Wearable Body Sensor Networks

S h e n z h e n , C h i n a , 2 2 n d D e c . 2 0 1 7

Wearable Body Sensor Networks

L e i W a n g , r e s e a r c h p r o f e s s o r , d e p u t y d i r e c t o r

I n s t i t u t e o f B i o m e d i c a l a n d H e a l t h E n g i n e e r i n g

S h e n z h e n i n s t i t u t e s o f A d v a n c e d T e c h n o l o g y

C h i n e s e A c a d e m y o f S c i e n c e s

OUTLOOK

Proprietary proof-of-concept systems

Technology evolution

Part 2

Part 1

Academic contributionPart 3

Translational effortPart 4

Ongoing research activitiesPart 5

PART 1 Technology evolution

OUTLOOK

1.1 Technical history – The beginning

The Wearable concept started on 1980s.

Wearable computing is the study or practice of inventing,

designing, building, or using miniature body-borne (i.e.

“Smart Clothing” (Mann, 1996a)).

Bearable Computing.

Constancy of interaction, that the human and computer

are inextricably intertwined.

Muti-task 1991: Started Wearable Computing project

at MIT.

1995 : World’s first convert wearable

computer – camera and display concealed

and in ordinary eyeglasses .

The father of Wearable Computing

Representative work

ICON: prof. Steven Mann

Thad Starner’s system Wearable Wireless webcam

Prototyping setup

Bluetooth transceiver kit

1.2 Technical history – The late 1990s and earlier 21st century

Millennium: wearable monitoring devices with focuses on

ASIC design

Wearable electronics

Sensium platform, and others around world

Vital Jacket (Biodevices).

Disposable electrodes embedded in T-shirt.

Bluetooth transmission, software.

Low-power wireless sensor interface platform.

Single-chip wireless

ICON: prof. Yong Lian

Representative work

Flexible wireless ECG sensor

Definition of ECG

ECG refers to the heart in each cardiac cycle, by the pacemaker, atrium, ventricle have been excited,

accompanied by changes in bioelectricity, through the skin of the electrode from the body surface leads to a

variety of forms of potential changes in the graphics.

ECG is the heart of the excitement of the occurrence, dissemination and recovery process of objective

indicators, where feel chest tightness, palpitations, palpitation, dizziness, vertigo, precordial discomfort or pain

and other symptoms are required ECG examination.

Value of ECG

Arrhythmia

Heart rate variation

Myocardial ischemia

Myocardial infarction

Conduction time

Cardiac output

1.2 many ECG monitoring prototypes

The Importance of Dynamic Continuous ECG Recording on Early Warning of Cardiovascular and

Cerebrovascular Events as an Example

Dynamic ECG monitoring is very important for the early detection of heart

disease, early treatment and early warning prevention;

Dynamic ECG monitoring can greatly improve the positive rate of heart

disease, For the heart physician to develop or adjust the treatment

strategy to help, Emergency alerts instrument can reduce the chance of

sudden cardiac death;

Dynamic ECG monitoring can provide health care data for medical

services, insurance companies and pharmaceutical companies to

improve the accuracy of health services.

ST-T severe ECG is an important indicator of

early coronary heart disease diagnosis;

Heart rate variability is an important factor in

predicting the occurrence of sudden death;

Reduce the risk of arrhythmia;

Evaluation of drug treatment tracking.

1.2 many ECG monitoring prototypes

1.3 Technical history – BSN earlier 21st century

Advances in wireless communication, sensor design, and

energy storage technologies have meant that the concept

of a truly pervasive (WSN) is rapidly becoming a reality.

Integrated micro sensors no more than a few millimeters in

size, with onboard processing and wireless data transfer

capability are the basic components.

Director of the Hamlyn Centre,

Imperial College London, UK

FREng IEEE Fellow

Representative work

ICON: prof. Guang Zhong

Yang

skeletal muscles

central nervous

peripheral nervous

rigid link segment

movement

external forces

1.3 Motion motion motion

Body Sensor Networks Symposium 2004

14th 13th

1.3 Body sensor network (BSN) conferences 2004-2018

1.4 Technical history – Wearable medical devices 2010s

Personal wearable medical devices and sensors have

become more and more prevalent and popular.

The development of BSN for medical applications

Standardized low-power wireless network with

communication protocols for BSN and clinically approved

wearable devices to be used as nodes for BSN.

Using wearable medical devices and sensors as the nods

of body sensor networks (BSN) could allow better long-

term monitoring of health condition.

Representative work

ICON: prof. Yuan

Ting Zhang

Research Interests:

Wearable medical devices

Unobtrusive physiological measurments

Body sensor networks

Physiological modeling

Cardiovascular health informatics

1.4 Current MEDICAL wearable devices

Wearable“TENS Transcutaneous electrical

nerve stimulation” Anti-pain device

Wearable insulin pump

– artificial pancreas

Wearable exoskeleton

- artificial muscle

Wearable hemodialysis

- artificial kidney

Wearable rehabilitation

functional stimulation shirtWearable shirt for atrial defibrillation

Wearable miniature

electrocardiogram

In recent years , Food and Drug Administration （FDA） approved a variety of wearable

medical equipment, were approved for medical use.

Artificial auxiliary organs Electrophysiological diagnosis

Functional electric stimulation

Go flexible

Chemical sensing devices made from flexible electrode

materials could be incorporated into clothing or attached

directly to the body .

Continuous physical – chemical - biological monitoring.

E-textile

Wearable robot (not only sensor, but also actuation)

Stretchable silicon

integrated circuit Skin-like devices for

blood oximetry

Energy harvester on the surface of heartE-Skin Tattoo BiosensorsFlexible Sensors for On-body Sensing

1.5 Wearable Devices – Present time

Representative work

ICON: prof. Joseph

Wang

1.5 Medical health is a key of area wearable devices- market expectations

The rapid warming of the wearable device market

has attracted many enterprises, manufacturers and

consumers. For now, the market is in the initial stage

and is waiting for the leader to appear.

China's wearable device sales have more than 10 billion ¥, reaching 11.49 billion, of which

70% involved in the field of medical health in 2016.

25 companies investing in the global wearable device market

Wearable technology is One of the ten cutting-edge technologies that affect the future of

mankind（World Economic Forum，2015）

glucose testing

Nature 531(7596), 2016

Electromagnetic

regulation

Science 345(6200)，2014

Flexible substrate

Science 355(59), 2017

diagnostic imaging

study

Nature 542（542）,2017

nanoporous long

nucleic acids

Nature 530（7589）,2016

Bionic photomicrographs

Nature ,531（7594）,2016

Bionic system

Science 356(1280), 2017

pressure monitoring

Nature, 527（456）,2015

Photosensitive material Multi-parameter sensor

Nature, 529(7587) ,2016

1.6 Wearable Body sensor network – near future new surge

Nature, 546（632）,2017

smart fabric artificial muscle

Science 343（6173）,2014

Flexible skin

Science 357(6353) ,2017

1.7 short summary

Physiological parameter detection: Develop new materials such as electrodes,

New biosensors and electronic fabrics, Core components of wearable

biosensor;

Wearable device integration: Bionic micro-nano fabircatiion, Low power IC

design and High density packaging, Flexible microsystems;

In-body data communication: Human body near-filed efficient communication

principle and safety theory;

Health status classification and prediction: Statistical learning method for

wearable data sets and Chronic disease risk prediction;

Wearable system energy supply: Nano-generator, Flexible light energy material,

Energy harvesting method using temperature gradient and Develop principle

prototype is developed;

Medical and health applications: Explore the integration of wearable medical

equipment and fashion, innovative design, Explore industry, group standards

and business models, Expand wearable robots and other new applications.

OUTLOOK

PART 2 Proprietary proof-of-concept systems

the first developed single-point flexible ECG acquisition system

Design patterned gold electrodes

Design of micro-pillared structures attachment layer

Configurable IC

Miniaturized hardware acquisition system

Design of a single point composite structure

2.1 ECG Patch system

the first developed single-point flexible ECG acquisition system

Design patterned gold electrodes

Design of micro-pillared structures attachment layer

Configurable IC

Miniaturized hardware acquisition system

Design of a single point composite structure

2.2 EEG glasses frame

Die:1.456mm*0.83mm

2.3 Analogue Front-end IC

YN

Low Noise, Low Frequency, Low Power ASIC

Parameter Value

Acquisition channels 2/4/8

Power consumption 80 uW/Chl

Input referred noise 1.5 uVrms

Programmable gain 40-8000

Bandwidth range 0.05~200 Hz

CMRR ~100 dB

BlocksPreamplifiers, filters, gain

amplifiers, clocks, reference, LDOs, SPI…

Package QFN32, QFN24,LQFP64

♣ Noise modulation Low noise

♣ Current-steering filter Low frequency

♣ Log domain circuit Low power

♣ Global CM feedback High CMRR

2.4 Fall detection

Predicted the fall time, the critical angle and developed one new method of fall warning

based on the BSN location optimization and parameter optimization

2.5 Human body communication

To achieve the transmission rate of 2Mbps human communication in vivo

experiments, bit error rate 1e-6

1

2

3

4

5

3. Patch heart rate meter

4. EEG monitoring glasses

1. Human body communication demonstration system

2. Motion sensing belt5. Temperature watch

2.6 other prototypes10-s video

2.7 Technology “Know how”

Flexible wearable core IC design, MEMS integration and e-Textile

technology development

Wearable human body communication technology research and

development and application of high-tech strategy

Wearable movement perception and its application in screening for

vulnerable population and sports rehabilitation evaluation

Mini ECG, brain electric eye frame, fall prevention belts, watches and other

wearable health new equipment development

PART 3 Academic contribution

- Selected SCI papers in 2015-2017

OUTLOOK

TITLE : Technique for Fetal ECG Extraction Using Single Abdominal Recording

Method: Singular value decomposition (SVD) and smooth window (SW)

techniques are combined to build reference signal in an adaptive noise

canceller (ANC) for fetal ECG extraction.

Conclusion: Validation of the proposed method with signals from a public dataset,

and a self-recorded private dataset showed that the proposed method achieved F1

scores of 99.61%, 98.58% respectively for the detection of fetal QRS

abdominal recording

y(n) = f(n) + x(n)

+

-reference

MECGx’(n)x̂(n)

f̂(n)

FECG

reference-formation

scheme

(SWSVD)

adaptive

filter

0 500 1000 1500 2000 2500-60

-40

-20

0

20

40第1路母体腹壁信号

200 400 600 800 1000 1200 1400-50

0

50

100


0 500 1000 1500 2000 2500-80

-60

-40

-20

0

20


1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300-50

0

50

100abdominal recording 2

1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300-500

0

500

1000thoracic recording 2

1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300-20

0

20extracted fecg

1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300-50

0

50

100abdominal recording 2

1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300-500

0

500

1000thoracic recording 2

1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300-20

0

20extracted fecg

MECGQRS-detection

smooth

SVD

concatenate

QRS-length (N segments)

No fetal QRS

QRS-extraction

Inter-QRSlength

abdominalrecording

estimated MECG

estimated QRS

estimated Inter-QRS

preprocess

High-Freq cutoff fh Low-Freq cutoff fb

Year:2017, Volume:17

3.1 – Wearable Computing (1/5)


TITLE : An explorative investigation of functional differences in plantar center of

pressure of four foot types using sample entropy method.


Method: sample entropy was used to quantify complexity and regularity of

medial-lateral and anterior-posterior displacements, and the vertical ground reaction

force of the center of pressure during the stance phase.

Conclusion: When investigating foot function, it is important to take into account dynamic

characteristics of the progression of the center of pressure that contain the dynamic information

about walking pattern.

TITLE : Automatic Extraction of Central Tendon of Rectus Femoris (CT-RF) in Ultrasound

Images Using a New Intensity-Compensated Free-Form Deformation-Based Tracking Algorithm

With Local Shape Refinement

Method: Proposed a new IC-FFD-based tracking algorithm with LSR for extracting the shape

deformation of CT-RF.

Conclusion: The proposed algorithm offers better tracking performance and serves as a

valuable tool for automatic quantitative analysis of CT-RF in sports science as well as

rehabilitation assessment.



TITLE : An investigation into the bilateral functional differences of the lower limb

muscles in standing and walking

Method: We investigated whether characteristics of left limb and the one of the right

limb have the same statistical characteristics using Wilcoxon rank-sum test, and studied

dynamic signal irregularity degree for sEMG activities via sample entropy.

Conclusion: At different speeds, active degrees of different muscles were significant

different between left limb and right limb.

Year:2016, Volume:


TITLE : Feature Selection and Predictors of Falls with Foot Force Sensors Using KNN-

Based Algorithms

Method: Describes a new algorithm for classifying fallers and non-fallers using K-

nearest neighbor (KNN)-based classifiers on force platforms.

Conclusion: LMPNN outperform the other algorithms with 100% of accuracy, 100% of

sensitivity and 100% of specificity, and reached the maximum when k was equal to 3.

0 2 4 6 8 10 12 14

0.7

0.8

0.9

1

k

The classification rate of LMPNN rule

Accuracy rate

Sensitivity rate

Specificity rate

0 2 4 6 8 10 12 140.2

0.4

0.6

0.8

1

k

The classification rate of PNN rule

0 2 4 6 8 10 12 140.2

0.4

0.6

0.8

1

k

The classification rate of LMKNN rule



TITLE : Freestanding electrostatic scratch drive microstructures using lamination of

photosensitive films for microfluidics and microrobotics applications

Method: The microstructures are developed using lamination of SU-8 photosensitive

films and deposition of copper (Cu), which has potential for large scale manufacturing.

Conclusion: The microstructures were actuated moving on an electric substrate by

varying the voltage. It was found that the microstructure step size is proportional to

the square of voltage. When 1000 V, 50 Hz electric field was applied, the step size was

0.1 μm and average speed could achieve 300 μm/min, which shows great potential in

microfluidics and microrobotics applications.


3.1 – Wearable Sensor (1/3)

TITLE: Tunable water sensitive polymeric composites with synergistic

graphene and carbon nanotubes

Method: The synergistic rGO-CNTs were found to magnify the water sensing,

which may attribute to the swelling effect on the CNTs entanglement segregated by

the rGO sheets. The findings may greatly benefit the exploration of nanocarbons in

the field of the flexible sensory materials.

论文里面的图片一张 Year:2017, Volume:199


TITLE: Toward a Smartphone Application for Estimation of Pulse Transit Time

Method: Presents a PTT estimation method based on photoplethysmographic imaging

(PPGi).

Conclusion: The proposed method is especially suitable for implementation in dual-camera-smartphones, which could facilitate PTT measurement among populations affected by cardiac complications.



TITLE : Characterization of In-body Radio Channels for Wireless Implants

Method: An inhomogeneous human body model was proposed to study the in-body

radio channels (I-BRCs) for wireless implants. In addition, the model was verified by

experimental measurements with a 45kg pig.

Conclusion: The result showed that the gain of I-BRCs at human body communication

(HBC) frequency band was insensitive with electrode sizes and electrode types.

Year:2017, Volume:17, Issue:5

3.1 – Wearable Communication (1/2)

TITLE : An Approach to Biometric Verification Based on Human Body Communication in Wearable Devices

Method: The gain S21 of volunteer’s forearm is acquired by VNA, and a threshold-

adaptive template matching (TATM) algorithm based on weighted Euclidean distance is

proposed for rapid verification in wearable devices.

Conclusion: The equal error rate (EER) based on TATM algorithm is 7.06% at verification

threshold T2=1.91.

Year:2017, Volume:17, Issue:1

3.1 – Wearable Communication (2/2)

To explore the frontiers of human physiology，Promote the integration of life science and

electronic technology, Solve the biomedical and electronic problems in the field of

population and health, and Raise the level of scientific and technological innovation.

Electronics Biomedical Science

Biomedical electronicsChip design

Circuit system

Signal

processing

… …

Biomedical micro -

nanosensor

Biomedical images

Biomedical Informatics

Biomedical SciencePhysics

The human body is a significant application area of the semi-conductor industry.

Institute of Biomedical Engineering, Imperial College.

PART 4 Translational effort

OUTLOOK

4.1 Low-cost Healthcare

One Target

Disciplinary Position: Multidisciplinary

Cross

Type Position：Industrial Technology

Research Institute

Mission Position : Promote new

industries

Low-cost

Healthcare

High-end medical images

Medical rehabilitation robotTarget Postion : World-class level

Three Significant Breakthroughs

Bring routine ECG examinations for Rural clinic via technology innovations

Proprietary IPs – lower thedevice cost

Improve the performance

Design flexibility, various approaches

Data exchange standardizations

Mobile Internet => mobile healthcare

4.1 Low-cost Healthcare

4.2 Technology translation

Participate in ten registered product standards written,

are approved by

Series of products obtained

medical device registration card

Solutions were injected into four companies with a range of primary healthcare equipments

4.3 CASE study Passing National standard YY1079- pain but worth doing

(up)--EGC-1C and ECG-1CMRR

(down)-iBUSS signal source and

test box

YY1079 Specification√Sensitivity

√ Noise level

√Baseline drift

√ Time constant

√ Input impendence

√ Calibration voltage

√ Input circuit current

√ High polarization voltage

√ 50Hz power line interference

√ Common mode rejection ratio

√Amplitude-frequency characteristic

Require tremendous DOMAIN knowledge on Biomedical Engineering

and Microelectronics

2016 the system in village clinic market share is

the first in China which the total share 30%

Cumulative number of the devices, successful bidder (top ten manufacturers)

Passed technical assessment of

Medical Equipment Association

4.5 Highlight - No. 1 market share

Hat

chin

g e

nte

rprise

s g

ot

multip

le r

ound

s of

finan

cing

① Proof-of-Concept

- Scientific Ideas

② Simulation and

Modelling

③ Prototyping

④ Demonstration of the

application – Business Model

⑤ Product Standards

⑥ Manufacture,

Marketing and Sale

Analog and digital IC design, embedded system development,

mechanical design(3D printing), data analysis

SCIENCE

PATENT

TECHNOLOGY

MARKET

CAPITAL

INDUSTRY

OUTLOOK

PART 5 Ongoing research activities

5.1 Modeling and Simulation for Wearable Communication

Ground

out in

电极耦合电极耦合

隔离器隔离器

Modeling based on field-circuitNumerical simulation with finite element

Fabrication of multilayer tissue mimicking phantoms

Electric effect

Thermal effect

Mechanical effect

Chemical effect

Dielectric properties

adjustable

High melting point

Easy to shape

High stability

Anti-corrosion

Weakening electrode

polarization effectMeasurement with

whole-body phantom

National Natural Science Funding Committee – U1505251

5.2EM-based Blood Glucose Monitoring / Personal Identification

in vivo experiment

Inhomogeneous media model

National Defense Innovation project

5.3 Wearable Robot for percutaneous coronary intervention

To improve Haptic To further reduce radiation To promote positioning accuracy

National Natural Science Funding Committee – U171320090

5.4 - Flexible wearable sensors – beyond ExG

Room-temperature liquid metal

based physical sensors

• FEA analysis of stretchable sensors

• Mechanical characterization of the sensors

• Electrical characterization of the sensors

Wearable graphene enhanced

sweat sensor

• Electrochemical characterization of the sensors

• Mechanical characterization of the sensors

Chinese Academy of Sciences – Key project

5.5 Bionic Self-tuning Soft Robot for Knee

49

Bone Movement Soft tissue EMG

Image Processing

Musculoskeletal Simulation

Identify the key muscles of knee affecting gait stability

Bi-planar X ray

Reducing Energy Cost in Biomechanics

Nanshan Innovation Team

中国科学院深圳先进技术研究院

THANK YOU

Lei Wang [email protected] 15818518450

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Wearable Body Sensor Networks