Sawan_Session3

8/8/2019 Sawan_Session3

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Brain Machine Interface : Bioelectronics

Based on 3D Chip Stacking

-- Research and Applications --

Page 2

Neuroscience High accuracy investigation tools are neededto study neural activity underlying cognitivefunctions and pathologies.

Neural Prosthetics Intracortical stimulation forvision recovery Neuro-motor prosthesis: paralysis, physical

impairments.

Mind driven rehabilitation systems.


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Sensing and subsequent treatment-- Neurons, regions, and neural coding --

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Primary Sensoryand motor cortex

Primary visual

cortex

Kandel et al., Principles of

neural science, 4ed

A. Sensory map B. Motor map

t

t

CodingIntents

Sensations


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Page 4

Medical Microsystems for the Recovery of Vital Neural Functions-- Main projects in our Polystim Laboratory --I. Sensors and sensor network (e-Health)

Sensors (pressure, volume, ENG, etc..) design and implementation

II. Vision for blinds Modeling & devices : Recording, monitoring and electrical stimulation

III. Bladder control Recuperate bladder functions : Sensing and electrical stimulation

IV. Respiration and gastric functions Catheters and signal processing

V. Optic and Ultrasound based medical devices Non-invasive diagnostic tools

VI. Laboratory-on-chip Diagnostic tools (neurotransmitter detection) and drug delivery.


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Smart medical devices-- Typical topology --

Modulator

Demodu-lator

Externalcontroller

Dataprocessing

Receiver

AC/DCSupply

Backtelemetry

Measure&

digitize

MUX

DeMUX

MainController

Stimuligenerator

Currentsources

Teststimuli

ElectrodesSkin

Page 5


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Brain Machine Interface : Bioelectronics Based on 3D

Chip Stacking

-- Outline --Introduction

I. Parallel sensing from the cortex Multi-channel multi-chip neural sensors Microelectrodes arrays & Integration/assembly

II. Microstimulation and Monitoring (treatment example) Intracortical visual implant

III. Efficient energy delivery and bidirectional data transfer

IV. Other project Lab-on-chip - based devices for better diagnostics

V. Research team, labs & facilities (Polystim & ReSMiQ)

Summary


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Parallel recording from the cortex-- Multichannel Implantable neural sensors --

Page 7

Ch1

Vertical integration of several ASICs

implementing different processing layers

Post-processing of the array base withphotolithography and wet etching

Cr-Au layer for contacts and metalpaths.


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Parallel recording from the cortex (Contd)

-- Design challenges and bottlenecks --

Data transmission bandwidth through tissues

Present low-power telemetry allows around 2 Mb/s

Energy transfer through tissues

Thermal effects start to appear near 50 mW/cm2

Size of implants

Very small leaving tissues untouched at implantation.

Design challenges are multidimensional

Power consumption, frequency band allocations and standards,testability and fault detection, SNR (noise considerations), etc.

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Page 9


-- Design challenges : Noise considerations --

Time (s)

Raw neural signal

Action potentials

Time (s)Needs to measure very low-voltages.Very Sensitive to Noise !

Voltage(V)


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Multi-channel neural recording interface-- Mounted ASICs: Mixed-signal front-end --

Mixed-signal front-end

Digita

lreadout

Micro-electrodes

array

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Conditioning: Amplification & FilteringConsumption : < 12 W

Digitization: 8 bits, 30 ksps/Ch.Consumption : 7.4 W

LN bioamplifier & dc

suppression SA

ADC


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Digital ASIC

-- On-chip AP detection and buffering --

Page 11

Absolute value detector and on-chip SRAM

Serial

bus

On-line AP detection & buffering(bandwidth reduction Strategy = up

to 48 times):

Absolute value detector

On-chip SRAM FIFOs and memory buffer


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Multi-chip integration-- Design of microelectrodes array --

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Medical gradestainless-steel

Electro-polishing

Epoxy basebuilding

Grinding ofthe baseandelectrodesinsulation

2mm


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Multi-chip integration(Contd)-- Chip stacking and bonding --

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Conductive tracesare developed onthe back side

Contacts are

rerouted in anyconfiguration

Wedge / ballbonders are usedfor connecting

ASICs


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Measured performances-- Mixed-Signal ASIC (CMOS 0.18 m)--

Page 14

100 Hz 9.2 kHzBandwidth

2.304 mm2

( 0.25 x 0.39 mm2/ch.)

Die size

680 WPower consump.

7 bitsENOB

< LSBINL, DNL

8 bitsResolution

30 kSps/chSampling rate

5.4 VrmsInput-ref. noise

72 dBMid-band gain

Summary of characteristicsMicrophotograph of the 16-channel chip

4 x 4 channels

sensor

Mult iplexing,

bias and test

circuits

1 mixed-

s igna l

c ha nne lBias circuits

Clock and con trol

signals generator

Test ing analog

mult iplexer

Digital multiplexers

Bioamplifier

Filter, amplifier,

ADC

-124 dB32 kHz 64 kHz

96 kHz

Inter-channel cross-talk < -57 dBbetween adjacent channels (< -67

dB between opposite sides.


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Measured performances (Contd)-- Low-power low-noise Bioamplifier --

Page 15

Summary of bioamplifercharacteristicsAnticipatedvalue Measuredvalue

52 dB V

10 kHz

Parameters

1.8 Vupplyvoltage

GainBandwidth

51.5 dB V

9.6 kHz

5.6 Vrmsnput refer-red noise

CMOS 0.18 mechnology260 m x 190 mrea size

5.0 Vrms

GOSSELIN,SAWAN, CHAPMAN,A Low-Power IntegratedBioamplifier With a New DC Rejection Scheme, IEEE Trans. onBiomedical Circuits & Systems, Vol. 1, No. 3,Sept.2007, pp. 184-192.


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Page 16

CMOS 0.18 mProcess

1.856 mm2Die size

64 bytes per ch.Output memory size

1.53 mW(96.5 W/ch)

Power consump.

16 MHzRef. clock freq.

5.1 to 51 kbits per

channel

Neural data rate

with BW reduction

1.25 kB (69% ofchip area)

Total on-chip SRAM

16 bytes per ch.Input FIFO depth

Microphotograph of the digital integrated

circuit

Summary of characteristics

Measured performances (Contd)-- Digital ASIC --


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Page 17

In vivo recording in the visual cortex of a rat

In vivo validation (Acute exp.)-- Performance of the Bioamplifier (contd) --

In vivo neural recording with rats

Anesthetised animal

Recording from 16 sites in theprimary visual cortex

Dept. of Psychology, Concordia and Montreal Universities, Montreal


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Stimulation Module (4x4) CMOS 0.18 m, ~60 000 Gates

Downlink

> 1 Mbps @ 13.56 MHz, D = 67%

Uplink : 200 kb/s

Power: 100 mW load; P (err) < 10-6

Downlink

Monitoring

CTRL

TEST

structures

MONITORING

R2R AMP

ELECTRODES

CONN / CTRL

DACs

BIAS

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The visual intracortical stimulator-- Implementation results --


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Brain Machine Interface : Bioelectronics Based on 3D

Chip Stacking

-- Outline --IntroductionI. Parallel sensing from the cortex

Multi-channel, multi-chip neural sensors Microelectrodes arrays & Integration/assembly

II. Microstimulation and Monitoring (treatment example) Intracortical visual implant

III. Efficient energy delivery and bidirectional data transfer

IV. Other project Lab-on-chip - based devices for better diagnostics

V. Research team, labs & facilities (Polystim & ReSMiQ)

Summary


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Wireless inductive link-- Power transfer efficiency --

VDC

LOAD

* *R1 MC1

L1 L2 C2

VsC3

~

V recVoltage

regulator

R2

Inductive link Rectifier

Linear

regulator

regulatorrectifierrflinktotal

= ~ 12 % Page 21

)2(2

1

21

2

2

11

222

DC

DC

VVVCkPCR

CVk

dioderecload

total

++

=


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Power transfer-- Efficiency & safety --

External Controller Implant

Switching

Regulator

ASK Demodulator /

DAC/Decoder

Data

ModulatorPA

Battery

Vdd Shuntregulator

Rectifier

LoadShiftKey(LSK)ASK/PSK Demodulator

Encoder

L2

C2

C1

L1

To/From

Other

parts

Skin

Page 22


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Wireless dedicated links-- The external interface --

Switching power amplifier (AP)

Modulator Demodulator

Power link

&

bi-directional

data

transfer

by

externalinductor

(antenna)

Control unit

- Power supply management

- PA calibration- Inductive link coupling

- Resonance frequency

- Extensive data processing

Frequency

generator

Power

source

UserInterface

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Wireless dedicated links-- The internal interface --

Shuntregulator

Rectifier LDO Reg 1SwitchedCapacitorDC/DC

LoadShiftKey(LSK)ASK/PSKDemodulator

ADCncoder MUX

Controller/Stimulator

VDD1

VDD2

VDDn

AnalogFront-Ends(1..n) Ts

ucoas

Ofchpno

LDO Reg 2

LDO Reg n

Start-upCircuit

ProtectionCircuit

Clock GeneratorCircuit

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RF LINK to Transfer Data

-- BPSK demodulation --

Hard-limited Costas loop circuit

Coherent : recover carrier / data

in the same loop

VCOLow Pass

Filter

Data

Out

Data In

Phase

Shifter 90

I branch

Q branch

Arm

LP Filter

m(t) sin(w1t+q1)

m(t) = 1 or 1

2 sin(w1t+q2)

2 cos (w1t+q2)m(t) sin(q1-q2)

m(t) cos(q1-q2)

sin 2(q1-q2)m(t)

2

Gilbert multiplier

Gilbert multiplier

Gilbert

multiplier

Arm

LP Filter

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VCOuadraturesignalgenerator

LoopFilter

Arm Filter

Arm FilterReceivercoil

I branch

Q branch

ClkDout

Data in

Choppermultiplier

Digital domain Analog domain

Requirements: 1) Fully integrated,2) Low power consumption, 3) Fully

differential


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Page 26

0.76 mW

at 4Mbps

4Mbps*

2.2 Mbps**

8Mbps***

13.56

MHz

CMOS

0.18m

QPSK

*Postlayout

**Measured

***Matlab

LPF

)sin( 21 qwt+ -+

Vd(t)

)cos( 21 qwt+

VCO

InputSignal

Vs(t)

90 -Phase Shifter

Data Out A

Data Out B

LPF

LPF

Voltage Controlled Oscillator Comparator

540 um

0.61 mW**

1.6 Mbps*

1.2 Mbps**

13.56

MHz

CMOS

0.18m

BPSK

BPSK QPSK

QPSK


-- Results : High data rate wireless link --


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Page 27

Testing Challenges-- Engineering and Medical Validations --

Functional tests (electrical, mechanical, ..)

Circuits, Package, Heat, Reliability, Toxicity, .

Self-test and fault detection after implantation

Noise considerations and grounding (multichannel aspect)

Analog/digital blocks, Scan and BIST, overhead resources power/area

In vivo measurement and validation

Humidity, temperature, Ion concentration, pH, interface to tissues,

Experiments in animals and humans: spontaneous or evoked activity

Ethics, experimental protocol and approvals.


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Page 28

Polystim neurotechnologies Laboratory

-- http: //www.polystim.ca -- Founded in 1994 Completed Degrees

70 M.R. & 17 Ph.D. Currently supervised students

12 M.R. (30% with scholarships), and 8 Ph.D. (50% with scholarships). Invited researchers, postdoctoral and research assistants 1 Technician & 1 Secretary Collaborators (Colleagues from)

Several medical institutes and research centers in hospitals Sciences and applied sciences programs

Support: NSERC, CIHR, FQRNT, CMC systems, CRC - DMI, FCI-DMI

Industry: Victhom HB, INLB, DALSA Semiconductor, Scanview, Biophage, etc.


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Design, tests, assembly, packaging and in vitro

validation facilities

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-- http://www.polymtl.ca/lasem --

CFI Room A345


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Un courant porteur pour le Qubec

Universit de MontralMcGill UniversityUniversit du Qubec Montralcole Polytechnique de Montralcole de technologie suprieureConcordia UniversityUniversit LavalUniversit du Qubec ChicoutimiUniversit du Qubec Trois-Rivires

http://www.ttp://www.resmiqesmiq.orgorgMohamad Sawan, Director

June 2009


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Un courant porteur pour le Qubec

Fabrication,integration,Prototyping &validationTest, diagnostic,verification &characterization

Specification,Designoptimization& simulationDesign methods,implementation,modeling

EmergingTechnologies &standards

LoC:Microfluidi

c,optic,

etc

Micro&nano-electronics

IndustrialControl

MedicalDevices Telecom.

optic&Wireless

Security,Mult

imediaRFIDSoC,Analog&Mixed-ignalPlatforms

TechnologiesRFIC,MEMS,Data

Convertors,etc.Net

works

Sensors

,

Actuator

sVideo&

audioApplictions

SignalProcessing

Algorithms,architectures,synthesis &co-design

Int.N

EWCAS

Conf.


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Multi-chip multi-channel 3D neural sensing from the cortex

Low-power, chip area, vertical integration and packaging

Test challenges: Noise, design ofin vivo experiments

Reliability and safety are important facts.

Typical SMD involve multi-disciplinary team : engineers, physicians,surgeons, health care professionals, etc;

Challenges at the level of intracortical microsystems are all important(power issues, assembly, microelectrodes);

Monitoring and recording permit to understand the accurate

functions at the CNS; Technology progresses will allow the creation of many more reliable

implantable devices;

Diagnostic tools based on LoC (neurotransmitters detection) anddrug delivery.

Summary


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Brain Machine Interface : Bioelectronics Based on 3D ChipStacking

Acknowledgments-- http: //www.polystim.ca --

Master & Ph.D. students Collaborators: Colleagues from different research centers Support: NSERC, CIHR, FQRNT, CMC systems, CRC-DMI, FCI-DMI Industry: Victhom, INLB, DALSA, Scanview, Clarovita.

Thank You

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