Brain-Computer Interface Technologies: Accelerating Neuro-Technology for Human Benefit

296 Pages·2019·8.275 MB·English

by  Claude Clément

Claude Clément
Brain-
Computer
Interface
Technologies
Accelerating Neuro-Technology for
Human Benefi t
Brain-Computer Interface Technologies
Claude Clément
Brain-Computer Interface
Technologies
Accelerating Neuro-Technology for Human
Benefit
Claude Clément
Campus Biotech
Wyss Center for Bio and Neuroengineering
Genève, Geneve, Switzerland
ISBN 978-3-030-27851-9 ISBN 978-3-030-27852-6 (eBook)
https://doi.org/10.1007/978-3-030-27852-6
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To our patients, who give us so much
motivation to continue.
To all my colleagues at the Wyss Center for
Bio and Neuroengineering and to all the
people I worked with in the past 30 years in
the field of active implantable devices.
Geneva, June 3, 2019
Preface
If we were able to sneak along our spinal cord and nerves, or to slip through by the
interface of our ears or eyes, we would enter in the limitless cosmos of the billions
of neurons living in our body which are making us as we are. The ancients were
thinking that our heart was the center of our emotions. It is not true. The heart is the
machine our body needs to preserve life, but what characterizes human beings, per-
sonal features, sensations, emotions, and feelings resides in our nervous system
where, in a majestic dynamic ballet, interconnections change, neurons die and
appear, and areas damaged by a traumatism receive help from other sections of the
brain. The way our synapses interleave is in a continuous evolution, and we ignore
the rules governing these changes.
For a long time, we could not do much more than “listen” to the brain by collect-
ing tiny electrical signals at the surface of the scalp using the well-known electroen-
cephalograms (EEG). These receivers, kept distant from the brain by the skin, scalp,
skull, and dura-mater, hear only a remote murmur: the choir of billion neurons.
Since the end of the 1980s, the advent of technologies in the field of active
implants has allowed us to place electrodes on or in the brain. We are now able to
hear, in detail, what the brain is saying. In our thirst of understanding everything,
neurosciences were first trying to grasp the overall complexity of the brain, even to
model or simulate it. We realize now that we should not compare the brain to a
computer. Connections between neurons are not governed by a binary system but
rather by multidimensional nonlinear relations of chaotic nature. This is the miracle:
from chaos appear motor actions, perceptions, emotions, feelings, memories, and
ideas. Today, and probably for many more years, we are not able to “program” soft
human particularities like love, attraction for another individual, survival instinct, or
duty to reproduce. Science does not explain falling in love, genius, or creation of a
unique piece of art.
Nevertheless, we have discovered that electrical signals, injected at appropriate
locations, may inhibit, modify, or influence the relations between the brain and its
environment. Clinical tests have shown that implanting electrodes in the nervous
system may treat a large variety of conditions, including cognitive, affective, and
psychiatric disorders. It raises fundamental questions in terms of ethics and society.
vii
viii Preface
Is “emotionally augmented human” a sustainable concept? Do we want to annihi-
late our differences and our personal characteristics?
We know that we will never reach the confines of our universe. We should also
realize that we should remain modest in our conquest of the brain. Finding rational-
ity in the never-ending dance of neurons is maybe a vain challenge. Shall we keep
untouched those mysteries which make us unique and unpredictable?
Genève, Switzerland Claude Clément
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Brain-Computer Interface (BCI) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Technology Versus Science . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 T his Is Not Science Fiction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3.1 Cochlear Implants (CI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3.2 Deep Brain Stimulation (DBS) . . . . . . . . . . . . . . . . . . . . . . 5
1.3.3 Spinal Cord Stimulation (SCS) . . . . . . . . . . . . . . . . . . . . . . 5
1.3.4 Sacral Nerve Stimulation (SNS) . . . . . . . . . . . . . . . . . . . . . 6
1.3.5 Vagal Nerve Stimulation (VNS) . . . . . . . . . . . . . . . . . . . . . 6
1.3.6 Various Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.4 Pioneers, Doers, and Dreamers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.4.1 Pioneers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.4.2 Doers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.4.3 Dreamers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.5 The Age of Neuro-Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.5.1 Convergence of Technologies . . . . . . . . . . . . . . . . . . . . . . . 14
1.5.2 Limitations of the Pharma- and Bio-Industries . . . . . . . . . . 14
1.5.3 Unmet Medical Needs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2 From Concept to Patient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1 Translational Medicine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.1 From Ideas to Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.2 Valley of Death . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.1.3 Multicultural Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.1.4 Setting Priorities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.1.5 Prepare a Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.1.6 Think About Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.2 Understanding Our Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.2.1 Regulated Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.2.2 Users’ Needs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
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2.2.3 Human Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.2.4 Implantology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
2.2.5 Think About Patients and Healthcare Players . . . . . . . . . . . 38
2.2.6 Do Not Listen to Engineers . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.2.7 Check What Others Are Doing . . . . . . . . . . . . . . . . . . . . . . 40
2.2.8 Search Reasons of Successes and Failures . . . . . . . . . . . . . 42
2.2.9 Cumulated Cash-Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2.2.10 Reimbursement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.2.11 Global Social Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.2.12 Intellectual Property (IP) . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3 Targets of Neuro-Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.1 Interfacing with the Nervous System . . . . . . . . . . . . . . . . . . . . . . . . 49
3.2 Invasiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.2.1 Noninvasive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3.2.2 Not So Invasive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3.2.3 Invasive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.3 I nvasive Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
3.3.1 Interfacing with the Brain . . . . . . . . . . . . . . . . . . . . . . . . . . 60
3.3.2 Interfacing with the Spinal Cord . . . . . . . . . . . . . . . . . . . . . 62
3.3.3 Interfacing with the Vagal Nerve . . . . . . . . . . . . . . . . . . . . . 63
3.3.4 Interfacing with Peripheral Nerves . . . . . . . . . . . . . . . . . . . 63
3.3.5 Interfacing with Organs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
3.4 Achievements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
3.4.1 Cochlear Implants (CI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
3.4.2 Deep Brain Stimulation (DBS), Parkinson’s
Disease (PD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
3.4.3 Spinal Cord Stimulation (SCS)
for Chronic Back Pain (CBP) . . . . . . . . . . . . . . . . . . . . . . . 80
3.4.4 Vagal Nerve Stimulation (VNS) . . . . . . . . . . . . . . . . . . . . . 82
3.4.5 Retinal Implants (RI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
3.4.6 Urinary Incontinence (UI) . . . . . . . . . . . . . . . . . . . . . . . . . . 85
3.4.7 NeuroPace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
3.4.8 Various . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
3.5 Long-Term Clinical Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
4 The Human Body: A Special Environment . . . . . . . . . . . . . . . . . . . . . 97
4.1 Active Implantable Medical Devices (AIMDs) . . . . . . . . . . . . . . . . 97
4.2 A Special Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
4.2.1 Not Negotiable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
4.2.2 Laws of Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
4.2.3 Surgical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
4.2.4 Reaction of Body Tissues . . . . . . . . . . . . . . . . . . . . . . . . . . 101
4.3 Biocompatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
4.4 Biostability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Contents xi
4.5 Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
4.5.1 Generalities on Corrosion of AIMDs . . . . . . . . . . . . . . . . . . 110
4.5.2 Specificities of Corrosion in the Human Body . . . . . . . . . . 112
4.6 C leanliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
4.7 S terility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
4.8 A ccelerated Aging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
4.9 H ermeticity and Moisture Control . . . . . . . . . . . . . . . . . . . . . . . . . . 125
4.9.1 Feedthrough (FT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
4.9.2 Hermetic Sealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
4.9.3 Leak Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
4.9.4 Moisture Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
4.9.5 Residual Gas Analysis (RGA) . . . . . . . . . . . . . . . . . . . . . . . 169
4.9.6 Near-Hermetic Encapsulation . . . . . . . . . . . . . . . . . . . . . . . 170
4.9.7 Insulation, Coating, and Potting . . . . . . . . . . . . . . . . . . . . . 174
4.10 Mechanical Robustness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
4.11 Electrical Robustness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
4.11.1 Electrostatic Compatibility (ESC) . . . . . . . . . . . . . . . . . . . . 182
4.11.2 Electromagnetic Compatibility (EMC) . . . . . . . . . . . . . . . . 183
4.11.3 MRI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
4.11.4 Coexistence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
4.12 Communication Through Tissues . . . . . . . . . . . . . . . . . . . . . . . . . . 191
4.13 Energizing Implants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
4.14 Implantable Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
5 B elow and Above-the-Neck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
5.1 Below the Neck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
5.2 The First Steps in the Direction of the Head . . . . . . . . . . . . . . . . . . 202
5.3 Above-the-Neck Implants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
6 Pioneers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
6.1 History of Active Implantable Medical Devices (AIMD) . . . . . . . . 211
6.2 N ew Fields: It Works! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
6.3 Missing Technology Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
7 Doers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
7.1 New Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
7.2 Opportunities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
7.2.1 Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
7.2.2 Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
7.2.3 Connectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
7.2.4 Implantability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
7.2.5 RF Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
7.2.6 Optical Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230