Medical telemetry basics-Telemetry in medical health care
This page on medical telemetry basics describes RF and wireless technologies for telemetry application in medical health care.wireless medical devices used for these applications are also covered.
Medical telemetry devices monitor patients' vital signs and other health related parameters. One of the example is wireless cardiac monitors. This application is widely used in hospitals, health care facilities and at home. Various wireless medical devices have been developed based on various needs. FCC has established new wireless medical telemetry service in the year 2000.
FCC 00-211 mentions RF frequency bands used for medical telemetry purpose. Frequency bands 608-614MHz, 1395-1400MHz and 1429-1432MHz are commonly used. For details refer Medical Telemetry Bands.
Following RF and Wireless technologies are used for medical telemetry and other applications.
• FCC devices(47 CFR Part 15)
• WMTS-Wireless Medical Telemetry Service
• cellular or mobile telephones
• wireless handheld computers and PDAs
• wireless local area networks (WLAN 802.11.a/b/g)
• wireless modems for laptop computers
• personal area networks technologies such as Bluetooth, UWB and Zigbee
• RFID-RF identification
The figure depicts various wireless medical devices used for medical telemetry application. The main goal of FCC is to ensure that wireless medical devices like other RF devices, operate in compliance with other spectrum users. In order to meet this, they should meet EMI/EMC and other EM radiation requirements.
Wireless Medical Devices
Wireless medical devices fall under two major categories viz. short range or long range. Short range technologies transmit data from the patient to a local receiver/monitor. The local receiver may stand alone or connect to a central monitoring station. Long range technologies generally transmit patient data directly to a remote monitoring location.
Available wireless technologies and FCC services to support short range patient monitoring will include following:
➤Inductive implantable medical devices for monitoring and control of cardio activities of the patients. These devices usually operate at 200KHz and covers distances of less than 1 foot.
➤MICS for communication between body implants and nearby controller. These devices operate at 401-406 MHz and covers about 10 feet.
➤ The devices based on wifi, bluetooth and zigbee are used for implanted or body worn medical devices. These wireless medical devices operates in various frequency bands and covers few hundred feets.
➤The devices based on UWB are used for medical telemetry and imaging. These are low power devices and covers distnaces upto few feets.
➤Implanted microstimulator devices are used as artificial nervous system. This helps to restore mobility to paralyzed limbs. These devices operate in 413 to 457 MHz frequency band and covers distance of few feet.
➤Wireless Personal Area Network of multiple body sensors are used to monitor and control various patients' functions . They operate in 2360-2400MHz band and covers few feets. They are known as medical body area networks(BANs).
Available wireless technologies and FCC services to support long range medical telemetry will include following:
➤WMTS(Wireless Medical Telemetry) uses unlicensed bands to communicate data from body sensors with remote monitoring systems. They operate in 600-1432 MHz frequency band and covers several hundred feets.
➤WiMAX technology provides data rate of 70Mbps with distances of several kms. They operate in 2.5 GHz frequency bands.
Figure mentions various wired and wireless medical devices. National Instruments provides solutions for medical RF signals recording and playback purpose. The solutions include both hardware and software(toolkit) deliverables. They provide RF and Wireless testing equipments for WBAN(Wireless Body Area Network), zigbee, WLAN(11n,11ac,11ad), bluetooth and more.