From: Joerg Hansmann (info_at_jhansmann.de)
Date: 2001-05-02 16:41:14
Hi,
----- Original Message -----
From: <sood_s_at_y...>
To: <buildcheapeeg_at_yahoogroups.com>
Sent: Monday, April 30, 2001 7:29 PM
Subject: [buildcheapeeg] Re: gathering hardware specifications
> I too am in the need of the specifications of the device as
> whomsoever I discuss for safety testing, asks for a detailed specs.
> So they are mandatory for 510(k) as well as 60601-1.
> I had a small set of details as follows (all I could get while I
> spent time with Yaniv):-
>
> Freq. Response: 0.5 Hz to 75 Hz.
> Amplitude : 50 microvolts
> transducers/leads : Ag-AgCl (preferably)
> Channels : two
> Power supply : Inbuilt rechargeable battery.
> Enclosure : Moulded plastic case of half the A4 size document.
>
> Please correct me if I am wrong and add to the details, please let
> me know.
Here are the specifications of the tested and running prototype.
Or did you want the specs of the new design ?
Specification of RS232EEG_01 (date:010502)
----------------------------
isolated power supply:
* input voltage: 7..12V dc, or 5V dc stabilized (from PC or mains adaptor)
* isolated with DCDC-converter(TMA0505S):
Isolation voltage Input/Output 1'000 VDC
Isolation capacity Input/Output 60 pF typ.
Isolation resistance Input/Output >1'000 Mohm
isolated RS232 Data-lines (opto-isolated)
* 2x 6N139 (RxD, TxD)
Viso > 2500 Vrms (Input-Output Momentary Withstand Voltage)
Resistance (Input-Output) Rio=10^12 ohm
Capacitance (Input-Output) Cio=0.6 pF
Microcontroller:
* Atmel AVR AT90S4433 at 7.3728Mhz
with 6 channel (multiplexed) 10 bit resolution ADC
EEG-amplifier:
* 2 channels
* about 100uVpp input range (adjustable)
* lower corner frequency: 0.25Hz
* upper corner frequency: 33.1Hz
* -3dB bandwidth: 32.9Hz
* noise: about 1uVpp over above specified bandwidth
* common-mode rejection: typ. 115dB
* Impedance, Differential 10^10ohm || 22nF
* Impedance, Common-Mode 10^10ohm || 60pF
misc.:
* 256Hz samplefrequency, (optional 200 Hz)
* 4 unused ADC-channels (input range +-2V)
* 4 TTL-inputs (for switches e.g. for marking events by the user)
* 4 LED-driver outputs (e.g. for light goggles)
* 1 PWM output
* hardware UART (RS232 transmission
parameters are: 1 startbit, 8 data bits, 1 stopbit, no parity, 57600 baud)
* on board calibration generator: 50uVpp 10Hz rectangle wave
* easy in system programmable uC-EEPROM/Flashrom
* uC-firmware written in AVR-GNU-C
At the moment communication direction is only from Atmel-processor to PC.
The hardware however supports full duplex communication. This feature
will be used in later firmware releases to support the PWM-output and
LED-Goggles.
sincerely,
Joerg
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:29 BST