Circuit design
I have designed a circuit that I know works because I have tested it extensively on persons in a wired headphone situation (hand-soldered by DIP), but I need someone to help take us to the next step - wirelessness, more current, and SMD.
Background…
tDCS and tACS both inject current into the body, the former uses direct current while the latter uses alternating current at (usually) adjustable frequencies. We want to be able to control the frequency of stimulation sent into the body because some frequencies enter people’s bodies better than others. What we are aiming for is adjustable tACS that can be controlled from a cell phone app, inside a device that can also play music.
Circuit specifications:
Wireless (bluetooth, i.e. smartphone compatible)
Two outputs to speakers that play audio. The device can act as traditional bluetooth headphones. Adjustable volume for listening. This volume adjustment can be done in software.
Two outputs that inject alternating current into the body. Adjustable power for stimulation. There should be hardware buttons for making these adjustments (digital potentiometer).
The device can eject adjustable amounts of current over a 15 kOhm load. The current amount should be an adjustable range from 0mA (device is music-only) to at least 0.3 mA, but not more than 1.1 mA. So ideally, we would max out at something like 12 Volts (12/15,000 = 0.8 mA).
Stimulation is performed over two electrodes attached to the skin on the left and right sides of the head. The current should be able to run from either left to right or right to left. I.e., it is alternating current…
One input that receives current from the body, for recording bodily electrical responses… Not a huge deal if it can’t be done.
Rechargable from microUSB
I have done enough research into this project to know what is likely needed, although you're free to suggest your own approach:
A bluetooth module (2.1 likely)
A 3.7V Lithium Ion battery (likely 100mAh or less).
A microUSB charging module
A boost converter (3.7V input, 9-12 V output ideally )
An op-amp
A digital potentiometer (two buttons on the device control voltage output from the op-amp)
Soldering marks on the PCB for attaching headphones, electrodes, and a battery.
I have deliberately left out some details that may make this task easier. Looking forward to hearing from you!
Hi
I am an experienced electronics engineer with more than 8 years of experience in my field. I can do it for you. I have read the details and would like to know about the already decided circuit
Relevant Skills and Experience
I have completed over 200 projects here , please review my profile to see the feedback from my previous employers I am waiting for your reply to start
Regards
Proposed Milestones
$700 USD - milestones
Hi There,
We have rich experience in dealing with TENS. We will ship ypu fully working prototype according to specs mentioned.
Feel free to contact us.
Relevant Skills and Experience
We are a company offering Product development services. We will fabricate the prototype and develop the apps (Android and IOS) to control the Device. Further more we will also do Enclosure design.
Proposed Milestones
$500 USD - Schematics, BOM
$500 USD - PCB layout, Gerber files, firmware
$500 USD - Prototype built, tested and shipped.
Hi there, I can do this project efficiently and in very little time . Please send me a private message , this is a public post.
I have some questions about the bluetooth you are using.
Relevant Skills and Experience
18 years experience , besides Bluetooth Low Energy couple projects ,
Proposed Milestones
$277 USD - 1
Hi, I am a circuit designer. I have done many projects related to LT Spice.
Relevant Skills and Experience
LT Spice
Proposed Milestones
$355 USD - Final
We can adjust the price after discussing the project details.
Relevant Skills and Experience
I'm an electronics engineer who has 6 years of experience. I have worked with many types of sensors, modules and embedded systems. See my portfolio for more details.
Proposed Milestones
$500 USD - Completion
You can check my profile.
Relevant Skills and Experience
Actual: Analog Designer at Infineon Technologies.
Past: Hardware designer at Continental Automotive.
Proposed Milestones
$20 USD - Check the concept
$400 USD - Circuit design and simulations
$135 USD - verification