Biometrics


Status of research on brainwave reading

After much research, We came to the conclusion that it is not possible to obtain reliable information "watching" the brain from the outside.

It's not about budget, It's about seeing the brain from the outside, then only see the result of the sum of the activities of all neurons of the brain together (with minor differences due to the position of the electrodes – so minimal that much of the time it's just noise or interference from the movement)

Whereby "patient" cannot "think of a pressed key" but I get with a different activity. And press is just a side effect of this intense activity. Basically you must learn to involve the entire brain and sync, in order to increase, for example,, alpha waves compared to Beta. An ordinary person cannot do it right, the best they can do it in a few seconds, but just focusing and standing firm.

A bit like saying: "to press up arrow key-on you must stop breathing until you see the button is pressed, to release it again to breathe and after a few seconds you will release "

Perform actions with the thought ?

To perform actions there are better methods. If budget issue Hawking students (https://it.wikipedia.org/wiki/Stephen_Hawking) they equipped its super processed helmet Chair. But they tried everything and in the end they chose to look eye-movements with a camera.

With a camera, for example,, eye closure you discover very quickly. With the closing of the eyes you can get four bits of information and many more with eye movements, myoelectric impulses, the direction and speed of the breath etc… With these techniques can easily get tens of bits per second while with an EEG, for how expensive, the response times are of many seconds for a single bit.

For Hawking have done just as well, If you look carefully, in all its recent pictures you see a camera hanging eyeglasses (and in some cases even more experimental sensors).

Stephen Hawking Stephen Hawking

And now Hawking can speak, Surf the internet and even write books. With the thought would never be able to do all these things.

If there was any possibility of using the thought wouldn't have budget problems. The only wheelchair costs as hundreds of MindWave and EmotivEEG and already had lithium batteries when none of us had even heard of.

Can we do better than the MindWave and EmotivEEG ?

Hate to say it, but we can't. Those two devices have been designed with great care and "trying" to obtain the best possible result. Yet the results are more or less confused (When it's good), and completely random (When the subject is not suitable for).

Subject unsuited? Apologies are always the same, you have to train more, It takes more concentration… In practice to press a button you have to relax completely and then focus for a few seconds. What you should do to write a message? Probably ten years of apprenticeship as a Buddhist monk.

Now the electrodes of a certain quality are all non-contact, but the results are always more or less the same: great instability and no security that if worked today will work tomorrow. Even with 24 endings and big devices with a closet have managed to have decent results.


Active electrodes (first version)

The first version, as from previous images, required a particular electrode with Silver tips. We thank Marco Vitali of: www.vitalibruno.com for having prepared a test enclosure in silver (see image). To make contact with the skin can do no better than silver, even gold is better, and toes help to go hair and to firmly hold the electrode.

Unfortunately, testing has shown that even with these electrodes just the slightest movement to create potential differences of the same order of magnitude of EEG signals (100 UV). To avoid this you have to degrease the skin with alcohol and press much with belt. And unfortunately it also happens that after some time the tips, as far as rounded, begin to annoy. In less than one hour you create markers in the skin which then lasts for a long time.

In conclusion, hate to say it, but this road is not reliable enough to be part of the system Theremino.


Active electrodes (non-contact)

Fortunately during rehearsals with the shell shield and silver with high impedance electrodes we discovered that even with a thin insulating layer between electrode and skin useful signals continued to pass by capacity.

We discovered the non-contact detecting EEG and ECG!!!
As usual, however it is difficult to get there first.
Just search “Do not contact electrodes” on Google…

Non-contact electrodes have many advantages, first of all the complete elimination of the galvanic connection with patient, then security to 100% without batteries or complicated power circuits with safety regulations impossible.

Advantages of the electrodes without contact:

  • Total security (the patient is electrically isolated)
  • Elimination of complicated isolation circuits
  • Eliminate the need to go to batteries
  • No galvanic contact voltages for which serves the silver
  • Being able to use the copper you do everything with multiple layers of printed circuit board
  • Better signal even if the patient moves
  • “Zero preparation” (You should clean your skin with alcohol)
  • No contact tips
  • The flat surface and easier to sterilize
  • Functioning even through clothing
  • Reduced performance you get even a few centimeters away
  • Reduced performance you can make fabric electrodes (moistened only by sweat)

First tests of the electrodes with signal generator

Those wishing to experiment with ThereminoEEG version 1.0 Please download it from here:
http://www.theremino.com/downloads/biometry#eeg

To test it you can use a pin set as input proportional Cap16 and move with a finger. If you move fast you can get beyond the 10 Hertz.

We are preparing the new PCB

Or sooner or later we will start these new tests PCB. The center circle on the right is the electrode that mates with the skin, the ring (and the back face all in copper that is not seen) isolate it from the environment with an active screen that reduces the effective ability to practically zero.

For the first tests we chose an external diameter of 30 mm and the total thickness is below the 5 mm. Are electrodes small enough to fit comfortably in their place them under an elastic band, but at the same time have very 6 cm paintings of active electrode.

The round shape is a major improvement, it becomes much easier to build them mechanically, and then the containers.

Version 2 – compensation capacity

This new version has a more complex compensation circuit, According to the simulations, should improve the functioning even electrodes away from skin. With strong ECG signals you can work even at incredible distances from the skin (10 mm and up to 20 mm with some degradation of bandwidth)

We are doing experiments to determine whether this compensation is actually needed and what are the best values of the components.

– – – – – – – –

Mounting the sensor

First of all keep in mind that we haven't tested so maybe it won't work right. May not work well or not at all for a thousand reasons, could auto-oscillate or collect power frequency interference to the point of being completely useless. Unfortunately the little time we have is leaving everything to the NetHAL and the NetMaster that will work in network and even in WiFi (but not with all kinds of Master Pin and with a single Adc).

Theremino NonContact electrode Theremino NonContact electrode Theremino NonContact electrode

The disc that you see on the left is the face that goes toward the skin. The side towards the skin from now we will call “at the bottom”.

Of course the metallic parts must not touch the skin so it will take even a layer of thin plastic sheet.. A thin plastic water bottles as well as dell #8217 & can fit. The plastic will “deep drawn” to hot to form a DRAM. Alternatively you might find a exact diameter short and very thin plastic.

The middle part of the first disc is the sensitive area that must mate capacitively with skin and that is terribly sensitive and should be shielded as much as possible from the incoming power frequency electric fields from & #8217; electrical system.

So around the sensitive area c & #8217; is a link called “on call”.

The second disc is the posterior aspect of the first disk and need to screen electrically sensitive zone centrale from components of the third disc that otherwise would pass for ability their signals to record sensitive doing hopelessly autooscillare everything.

Around the first and second holes are metalized disk acting as a Faraday cage and help to shield the little signal that could have come from the sides.

Both l & #8217; ring that the back face are connected with a small wire that will go through a small hole to do in silver rectangle “GUARD” the third disc. You connect them to “GUARD” instead of mass because otherwise the ability to ground completely would Dim the signal.

In the next image we see the silver rectangle where you will make the hole where it passes the wire that will be paid to “GUARD” the first disc. And also the rectangle “In” will have a small hole with a small wire that will be paid to “In” the first disc.

Theremino NonContact electrode

We didn't do the holes in plots GUARD and IN the third disk because you thought you mount it with the component side to the first disk and then do double sided with the back completely at the top and connected by copper by holes to its mass. But this Assembly would have made it impossible to do tests. For example,, change a component or solder a tad bit somewhere to make measurements.

Whereby the prototypes (yet to try) We did the third disc to a face alone and assemble with components to high #8217 &; (not to the skin). But be careful with this kind of installation you will have to pay attention to two things:

1) The outer ring of holes are not metallic and then do not touch the outer face of the first disk.

2) That the components will not be left uncovered but you must add a disk “all copper” for schermarli to top #8217 &;. This last screen will be paid with a single side wire, so that you can uncover to access components and then close during the functional test.

And finally, at three pitches on the right: SIGNAL, + 5 and GND, settled three soft wire that will go to a Master Pin configured as Adc16.

– – – – – – – –

For those who want to experiment, Here's the project at present (as soon as we have time to improve)
Eagle project downloads + simulations + 3D images
Sensor_NonContact_V2

  1. Maximum says:

    Thanks for the replies.
    I'm going out for a moment from the parent topic giving an info maybe useful, on the supply of PCs.
    I wanted a pc powered by CC, maybe even with any battery, the info in the net were contradictory, and no experience guaranteed, Finally after much searching I found a power supply, great a matchbook input from 6 V ( for a short time ) ideal to 8 V up to 24V, ( output, power values of a pc) with voltage extreme cooling, successful use ( for over 1 year ) my desktop pc, now for convenience use in series a second power supply, but energy efficiency is improved, ( from 3,5 to 2,5/2,3 amp/h) I also used a car battery.
    The efficiency of these power supplies is ca. of 95% at 50% by use of their resources, That's 125 W and use ca 2,2/2,7 amp/h.
    Returning to appliances in question:
    Electrodes must not penetrate the skin at acupuncture dfference.
    There are limited areas and lines on the skin that depending on the person or his particular psycho-physical conditions of time become iperestesiche.
    The use of weak faradic, applied on the surface of the skin is intended to identify these areas.
    I am studying this topic and will be completed between 5 months, personal interest, If you expect a development on the subject you can see through the techniques that I acquire as you then interpreted key technique
    The current is the most efficient for both find that excite skin, Let's say if you want to stay on the simple a generator just, the rest he does practice and experience.
    I downloaded EEG V1 there are directions on how to connect to the master.
    With this program and we say suitable sensors, You can find areas of skin with different electric charge, This is the purpose of the project ?

    • Maurizio says:

      Hi Max,
      From what I understand, use a PC which can be connected to a battery, and this is definitely an asset.
      However, because the system is secure, It is good to also cure the isolation of the downstream part of the power supply than mass, so the subject under test is not subject to potential differences.
      With regard to your search, I understand that you're dealing with traditional Chinese medicine, in its modern electrical implications of points and meridians.
      Meanwhile, I suggest you do practical experience on some human subject using information relating to Shiatsu, What that allows you to capture a certain sensitivity to the position of the meridians.
      As regards the electrical points, I urge you to be careful. Years ago I tried on myself a small tool specially designed for this purpose, a new electronic magazine kit.
      Some points located them painlessly, but for one in particular felt such a shock that I stopped using it forever.
      Since then I forced myself to do always much attention before to stimulate current steps on the skin.
      As you say, the conditions of the person affect the conductivity of certain areas, and how acupuncturists are well aware, the most sensitive areas are usually the ones to be treated.
      EEG reading deals with alternating signals, While in your case (as far as I know) It is more correct to read DC signals.
      However, from a theoretical point of view the points could also cause a read alternating current variation resulting from the body's internal processes (brain, heart), but for this purpose I don't think fit the electrodes without contact, not because of the lack of contact but because you need something to read on a surface point source.
      I guess I can speak on behalf of the other co-workers by saying that we are available to assist you with your research, consistent with the free time available to us, and only for experiments that do not ever endangered people.

  2. Maximum says:

    Hello Maurizio,
    the skin is the boundary between man and environment, There are doors dedicated interchange, can be activated, According to the mood, According to various external environmental conditions, the hours of the day and night, According to the link with the subject's organs and psychic areas hyper or ipoattive etc.
    If the unit worked, It could be that you've touched a point some highly, hard to say now.
    If it happened on certain lines, mechanical or electrical action above a certain frequency threshold , the responding.
    You have to know which organs and psychic aspects belongs to the point you want to stimulate, We measure the response ( micro-milli amp ) set the unit to a level barely noticeable from the subject, do not Pocket the cute talking is treated with pulses.
    An electrical appliance aims to get to the root of the person..
    Thanks for availability.

    • Maurizio says:

      Hi Max.
      I see that your knowledge of TCM (Traditional Chinese Medicine) are extensive.
      I get the impression that you're a professional operator, not a fan like me.
      The interactions you cite (in particular those related to the psychic state) I was quite intrigued, Recalling past experiments.
      Using a sensor like the one you're assuming (or more sensors, to monitor multiple points simultaneously), It would be interesting to try to induce psychic States to verify how and to what extent these points are activated.

    • Maurizio says:

      This could be one interesting idea
      http://www.biophysics-research.com/Validazione.aspx

  3. Maximum says:

    Hello Maurizio,
    my interest is personal, the way to know is long in practice, few concepts not make me expert.
    In that site there are principles that can be shared, Hopefully, those valid researchers can continue undisturbed research.
    First I have to find a schema of Stimulator, or maybe just a stimulator by trade, I need to delve into.
    An electrical impulse seems sufficient just perceived and precise control of electric parameters.
    The psyche is important as connected to the body, It is remarkable how progress is tiring, the collapse effortlessly, must be a fundamental law life.

  4. Maximum says:

    Hello Maurizio,
    I read a work of 76 by some researchers, including Becker, He spent years in research of psychoenergtic system, they performed measurements on the meridians of agopuntira, resistance & conductivity, repeatable measurement that confirmed the position of the meridians Lin and P.
    And’ been used a Wheatstone bridge as a constant source of direct current, the output of the circuit was a direct reading of the conductivity of the skin, quote of the document concerning evidence.
    In other cases, there is always the use of Wheatstone bridge (Backster and others , plant size ).
    I have Japenese to combine with a tester to amplify the feeling X 10 or X 100.
    Purpose try to find lines and points, likely then depend on the used electrodes and connections, thereof between the device and the body.
    I saw a device as big as a razor ( to stack ) you hold it in one hand and put the tip on the skin, This once on emnette a continuous sound, Watch your tone when it detects a some point.
    Build something similar with display would be fine anyway.

    • Maurizio says:

      Hi Max.
      In a few lines you wrote very. Many concepts, though not in detail, already knew them.
      You mentioned researchers with whom you will get many results in google.
      Could you give some links to documents you've read, or get it by email?
      I would love to help you, but you need to provide more details about the direction in which you want to move.
      Build a system of reading the skin resistance, itself is pretty simple, as you have seen there are in network diagrams.
      But if you want to build something specific, then we can study it together.

  5. Maximum says:

    Text read:
    electrophysiological correlates of acupuncture points and meridians.
    You download the pdf writing the phrase on google, I don't have your email to send you the document.
    About other experiences with Wheatstone bridges I reads but not detailed works, I refer to Backster or Marcel Vogel, they used this device even with plants but for different purposes, you notice how they chose to measure resistance instead of the voltage, in the pdf instead measured the voltage also, my interest is to find spots and lines on how is secondary.

  6. Maurizio says:

    Hi Max.
    Looking in google's electrophysiological correlates of acupuncture points and meridians pdf” you find the document that you cite, and a series of documents that reference, for the most part, an interesting research done using an array of sensors to peaks, also quoted from the first document.
    I read quickly the document you mentioned.
    There are no details about schemas used, However contain two different types of readings, Wheatstone bridge with electrostatic voltmeter, this case with readings difficult to perform.
    Interesting the part where they say that using voltages above 3 volts for conductivity measurements produce successively reading DC voltage greater than normal for a few hours after application.
    And very interesting the theory that physical pain is related to DC signal transmission.
    The first thought that comes to me, reading about these experiments, is to use a small robotic arm, equipped with an electrode designed to make no friction on the skin, with constant pressure, you make a two-dimensional scan of a sufficiently wide, so you can then view a color image of map of skin conductance.
    Another interesting experiment (certainly easier to do) is continuous measurement of the conductance of a point during physical or psychological stimuli in an area related to the issue, displaying the result on a graph.
    But these are my ideas a little classic’ visionary.
    What you need, at the time, If I understand, is an easy way to start to locate the points.
    With the data available, I would say that you need to use a reader with conductance voltage below 3V.
    As soon as I can do some testing using hardware and software system Theremino, to see if I can read something sensible and repeatable, without the need for specific circuits.
    But you have to be patient, because I do in his spare time. It may take several days.

  7. Maximum says:

    Hello Maurizio,
    no problem for the time, is substantially the availability.
    You should be able to have my mail at the time I had exchanged messages with Livio, If you want I can send the diagram ( I already have all the components ) I found resistance detector, though with Theremino for graphics and flexibility and technology would be much better, at your discretion, Maybe you could try for a comparison, as long as it is technically sensible suggestion.
    I can confirm that a direct current ( I have to inform me on the output voltage of the electrodes ) generates an electrical response on the lines or points ( potentially ) iperestesici measured in micro/milliamps, This indicates if the underlying psychological and physical bonding is ipo or hyperactive.
    To have constant pressure, you could also use some fixed weight imposed upon a wheel with the handle to move it on the skin.
    If I can build it.
    About the pain let's keep it in abeyance as an argument, I svaruiate personal experiences.
    I share your visions, Temo's for nonconformity to clarity, the male pierces the mists of the unknown using quality provided by mother nature.
    The fantasy, precious dowry in artists where probably is free to ride, the scientists and researchers is then taken by the hand by reason.
    I confirm,Ideally, a simple device ( always that simple is synonymous with effective ) that shows a difference of electrical parameter or otherwise between a point known as some compare him to another neutral.

  8. Joseph says:

    In this year and a half I had to catch up on many subjects. I'll start with the experiment # 1 Brain. Any criticism or suggestions are welcome. Thank you. Kind regards.

  9. Livio says:

    Domenico wrote:
    With the system Theremino you can detect very low frequency electromagnetic waves in the environment, Let's say from 0 Hz -100 Hz, and maybe with a response from the entire spectrum in real-time?
    I'm experimenting with Spectrum Lab, but I can't find an interface system, specific to intercept these frequencies. I don't know if you have created something similar with the system Theremino, or give me directions about.

    Answers:
    This feels electromagnetic fields up to 300 Hz with very high sensitivity:
    http://www.theremino.com/hardware/inputs/meteorology-sensors#emf

    It also has a logarithmic output, as explained here:
    http://www.theremino.com/technical/tables-and-notes#scales

    Then measure, in a single range, from the weakest to the strongest.

    Be aware though that the antenna should be made specifically (with adequate size) It must be a coil or a stylus, Depending on whether you want to detect magnetic or electrical fields.

    However, this circuit does not distinguish the frequencies and produces a single value that is the sum total of all disturbances in the useful range.

    Instead your words suggest to do the analysis of spectrum and this idea is very interesting because it would read more info, but most of all because it would not be fooled by the omni-present 50 Hz mains.

    Spectrum analysis with sound card and DAA
    ——————————————————————————————
    Or you could attach a reel or rod antenna to the microphone input of any sound card. Then raise the maximum input level and finally use the DAA to make spectrum analysis.
    http://www.theremino.com/downloads/uncategorized#daa

    EEG spectrum analysis with DiffMeter and Theremino
    ——————————————————————————————
    Or you could connect the DiffMeter to a rod antenna or a coil and plug it into a Pin configured as Adc16

    The DiffMeter will be set to low common-mode (+/- 3.3 Volts)
    http://www.theremino.com/hardware/inputs/sensors#diffmeter
    by setting values as follows:
    – R3, R4, R5 and R6 = 10 Mohm
    – Trimmers from 470 Kohm
    – R9 by 0 ohm up to 150 k depending on the required sensitivity

    Then to make the Theremino you could use the EEG spectrum analysis that is designed to control the electrodes of electro-brain-cardiogrammi, but it is also perfect for all kinds of spectrum analysis, the low frequencies.
    http://www.theremino.com/wp-content/uploads/2013/05/Theremino_EEG_V1.0.zip
    http://www.theremino.com/blog/biometry

    The Theremino EEG currently reads only the slot ZERO, so you have to set the Pin of ADC to write on the slot "0"

    Spectrum analysis with DiffMeter and Max/Msp
    ——————————————————————————————
    Once the signal is read from DiffMeter and brought on a Slot by ADC, It would also be possible to divert it to external programs like Max/Msp…
    http://www.theremino.com/downloads/foundations#maxmsp

    Or to programs that can communicate over UDP with OSC letters
    http://www.theremino.com/downloads/foundations#osc

    Then theoretically also Spectrum Lab should be able to read our data. But we don't know him and so we don't know whether it is possible to equip it with a PlugIn or something like that, to read our slots.

  10. Joseph says:

    Here's my experience. From the beginning I have always struggled with the size. Before the mm, then the tenths,then the hundredths and thousandths. The catch was always the same: connect 20/40/100 pins of the chip to external components. Passive smd sizes were and are huge compared to the chip. For my applications I chose Microchips and Texas. The first for the cost, the second because it had more choices of micro with analog inputs. But the problem of size still remained and forced me to constant compromise and exasperated circuit. Manufacturers build their chips on the basis of market demands, especially automotive, Mobile etc. I had always, in each component, or a lack or surplus of performance. I had an idea. Ask manufacturers to put on a single chip the functions of other. Basically assemble standard functions on one chip. The answer is "Yes". Aside from the costs, the main reason why I didn't go ahead was legal. Meaning that if your application request by me was a success, the Builder appropriated the project without pay anything. As for ECG and Wearable Sensors typically, If you look on Texas are any components with its application. There are also wireless chips and many other useful components in order. Assemble them in single chip would be great. Obviously
    before you make the evidence for example with Theremino to develop the project, then you choose the components. In the end though it lacks an important element which is the doctor. Does any one but a University researcher who knows maybe even quantum physics. If you have news of any body sensor, not to assemble, I will be grateful if you wireless or Bluetooth you will communicate. Greetings and thanks. Joseph.

  11. Alberto says:

    Good evening, I am a young student who is developing a simple BCIV for a school project. I would particularly like to delve into the software used to process the signals. As has been written? Which methods of analysis were used and how they were a ti implemented?

    Thank you in advance.

  12. Anonymous says:

    I can not associate Theremino V4 module Theremino_EEG _V 1.0. In other applications, it works. Tell me what’s the problem ?.

    • Livio says:

      Theremino EEG is a simple and experimental application and so…

      1) The HAL application is not included in the Theremino EEG zip-file.
      2) The Theremino EEG application does not starts automatically the HAL applicaton.
      3) The input slot is fixed to the slot ZERO

      You can try EEG changing the slot zero value with the SlotViewer

      Then you have to download the last HAL application.

      Then you start the HAL application manually and set the ADC Pin parameters to the slot ZERO.

      In the future you could also start all automatically, as explained here:
      http://www.theremino.com/en/downloads/foundations#starter

  13. Anonymous says:

    Thank you.

  14. Maximum says:

    Good morning,
    Theremino DIL-V3 master might measure the frequency of an electronic board ? It is low frequency 1 to 1000 Hz splitting the measure must be of 1 Hz. because if I need to be able to see for example rule 357 Hz or 249 Hz.
    Since I would also see the waveform of this card can be used as an oscilloscope ?

    • Livio says:

      You sure can measure a frequency.

      Attention only to not send too much tension (beyond the 3.3 Volts or below zero Volts) with too much current (In addition 100 UA). The inputs are protected and do not break, but may break the USB transmission. So it is good to add a resistor in series with the signal, placed next to the input pins of the Master. A 10 k resistor is fine until a few volts too. If you have very high voltages 12 volts or more. then you should use a 100 k resistor or an appropriate divider.

      All pins of all versions of Master, and even the slave “Servant”, can be set as “Counter” and then set to measure the frequency. Try it even if you get more precision by setting them as “Period”.

      Some special Pin can be set as “FastCounter” and measure frequencies even high enough (up to 50 MHz)

      Here shows the Pin that you can use with the various versions of modules:
      http://www.theremino.com/hardware/devices

      Here are long explanations for all types of pins, one by one:
      http://www.theremino.com/technical/pin-types

      See the signs
      —————————————————
      To see the shape of the signals you need to set the Pin as ADC16. The same considerations already written on the maximum voltage 3.3 Volts, as well as on any resistors or voltage dividers to add.

      Then you should also write some software, a small oscilloscope.
      Currently the only application already written that does something like this from a Slot (and only from slot 0) is the “Theremino EEG”, that you download from this page:
      http://www.theremino.com/blog/biometry

      With a few tweaks you could turn it into a more complete oscilloscope.

      A true oscilloscope
      —————————————————-
      To get all the performance of a true oscilloscope, and also a more precise frequency measurement, You should use the Theremino DAA that you download from here:
      http://www.theremino.com/downloads/uncategorized#daa

      But be careful: If you use the DAA the signal must come from the sound card. Then the Master and the HAL are not used!

  15. Carlo says:

    Good evening,
    Let me start by saying that I made a counter gaiger theremino system extremely reliable and therefore I commend you for the many insights you offer.
    Now I wanted to experiment with e-meter and lie detector. It's not clear to me, however, in the project e-meter what kind of sensors can be used.
    Thanks again and keep up the good work
    Carlo

    • Maurizio says:

      Hello Charles.

      In fact, I checked and in the downloadable version of emotion meter there is documentation on the electrodes.
      Intentionally, the application name theremino is emotion meter, to differentiate it from the devices you citi, used by a well known Association.
      Unlike those systems, the theremino emotion meter is based almost exclusively on software.
      At the time, the project is stopped, but we can certainly help you if you'd like to learn more.
      I've taken care of me for a while, but I could not reproduce the behavior of the original machine, I had seen him in action many years ago, and I've had no time to do other experiments, that would require, inter alia, the use of volunteers for testing practices.
      Original device electrodes were two cans of tinned iron (in the years 80 stranded very easily by removing the paper label from cans of spray paint).
      Years ago I tried with other materials, and I did other tests recently, When we began the project emotion meter, and I can tell you that the electrodes in different metals from tinned iron malfunction.
      Modern devices used by the Association, and other independent operators, use electrodes in plastic coated in silver, that seems to be currently the best solution.
      The electrodes are held in the hands, impugnandoli as the knobs of the bike, but in an upright position. The subject must not wear rings or other metallic materials that may be in contact with the electrodes, Why would produce distorted measurements.
      For connecting to the master theremino, the first tests were made by connecting a grounding electrode and one to an input, with a pullup resistor.
      I remind you that this system can become potentially dangerous, Since the subject is connected to an electrical system through a low-resistance electrodes to the skin.
      To ensure the safety, You must have all the system functions to battery, and you need to be sure that the maximum voltage applied between the electrodes is very low.
      For this reason, the original machines worked exclusively with rechargeable battery, and it was not possible to use it while charging.
      Let us know if you need more information about the tests.

      Hello
      Maurizio

  16. Angel says:

    Hello, I'd like to detect brain signals ,theta alpha beta gamma delta waves which then would correspond to various Hada States ranging from waking to sleep or meditation. You have already done something about it ? Once there was a brain olotester that gave a clear picture of all levels of signals I mentioned, by examining their consistency…It would be fascinating to be able to do it with theremino!
    Thank you

  17. Angel says:

    I have not explained well… I don't want to operate devices in thought but just read the signals emitted by the brain ranging from a few hertz to approximately 13 Hertz…

  18. Franco says:

    Good evening, are interested in experiencing the electrodes without contact version 2 , could you help me to understand how are assembled and connected the two printed circuit boards, I have found no indication in this regard.
    Any other further indication about it, It would be a beautiful gift.
    Thank you.

    Franco

    • Livio says:

      Hard to explain in a post like this for which we have added images and text best we could write. I hope you can be of help. Hopefully we will complete upon request to clarify details that are hard to understand.

      Anyway, remember once again that there is a good chance that not work. It is a difficult project, the input impedance is almost endless. You may have all kinds of defects and to solve them it would take a lot of experience with such high impedance circuits.

      • Franco says:

        Thank you very much, I try anyway and if you don't bother, I would like to inform you about any obstacles or successes.
        Thanks again.

        • Livio says:

          Do not disturb for sure, only regret not being able to do more to help you. Did you see the new images and text? There is something you don't understand? If write us as well and we'll try to improve it.

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