© IMEC 2012

BAN AND PN

IN HEALTH

GUIDO DOLMANS

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HEALTHCARE GOES WIRELESS

2

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BODY AREA NETWORKS AT IMEC

Future generation pHealth solutions

3

Necklaces/patches Watch-type Headsets

© IMEC 2012

BODY AREA NETWORKS (BAN)

The main bottleneck to achieve energy autonomy in BAN is the design of an ultra low power yet reliable wireless system.

Wireless networks for

communication among

sensor nodes

operating on, in or around

the human body

in order to monitor vital

body parameters and

movements

BAN INTRO

This Workshop:Cardiovascular Patch System Design

IEEE Standards for BAN and PN

© IMEC 2012

HISTORY OF ECG MONITORING

1903: how it all startedBedside (mains operated)

Handheld (2xAAA battery operated;

2 hours autonomy)Patch with match-box size clip-on (7 days autonomy)

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CARDIAC MONITORING IN 2008

6

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CARDIAC MONITORING IN 2010

Piix by Corventis

Digital plaster by

Toumaz

VitalSens by ST+D

Zio by iRhythm

© IMEC 2012

KEY CHALLENGES

Long-term autonomy ▸ Ultra-low-power circuit designs: analog, digital and RF

Wearable and Comfortable▸ Integration technologies for flexible and stretchable systems

Robust (in every-day life settings)▸ Motion artifact detection... and compensation

Connected▸ To mobile phones, EPR, healthcare networks

Increased diagnostic functionality▸ From raw data to information to knowledge, multi-modal

And... low cost8

© IMEC 2012

2010-2011: IMEC ECG NECKLACE Wireless,

connected, ‘on-the-move’

Wearable | with adjustable electrode leads

Robust | monitoring in every-day life situations

Low-power | 24/7 recording for > 1 week

Smart | instantaneous RR and HRV analysis

© IMEC 2012

IMEC CONNECTS YOUR HEALTH

Manage your vitals from your mobile BAN interface to Android Phone

24/7 connectivity to public network

Instantaneous alert

▸ Emails

▸ Text messages

BAN data available globally over the internet

▸ Real-time check

▸ Link to EPR

© IMEC 2012

CURRENT IMEC ECG

SYSTEMS TOWARDS

FLEXIBLE PATCH:

1. NECKLACE

2. FLEXIBLE PATCH

Marketing specification

▸ Patch to be worn continuously for at least 7 days

▸ Comfortable: flexible, stretchable, thin

▸ Fully disposable

▸ Medical grade quality; monitor arrhythmia patient

▸ Works well in daily life including sports

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© IMEC 2012

POWER BREAKDOWN

Component Products

Micro-controller TI MSP430

Wireless Nordic nRF24L01

ADC AD7466 ADC

Power manager LTC3100

Sensor,read-out Imec’sbiopotential

Micropower 16 mAh Li-Ion battery, or

200 µW harvester with

rechargeable battery

Power consumption for a sensor node based on the

Nordic RF24L01. The total power consumption

equals 1299 µW.

© IMEC 2012

IMEC DEVELOPS NOVEL RADIOS WITH RECORD

LOW POWER CONSUMPTIONRadiopower

Data rate

100 mW

10 mW

1 mW

1 Mbps 10 Mbps 100 Mbps100 kbps

0.1 mW

WiMedia

Bluetooth

Zigbee

Impulse UWB

unique combination of low power and high data

rate

Narrow Band

10 to 100 lower power than BT, Zigbee &

alternatives

Event-driven

<50 uW continuously on

imecImpulse UWB

Short-range BAN

event-driven radio

Extended-range PAN

© IMEC 2012

PERFORMANCE COMPARISON

[1] Chen, JSSC07

[2] Shi, VLSI08

[3] Ayers, CICC08

[7] Raja, ASSCC08

[8] Chee, JSSC06

[9] Daly, JSSC07

Tx

front-end

Freq.

(GHz)

Pout

(mW)

η

(%)

Data-rate

(Mbps)

FOM

(nJ/bit/mW)

Imec 2011-

BAN2.4 1 24 1/10 2.53/0.253

[7] 0.433 0.054 4.5 10 0.97

[8] 1.9 1 28 0.156 11.54

[9] 0.9 0.6 6.9 1 14.4

Rx

front-end

Freq.

(GHz)

Sensitivity

(dBm)

Data-rate

(Mbps)

Power

(mW)

Imec 2011-

BAN2.4 -75 5 0.534@1/1.2V

[1] 2.4 -60 1 2.8@1.2V

[2] 5 -60 1.2 6.6@1.2V

[3] 0.9 -70 1 0.4@1.3V

© IMEC 2012

BAN RADIO POWER CONSUMPTION

SUMMARY

• Digital baseband is running at 6MHz clock

• Input signal is 1Mbps 3MHz oversampled

© IMEC 2012

IMEC BAN RADIO PROVIDES 10X

IMPROVEMENT OVER BT OR ZIGBEE

This work

10x improvement

© IMEC 2012

ML 505 FPGA

Board

BAN radio

Test Board

1st demo: Lab evaluation board

2nd demo: μP control and

connected to battery

Testing with battery and

ECG source

3rd demo: ECG necklace

The IMEC route to a flexible patch starts with a

necklace

© IMEC 2012

POWER REDUCTION WITH IMEC WIRELESS

Component Products

Micro-controller TI MSP430

Wireless Imec’sBAN Radio

ADC AD7466 ADC

Power manager LTC3100

Sensor,read-out Imec’sbiopotential

Micropower 16 mAh Li-Ion battery, or

200 µW harvester with

rechargeable batteryPower consumption for a sensor node based on

imec’s ban radio. The total power consumption

equals 362 µW.

© IMEC 2012

TOTAL SYSTEM APPROACH:

POWER ESTIMATION TOOL

© IMEC 2012

SECOND WAY: REDUCE MICROPROCESSOR POWER

Component Vdd

µC: EFM32G890 2.2

Radio:Nordic nRF24L01 2.2

ADC: MSP430 2.2

Power Manager: TP780

Bio-potential: imec 3.0

Battery:140 mAh Li-Ion 3.7

Arrhythmia local

369µW

=168%

Power management dominant

Use Cortex M3 based processor with

embedded frequency and power

management (130nm instead of

180nm)

Optimize implementation of algorithm

for the processor: biggest gain...

Power management power

dominated

© IMEC 2012

JOINT OPTIMIZATION: REPLACE CORTEX-M3 PROCESSOR

BY OWN ASIP DESIGN AND USE IMEC RADIO

Component Vdd

µC: imec 1.2

Radio:imec 1.2

ADC: imec 2.2

Power Manager: LTC3100+C

Bio-potential: imec 2.2

Battery:140 mAh Li-Ion 2.4

Arrhythmia local

96µW

=15%

Power figures from system level simulator

with measured component power of real Si

2 frequency domains; 14 voltage domains

Low retention voltage SRAM

Optimized for low duty cycling

VLIW, SIMD-4

Specialized instruction set

Generated C compiler

Autonomy on printed battery of 6cm2: 2.2 days

Autonomy of necklace: 3.5 months

2010

© IMEC 2012

WHAT IS STILL POSSIBLE TO REACH 50µW?

1. Reduce processor Vdd to 0.7V

• Works!

2. Reduce supply voltage instrumentation amplifiers to 1.2V

• Works!

3. Reduce battery voltage to 1.5V

• Possible since all circuits operate on 1.2V

Bottom line

• Estimated power consumption: 51 µW

• Autonomy on 6 cm2 thin film printed battery: 6 days

Can we replace the primary battery with energy harvesting?

• Radio-Frequency

• Thermo-electric generator

© IMEC 2012

WIRELESS: NOT ALONE BUT

EMBEDDED IN STANDARDS

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Bluetooth v1.0

IEEE802.15.1

WPAN / Bluetooth

BT v1.1, v1.2

BT EDR v2.0, v2.1

BT HS V3.0

IEEE802.15.3

High rate WPAN

IEEE802.15.4

Low rate WPANIEEE802.15.4a

Alt PHY

IEEE802.15.6

BAN

BT LE V4.0

IEEE802.15.4j

MBAN

© IMEC 2012

CURRENT STANDARDIZATION ACTIVITIES FOR

SHORT RANGE WIRELESS RADIOS

Interesting IEEE standardization activities for short range wireless:

▸ IEEE 802.15.4n (TG 4n); China Medical band. This amendment to IEEE 802.15.4 PHY/MAC is made to utilize

approved 174-216 MHz, 407-425 MHz and 608-630 MHz medical bands in China

▸ IEEE 802.15.4q (TG 4q); ULP group. Motivation is to make progress towards Ultra Low Power Sensor Networks.

Focus on small node size, power efficient nodes, high reliability, use of globally available unlicensed band (such as 2.4

GHz). This work will define a new 2.4 GHz PHY of IEEE 802.15.4. Current 15.4 TRX consumes 30-100mW power.

New RF architecture choices are needed: Low IF, Uncertain IF, Sliding IF, Super Regenerative Receiver. Imec has a

strong position in novel RF architectures.

Standards Activities Board

IEEE Standards Association

802.3CSMA/CD

Ethernet

802.5Token

Passing

Ring

802.11Wireless

WLAN

802.15Wireless

Personal

Area Networks

802.20Mobile

Broadband

WirelessAccess

802.19Co-existence

TAG

Sponsor

IEEE 802

Local and Metropolitan Area Networks(LMSC)

Sponsor Sponsor Sponsor

802.17Resilient

Packet

Ring

802.18Radio

Regulatory

TAG

802.16Broadband

Wireless

Broadband Access

802.21Media

Independent

Handoff

802.1Higher

Layer

LANProtocols

802.22Wireless

Regional

AreaNetworks

© IMEC 2012