Advances in electronic monitoring are revolutionizing healthcare, but the real benefits won't arrive until these new devices can be seamlessly interconnected.
Can you imagine a world without mobile phones, the Internet, or laptops? How would our world be different?
Billions of emails are sent daily. Hundreds of thousands of computers are used every day. How many mobile phones do you have at home? To make things even more exciting, many devices which were not previously connected are being "plugged in": refrigerators, TVs, photo frames, ovens, washing machines, and healthcare devices.
What is the value of connecting healthcare devices?
You might ask yourself, "Why would we want to connect medical devices?" Picture an elderly person resting at home after years of hard work. Suddenly, that person receives an appointment reminder from their mobile phone indicating that they are to perform a routine health check. The person goes to their living room where a small, easy-to-use, portable blood pressure monitor assists in executing the test. The data is transmitted automatically to the preferred health repository where an algorithm is executed to evaluate the patient's status. There is no need to call the physician. In other cases, the automated diagnosis could set up a patient-physician video conference for further evaluation. As you can probably already imagine, the technology is available to do this now.
Imagine a situation where a different subject wants to lose weight over a predetermined period of time. The subject wears a coin-sized activity monitor to track how many steps are taken. The monitor then calculates how many calories are burned. Let's imagine that this person jogs for 30 minutes and then has lunch afterwards. The activity monitor has already transmitted the burned-calorie data to their mobile phone, which automatically links to a web application to process the data. The mobile phone serves as a display and suggests a varied menu to help our subject achieve the goal of losing weight.
The next example involves a diabetic patient. Our patient is listening to their favorite music on their mobile phone when the device interrupts to advise the patient to measure their glucose level. Our patient plugs in a small add-in which works with most standard mobile phone connectors and allows the patient to execute the test. This add-in is a portable glucose meter which uses the phone's graphic LCD to report measurements and uses its connectivity to update the preferred health repository. The physician can then track the progress of the treatment. The mobile phone accessory can also communicate to a wearable insulin delivery device to release the correct dose.
What are the challenges of healthcare device connectivity?
Technology businesses are very similar. Most standard technologies are sucessful in the consumer market and medical/healthcare devices are not an exception. Do you remember the battle over videotape formats in the 1970s and 1980s, or the recent audio player debate where a magnetic optical disc and flash memory were the contestants? What are the standard technologies for medical/healthcare device connectivity?
There are not very many major portable medical device manufacturers who can comply with the most exhaustive medical device regulations, such as the FDA. There is some standardization for medical device connectivity, but the standardization level is no different from that of general portable consumer applications, and in fact, medical device advancements are being driven by it.
The move toward standards has started to evolve with the creation of consortiums, consisting of medical device manufacturers, pharmaceutical companies, technology vendors, and service providers, whose aim is to develop standards for multi-vendor connectivity. This can help achieve consensus among suppliers and therefore create a whole new market of services and products and eventually change the way healthcare is delivered.
Selecting a standard
One of the strongest organizations in terms of medical device standardization is the Continua® Health Alliance (http://www.continuaalliance.org). This organization unites smart technology and medical devices with healthcare industry leaders to empower patients not only to exchange vital information, but to change the way they manage health and wellness. The Continua Health Alliance is a forum consisting of more than 230 member companies who have come together to promote multi-vendor device interoperability by forming workgroups to set standards for medical systems.
In order to build trust, this organization has created a product certification program with a recognizable logo which signifies interoperability with other certified products. Additionally, products that carry this logo may have a competitive advantage and may provide benefits such as being considered "easy-to-use," following Continua Health Alliance standards, or "future proofed" — meaning that they won't become prematurely obsolete. The products can be sold through multiple channels, such as directly to consumers and through prescriptions written by healthcare providers, or sold by governments, health plans, or other service providers to their constituents.
Being part of such an organization has additional benefits, such as promotions in different channels. All of these products and services are creating a whole new market, and opportunities around medical devices will keep growing in the upcoming years.
Semiconductor vendors address medical connectivity needs
The semiconductor vendor was not traditionally involved at this level of the portable medical device application. Historically, the "secret sauce" of the application has been kept, and will continue to be kept, by the medical device manufacturer. It makes sense, as medical innovations are possible only after years of research, development, and comprehensive testing. However, connectivity is not the core competence of the medical device manufacturer. Therefore, there is an opportunity for the semiconductor vendor to provide key differentiations by offering a software suite capable of transmitting this data. One might think that common protocols, such as USB or Ethernet, could be used in medical applications. That is partially correct. The only difference from a conventional consumer application is having to deal with sensitive data that directly impacts diagnostics and therefore a person's health.
The medical device manufacturer needs to take advantage of existing communication protocols popular in consumer applications for two main reasons. The first is cost, which is associated with design cycles, service providers, and semiconductor technology availability. The second is associated with end-user acceptance and usability. Why would one want to transfer data through a custom adapter or protocol if at the end it is going to be analyzed by a physician or the sender on a tablet computer that has USB or Wi-Fi. Medical devices need to utilize the same protocol to communicate with consumer products and among themselves, but they still need to keep a formal data structure to preserve device interoperability and to correctly process and link related data. This is solved by adding an extra software layer between the communication protocol and the application.
Standards such as IEEE 11073-20601 (Optimized Exchange Protocol) are defined under Continua Health Alliance device interoperability guidelines. Microcontroller and microprocessor vendors such as Freescale Semiconductor offer software suites like the Freescale Medical Connectivity Library, which allows the medical device designer to apply various device specializations defined by the standard without worrying about the implementation details of the protocol (see Figure 2). The library is transport- and platform independent, allowing the use of different transport technologies, such as Ethernet or USB, or platforms such as MQX (a complimentary RTOS from Freescale). Under these conditions, a USB-enabled glucometer could communicate with a manager application which transfers the data (under the same medical specialization protocol) through Ethernet to a health repository webpage. This manager application could be running on a tablet computer with Bluetooth® wireless technology or on a concentrator node in a hospital enabled with ZigBee® technology. Both of them could have connectivity to the Internet and communicate with each other independently.
Additionally, Freescale offers its customers a complimentary USB stack that features the Personal Healthcare Device Class (PHDC). The PHDC is a standard implementation of USB for medical devices. IEEE 11073 is also the foundation of the USB stack with PHDC. This provides structure to the communication interface by defining commands to access data, structuring data to be transmitted, and defining communication states. Figure 1 shows the proposed software architecture.
Figure 1: Freescale USB stack with PHDC support.
Figure 2: Freescale Medical Connectivity Library.
Freescale offers this ready-to-use software as part of the TWR-MCF51MM-KIT and TWR-S08MM128-KIT development board demo programs. The demo emulates a glucometer and a weight-scale device. With the push of a button, one can switch between the devices and the manager application (running on a PC) will recognize the device as a USB PHDC device (glucometer or weight scale). The manager application running on the PC transfers the data through Ethernet and uploads it to a well-known health repository, http://www.google.com/health. This proves the concept and enables users to develop applications that follow Continua Health Alliance guidelines. Freescale is not responsible for certifying the application. The medical device vendor would need to apply for certification at Continua Health Alliance to ensure compliance, and to be allowed to use the consortium logo and additional benefits.
The USB stack with PHDC and the Medical Connectivity Library helps medical device vendors improve time-to-market and optimize budgets. The software suites have been ported to several 8-bit and 32-bit microcontroller devices and are planned to be ported to additional devices in the future. Freescale offers a wide range of microcontrollers with an integrated measurement engine (operational and transimpedance amplifiers, 12-bit DAC, 16-bit ADC and internal voltage reference). These devices are ideal for portable medical applications requiring signal instrumentation such as pulse oximeters, blood pressure monitors, and glucometers. Entry level devices are those in the 8-bit 9S08MM family, followed by the MCF51MM 32-bit ColdFire® V1 ultra-low-power microcontroller, and expanding to the recently announced high-performance ARM® Cortex™-M4 based Kinetis™ K50 microcontroller. These devices provide multiple connectivity options such as a USB device and the host or an Ethernet controller (see Figure 3).
Standardization is critical, especially as new markets emerge. Being a part of big alliances with important member companies is vital to ensure the interoperability and sustained development of personal medical devices. The Continua Health Alliance is a benchmark organization in the medical device industry by providing product certifications.
Figure 3: Freescale Kinetis K50 based pulse oximeter system diagram.
Semiconductor companies have started to differentiate themselves when approaching a medical device vendor. Companies like Freescale offer complimentary software suites to help reduce time-to-market and speed development. Freescale is a promoter member of the Continua Health Alliance and supports the advancement of the Continua vision. Microcontrollers like the 8-bit S08 9S08MM, the 32-bit ColdFire MCF51MM MCU, and the ARM Cortex-M4 based Kinetis K50 microcontroller integrate a measurement engine to enable future portable medical/healthcare devices.