Post by UniverseSeven on Nov 14, 2004 2:05:10 GMT -5
CNCT at University of Michigan
Center for Neural Communication Technology
Background on Silicon Substrate Probes
"Our work on microelectrode arrays for single-unit recording in the central nervous system really began many years ago with early work done at Stanford [7,8,9]; however, more recent efforts began in the early 80s." www.engin.umich.edu/center/cnct/backind.html
"Openings in the upper dielectrics along the probe shank define STIMULATING or RECORDING sites"
They have scaled down the amount of information revealed on their site. There used to be reference to human subjetcs and many reference to the HUMAN brain etc...the "investagators" and "collaberators' are the people who implant the devices unknowingly in people dentists, docters etc..They offer various brain recording and stimulting probes for free as long as you give them your data.
The below text used to be on the site and has been removed.
TRANSCRIPTION OF FURTHER CNCT SITE DETAILED TEXT:
------------------------------------------------------------------------
With support from the NIH/NCRR, the Center for Neural Communication
Technology (CNCT) is able to offer a variety of probes to
neuroscientists. The fabrication process for these probes gives great
freedom in their design for recording and stimulation in the central
nervous system. Their small size and fine features permit multichannel
interaction with the tissue on a scale that approaches the size of the
cells of interest.
While the probes are not the perfect tool for every application, they do
offer several advantages over conventional electrodes. These include
batch fabrication which leads to very reproducible geometrical and
electrical characteristics, the ability to include multiple sites on a
single substrate at accurate dimensional relationships to one another,
the capacity to integrate a multichannel interconnect for chronic
applications, the potential for inclusion of on-chip electronics for
signal conditioning and/or stimulus generation, and the ability to
produce virtually any two-dimensional shape. The extensive design
freedom offered by the technology has resulted in a variety of different
probes which should satisfy the needs of investigators in many different
disciplines. If you would like to receive probes from the CNCT, please
fill out an application form .
The distribution of passive probes to investigators both internal and
external to the University of Michigan began in late 1988. One of our
goals has been to obtain information on how the probes perform in a
variety of applications, and to use this information to further optimize
their design. The probes are currently available free-of-charge through
support from the NIH National Center for Research Resources. The only
method of "payment" which is currently required from users is feedback
on probe performance to aid in the continuing effort to better
understand and improve the technology.
Acute Probes
Since acute probes are generally available in greater numbers, are
simple to package, and are easy to handle, they are a good entry point
to using the technology. A schematic of an acute probe and its basic
features is shown in Figure 1. The different acute designs offered in
the catalog (available for download in pdf format, or email
jfh@umich.edu for a hardcopy) vary in the number of shanks, the length
and width of the shanks, and in the spacing and surface area of the
conductive sites.
Acute probes are mounted and electrically connected to PC boards using
ultrasonic bonding as shown in Figure 2. Exposed connections are
stabilized and insulated with epoxy. The pins on the PC board mate
directly to standard integrated circuit DIP sockets permitting easy
handling and connection. Such a socket is mounted on the front end of
our custom-designed preamplifier (see below) and connected to high-input
impedance amplifiers. The preamplifier is designed to be mounted on a
microdrive directly above the animal preparation. In this way, the
entire electrode package can be lowered to the preparation with minimal
handling and precise electrode insertion can be achieved. This acute
packaging scheme has proven to work well for most preparations and is
provided as a standard item. We will, however, provide custom acute
packaging for users who provide their own connectors.
Once packaged, the probe site impedances are tested at 1kHz in saline.
The investigator is provided with the impedance characteristics for each
probe, and a site map which relates the sites on the probe to the pins
on the PC board. Maps are also available for download. Probes are
typically provided in groups of 6-10.
Chronic Probes
Many investigators are interested in performing chronic experiments. We
currently offer chronic probes only to CNCT collaborators and to
investigators who have gained experience with acute probes and who are
willing to work with us to understand and improve chronic recordability.
Recording sites on chronic probes tend to increase in impedance and
degrade in recording quality over time. Internal Research Project 2 is
aimed at understanding this degradation, and developing ways to prevent
or remedy it. We hope to bring chronic probes into the general
distribution effort in the near future.
For a floating electrode configuration, chronic assemblies utilize a
probe with an integrated flexible silicon ribbon cable as the
interconnect (Figure 3). In this configuration, the probe shank is
inserted into tissue and the flexible cable forms the interconnect to
the percutaneous connector. Probes have also been packaged for
investigators in non-floating chronic configurations. In this case, a
non-cabled probe is attached directly to the percutaneous connector.
Custom Design
Some investigators wish to obtain devices which are designed
specifically for their application. In fact, many of the devices in our
catalog are based on designs that were submitted by investigators
external to the CNCT. Custom design is a service which is offered by the
Center to investigators who, through experience with existing designs,
have determined that a special design is required for their study. New
design runs occur approximately once a year with up to 20 designs per
run.
the rest at www.raven1.net/centneur.htm
GO HERE!http://members.tripod.com/~mdars/meth/meth.htm
Center for Neural Communication Technology
Background on Silicon Substrate Probes
"Our work on microelectrode arrays for single-unit recording in the central nervous system really began many years ago with early work done at Stanford [7,8,9]; however, more recent efforts began in the early 80s." www.engin.umich.edu/center/cnct/backind.html
"Openings in the upper dielectrics along the probe shank define STIMULATING or RECORDING sites"
They have scaled down the amount of information revealed on their site. There used to be reference to human subjetcs and many reference to the HUMAN brain etc...the "investagators" and "collaberators' are the people who implant the devices unknowingly in people dentists, docters etc..They offer various brain recording and stimulting probes for free as long as you give them your data.
The below text used to be on the site and has been removed.
TRANSCRIPTION OF FURTHER CNCT SITE DETAILED TEXT:
------------------------------------------------------------------------
With support from the NIH/NCRR, the Center for Neural Communication
Technology (CNCT) is able to offer a variety of probes to
neuroscientists. The fabrication process for these probes gives great
freedom in their design for recording and stimulation in the central
nervous system. Their small size and fine features permit multichannel
interaction with the tissue on a scale that approaches the size of the
cells of interest.
While the probes are not the perfect tool for every application, they do
offer several advantages over conventional electrodes. These include
batch fabrication which leads to very reproducible geometrical and
electrical characteristics, the ability to include multiple sites on a
single substrate at accurate dimensional relationships to one another,
the capacity to integrate a multichannel interconnect for chronic
applications, the potential for inclusion of on-chip electronics for
signal conditioning and/or stimulus generation, and the ability to
produce virtually any two-dimensional shape. The extensive design
freedom offered by the technology has resulted in a variety of different
probes which should satisfy the needs of investigators in many different
disciplines. If you would like to receive probes from the CNCT, please
fill out an application form .
The distribution of passive probes to investigators both internal and
external to the University of Michigan began in late 1988. One of our
goals has been to obtain information on how the probes perform in a
variety of applications, and to use this information to further optimize
their design. The probes are currently available free-of-charge through
support from the NIH National Center for Research Resources. The only
method of "payment" which is currently required from users is feedback
on probe performance to aid in the continuing effort to better
understand and improve the technology.
Acute Probes
Since acute probes are generally available in greater numbers, are
simple to package, and are easy to handle, they are a good entry point
to using the technology. A schematic of an acute probe and its basic
features is shown in Figure 1. The different acute designs offered in
the catalog (available for download in pdf format, or email
jfh@umich.edu for a hardcopy) vary in the number of shanks, the length
and width of the shanks, and in the spacing and surface area of the
conductive sites.
Acute probes are mounted and electrically connected to PC boards using
ultrasonic bonding as shown in Figure 2. Exposed connections are
stabilized and insulated with epoxy. The pins on the PC board mate
directly to standard integrated circuit DIP sockets permitting easy
handling and connection. Such a socket is mounted on the front end of
our custom-designed preamplifier (see below) and connected to high-input
impedance amplifiers. The preamplifier is designed to be mounted on a
microdrive directly above the animal preparation. In this way, the
entire electrode package can be lowered to the preparation with minimal
handling and precise electrode insertion can be achieved. This acute
packaging scheme has proven to work well for most preparations and is
provided as a standard item. We will, however, provide custom acute
packaging for users who provide their own connectors.
Once packaged, the probe site impedances are tested at 1kHz in saline.
The investigator is provided with the impedance characteristics for each
probe, and a site map which relates the sites on the probe to the pins
on the PC board. Maps are also available for download. Probes are
typically provided in groups of 6-10.
Chronic Probes
Many investigators are interested in performing chronic experiments. We
currently offer chronic probes only to CNCT collaborators and to
investigators who have gained experience with acute probes and who are
willing to work with us to understand and improve chronic recordability.
Recording sites on chronic probes tend to increase in impedance and
degrade in recording quality over time. Internal Research Project 2 is
aimed at understanding this degradation, and developing ways to prevent
or remedy it. We hope to bring chronic probes into the general
distribution effort in the near future.
For a floating electrode configuration, chronic assemblies utilize a
probe with an integrated flexible silicon ribbon cable as the
interconnect (Figure 3). In this configuration, the probe shank is
inserted into tissue and the flexible cable forms the interconnect to
the percutaneous connector. Probes have also been packaged for
investigators in non-floating chronic configurations. In this case, a
non-cabled probe is attached directly to the percutaneous connector.
Custom Design
Some investigators wish to obtain devices which are designed
specifically for their application. In fact, many of the devices in our
catalog are based on designs that were submitted by investigators
external to the CNCT. Custom design is a service which is offered by the
Center to investigators who, through experience with existing designs,
have determined that a special design is required for their study. New
design runs occur approximately once a year with up to 20 designs per
run.
the rest at www.raven1.net/centneur.htm
GO HERE!http://members.tripod.com/~mdars/meth/meth.htm
