IEEE Solid-States Circuits Magazine - Fall 2021 - 89
activity and treat the symptoms of
advanced neurological disorders.
For example, deep brain stimulation
devices [Figure 1(a)] provide electrical
stimulation to regulate dysfunctional
neural circuits, much like a pacemaker
for the brain, and are used to treat
Parkinson's disease, dystonia, and
more [2]. The devices consist of very
long electrodes that are implanted
in deep brain structures and a pulse
generator that is implanted in the
chest cavity and transmits waves of
voltage or current to targeted brain
regions. Similarly, peripheral nerve
stimulators are used to regulate physiological
functions, from modulating
blood pressure [3] to easing inflammation
in rheumatoid arthritis [4].
Neural stimulation can also be used
to provide sensorimotor feedback to
BMIs, enabling tactile and proprioceptive
reactions [5]. These technologies
significantly impact the quality of life
for many patients, but there remain
numerous opportunities for improvement
in miniaturization, intelligence,
and the invasiveness of implantation.
Implantable neural interfaces are
medical devices that require U.S. Food
Peripheral nerve stimulators are used
to regulate physiological functions, from
modulating blood pressure to easing
inflammation in rheumatoid arthritis.
and Drug Administration approval, and
they are designed by interdisciplinary
teams that, importantly, include biologists
and clinicians. Patient safety and
the invasiveness of implantation are of
paramount concern, making implant
volume and power dissipation key
to designs. Wireless ICs have paved
a path toward fully implantable and
minimally invasive neural interfacing.
The black elements in Figure 1(b) are
the components required for a bidirectional
(recording and stimulating),
wireless neural interface. A power
source, typically in the form of a battery,
antenna, or energy harvesting
element, is used to power the implant.
Wireless data transmission eliminates
cables, enabling surgeons to close
implant incisions, greatly reducing
infection risk. Mixed-signal recording
circuits amplify and digitize neural
signals from the electrodes, while stimulator
circuits and a controller provide
the needed voltage or current to
excite the neural tissue. In a closedloop
device, integrated edge compute
and machine learning [Figure 1(b), in
gray] can reduce the wireless burden
by enabling devices to make decisions
in situ and with low latencies. These
building blocks are common across
many types of BMIs and neurostimulation
implants, and the past decade
has included significant advances in
the design of all these components.
There are three major trends driving
current technological progress
in neural interfaces, including the
following:
1) sensor-IC integration for scaling
the number of electrodes
2) closing the loop
3) miniaturizing wireless implants.
Cortical Recording
Implanted System
Recording Path
Wireless Implant
LNA
ADCTx
Stimulating Path
DAC
Reference
Deep Brain
Stimulation
Electrode Interface
[6]
2 mm
(a)
(c)
FIGURE 1: (a) Two clinical neural interfaces: a percutaneous neural recording implant similar to [1], and a deep brain stimulator. (b) Components
for an implantable bidirectional (black) or closed-loop (black and gray) wireless neural interface. (c) Example neural interface electrodes.
[From left to right (adapted from Utah microelectrode array [6], SENSIGHT by Medtronic [7], ultrathin polymer threads by Neuralink
[8], high-density neural matrix [9], Stentrode by Synchron [10] and ultraflexible syringe-injectable mesh [11]).] LNA: low-noise amplifier; ADC:
analog-to-digital converter; Tx: transmitter; ML: machine learning; DAC: digital-to-analog converter; Rx: receiver.
IEEE SOLID-STATE CIRCUITS MAGAZINE
FALL 2021
89
[7]
[8]
[9]
Controller
ML
(b)
[10]
[11]
Power Supply
Rx
IEEE Solid-States Circuits Magazine - Fall 2021
Table of Contents for the Digital Edition of IEEE Solid-States Circuits Magazine - Fall 2021
Contents
IEEE Solid-States Circuits Magazine - Fall 2021 - Cover1
IEEE Solid-States Circuits Magazine - Fall 2021 - Cover2
IEEE Solid-States Circuits Magazine - Fall 2021 - Contents
IEEE Solid-States Circuits Magazine - Fall 2021 - 2
IEEE Solid-States Circuits Magazine - Fall 2021 - 3
IEEE Solid-States Circuits Magazine - Fall 2021 - 4
IEEE Solid-States Circuits Magazine - Fall 2021 - 5
IEEE Solid-States Circuits Magazine - Fall 2021 - 6
IEEE Solid-States Circuits Magazine - Fall 2021 - 7
IEEE Solid-States Circuits Magazine - Fall 2021 - 8
IEEE Solid-States Circuits Magazine - Fall 2021 - 9
IEEE Solid-States Circuits Magazine - Fall 2021 - 10
IEEE Solid-States Circuits Magazine - Fall 2021 - 11
IEEE Solid-States Circuits Magazine - Fall 2021 - 12
IEEE Solid-States Circuits Magazine - Fall 2021 - 13
IEEE Solid-States Circuits Magazine - Fall 2021 - 14
IEEE Solid-States Circuits Magazine - Fall 2021 - 15
IEEE Solid-States Circuits Magazine - Fall 2021 - 16
IEEE Solid-States Circuits Magazine - Fall 2021 - 17
IEEE Solid-States Circuits Magazine - Fall 2021 - 18
IEEE Solid-States Circuits Magazine - Fall 2021 - 19
IEEE Solid-States Circuits Magazine - Fall 2021 - 20
IEEE Solid-States Circuits Magazine - Fall 2021 - 21
IEEE Solid-States Circuits Magazine - Fall 2021 - 22
IEEE Solid-States Circuits Magazine - Fall 2021 - 23
IEEE Solid-States Circuits Magazine - Fall 2021 - 24
IEEE Solid-States Circuits Magazine - Fall 2021 - 25
IEEE Solid-States Circuits Magazine - Fall 2021 - 26
IEEE Solid-States Circuits Magazine - Fall 2021 - 27
IEEE Solid-States Circuits Magazine - Fall 2021 - 28
IEEE Solid-States Circuits Magazine - Fall 2021 - 29
IEEE Solid-States Circuits Magazine - Fall 2021 - 30
IEEE Solid-States Circuits Magazine - Fall 2021 - 31
IEEE Solid-States Circuits Magazine - Fall 2021 - 32
IEEE Solid-States Circuits Magazine - Fall 2021 - 33
IEEE Solid-States Circuits Magazine - Fall 2021 - 34
IEEE Solid-States Circuits Magazine - Fall 2021 - 35
IEEE Solid-States Circuits Magazine - Fall 2021 - 36
IEEE Solid-States Circuits Magazine - Fall 2021 - 37
IEEE Solid-States Circuits Magazine - Fall 2021 - 38
IEEE Solid-States Circuits Magazine - Fall 2021 - 39
IEEE Solid-States Circuits Magazine - Fall 2021 - 40
IEEE Solid-States Circuits Magazine - Fall 2021 - 41
IEEE Solid-States Circuits Magazine - Fall 2021 - 42
IEEE Solid-States Circuits Magazine - Fall 2021 - 43
IEEE Solid-States Circuits Magazine - Fall 2021 - 44
IEEE Solid-States Circuits Magazine - Fall 2021 - 45
IEEE Solid-States Circuits Magazine - Fall 2021 - 46
IEEE Solid-States Circuits Magazine - Fall 2021 - 47
IEEE Solid-States Circuits Magazine - Fall 2021 - 48
IEEE Solid-States Circuits Magazine - Fall 2021 - 49
IEEE Solid-States Circuits Magazine - Fall 2021 - 50
IEEE Solid-States Circuits Magazine - Fall 2021 - 51
IEEE Solid-States Circuits Magazine - Fall 2021 - 52
IEEE Solid-States Circuits Magazine - Fall 2021 - 53
IEEE Solid-States Circuits Magazine - Fall 2021 - 54
IEEE Solid-States Circuits Magazine - Fall 2021 - 55
IEEE Solid-States Circuits Magazine - Fall 2021 - 56
IEEE Solid-States Circuits Magazine - Fall 2021 - 57
IEEE Solid-States Circuits Magazine - Fall 2021 - 58
IEEE Solid-States Circuits Magazine - Fall 2021 - 59
IEEE Solid-States Circuits Magazine - Fall 2021 - 60
IEEE Solid-States Circuits Magazine - Fall 2021 - 61
IEEE Solid-States Circuits Magazine - Fall 2021 - 62
IEEE Solid-States Circuits Magazine - Fall 2021 - 63
IEEE Solid-States Circuits Magazine - Fall 2021 - 64
IEEE Solid-States Circuits Magazine - Fall 2021 - 65
IEEE Solid-States Circuits Magazine - Fall 2021 - 66
IEEE Solid-States Circuits Magazine - Fall 2021 - 67
IEEE Solid-States Circuits Magazine - Fall 2021 - 68
IEEE Solid-States Circuits Magazine - Fall 2021 - 69
IEEE Solid-States Circuits Magazine - Fall 2021 - 70
IEEE Solid-States Circuits Magazine - Fall 2021 - 71
IEEE Solid-States Circuits Magazine - Fall 2021 - 72
IEEE Solid-States Circuits Magazine - Fall 2021 - 73
IEEE Solid-States Circuits Magazine - Fall 2021 - 74
IEEE Solid-States Circuits Magazine - Fall 2021 - 75
IEEE Solid-States Circuits Magazine - Fall 2021 - 76
IEEE Solid-States Circuits Magazine - Fall 2021 - 77
IEEE Solid-States Circuits Magazine - Fall 2021 - 78
IEEE Solid-States Circuits Magazine - Fall 2021 - 79
IEEE Solid-States Circuits Magazine - Fall 2021 - 80
IEEE Solid-States Circuits Magazine - Fall 2021 - 81
IEEE Solid-States Circuits Magazine - Fall 2021 - 82
IEEE Solid-States Circuits Magazine - Fall 2021 - 83
IEEE Solid-States Circuits Magazine - Fall 2021 - 84
IEEE Solid-States Circuits Magazine - Fall 2021 - 85
IEEE Solid-States Circuits Magazine - Fall 2021 - 86
IEEE Solid-States Circuits Magazine - Fall 2021 - 87
IEEE Solid-States Circuits Magazine - Fall 2021 - 88
IEEE Solid-States Circuits Magazine - Fall 2021 - 89
IEEE Solid-States Circuits Magazine - Fall 2021 - 90
IEEE Solid-States Circuits Magazine - Fall 2021 - 91
IEEE Solid-States Circuits Magazine - Fall 2021 - 92
IEEE Solid-States Circuits Magazine - Fall 2021 - 93
IEEE Solid-States Circuits Magazine - Fall 2021 - 94
IEEE Solid-States Circuits Magazine - Fall 2021 - 95
IEEE Solid-States Circuits Magazine - Fall 2021 - 96
IEEE Solid-States Circuits Magazine - Fall 2021 - 97
IEEE Solid-States Circuits Magazine - Fall 2021 - 98
IEEE Solid-States Circuits Magazine - Fall 2021 - 99
IEEE Solid-States Circuits Magazine - Fall 2021 - 100
IEEE Solid-States Circuits Magazine - Fall 2021 - 101
IEEE Solid-States Circuits Magazine - Fall 2021 - 102
IEEE Solid-States Circuits Magazine - Fall 2021 - 103
IEEE Solid-States Circuits Magazine - Fall 2021 - 104
IEEE Solid-States Circuits Magazine - Fall 2021 - 105
IEEE Solid-States Circuits Magazine - Fall 2021 - 106
IEEE Solid-States Circuits Magazine - Fall 2021 - 107
IEEE Solid-States Circuits Magazine - Fall 2021 - 108
IEEE Solid-States Circuits Magazine - Fall 2021 - 109
IEEE Solid-States Circuits Magazine - Fall 2021 - 110
IEEE Solid-States Circuits Magazine - Fall 2021 - 111
IEEE Solid-States Circuits Magazine - Fall 2021 - 112
IEEE Solid-States Circuits Magazine - Fall 2021 - 113
IEEE Solid-States Circuits Magazine - Fall 2021 - 114
IEEE Solid-States Circuits Magazine - Fall 2021 - 115
IEEE Solid-States Circuits Magazine - Fall 2021 - 116
IEEE Solid-States Circuits Magazine - Fall 2021 - 117
IEEE Solid-States Circuits Magazine - Fall 2021 - 118
IEEE Solid-States Circuits Magazine - Fall 2021 - 119
IEEE Solid-States Circuits Magazine - Fall 2021 - 120
IEEE Solid-States Circuits Magazine - Fall 2021 - 121
IEEE Solid-States Circuits Magazine - Fall 2021 - 122
IEEE Solid-States Circuits Magazine - Fall 2021 - 123
IEEE Solid-States Circuits Magazine - Fall 2021 - 124
IEEE Solid-States Circuits Magazine - Fall 2021 - 125
IEEE Solid-States Circuits Magazine - Fall 2021 - 126
IEEE Solid-States Circuits Magazine - Fall 2021 - 127
IEEE Solid-States Circuits Magazine - Fall 2021 - 128
IEEE Solid-States Circuits Magazine - Fall 2021 - 129
IEEE Solid-States Circuits Magazine - Fall 2021 - 130
IEEE Solid-States Circuits Magazine - Fall 2021 - 131
IEEE Solid-States Circuits Magazine - Fall 2021 - 132
IEEE Solid-States Circuits Magazine - Fall 2021 - 133
IEEE Solid-States Circuits Magazine - Fall 2021 - 134
IEEE Solid-States Circuits Magazine - Fall 2021 - 135
IEEE Solid-States Circuits Magazine - Fall 2021 - 136
IEEE Solid-States Circuits Magazine - Fall 2021 - 137
IEEE Solid-States Circuits Magazine - Fall 2021 - 138
IEEE Solid-States Circuits Magazine - Fall 2021 - 139
IEEE Solid-States Circuits Magazine - Fall 2021 - 140
IEEE Solid-States Circuits Magazine - Fall 2021 - 141
IEEE Solid-States Circuits Magazine - Fall 2021 - 142
IEEE Solid-States Circuits Magazine - Fall 2021 - 143
IEEE Solid-States Circuits Magazine - Fall 2021 - 144
IEEE Solid-States Circuits Magazine - Fall 2021 - 145
IEEE Solid-States Circuits Magazine - Fall 2021 - 146
IEEE Solid-States Circuits Magazine - Fall 2021 - 147
IEEE Solid-States Circuits Magazine - Fall 2021 - 148
IEEE Solid-States Circuits Magazine - Fall 2021 - 149
IEEE Solid-States Circuits Magazine - Fall 2021 - 150
IEEE Solid-States Circuits Magazine - Fall 2021 - 151
IEEE Solid-States Circuits Magazine - Fall 2021 - 152
IEEE Solid-States Circuits Magazine - Fall 2021 - 153
IEEE Solid-States Circuits Magazine - Fall 2021 - 154
IEEE Solid-States Circuits Magazine - Fall 2021 - 155
IEEE Solid-States Circuits Magazine - Fall 2021 - 156
IEEE Solid-States Circuits Magazine - Fall 2021 - 157
IEEE Solid-States Circuits Magazine - Fall 2021 - 158
IEEE Solid-States Circuits Magazine - Fall 2021 - 159
IEEE Solid-States Circuits Magazine - Fall 2021 - 160
IEEE Solid-States Circuits Magazine - Fall 2021 - 161
IEEE Solid-States Circuits Magazine - Fall 2021 - 162
IEEE Solid-States Circuits Magazine - Fall 2021 - 163
IEEE Solid-States Circuits Magazine - Fall 2021 - 164
IEEE Solid-States Circuits Magazine - Fall 2021 - Cover3
IEEE Solid-States Circuits Magazine - Fall 2021 - Cover4
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2019
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2019
https://www.nxtbook.com/nxtbooks/ieee/mssc_2019summer
https://www.nxtbook.com/nxtbooks/ieee/mssc_2019winter
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018fall
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018summer
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018spring
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018winter
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2014
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2014
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2014
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2014
https://www.nxtbookmedia.com