Healthcare costs around the world are rising as the population ages. The proportion of the population of the world aged 65 and over is set to double over the next 25 years, from a little over 7 per cent today to 15 per cent. In the developed world, the rise will be even higher as average life expectancy is already higher. Although people will live longer, many will live with chronic medical conditions that require regular treatments and consultations. The result is likely to be a dramatic increase in the cost of healthcare, whether financed by state taxation or insurance costs.
A key issue is the amount of time that people need to stay in hospital after a treatment so that they can be observed before receiving more treatment or are considered healthy enough to discharge. Hospital treatment costs are much higher than if the patient can stay at their home and receive instead a series of brief consultations from a nurse or doctor. However, appropriate medical staff is not always close enough to allow travel to a surgery by a patient. Specialist medical staff work in city hospitals but in a developed nation a quarter of the population will live in rural areas and do not find it easy to travel for consultations.
Figure 1. low power siliconlabs
The stress of travelling to a surgery to have measurements of heart rate, blood pressure and other physical attributes is stressful in itself and can lead to situations where the patent receives the wrong level of treatment for their actual conditions. If doctors had access to measurements taken over a longer period during real-world activities they would have a much better idea of the patient’s progress.
Governments around the world have also come to the realization that if some chronic conditions, such as type-two diabetes or cancer can be prevented instead of needing acute treatment, this will slow the relentless rise in healthcare costs.
In both of these cases, information technology in the form of the Internet of Things (IoT) provides the core of the solution. Wearable sensors and portable monitoring systems have the potential to extend the reach of medical staff out to the home and provide them with the ability to react much more quickly to changes in the patient’s condition and provide more appropriate healthcare. At the same time, because IT can be used to only signal important changes received over the IoT, overall costs are reduced by not having doctors and nurses perform consultations when they are not necessary.
Using the IoT, sensors are deployed around the patient’s body to the points where they are needed. These sensors would be used to monitor vital signs such as heart rate, blood pressure and respiratory rate, in the case of patients who have suffered congestive heart failure or are considered high risk for a heart attack.
Figure 2.
If a patient has had a stroke or is suffering from mobility issues either leading up to or post hip-replacement surgery, accelerometers and similar motion sensors can be deployed around the body to ensure they are moving well and also to alert emergency services if they suffer a fall. Researchers have also found that in the case of rehabilitation, they get a better sense of the effective mobility of a patient if they can determine how well a patient climbs and descends stairs and gets out of a chair rather than simply walking across a doctor’s surgery.
Wearable IoT goes far beyond treatment of medical conditions. It can help reduce injury and boost wellness. People who wear simple exercise-monitoring wristbands find that working out how many steps they have taken that day changes their behaviour. GPS-enabled sports watches are already in widespread use by athletes, amateur and professional alike. The same IoT technology proposed for medical sensors can be used to prevent injury, such as damage to knees caused by bad running posture, through the use of accelerometers worn on the legs, perhaps sewn into a pair of leggings. Similar sensors incorporated in a vest could help prevent the poor posture that leads to back pain. In these cases, exercise programs in a smartphone or tablet would advise interactively on better ways to run or sit and warn the user that they are slipping into bad habits when they lose concentration.
The sensors used for wellness need not be entirely wearable. For people suffering from debilitating conditions such as dementia that threaten to remove their ability to live independently, sensors and displays placed around the home can help them. The sensors detect what kinds of activities the occupant is trying to perform and can present reminders and help on the displays as they move around their home.
The unifying theme behind these different applications is that of intelligent sensor fusion. Smart sensors wirelessly relay data about changes in circumstance to a monitoring unit which assimilates the incoming information and makes decisions on what to do next. For example, a sudden change in heart rate flagged by one sensor may simply be through additional exertion. But if accompanied by difficulty breathing picked up by another sensor may trigger the monitoring unit to send an alarm to a nearby medical specialist over the cellular connection of a mobile phone.
The key component technologies therefore are low-power microcontrollers and sensors that either have built-in wireless support or can communicate with low-power RF devices that are able to fit in a compact package. The key wireless technologies for wearable and smart-home applications are Bluetooth Low Energy (BLE) and ZigBee. Both are designed for low-energy consumption, a key requirement for devices that users do not want to have to recharge every day.
Given its compatibility with smartphones, BLE has important advantages for wellness devices that are sold to consumers over the counter as well as for more specialised medically oriented devices. BLE is well supported by component manufacturers such as CSR and STMicroelectronics for both sensor devices and monitoring hubs, where BLE is often coupled with WiFi, allowing easy transfer of data to the internet. However, ZigBee has longer range, suiting it to use where sensors need to be integrated in the home and are not just deployed around the body.
Microcontroller suppliers such as Atmel, Freescale Semiconductor and Texas Instruments have developed IoT-capable processors that can handle BLE and ZigBee protocol stacks. These offerings are scalable through support for 8-bit and 32-bit cores, depending on the complexity of the software needed by each particular sensor node.
IoT-oriented MCUs often incorporate specialised low-power support such as hardware state machines that offload much of the real-time sensor processing from the core processor itself. This allows the processor to spend much of its time in a low-energy sleep mode, only waking up when the peripheral hardware indicates that a sensor has picked up a sudden change in activity or condition. Because a high proportion of time is spent in sleep mode – often higher than 99 per cent – overall energy consumption is kept to a minimum and ensuring longer periods between recharge.
Through dedicated silicon support, the IoT is set to revolutionise the world of healthcare and promote a shift in thinking to ongoing wellness, and heading off the need to deal with the consequences of illness.
