Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the...
Transcript of Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the...
![Page 1: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/1.jpg)
1
Kyiv Public Presentation:
The State of the Art in
Neural Interfaces
Dan Merrill PhD
3 November 2016
![Page 2: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/2.jpg)
Outline
2
• What is a neural interface?
• Organization of the nervous system
• Applications of neural interfaces
• Success stories
• Two primary objectives: Effectiveness and safety
• Peripheral and central interfaces
• Specific devices used as neural interfaces
• What is the future? Risks and ethical considerations
![Page 3: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/3.jpg)
What is a Neural Interface?
3
A neural interface is an engineered
(man-made) device which connects to
the human nervous system, for the
purpose of augmenting, replacing or
repairing nervous system functions
which have been degraded or lost.
![Page 4: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/4.jpg)
Organization of the Nervous System
• Sensory organs � processing � output to muscles and glands
• Central nervous system (CNS): The brain and spinal cord
• The human brain contains between 80 and 90 billion neurons
• Peripheral nervous system (PNS): Neurons outside of the CNS
• The PNS can be divided into divisions both structurally and functionally
4
![Page 5: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/5.jpg)
The Neuron
5
Cell body:
20 to 100 μm dia.
Axon:
0.1 to 10 μm dia.
Up to 1 meter long
Neurons carry information,
one to another,
like links in a chain
![Page 6: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/6.jpg)
Brain Structure
6
Coronal (front to back) plane
Sagittal (left to right) plane
Gray matter / cerebral cortex
Unmyelinated cell bodies
Only ~ 2 - 4 mm thick
White matter
Myelinated axons
Human brain facts:
3 lbs
1,100 – 1,500 cc
80 - 90 billion neurons
![Page 7: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/7.jpg)
Applications of Neural Interfaces
7
Foot Drop
Facial Palsy
Dysphagia
Cerebral Palsy: Spasticity
Spinal Cord Injury: Respiration, Cough
Arm Rehabilitation
Incontinence, Sexual Function
Gait Rehabilitation
Stroke,Traumatic Brain Injury
Pressure Ulcers
Nerve Repairand Regrowth
Amputation
![Page 8: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/8.jpg)
Bioelectric Medicine / Electroceuticals: Trading Drugs for Devices
Worldwide:
• Diabetes: 1/3 billion
• Obesity: 3/4 billion
• Hypertension: >1 billion
• Cardiovascular disease:
31% of all deaths globally
8
The autonomic nervous system controlling the chest, gut, blood vessels
![Page 9: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/9.jpg)
Purposes of Neural Interfaces
• Functional Electrical Stimulation (FES) is electrical stimulation of nerves or muscles in order to cause coordinated muscle contraction, yielding immediate replacement or augmentation of lost or degraded function
• Therapeutic Electrical Stimulation (TES) is intended to assist in long-term repair of the body, by
• inducing neural plasticity (the ability of the nervous system to change),
• development of alternative control pathways,
• muscle strengthening, or stretching of spastic muscles 9
![Page 10: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/10.jpg)
Purposes of Neural Interfaces
• Implanted devices are placed inside the body
• External devices have electronics placed outside the body (usually sitting on top of the skin), and may be either
• Transcutaneous: all parts of the device are outside the body, including electrodes which sense or stimulate
• Percutaneous: electronics are outside the body, and a lead wire passes through the skin to electrodes inside the body
10
![Page 11: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/11.jpg)
Purposes of Neural Interfaces
• Instruments generally perform the functions of observing and controlling
• In the context of a neural interface, these are called sensing and stimulating
• A sensing interface records the electrical activity which is occurring in the nervous system
• A stimulating interface generates electrical signals in the nervous system
• If we stimulate a sensory neuron, a person may perceive a sensation
• If we stimulate a motor neuron, muscle contraction may occur 11
![Page 12: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/12.jpg)
An Example of Sensing and Stimulating
12
![Page 13: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/13.jpg)
Success Story 1: Restoration of Sensation / Clark Lab
13
Virtual door with
handle
Decode of muscle signals
enables movement of
digits and wrist
13
Sensation via USEA
stimulation
![Page 14: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/14.jpg)
Success Story 1 / Clark Lab
![Page 15: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/15.jpg)
Success Story 2: Prosthesis Control, with Sensation / Tyler Lab
15
![Page 16: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/16.jpg)
Success Story 2: Prosthesis Control, with Sensation / Tyler Lab
16
![Page 17: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/17.jpg)
Success Story 3: Treatment of Parkinson’s Disease
17
Targets within the brain for movement disorders: • Subthalamic nucleus (STN)• Thalamus• Globus pallidus (GPi)
![Page 18: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/18.jpg)
Success Story 3: Treatment of Parkinson’s Disease
18
![Page 19: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/19.jpg)
Effectiveness and Safety
The two primary objectives for a medical device, or medicine, are:
• Effectiveness: achieving the desired response
• Safety: not causing damage
These are sometimes contradictory objectives. An invasive implanted device, which is generally riskier than an external device, often gives better performance
A culture is defined by the balance point between effectiveness and safety
19
![Page 20: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/20.jpg)
Specific Objectives
Stimulation devices
• Effective
• Deliver enough charge to cause the desired response
• Reliable: Properties are stable over intended device lifetime
• Safe
• No chemical reactions causing damage to tissue or device
• Biocompatible: Device doesn’t damage tissue, and vice versa
Recording devices
• Effective
• Sensitive: Records small signals of interest
• Selective: Doesn’t record the wrong signals
• Reliable: Properties are stable over intended device lifetime
• Safe: Passive device is biocompatible 20
![Page 21: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/21.jpg)
Smaller is Better
21Joe Schulman, ca.1963
![Page 22: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/22.jpg)
Smaller is Better
22
Integrated circuit of the Bion implanable stimulator: 1.07 mm x 5.49
mm, and contains the equivalent of 20,000 transistors
![Page 23: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/23.jpg)
Central and Peripheral Interfaces
Central interfaces connect with the brain or spinal cord
• More invasive, more risky
Peripheral interfaces connect with nerves
• Less invasive, less risky
23Central InterfacesPeripheral
Interfaces FINE
USEA
USEA
DBS ECoG
![Page 24: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/24.jpg)
Effectiveness and Safety:Recording from the Brain
Scalp EEG
• Selectivity: 6 to 8 cm3
• Sensitivity: Amplitudes 10 to 100 μV
• Invasiveness: Minimal
24
![Page 25: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/25.jpg)
Effectiveness and Safety:Recording from the Brain
Scalp EEG
• Selectivity: 6 to 8 cm3
• Sensitivity: Amplitudes 10 to 100 μV
• Invasiveness: Minimal
Penetrating Microelectrodes
• Selectivity: Less than 1 mm3
• Sensitivity: Up to a few mV
• Invasiveness: Highly25
![Page 26: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/26.jpg)
Effectiveness and Safety:Recording from the Brain
Scalp EEG
• Selectivity: 6 to 8 cm3
• Sensitivity: Amplitudes 10 to 100 μV
• Invasiveness: Minimal
Subdural Electrocorticography
• Selectivity: Less than 1 cm3
• Sensitivity: Up to hundreds of μV
• Invasiveness: Moderate
Penetrating Microelectrodes
• Selectivity: Less than 1 mm3
• Sensitivity: Up to a few mV
• Invasiveness: Highly26
![Page 27: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/27.jpg)
Effectiveness and Safety:Recording from Muscle
Surface Electromyogram (EMG)
• Selectivity: Modest
• Sensitivity: Modest
• Prosthesis performance:
Sequential control
• Invasiveness: Minimal
27
Intramuscular EMG
• Selectivity: Excellent
• Sensitivity: Excellent
• Prosthesis performance:
Simultaneous multiple
degree-of-freedom control
• Invasiveness: Moderate Myoelectric Implant
![Page 28: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/28.jpg)
Technologies of the Future (?)
Material interfaces with mechanical properties
like human tissue: Thin, flexible electrodes
28
Organic devices that self-integrate into tissue
Small, high-channel count electrodes �
allows study of complex neural networks
![Page 29: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/29.jpg)
Risks and Ethical Considerations
• Who decides the balance of effectiveness vs. safety? The patient? The government?
• How do expensive, complex devices get fairly partitioned into society?
• Who pays? Class stratification?
• Memory replacement
• In early stages of development, but it is coming
• When does the sense of self change? If I receive another person’s memories, or fabricated memories, am I still me?
• Replacement of lost function vs. augmentation
• Will we create a super-class of humans? Who chooses? The wealthy? The powerful? The government? 29
![Page 30: Kyiv Public Presentation · Pu ˆoses of Neu l Inte aces • Instruments generally perform the functions of observing and controlling • In the context of a neural interface, these](https://reader035.fdocuments.in/reader035/viewer/2022071023/5fd810f61268eb321c180ddb/html5/thumbnails/30.jpg)
ДУЖЕ ТОБI ДЯКУЮ
30