Wearable electronics in medicine
In what areas of medicine are wearable electronics used?
We see that modern wearable devices are penetrating deeper and deeper into our lives. And, of course, medicine as one of the fastest growing areas is one where various mobile technologies are being used more and more often. We can see this on the example of various watches, wearable devices. But you need to understand that, of course, the main driver of medical progress is more complex devices, such as pacemakers, heart rate recording devices and various sensors located in internal organs. Therefore, I would still like to separate such a real complex medical and something that everyone is familiar with, some simpler things. Where is the watershed? What is a real medical technology, and what is more for fun, although it is clear that one thing flows into another?
Medical technology implies not only accuracy, but also that its application affects the clinical outcome. In medicine, we try to focus not on some soft indicators, changes, but on whether these changes then lead to a serious improvement in the prognosis, to the fact that treatment is effective or ineffective. We are conducting clinical trials. Therefore, in order for this or that technology to penetrate into medicine, we must clearly understand that it has been tested as part of a clinical study and its application is accurately translated into a change in treatment strategy, into the prognosis of certain patients.
Let's start with simpler things. Everyone knows about smart watches. And when we talk about wearable sensors, we usually remember watches or some such simple devices. What can they do? They have optical sensors, electrical sensors and motion sensors.
This means that an electric sensor can record an electrocardiogram. Today, its recording is not very good, and we can use the data that the sensor gives us to understand what the heart rate is and how regular it is. This gives information as to whether one of the types of arrhythmia has developed, which is simply caught when we see that the heart contractions are irregular. But we can't catch more complex types of arrhythmias that are more interesting to us today. Therefore, unfortunately, simple devices like smartphones, watches, and the quality of recording a cardiogram are not enough to make medical decisions for the most part.
There are more sophisticated devices that can be used to record a cardiogram by patients with higher accuracy. And there is still a continuation of this technology. That is, now there are very small sensors that are mounted under the skin and can record an electrocardiogram for a very long time.
What is the practical interest, if we still return to this watch, which everyone has, and the technology is developing? The most interesting is the recording of a cardiogram when moving. Because if we can accurately record the heart rate during a particular physical activity, we can select very correct loads for different people. But even here we face a problem, because so far most wearable devices do not record a cardiogram cleanly enough. There are a lot of artifacts when moving. But there are already devices that are fixed on the chest, and they allow you to record a cardiogram much more accurately. But you need to understand that it is convenient to use them if the so-called cardiopulmonary test was conducted beforehand and we found out what the anaerobic threshold is, what the peak oxygen consumption is, we can associate the correct heart rate with what happens to human muscles. Therefore, they still should not go completely separately. We need to know a little more about a person in order to accurately apply the technology.
Optical sensors can detect saturation, that is, the equivalent of blood oxygen saturation. In principle, this is a very useful thing, but for those people who have severe respiratory failure. This indicator practically does not change in healthy patients. Therefore, if you are healthy enough, your saturation will be normal in a variety of conditions.
And optical sensors can also detect the shape of the pulse wave. You probably remember about the Chinese pulse diagnostics. Today there is a rebirth of pulse diagnostics, and by the shape of the pulse wave we can pull out a large number of very different characteristics in relation to the cardiovascular system. But again, the problem here is the quality of the recording. Very small hand movements lead to pronounced artifacts, and the informative value of this study is significantly reduced. In principle, we can do this by the shape of the pulse wave, analyzing it, such conclusions as how rigid our vessels are, how much they have changed, for example, in connection with arterial hypertension.
The future of optical sensors and wearable devices is a non–invasive analysis of the levels of biological components, without blood sampling. And today, a huge number of large companies are working to create an optical sensor for measuring glucose levels, which would greatly help a large number of patients suffering from diabetes. Unfortunately, such a sensor has not yet been created today. The error value is quite large for such a sensor. It is assumed that the sensor that will measure glucose levels will work due to technology such as spectroscopy.
There are technologies that you can find in your mobile device, but which are not very validated from the point of view of science. The first technology is the assessment of sleep phases. In principle, many manufacturers say that they can do this, somehow penetrate into the way you sleep, into the quality of sleep, into the sleep phases. They do this by combining an assessment of the electrical activity of the heart, changes in pulse and changes in pulse waves, changes in oxygen saturation. Unfortunately, so far both mobile devices and even semi-professional versions of medical devices are very inaccurate. The science of sleep – somnology is a large and rapidly developing science. And yet it is right that if we want to find out what happens to sleep, we need to use specific equipment, very complex. The research method is called polysomnography. Unfortunately, simple sensors do not allow today to penetrate deeply and evaluate the quality and phases of sleep.
And the second technology is the so–called stress level assessment. The mobile device says that it can assess how pronounced the stress level is. It usually does this using a method of assessing heart rate variability. To put it very simply, the worse things are with stress, with various systems in the body, the more clearly the heart beats. In a very sick person, it beats like a metronome. And accordingly, it can change its frequency in one direction or the other in a certain period of time, and the more widely it can change it, the lower the stress level is considered.
But this technique is actually very superficial, and there are a lot of mistakes in it. Therefore, you should not really trust this method of research. It's more of a toy than a serious thing.
So what else can the device do? Mobile devices have an accelerometer. It helps to assess the level of physical activity and mobility. It is very convenient to use it as a fitness tracker if you want to quantify your level of physical activity. But it has another use: the sensor also allows you to understand whether an elderly person has fallen or not. This can give important information to people who are responsible for his health.
Image recognition systems are an important driver in the development of medical technologies. And the camera that is built into the device has a very high resolution. And due to the fact that today we have a very large number of image recognition technologies based on neural networks, we are moving further and further to ensure that our medical device helps us, through cameras and analytics, to better understand what is happening to us.
Probably the biggest progress here is in dermatology. Because there are programs that can analyze various skin formations, in particular nevi (colloquially – moles), and with a fairly high probability indicate what the risk is that this formation is malignant. And there are more and more such technologies that allow us to find out what is happening to us through image recognition.
In addition to skin formations and what happens to us in terms of emotions, it can be the recognition of the calorie intake of food. There are programs – and they are being improved all the time – that allow, after photographing a portion of food, analyzing it using a neural network, to assume quite accurately what kind of calories. And you don't need to write down or keep a complicated diary: the program itself will calculate the number of calories after you make edits, and it will understand what your standard diet is. This is very useful for people with obesity. This is a block of simple technologies that everyone can approach.
There are medical technologies that are developing in parallel. One of the key trends in the West is the creation of such a hospital at home. A hospital is not the place where a patient should be observed. Even severe patients should be observed in the hospital as little as possible, because intrahospital infections and other factors are very dangerous. Therefore, today they are trying to move the diagnostic part to the house. And there a person can be surrounded by a variety of sensors that can have varying degrees of mobility.
Today, probably the most interesting devices that we have are various intracardiac devices, pacemakers and more complex devices, cardioverters–defibrillators that can restore the heart rhythm in severe arrhythmia. We see that today manufacturers are installing more and more sensors on the tips of these devices, which are installed in the heart. That is, pressure sensors appear there, and this is a completely different medicine. If we can understand that the pressure in the cavities of the heart increases, for example, in humans, we can predict the decompensation of heart failure long before. And today, mobile technologies are developing, particularly in the United States, in such a way that a doctor can receive information, including through remote channels, about how the pressure inside the heart cavities changes, and make medical decisions much faster.
Of course, there is a question of security here. It is known that major manufacturers of pacemakers periodically release new firmware updates of pacemakers with updates that protect them from hacking, because the downside of such mobility is, unfortunately, the risks associated with hacker attacks.
And we see that gradually, after all, a large class of very different devices that collect information about him turns on between the patient and the doctor. So far, this is an unformed science. But I am sure that in the near future this layer will become more and more clear, there will be more and more technologies that help the doctor make decisions about what is happening to the patient, and the patient will receive more accurate information about the state of his health.
In this case, I am still a skeptic and I believe that for a long time the quality of sensors of ordinary wearable devices – smart watches, smartphones – will not be enough to make judgments about what is happening to the human body. Where there can be real progress in the coming years is the recording of a cardiogram during physical activity and the accurate dosing of proper physical activity. In sports medicine, for athletes, for those who climb mountains, for climbers, mobile devices can be extremely useful. But for an ordinary person, healthy enough, these devices will remain a toy for a long time.
At the same time, more sophisticated devices that can be used at home have already been developed for seriously ill people. And here, too, we expect very serious progress. The greatest benefit from such devices can be obtained by cardiovascular patients with various arrhythmias and elderly patients with neurological diseases.
About the author:
Yaroslav Ashikhmin – Candidate of Medical Sciences, Deputy chief physician, chief therapist of the Ilyinsky Hospital.
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