m8ta
You are not authenticated, login.
text: sort by
tags: modified
type: chronology
{816} is owned by tlh24.
[0] Vyssotski AL, Serkov AN, Itskov PM, Dell'Omo G, Latanov AV, Wolfer DP, Lipp HP, Miniature neurologgers for flying pigeons: multichannel EEG and action and field potentials in combination with GPS recording.J Neurophysiol 95:2, 1263-73 (2006 Feb)[1] Otto KJ, Johnson MD, Kipke DR, Voltage pulses change neural interface properties and improve unit recordings with chronically implanted microelectrodes.IEEE Trans Biomed Eng 53:2, 333-40 (2006 Feb)

{607}
hide / / print
ref: notes-2000.09 tags: BMI recording technology Chapin Nicolelis battery Wolf date: 01-06-2012 03:09 gmt revision:4 [3] [2] [1] [0] [head]

from the book "Neural Prostheses for Restoration of Sensory and Motor Function" edited by John Chapin and Karen Moxon.

Phillip Kennedy's one-channel neurotrophic glass electrode BMI (axons apparently grew into the electrode, and he recorded from them)

Pat Wolf on neural amplification / telemetry technology

battery technology for powering the neural telemetry

{212}
hide / / print
ref: life-notes-2007 tags: electrode assay technology electrophysiology hack ad-hoc date: 01-03-2012 07:10 gmt revision:3 [2] [1] [0] [head]

properties of electrodes that are to penetrate the pia mater of a rhesus macaque:

  1. must easily go into a canned peach (in heavy or light sauce, it does not matter)
  2. does not go into pineapple cross-grain
  3. does go into the end-grain of pineapple
  4. penetrates the skin of a red grape (somewhat fresh) ~= pia
    1. The pia is a bit more tough than this, but is much less firm - if you are implanting electrodes that are any less than extremely sharp - e.g. etched - it will dimple the surface and not penetrate. Very sharp electrodes are key for getting through this tough membrane - which is even tougher in humans!
      • dimpling seems to silence cortical activity (observational evidence for this only)
      • however, once implanted lower-impedance electrodes work better. Low current microstimulation may be able to round the sharp tips of tungsten electrodes - we may want to test this.
    1. microdissection of the pia often damages the surface vasulature of the cortex, leading to localized infarctions, and hence should be avoided (unless you are really good)
    2. Bunching multiple elctrodes into one shaft - that is, making the shaft thicker and duller (albiet staggered) is not a good strategy for entering the brain (need to test the present monkeys).
  1. Cortical layer V (location of large pyramidal cells + betz cells in M1) in humans is 3-3.5mm below the surface, and ~1.6mm deep in rhesus. microwire/microwire arrays should have at least 2mm free wire length if intended for monkeys, and 4mm free wire if intended for humans.
    1. M1/S1 / central sulcus region is mostly inactive under isoflouro anesthesia, somewhat mangled/depressed with light ketamine, and silent with fentanyl. So, be careful with intraoperative recordings - the monkey/rat may be too deep, hence no cells to listen to!

{744}
hide / / print
ref: Merletti-2009.02 tags: surface EMG multielectrode recording technology italy date: 01-03-2012 01:07 gmt revision:2 [1] [0] [head]

PMID-19042063[0] Technology and instrumentation for detection and conditioning of the surface electromyographic signal: state of the art

  • good background & review of surface EMG (sEMG) - noise levels, electrodes, electronics. eg. Instrumentation amplifiers with an input resistance < 100MOhm are not recommended, and the lower the input capacitance, the better: the impedance of a 10pf capacitor at 100hz is 160MOhm.
  • Low and balanced input impedances are required to reduce asymmetric filtering of common-mode power-line noise.

____References____

[0] Merletti R, Botter A, Troiano A, Merlo E, Minetto MA, Technology and instrumentation for detection and conditioning of the surface electromyographic signal: state of the art.Clin Biomech (Bristol, Avon) 24:2, 122-34 (2009 Feb)

{365}
hide / / print
ref: Akin-1995.06 tags: Najafi neural recording technology micromachined digital TETS 1995 PNS schematics date: 01-01-2012 20:23 gmt revision:8 [7] [6] [5] [4] [3] [2] [head]

IEEE-717081 (pdf) An Implantable Multichannel Digital neural recording system for a micromachined sieve electrode

  • Later pub: IEEE-654942 (pdf) -- apparently putting on-chip isolated diodes is a difficult task.
  • 90mw of power @ 5V, 4x4mm of area (!!)
  • targeted for regenerated peripheral neurons grown through a micromachined silicon sieve electrode.
    • PNS nerves are deliberately severed and allowed to regrow through the sieve.
  • 8bit low-power current-mode ADC. seems like a clever design to me - though I can't really follow the operation from the description written there.
  • class e transmitter amplifier.
  • 3um BiCMOS process. (you get vertical BJTs and Zener diodes)
  • has excellent schematics. - including the voltage regulator, envelop detector & ADC.
  • most of the power is dissipated in the voltage regulator (!!) - 80mW of 90mW.
  • tiny!
  • rather than using pseudoresistors, they use diode-capacitor input filter which avoids the need for chopping or off-chip hybrid components.
  • can record from any two of 32 input channels. I think the multiplexer is after the preamp - right?

____References____

Akin, T. and Najafi, K. and Bradley, R.M. Solid-State Sensors and Actuators, 1995 and Eurosensors IX.. Transducers '95. The 8th International Conference on 1 51 -54 (1995)

{861}
hide / / print
ref: -0 tags: radiolab what does technology want Kevin Kelley teleology date: 12-19-2010 06:23 gmt revision:1 [0] [head]

What does technology want? An interview with Steven Johnson and Kevin Kelly at the New York Public Library, usefully condensed to a half-hour segment for the RadioLab podcast.

  • Many of the ideas are not new - its teleology: a means of understanding the world by interpreting everything in terms of 'wants' and 'desires'. As Douglas Hofstadter explains in his book, __I am a Strange Loop__, this is really just a cognitive shortcut - not much more, not much less - which allows us to interpret things which exhibit attractor-like dynamics. Hence, as the comments on the page note, the title is to some degree just a semantic trick.
  • That said, the idea behind the title is very interesting: technology, by virtue of being subject to recursive selection, iterative refinement, code reuse (aggressive copy-paste, idea promiscuity) just like biological organisms will open-system violate the second law of thermodynamics. (They don't actually say this, but that's my interpretation).
  • Here's my logic: Imagine a statistical distribution - a population of things, animals, ideas, products, whatever. Pass them through a statistical selection process, be it evolution, the marketplace, the predictive models of your mind & associated decision making processes, a political system (ok, maybe here), the immune system, the modern attention economy (maybe here, too). This gives you a new population of things, which the selective process has impinged a degree of information about itself (the real world, usually) upon. Duplicate, spawn some more, run it through the selective process recursively ad infinitum, and the (Shannon) information contained in the resulting populations will increase. Things do not tend toward disorder.
  • That carries some heavy caveats - the information content of the selection system (which may be interpreted as applying a 'fitness' or 'objective' function) must be, at every point, much higher than that of the population for the transfer to occur. In the real world, that's easy - the information content of even a minute of life is far greater than that of our DNA! Furthermore, due to {825 coevolution} -- other organisms are our world - the information content of the selective process continually increases.
    • This implies that in some stable evolutionary niches, e.g. algae, the Shannon information of the genome must be approximately the same as the expected (as in, integral) information content of the selectively-important events of it's life. (Yea, I don't know about that either..too wishy-washy and intuitive to be useful; also algorithmic complexity doesn't scale linearly).
  • Some selection systems don't seem to be evolving to increasing complexity, however.
    • The political system: lots of problems. (1) The population is small. (2) The population (candidates) has strong incentive to mislead the selective process (the voters) (3) The information passed from selective process to population is low (a few bits every 4 years, times however many senate seats there are, divided by partisanness/statistical dependence between the bits).
    • I am happy to say, the communication issue (3) seems to be getting better - we know more about what out leaders are doing, and they know more about us - but it is imperfect, filtered through a system (the media) who holds a different objective (garners interest) than the ultimate population (who wants, roughly, security and wealth).
    • The attention economy: very strong highpass characteristics (novelty rather than truthiness), strong limits on individual complexity in the population (the ideas must be conveyable). Yet! there is strong co-evolution. (Anyway, hell, it's supposed to keep us amused, doesn't it do that? It has never been proposed to be able to solve global problems..)
    • In both politics and media, our desire for novelty may be good - it directly forces the investigation of new ideas (new members of the population). New interpretations of events are continually sought; perhaps this is a worthy price to pay for losing a bit of objective reality?
      • This should be quantifiable using Bayes' rule, then tested in an experiment. That said, the loss-function for the reality weighting is dependent on estimates of environmental change.
  • Once again I have wandered away from the original subject. Oops. Yea, the other sections - about __Where Good Ideas Come From__ is basically common knowledge now / well covered by Thomas Kuhn. All good ideas are conceived by different people in different places at the same time; insight takes time and effort, and is seldom a eureka moment; often what is required is a perceptual shift, as per the discovery of air, again what Kuhn has covered.

This blog is probably failing in the attention economy. Again, oops ;-)

{364}
hide / / print
ref: Linderman-2006.01 tags: neural recording technology compact flash stanford Shenoy 2006 date: 04-15-2009 20:55 gmt revision:3 [2] [1] [0] [head]

PMID-17946450[0] An Autonomous, broadband, multi-channel neural recording system for freely behaving primates

  • goal: recording system for freely-behaving animals.
    • problems: battery life, size
    • cannot sample broadband.
    • non autonomous.
  • solution:
    • compact flash, ARM core
    • accelerometer?
    • mounted inside the monkey's skull in the dental cement.
  • specs

____References____

[0] Linderman MD, Gilja V, Santhanam G, Afshar A, Ryu S, Meng TH, Shenoy KV, An autonomous, broadband, multi-channel neural recording system for freely behaving primates.Conf Proc IEEE Eng Med Biol Soc 1no Issue 1212-5 (2006)

{593}
hide / / print
ref: notes-0 tags: robots Tokyo Institute of Technology date: 09-04-2008 17:30 gmt revision:5 [4] [3] [2] [1] [0] [head]

Robots & others designed & made at the Tokyo Institute of Technology (from the Hirose / Fukushima Robotics lab)

  • snake robots
  • gripper
      • with human-crushing, kid-grabbing power. frightening!
  • walking robots
      • -- 1994. can climb a 70 degree slope!
    • --window washing robot.
    • -- skating robot: walk ; skate. movie -- wow!
  • wheeled robots
  • other
    • -- prismatic, variable-speed eccentric linear drive. sorta like harmonic drive for linear motion? link

{440}
hide / / print
ref: bookmarks-0 tags: neurotechnology companies date: 08-30-2007 17:02 gmt revision:0 [head]

{23}
hide / / print
ref: Vyssotski-2006.02 tags: neurologger neural_recording recording_technology EEG SUA LFP electrical engineering date: 02-05-2007 06:21 gmt revision:6 [5] [4] [3] [2] [1] [0] [head]

PMID-16236777[0] Miniature neurologgers for flying pigeons: multichannel EEG and action and field potentials in combination with GPS recording.

Recording neuronal activity of animals moving through their natural habitat is difficult to achieve by means of conventional radiotelemetry. This illustration shows a new approach, exemplified by a homing pigeon carrying both a small GPS path recorder and a miniaturized action and field potential logger (“neurologger”), the entire assembly weighing maximally 35 g, a load carried easily by a pigeon over a distance of up to 50 km. Before release at a distant location, the devices are activated and store both positional and neuronal activity data during the entire flight. On return to the loft, all data are downloaded and can be analyzed using software for path analysis and electrical brain activity. Thus single unit activity or EEG patterns can be matched to the flight path superimposed on topographical maps. Such neurologgers may also be useful for a variety of studies using unrestrained laboratory animals in different environments or test apparatuses. The prototype on the hand-held pigeon records and stores EEG simultaneously from eight channels up to 47 h, or single unit activity from two channels during 9 h, but the number of channels can be increased without much gain in weight by sandwiching several of these devices. Further miniaturization can be expected. For details, see Vyssotski AL, Serkov AN, Itskov PM, Dell Omo G, Latanov AV, Wolfer DP, and Lipp H-P. Miniature neurologgers for flying pigeons: multichannel EEG and action and field potentials in combination with GPS recording. [1]

____References____

{64}
hide / / print
ref: bookmark-0 tags: neural_recording recording_technology electrical engineering DSP date: 0-0-2006 0:0 revision:0 [head]