to touch and operate the device. And then functional testing on a patient monitor or any other medical device is critical, to ensure that those two things I talked about at the beginning that the patient is being diagnosed correctly, and that the treatment is being monitored correctly for efficacy. So it should be included for sure. Because it does enable and ensure both of those things are done correctly and effectively.


- [Katia Katashinskaia] Right, next question we have here is the management of my facility, procured a gun thermometer monitor that had an error margin of plus or minus two degrees Celsius. I told them we can't tolerate that error margin. Can you elaborate on it if you agree with me and explain why you agree or don't agree? And I think here I will start answering the question. And with that, I will go back to the body temperature slide here because I think it will be beneficial to kind of see it in a picture. But if you're talking about accuracy of the body temperature measurement and here we're talking about kind of the shell temperature measurement, right? With a gun. And, what I wanted to show here was, you know, this image again, if you were talking about the error of a couple of degrees Celsius, that is actually pretty significant. So unlike Fahrenheit, the Celsius scale is a lot more a condensed. So the normal body temperature let's say is 37 or 36.6 degrees Celsius whereas the two more degrees or two degrees less already takes it to kind of closer to an extreme. Which is why we would not recommend to agreeing with that sort of error and a recommended more accurate device for body temperature measurement.


- [Michael Raiche] And it depends where it's being used too. I think if you're using it to allow entry into a building, you might have a different acceptable range than if you're diagnosing a patient. And again, there are different technologies that have better accuracy in terms of the application. If you think about dermal, oral, all of those different ways. Some are better than others. And some are more prone to outside temperature or whatever might be might be happening. So it does depend on the application as well.


- [Katia Katashinskaia] Correct, and, oh, actually the next question is really great and which is something that Michael briefly mentioned in the presentation today, but it will be good to elaborate on it a little bit which is, will there be any variation in SpO2 measurement based on skin color? And which is exactly what we were sharing in chat before.


- [Michael Raiche] Yeah, and there will be. The way it's measured, is through the perfusion, right? So it's going to be a measurement of how much light can shine through that finger? And different skin tones allow for different amounts. And what you guys should be doing is ensuring that, that pulse oximeter would work for all skin tones. And that's something that, functional testers like spot or spotlight allow for. Because you wanna make sure that at every skin tone, that the device is still within tolerance. So, it does have an effect. And that's kind of, yeah, that's definitely has an effect. And don't forget the other ones, right? The finger thickness, right? The ambient light artifact, right? You're measuring light. So the light in the room can affect it as well. Yeah, so definitely adjust for those different parameters, to ensure that you're having the most complete test program possible.


- [Katia Katashinskaia] They're nice and with that, actually, Dan, is suggesting that we're already at time. So thank you all very much for your questions. Thank you all very much for attending today's webinar. We always hope that you learn something new when you come to our events. If there are some questions that you've asked us today and we had so many, and we didn't get to your question, please do not hesitate and reach out to us by email. We'll make sure to answer your questions. And with that, we're our time today. Again, thank you all very much. Please go to flukebiomedical.com to watch other on-demand webinars. Definitely use our Advantage Training Center. It's a free course on medical device quality assurance and testing. And yeah, we will see you in the next event.

In this video we will cover:

  • Each vital sign parameter
  • Patient monitoring and testing technology
  • Innovations in the patient simulation field

Michael Raiche, Fluke Biomedical Business Unit Leader
Katia Katashinskaia, Fluke Biomedical Product Manager

Fluke Biomedical

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