Data Acquisition for Biofeedback Data Acquisition for Biofeedback System Using LabVIEWSystem Using LabVIEW

Final PresentationFinal Presentation

Performed by Rapoport Alexandra

Supervised by Eugene Rivkin

Eli Shoshan

Technion

Department of Electrical Engineering

The High Speed Digital Systems Laboratory

Spring 2003Spring 2003

General Concepts of General Concepts of BiofeedbackBiofeedback

Used for training of self control.Used for training of self control. The emotional state of a person is The emotional state of a person is

determined according to physiological determined according to physiological parameters such as skin resistance, skin parameters such as skin resistance, skin temperature, EEG, heart rate, etc.temperature, EEG, heart rate, etc.

The response of the system is usually The response of the system is usually given by sound or visual presentation.given by sound or visual presentation.

System StructureSystem Structure

LabVIEW interpretationPCI 6035EPCI 6035E

4x16 bit4x16 bit

4

4

ch

an

nels

ch

an

nels

Temperature to VoltageTemperature to Voltage

Resistance to VoltageResistance to Voltage

Two parts Two parts isolatedisolated

AC

con

trol

AC

con

trol

Clock settingsClock settings

Temperature DetectorsTemperature Detectors

Temperature detectors – one for each side.Temperature detectors – one for each side.Two terminal IC temperature transducer AD590Two terminal IC temperature transducer AD590Voltage sources (5V batteries)Voltage sources (5V batteries)Low pass filter MAX291 – one for each sideLow pass filter MAX291 – one for each sideAnalog isolation amplifier HCPL7850Analog isolation amplifier HCPL7850ResistanceResistanceCapacitorsCapacitors

Temperature Sensor CircuitTemperature Sensor Circuit

30kOhm

Impedance SensorImpedance Sensor

ElectrodeElectrode 3-terminal adjustable current source LM3343-terminal adjustable current source LM334Voltage source (5V batteries)Voltage source (5V batteries) Low Pass filter MAX291Low Pass filter MAX291Analog switches MAX4654Analog switches MAX4654Analog isolation amplifier HCPL7850Analog isolation amplifier HCPL7850CapacitorsCapacitors

Impedance Sensor CircuitImpedance Sensor Circuit

20kohm

20kohm

A/D SpecificationsA/D Specifications

A/D card used: A/D card used: LabVIEW card PCI 6035ELabVIEW card PCI 6035E

12 channels (4 channels used)12 channels (4 channels used) 16 bit each16 bit each Voltage limits: -10..10V Voltage limits: -10..10V

General System SchemeGeneral System Scheme

A/DA/D

PCI 6035EPCI 6035E

++

LabVIEWLabVIEW

softwaresoftware

SignalSignal

Pull down (unused 6035E inputs)Pull down (unused 6035E inputs)

SignalSignal

Temperature Temperature SensorsSensors

Impedance Impedance SensorsSensors

AC controlsAC controls

Hardware ImplementationHardware Implementation

• Circuits were not wied, but the full Circuits were not wied, but the full schematic drawing was made.schematic drawing was made.

Physiological RangesPhysiological Ranges

• Overall range: Overall range: 50..2000kOhm50..2000kOhm

• Relaxation: Relaxation: 800..2000kOhm800..2000kOhm

• Mild stress: Mild stress: 300..800kOhm300..800kOhm

• Severe stress: Severe stress: 50..300kOhm50..300kOhm

• Overall range: Overall range: 26..36ºC26..36ºC

• Relaxation: Relaxation: 34..36ºC34..36ºC

• Mild stress: Mild stress: 30..34ºC30..34ºC

• Severe stress: Severe stress: 26..30ºC26..30ºC

Skin Resistance Temperature

Voltage Measurement Voltage Measurement RangesRanges

• Overall ranges:Overall ranges:

0.17..8.45V (for 0.17..8.45V (for 2525ºC room temperature)

• Phasic voltage Phasic voltage range: range: 16.9..84.5mV16.9..84.5mV

• Overall range:Overall range:

8.916..9.486V8.916..9.486V

Skin Resistance Temperature

Software SpecificationsSoftware Specifications

• LabVIEW6 based interpretationLabVIEW6 based interpretation• Two interfaces:Two interfaces:

Patient interfacePatient interface Examiner interfaceExaminer interface

• Range settings availableRange settings available

User’s InterfaceUser’s Interface

• Measurement setupMeasurement setup• Graphical representationGraphical representation• Qualitative state evaluation for trained Qualitative state evaluation for trained

personperson

SettingsSettings

• RangesRanges• Sampling frequencySampling frequency• Time resolutionTime resolution• Environment variables (room Environment variables (room

temperature)temperature)

Settings Window ScreenshotSettings Window Screenshot

Research Window Research Window ScreenshotScreenshot

Training Mode ScreenshotTraining Mode Screenshot

Signal SimulationSignal Simulation

• Three sine waves with random Three sine waves with random parameters according to parameters according to measurement mode (temperature or measurement mode (temperature or resistance)resistance)

ConclusionsConclusions

• Software part of the project has been Software part of the project has been implementedimplemented

• Hardware part of the project has not Hardware part of the project has not been wired up, but the full schematic been wired up, but the full schematic drawing was made.drawing was made.

• For signal simulation voltage For signal simulation voltage generator has been implemented in generator has been implemented in LabVIEW 7.0 environmentLabVIEW 7.0 environment