With an aging population, a rise in chronic diseases and emerging countries requiring the development of healthcare infrastructure, there is a pressing need to transform the care that is provided. In our current healthcare system, the patient is not asked to take an active role. People know the balance of their bank account but not what their blood pressure or heart rate is. The outcome is that people usually react too late and when they are finally diagnosed, treatment is more expensive and has more physiological impact than if the disease had been detected earlier.
The first step toward a prevention-based system is to educate people about their health and to provide them with the tools that allow them to take ownership of it, such as measurement devices to assess their vital signs or treatment devices like auto-injectors for self-administering drugs. To make this possible, medical device manufacturers need to bring professional equipment into people’s homes, and this brings with it several challenges. Such devices would have to be cost-effective, in order to be accessible to the broadest audience possible, and portable, which dictates that they be battery-operated and wireless. These devices must also be easy to use as the user will no longer be a professional, so development of advanced user interfaces, safety, security and high levels of automated operation will be the key to success.
Cost-effective, portable and connected
Those new requirements for medical device designers – cost-effective, easy to use, portable and wireless connectivity – were until recently unattainable goals, but recent advances by semiconductor suppliers are making this a reality today. Freescale, for example, is using ARM low-power processors to design advanced microcontrollers in the Kinetis portfolio, which uses Cortex-M4 and M0+ processor cores.
A perfect example is the blood glucose monitor. This device usually has five or six different modes of operation: standby while in your pocket/bag; wake up and wait for a blood drop to be applied on the test strips; measurement of the electrochemical reaction; processing of the samples; logging of the results; and display of the data. To run all of these steps, older processor technology would have to be working at its maximum-performance operating point for the entire measurement cycle (except when in standby), which would be a massive drain on the battery and therefore not meet the requirements for a portable device. Today, however, the latest microcontroller devices integrate that processing system on a single chip, resulting in low-power systems, which more than halve the energy used by the device, thereby doubling the period of time between battery replacements or recharge cycles.
Achieving a high level of safety and making the certification process easier are the key advantages of an integrated solution, as the number of components is reduced and the interaction between the different features is clearly documented. One of the biggest concerns for medical device companies is the product-certification process, and to ensure that a component selected, used and certified in a product does not cease to be manufactured during the product lifetime. This concern is addressed by the single-chip solutions; for example, Freescale can offer a 15-year longevity programme to its medical customers on certain products, supporting the need for cost-efficiency, as it may prevent an expensive recertification of a product if a component goes out of production during its lifetime.
Case study
A current impressive example of this advanced technology is Insulet’s OmniPod, a tubeless insulin pump. Conventional pump therapy includes an insulin pump, reservoir, an infusion set and tubing that connects the insulin pump to the infusion set – keeping the patient tethered to the pump 24/7. The revolutionary OmniPod design has only two parts: a wearable pod that delivers the insulin and a PDA-type device called a Personal Diabetes Manager (PDM). The pod is worn for three days and then replaced. It holds 200 units of rapid-acting insulin, which covers the requirements of almost 95% of type 1 diabetes patients.
Kevin Schmid, Insulet’s VP of business development, said: "Ultimately, our goal is to provide superior treatment options for people with diabetes and to make diabetes an ever smaller part of life." Meeting that goal required expertise beyond Insulet’s core competency, so when it came to finding a silicon provider, the company searched for a partner who would provide a custom chip.
"We saw that Freescale had the right microcontrollers to control size and cost for the disposable pods, and RF connectivity for the PDM and pod to communicate wirelessly," added Schmid. The two companies worked through a close collaboration to produce a customised microcontroller design that consumes very little power and enables communication between the PDM and the pod using an integrated radio.
A decentralised approach
The next phase in using technology to reduce healthcare costs is to move from a hospital-centric system to a decentralised approach in which people measure their vital signs themselves. To achieve this, we must first ensure that medical devices are connected so that the information they provide can reach the doctor through secure databases without the need for the patient to be physically present. Smart homes are the basis of this system, where patients can transmit vital health data from their home to the physician’s office and in turn receive personalised health-coaching tips from the practitioner or smart knowledge-based information systems located in the cloud.
Furthermore, in smart homes, networked devices and telehealth systems can act in programmed ways if a medical problem were to occur within the home, with the care centre, depending on the pre-set alert level, being automatically alerted should the situation warrant it. Home telehealth systems are expected to become ubiquitous and will generally consist of a central health hub managing multiple biometrics devices as well as security and assisted-living sensors. This will allow people with illnesses or disabilities to remain in the comfort of their own homes while retaining a high quality of life.
There is compelling evidence to support the value of remote monitoring for individuals with chronic conditions, including:
- 35-56% reduction in mortality
- 47% reduction in risk of hospitalisation
- six days’ reduction in length of hospital admission
- 65% reduction in office visits
- 40-64% reduction in physician time for checks
- 63% reduction in transport costs.
The next phase in introducing telehealth is effective delivery of a care plan to patients suffering from chronic disease. Home telehealth devices should focus on users and services and make the underlying electronic technology used in patient-centric devices as unobtrusive as possible. Patients have to be comfortable and confident that they can trust the devices delivering their healthcare. The platform technologies should be flexible enough to accommodate device personalisation according to diagnosis and patient-led requirements and have a user interface that is simple and understandable. The latest technology described above allows device manufacturers to develop such user interfaces and make products as user-friendly as possible using a reference platform. The platform features Ethernet and Wi-Fi to ease internet connectivity to the cloud, and USB, Bluetooth and ZigBee to guarantee interoperability with biometric devices that is compliant with the Continua Health Alliance guidelines.
Advanced security features are also provided by the reference platform, such as authenticated start-up and hardware-based encryption, which will allow designers to implement data privacy schemes and govern levels of medical data access. These embedded security features will also simplify the integration of telehealth platforms into medical health networks. For example, the Home Health Hub Reference Platform is being integrated with Microsoft’s HealthVault cloud service, where authenticated and encrypted home-based medical measurement results can be transmitted and monitored by a triage centre that would be alerted in real time if a vital statistic moved outside previously set limits.
Future areas for improvements that can help deliver efficient and cost-effective healthcare is the diagnosis of the patient’s illness. Today, this process has already changed in some hospitals where nurses can use instruments to perform diagnostic analysis at the bedside, saving time, money and making the patient’s life more comfortable. The next step will be to deploy these devices at clinics and eventually in people’s homes, where they will be able to self-screen. The first device of this kind has been around for years: the pregnancy test. The second is changing the life of millions of diabetics: the blood glucose monitor. What’s coming next? The Freescale medical team, driven by Dr José Fernández Villaseñor, is working on a new generation of biochemical sensors. This technology is based on ion-sensitive field-effect transistors (FETs), and these sensors are then used to create immunological-sensitive FETs, which can subsequently be used to detect pH, as well as antigens and antibodies of specific pathogens that are the cause of a wide array of infectious diseases.
Future possibilities
Wearable devices, like smart plasters that record body temperature, respiration or ECG, are getting close, but their size, weight, power consumption and price still need to be reduced. Technological advances are moving medical electronics forward at a rapid pace. Another exciting innovation is the harvesting of energy from the heat of the body or from movement to deliver the power needed to run these portable healthcare devices continuously without the need for batteries, and this will affect their size and weight in such a way as to turn them into unobtrusive, wearable accessories. We anticipate that the industry will be able to deliver such solutions within the next five years.
