Remote Health Monitoring Courtesy of the Internet of Things

Image source: Nature  

Introduction  

Devices like stethoscopes can tell physicians a lot about the condition of a patient’s heart. Similarly, thermometers can also ascertain a patient’s body temperature. These are vital pieces of information that are invaluable to monitoring health. However, the information is only available at the patient’s bedside, and there must be a skilled clinician at the patient’s side to take the reading.  

Part of the problem has been alleviated through the development of a wide range of sensors that can continuously monitor heart rate, temperature and more. Once installed, they can take readings as often as necessary with no human help. Better yet, these readings can be stored in local memory, giving clinicians the opportunity to monitor glucose levels, heart rate, temperature and a myriad of other biological indicators over any length of time.  

But what about monitoring people who aren’t in the hospital? How about monitoring individuals as they go about their daily lives? How does, for example, glucose level, heart rate or temperature vary over the course of a normal day? The analysis of these sorts of data can endow physicians with unparalleled insight into patient health. It would be able to indicate possible courses of treatment or, better yet, indicate that no treatment will be necessary at all.  

This now is not only possible but done every day, and it’s made possible by the Internet of Things (IoT).  

What is the IoT?  

Whether you call it the Internet, the Internet of Things (IoT), the Industrial Internet of Things (IIoT) or the Medical Internet of Things (MIoT), it’s all the same Internet. It’s the same thing as the planet-wide network over which you’re now reading this article. It’s basically just semantics, with IIoT standing out somewhat as it is often used in situations where network glitches can lead to serious or catastrophic failure.  

The mobile medical devices we’ll be discussing here generally connect to the larger Internet via Bluetooth, Wi-Fi, LoRa, Zigbee or via the newer, fast evolving cellular technologies. These are described in detail in the Electropages article IoT Wireless Communication: The Core of Industrial IoT Connectivity.  

As we’ll see, the IoT not only makes real-time remote health monitoring possible, but it also facilitates in-patient care as well.  

PPG Sensors  

PPG sensors (Photoplethysmography) are non-invasive, LED-based devices that can measure blood flow. In an extremely useful video^[1], Dr Cailbhe Doherty of Dublin’s University College explains the way they work and their wide applicability to remote health monitoring.  

LED’s shine light composed of various wavelengths onto the skin. In a manner akin to radar, some of the light is reflected back and measured. As the heart beats, the amount of blood in the “microvascular bed” of your skin changes, and the reflected signal also changes. These changes can be analyzed to determine not only heart rate but other medically useful parameters. These include respiratory rate, blood pressure, blood oxygen saturation (SpO2) as well as sleep apnea and atrial fibrillation.  

Image source: Dr Doherty Video (4:05), University College Dublin  

The image above illustrates a PPG device, part of a smartwatch, shining LED light on a person’s wrist, with the reflected light patterns used to ascertain heart rate. The smartwatch communicates with the user’s smartphone, which, through its cellular connection, can forward the data to physicians or analytical engines located anywhere in the world.  

Blood Sugar  

Diabetes is a scourge, affecting the health of hundreds of millions of people worldwide. Being able to continuously monitor blood sugar levels has proven to be a major step forward in efforts towards monitoring and controlling this devastating disease.  

There are two methods used by sensors to ascertain blood sugar levels:  

• Continuous glucose monitoring (CGM) sensors monitor glucose (sugar) levels in interstitial Fluid (see glossary).  
• Blood glucose monitoring (BGM) directly measures sugar levels within the subject’s tiny capillary blood vessels.  

Abbott Laboratories ^[2] glucose biosensors work on the CGM model, and to gain access to interstitial fluids,  the skin must be breached. But fortunately, this breach is achieved via “a thin, flexible filament that painlessly sits just below the surface of your skin” and the filament itself “is about the same width as three human hairs.”  

The overall biosensor that mounts the filament output of the biosensor is a “circle-shaped piece of health tech that’s the size of a small coin.” Its output transmits to an app that resides on the user’s smartphone, which first translates the biosensor’s output into useful information and then sends it along to the IoT. The result is a record of the user’s blood sugar levels, which vary with the time of day, activity levels, food consumption, and other factors.   

Security  

Medical IoT not only reads patient medical data to assist in patient assessment but, as in other types of IoT scenarios, may also initiate actions. For example, a now common application is the IoT-enabled drug infusion pump. As described by Bluegoatcyber^[3], “In 2015, hackers gained access to a prominent hospital’s network, taking control of its IoT-enabled drug infusion pumps. This incident served as a wake-up call, highlighting the urgent need for robust security measures to protect against such threats.”  

Blue Goat suggests five essential steps to prevent this sort of catastrophe:  

• Establishing a Robust Security Framework 
• Regular Software Updates and Patches 
• Implementing Strong Authentication Measures 
• Ensuring Data Encryption 
• Conducting Regular Security Audits  

In the future, the company expects the increased use of AI and machine learning methodologies to be applied to medical IoT security. Additionally, governments are imposing their own security mandates. The European Union, for example, has established its Medical Device Regulation (MDR), mandating criteria for cybersecurity and data protection in medical devices.    

Linking it All Together with the IoT  

The image below gives a nice illustration of the way that remote health sensors work.  

Image source: mdpi  

In this instance, it’s ECG readings that are being monitored. This information is fed into a microcontroller that does the signal conditioning and analysis. It also animates a local display and, critically, feeds a Wi-Fi device, which transmits the data over the cloud to an IoT server. From there, it can, of course, reach any place, including research scientists and the subject’s hospital. Of note, the whole system residing on the subject uses so little power that it can be animated by a device called an energy harvester, which generates electricity by harnessing the energy that can be gleaned from the motion of the subject’s body.  

There is another semantics issue that varies from source to source. The various literatures available from a range of legitimate sources differ on just what is considered the IoT. Here we see the IoT beginning at the IoT server. Other sources consider the link between the sensor and the microcontroller and the Wi-Fi device to also be constituents of the IoT.  

More important to note that in other similar applications, the microcontroller can be an APP resident on the user’s smartphone, and the smartphone can send the signal along via its built-in Wi-Fi or cellular transceiver.  

Wrapping Up  

Modern medical sensors turn heart rates, blood glucose levels and other important bodily measurements into digital representations of themselves, and these readings, taken over any length of time, can be saved into computer memory. Then researchers and clinicians alike will have not merely a one time reading, but a complete picture of how the value unfolds over time.  

Modern sensors can either be patched into the IoT, or they may have IoT access built directly into them. This provides clinicians. Located anywhere, with the invaluable advantage of seeing how a person’s heart rate, for example, varies as the subject goes about their daily life.  

We’ve only detailed two of the most important medical parameters, pulse rate and sugar level, in this report. There are many others, to be covered in detail in subsequent reports.  

As noted, other closely related medical IoT devices, such as infusion pumps, not only read data but also take direct action by enabling drug flow. That’s one of the many reasons why data security is such a growing concern, because without such precautions, hackers could break in and cause fatal amounts of drugs to be pumped into unsuspecting patients, doing damage that could prove fatal.  

Challenges and Opportunities  

In an earlier Electropages article, we define a process called predictive maintenance. Here, various industrial parameters, such as heat, voltage and more are measured and transmitted to remote data engines housed in data centers. There, they are compared to past readings and past industrial results and used to predict likely failures.  

The same thing can, and is already starting to be done with medical readings. Being able to do this with data taken from an ambulatory subject will make the methodology even more powerful and more useful.  

Another process used by the industry was detailed in our Edge Computing article. With this process, much of the data crunching takes place at the source. This means that less raw data will need to be sent over the Internet. With the Internet being hugely overburdened by artificial intelligence development and crypto mining, slowdowns can be avoided. And with less data being transmitted, costs of operation will decrease.   

References    

1. Photoplethysmography (PPG): Origins to Modern Applications in Wearable Technology. Dr Cailbhe Doherty  
2. How Do Continuous Glucose Monitoring Devices Work? Abbott Laboratories  
3. Securing IoT-Enabled Medical Devices: 5 Essential Tips. Blue Goat Cyber  

Glossary of Terms  

• Interstitial Fluid. As defined by the National Cancer Institute, It is “Fluid found in the spaces around cells. It comes from substances that leak out of blood capillaries (the smallest type of blood vessel). It helps bring oxygen and nutrients to cells and to remove waste products from them.” 
• PPG (Photoplethysmography) sensors are non-invasive, LED-based devices that that measure volumetric variations of blood circulation from which the heart’s pulse rate can be determined.  
• Continuous glucose monitoring (CGM) sensors measure glucose levels in the body’s interstitial Fluid