The internet of medical things (IoMT) bringing better healthcare for all
Bringing these powers to healthcare, the Internet of Medical Things (IoMT) now provides the opportunity to further enhance the power of today’s medical technology to deal with the challenges facing care providers, including the rising costs of in-person care delivered by experts and the increasing numbers of patients - particularly elderly patients - needing care. According to figures from the United Nations, the world population is set to rise from about 7 billion in 2015 to 9.6 billion by 2050. 1.5 billion of these will be over 65, and there will be 3.7 million people aged 100 and over; nearly eight times as many as there are today.
By combining advanced sensing, on-board intelligence, connectivity and powerful applications in The Cloud, IoMT devices can change the way consumers interact with service providers, and the way services are delivered, and so broaden access, raise standards of care, and mitigate financial burdens on providers.
A wide array of connected devices is already emerging, ranging from wellness products such as fitness bands and smartwatches that empower users to manage their own health, to home-monitoring devices such as fall detectors and home-treatment devices that enhance the safety and standards of outpatient care, to various types of equipment for expert use. These can range from portable high-performance diagnostic equipment like 3D scanners, to automated equipment for delivery of drugs or pain relief, high-performance scanners and remote-controlled surgical equipment.
"According to figures from the United Nations, the world population is set to rise from about 7 billion in 2015 to 9.6 billion by 2050. 1.5 billion of these will be over 65, and there will be 3.7 million people aged 100 and over; nearly eight times as many as there are today." "Martin Keenan, Technical Manager, Avnet Abacus
Evolving Sensor Expectations
Close to the patient, IoMT requires large numbers of sensors for intensive monitoring of patients’ vital signs and relevant environmental factors, as well as actuators for controlling items such as infusion pumps. Key attributes of such devices are low cost and low power consumption, as well as small size and – ideally – quick and easy non-invasive connection to the patient, in the case of vital-signs sensors. Where components such as sensors do come into contact with a patient’s skin, packaging that is both safe and compatible with cleaning chemicals or sterilisation methods becomes a vital concern.
A significant proportion of medical monitoring revolves around sensing temperature and pressure. NTC thermistors, for example, are widely used for localised temperature monitoring during cancer research or treatment, or to monitor patient status during procedures such as heart surgery. Thermistors such as Amphenol Advanced Sensors Thermometrics sensors can have head sizes of less than 1mm allowing integration in a hypodermic needle for direct measurement of intramuscular temperatures or cell temperatures.
Thermometrics sensors, or alternatives such as TDK’s G15 or S8 types, are also widely used in probes for digital fever thermometers, which have largely replaced conventional glass thermometers for measuring human body temperature. Unlike the glass thermometer, which must be read on the spot and the temperature recorded manually, a digital thermometer connected as an IoMT device can automatically append the temperature reading and timestamp to the patient’s record.
Pressure sensing is critical in equipment ranging from home blood-pressure cuffs and CPAP (Constant Positive Air-Pressure) machines for controlling sleep apneas to pre-natal equipment, respirators, and heart-condition/blood-pressure monitoring in surgical or intensive-care situations. Amphenol Advanced Sensors has designed its NovaSensor NPC-100 and NPC-120 disposable sensors (figure 1) to maintain high sensitivity and linearity better than 1% in the physiological operating pressure range. The sensors are used in equipment such as infusion pumps and kidney dialysis machines, and are packaged using a combination of polycarbonate and medical-grade dielectric gel. Amphenol Avvanced Sensors' NPA series surface-mount pressure sensors are also well suited to applications such as CPAP devices, blood-pressure monitors, and first-responder equipment.
Figure 1. Pressure sensors made using clinically safe materials can satisfy a wide range of medical-monitoring requirements.
Non-invasive sensing minimises the expertise and time needed to connect patients to essential monitoring equipment, thereby enabling medical professionals to treat more patients. On the other hand, greater ease of use and comfort for the wearer enables patients themselves to take more responsibility for administering their own care at home.
A patient’s heart rate, for example, can be monitored accurately in a hospital setting without contact against the patient’s skin, using a ballistocardiographic (BCG) sensor. BCG sensing detects vibrations caused by the pumping of blood through major arteries, and the opposing recoil effect. When a patient is lying in bed, this effect causes the bed to vibrate due to the blood flow. Murata has combined its ultra-sensitive MEMS accelerometers with a microcontroller and proprietary algorithm (figure 2) to create a contactless bed sensor that is able to detect heart rate data by monitoring these vibrations. Several other vital signs can be detected, including respiration rate, heart-rate variability and relative stroke volume, as well as bed-occupancy indication and event timestamps. The sensor is available as a complete connectable node with built-in Wi-Fi transceiver (SCA11H), or as a solderable module for OEM use (SCA10H).
Figure 2: BCG heart rate monitoring with ultra-sensitive MEMS accelerometer.
Connecting for Control and Security
Connectivity is crucial in the IoMT, to consolidate collected data for analysis in The Cloud, and for remotely controlling automated actuators. Devices may be connected either to a local concentrator or gateway, or directly to a native IP infrastructure such as a LAN or WAN. Bluetooth®, including Bluetooth Smart, is a popular IoT connectivity solution, and is already widely used for connecting wearable devices to a smartphone to perform local processing and push data to The Cloud.
Personal medical devices such as home-use monitors are ideal platforms for embedded Bluetooth, and can take advantage of wireless modules that are already proven in the mobile industry. Murata has shipped more than half a billion of its LBMA series of Bluetooth modules, which are now available in a tiny 3.5mm x 3.5mm outline, and recently introduced its latest LBCA series Bluetooth Smart module in a 5.4mm x 4.4 mm outline without antenna. This latest device has deep-sleep current of less than 0.6µA and, depending on the application, can operate for four years or more from the energy contained in a single CR2032 coin cell.
Devices capable of operating for extended periods without changing the battery can be designed as sealed-for-life disposable units, or may be powered by rechargeable batteries featuring advanced lithium technologies such as LiFePO4 (lithium-iron-phosphate), Li-ion or LiPo (lithium polymer). RRC Power Solutions has a large range of standardised battery packs and corresponding charging technology that save the costs of development, tooling and agency approvals. It is worth noting that smart batteries from vendors such as RRC present a compelling case where high performance and reliability are critical, by supporting features such as smart charging resulting in longer battery lifetime, and usage recording, which can be effective in preventing unauthorised use or mistreatment. To find out more about RRC’s range of battery packs and charging technology, download our standard batteries catalogue.
A further aspect of connectivity to consider is the use of RFID tagging to verify the identity and authenticity, not only of devices but also drugs and other pharmaceuticals. Counterfeit products present a perennial threat to healthcare, and this can be expected to extend to IoMT applications. Murata’s MAGICSTRAP® NFC/RFID tags are less than 1mm thick and designed to be embedded in injection-moulded assemblies during manufacture. This enables connected medical “things” to identify themselves to each other, using technology that is highly resistant to hacking or tampering. The presence of an incorrect or unknown device introduced to the network can be quickly detected and an error message sent to The Cloud.
By connecting smart devices across the Internet, the IoMT delivers enhanced control and monitoring capabilities that enable higher standards of care for increasing numbers of patients. Enhancements to sensor accuracy, ease of use and wearer comfort will ensure the full benefits of the IoMT reach all the way to the patient. Combined with low power consumption, versatile connectivity and security, this technology can help improve the delivery of healthcare services in all regions of the world.
As Technical Manager, Martin is responsible for marketing strategy across IP&E, power and battery products into key market segments. Martin has over 15 years' experience in electronics having begun his career at Nortel Networks, and since occupied roles at RS Components, Avnet and Altera.
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