Toward Safe and Effective Wireless Medical Devices

and Systems

Donald WittersOffice of Science and Engineering Laboratories

Center for Devices and Radiological Health Food and Drug Administration

Safe, effective, reliable, and secure wireless

medical devices integrate risk management into the

design, testing, deployment and maintenance.

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Overview

Risks for RF wireless medical devices

Considerations to manage risks

Challenges and opportunities Summary

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Wireless Medical Device Issues

Wireless technology is dynamic & changing

EMC: RF wireless is both a source and victim for EMI

Competition/coexistence among users

Convergence, interoperability Security Standards

Key Terminology

Radio frequency (RF) wireless medical device - a medical device that includes at least one function via RF wireless communications include data transfer, device control,

programming, power transmission, remote sensing and monitoring, and identification

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Wireless Wireless TechnologyTechnology

Wi-FiWi-Fi

MedRadio MedRadio (MICS)(MICS)

Mobile Mobile PhonesPhones

WMTSWMTS

Mobile Mobile RadioRadio

GPSGPSWiMaWiMaxx

CognitivCognitive Radioe Radio

DTVDTV

RFIDRFID

BluetoothBluetooth NFCNFCZigbeeZigbee

Wireless Medical Devices*

*Based on sample of 303 wireless medical devices.*Based on sample of 303 wireless medical devices. 7

MRI 2%Hearing Aids 2%Endoscopic Surgical Tool

1%

Doppler 1%Wireless Networking Accessory

2%

Aspirator <1%Hemodialysis 1%Wetness Detection 1%Urodynamic Measurement System

<1%

EMC and Wireless Technology Standards and Documents

•IEEE 802.11, IEEE 802.11, Bluetooth, ZigbeeBluetooth, Zigbee

•Cellular TelephoneCellular Telephone•RFIDRFID•MedRadio (MICS), MedRadio (MICS), WMTSWMTS

•IEC 60601-1-2 Medical Elect. IEC 60601-1-2 Medical Elect. equip.equip.

•ISO 14708-1 Active ISO 14708-1 Active implantableimplantable

•ISO 14117 (PC 69) ISO 14117 (PC 69) pacemakers, ICDspacemakers, ICDs

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EMC Terminology

Electromagnetic Interference (EMI)Disruption of the device function by Electromagnetic energy (EM)

Radiated EM (e.g. radio waves)

Conducted (e.g. AC power surges)

Electrostatic discharge (ESD)

Electromagnetic Compatibility (EMC)Device functions properly in its EM environment (immunity);

Device EM emissions do not cause EMI in other devices

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Inhibited ventricular Inhibited ventricular stimulationstimulation

RFID Testing with Implantable Cardiac Pacemakers

Implantable cardiac Implantable cardiac

pacemaker and leadpacemaker and lead

From S. Seidman et. al. In vitro tests reveal sample radiofrequency identification readers inducing clinically significant electromagnetic interference to implantable pacemakers and implantable cardioverter-defibrillators, JAMA 2010. 10

Medical Device EMC Considerations

Reference standards IEC 60601-1-2 std. covers most medical electrical equipment

Active implants ISO 14117 (PC69), EN 45502, ISO14708-1

Emissions and immunity testing important to include active wireless links test findings pass/fail criteria deviations from standard

Device modifications User information

IEC 60601-1-2 requirements

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Additional EMC Considerations

Special Concerns Cell phones, Security systems, RFID MRI exposure Special environments?

Present standards can be inadequate for wireless medical device concerns IEC 60601-1-2 3rd Ed. and IEC 61326-1 allow an

exclusion from testing in the RF wireless frequency band

IEC 60601-1-2 4th Ed. is different with immunity testing in common RF emitter bands

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Comparison of Sample Wired vs. Wireless Active Medical Devices (Since 1996)

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Wireless Medical Device Considerations

Overall risk management Choice of wireless technology Wireless functions & performance

Wireless data integrity Quality of Service Wireless Coexistence

Wireless security EMC Information for user

Final RF Wireless Medical Device Guidance

http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm077210.htm

Wireless technology not covered in this guidance:MRI, X-ray, CT, RF/microwave diathermy

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Medical Wireless Risks & Priorities

Shared risk environment Risk related to device/system intended use, and wirelessly enabled functions and needed performance

Consequences of not getting data across wireless link correctly, timely, and securely

RiskRisk

Life critical Life critical functions, high functions, high priority alarms, priority alarms, therapy, remote therapy, remote

controlcontrol

Low priority data, No Low priority data, No therapy or alarmstherapy or alarms

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RF Frequencies Used by Wireless Medical Devices*

*Based on sample of 324 wireless medical devices*Based on sample of 324 wireless medical devices

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Frequency0-10KHz10KHz - 100KHz101KHz - 1MHz1.1MHz - 10MHz

10.1MHz - 100MHz

402MHz - 405MHz432MHz - 434MHz608MHz - 614MHz800MHz - 900MHz916.5MHz919.8MHz1.395GHz - 1.4GHz1.8GHz - 1.9GHz

Ex. Wireless User Information (1)

The X system was designed and tested for RF wireless connections to an appropriately configured and secured WLAN within the {Healthcare} facility. The following equipment and configurations were tested for wireless connection and transmission of X system data and information at the specified Quality of Service.

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Ex. Wireless User Information (2)Wireless Equipment needed for the X system wireless functions:

Model A1 Portable Data Terminal (PDT)X System was used for development and testing with the following features:

• Integrated wireless technology IEEE 802.11b/g operating in the 2.4 GHz Industrial, Scientific, Medical (ISM) frequency band

• 64 MB RAM• Integrated laser bar code readerRF wireless equipment needed to support a WLAN at the {Healthcare} facility: - model B1 Dual Band Wireless Access Point certified for IEEE 802.11b/g technology - Integrated PC Network Cards certified for IEEE 802.11b/g technology 19

Wireless Protocol Used by Medical Devices*

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GSM/GPRS 1%Medical Implant Communication Service

1%

Medical Device Telemetry Service

<1%

Ultra Wideband Frequency Spectrum

1%

NRMI (Near Field Magnetic Induction)

<1%

*Based on sample of 326 wireless medical *Based on sample of 326 wireless medical devicesdevices

Example QoS Information (1)

Understanding Wireless LAN Quality of Service

To achieve the same level of wireless quality of service demonstrated during testing wireless X device system needs the following service:• Maintain the network according to IEEE 802.11a/b/g standards with encryption.• Traffic on the 802.11 wireless network does not peak at more than sixty percent (60%) for a sustained interval of thirty (30) seconds or more when measured over any continuous six (6) hour period.

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Example QoS Information (2)

Understanding Wireless LAN Quality of Service (cont.)• Handheld devices for the wireless X device system must be configured to 802.11b or 802.11g, channel 6.• Minimum available data rate at the desired location of service must be 2 Mbs.• Recommended wireless network security protocol of WPA2 encryption.• The wireless LAN must have a minimum of two (2) wireless access points with a physical separation of no more than 50 m.• Handheld devices for the wireless X device system must be at least one (1) meter and no more than twenty-five (25) meters from a wireless access point to maintain connectivity.• The error rate of data transfer must be less than 2% dropped packets.

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Device wireless Device wireless linklink

Sample wireless Sample wireless interfererinterferer

Sample wireless Sample wireless interfererinterferer

Sample wireless interfererSample wireless interferer

Sample wireless interfererSample wireless interferer

Distance & Distance & orientationorientation

Coexistence Coexistence TestingTesting

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Wireless Security Considerations

Wireless security issues Open architecture Multiple combinations of technology Rogue wireless users Health Insurance Portability and

Accountability Act (HIPAA) issues Wireless security considerations

Authentication – to ensure authorized users

Encryption – to secure sensitive data and wireless links 24

Security of Wireless Signals and Data

• Approaches• Part of comprehensive security plan

and procedures• see FDA’s draft guidance “Content of

Premarket Submissions for Management of Cybersecurity in Medical Devices.” (http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm356186.htm)

• Use the most up-to-date wireless security encryptions 25

Ex. Wireless Security Information (1)

Wireless Security and SSID

The WPA2 wireless security encryption protocol is strongly recommended for all users of the X medical device system in addition to all other security protocols and procedures that are used by the healthcare facility systems.

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Ex. Wireless Security Information (2)

Wireless Security and SSIDThe X wireless medical device system was designed and tested to work with wirelessly enabled platforms using the IEEE 802.11b/g protocols, which runs under a network ID (SSID) that is broadcast by default to 802.11 capable hardware. To securely operate X wireless medical device system it is recommended that the wireless broadcasting of the SSID be disabled so that only devices communicating over the {Healthcare} facility defined SSID can transmit and receive on the same network. 27

Information for Set-up and Use Information to properly configure, deploy,

use and maintain the wireless device system Wireless functions and performance Limitations, environments, proximity of other wireless,

international regulations if appropriate Specific wireless technology (e.g., IEEE 802.11b/g/a),

frequencies, wireless modulations, effective radiated RF power

QoS, recommended security information (e.g. WPA2) EMI recognition & mitigation information FCC labeling as appropriate

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Maintaining the Wireless Device

Device Life Cycle EMI/EMC issues Accessories, additional equipment (e.g.

modems) Repeated failures at same location or

other locations Servicing

Maintaining wireless integrity and performance

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Challenges and Opportunities Rapidly changing wireless technology,

limited spectrum Wider integration and greater need for

shared risk management Increase in home health care with more

functions and less on-site management Need for information and standards for

safe, secure, and reliable medical systems

Opportunity to create products and pathways for wireless in healthcare

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Summary

Medical wireless technology is rapidly evolving and helping to drive innovation in health care.

Safe, secure, and reliable wireless medical systems require risk management.

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Summary Considerations for wireless

medical systems include: Wireless technology, functions and

characteristics QoS, data integrity, coexistence, security,

EMC, user information & maintenance Many challenges and

opportunities for research, products, standards, and guidance to meet present and future needs.

Safe, secure, and reliable wireless medical device

systems require risk awareness and management

focused on key considerations including wireless performance, security, and EMC.

Donald WittersDonald WittersCenter for Devices and Center for Devices and Radiological Health, Food and Radiological Health, Food and Drug AdministrationDrug Administration

10903 New Hampshire Ave.10903 New Hampshire Ave.

Building 62, Room 1130Building 62, Room 1130

Silver Spring, MD 20993-0002Silver Spring, MD 20993-0002

USAUSA

Phone: 301/796-2483Phone: 301/796-2483

donald.witters@fda.hhs.govdonald.witters@fda.hhs.gov

FDA Semi-Anechoic Chamber