Optical Simulation System for Brain Waves Detection & Measurements

1. Optical Simulation System for BrainWaves Detection & Measurements FRS Presenters: Yevgeny Safovich 307015578 Nadav Pilnick 028824449 Supervised By: Hen Brodney

2. Definition of Terms • Element – a unit filled with a single color • Pattern – collection of atomic Elements • Step – definition of Patterns changing with a specified frequency and a D.C. • Program – a set of Steps • Supervisor – the programmer of the Patterns and the steps • Operator – the tester of the person examined, will select the predefined steps

3. Problem Definition • Measure eye vision quality objectively • The vision should be measured (almost) without cooperation of the person being examined

4. Project Objectives/Goals + Needs Analysis • Output programmable Patterns by programmable Steps to the Monitor • Output an electrical pulse • The above should be synchronized • The following should be programmable by the supervisor: • Programs • Patterns • Steps • The following should be selected by the operator: • Select program to be used

5. Constraints & Definitions • 3 pairs of colors: • Blue, Yellow • Green, Red • Black, White • Each pair has its own “blank” color: the average of the colors in the pair • Steps frequency: 0.5Hz – 10Hz, resolution 1Hz • dx = The delta between the Monitor output and the electrical pulse output. 0.5ms < dx < 1.5ms

6. Solution • Write a software application which will do the following: • Allow the supervisor to program the programs, steps, patterns for the required tests • Allow the operator to select a program to use • Output the programmed graphics to the monitor synchronized with an electrical pulse • The electrical pulse above will lead to a measurement of the waves within a human’s brain • The measurement of the waves within a human’s brain is out of the scope of the project. learn the video interface

7. Operator Computer Video Card Brain Waves meter Monitor Human * The red interfaces should be synchronized Solution Algorithm

8. Operator Computer Video Card Monitor Human Brain Waves meter t t1a t1b t2 t3 t4 t5 Timing • 0.5ms < |t5 – t3| < 1.5ms • |t4 – t3| - We suppose this time does not matter and is taken care of by the “Brain Waves meter” • |t3 – t2| - We suppose this interval is negligible • |t2 – t1b| - The major problem of the project, discussed below • |t5 – t1a| - A problem discussed below

9. Timing cont. • We have 2 major issues: • Output of the graphics delay • The time it takes for the screen to show the data since it was sentto the video card • Output of the electrical pulse delay • The time it takes for the output port to change the output level since the opcode was sent to the processor • Supposed the above are constant (deterministic) we can force synchronization

10. Q1 Q2 Q3 Q4 Pattern programming • The way to define a pattern: • Squares: Size, Colors (2 colors) • Bands: Size, Colors, Type (horiz., vert.) • Q1: Element type • Q2: Element type • Q3: Element type • Q4: Element type • Example: Pattern1 • Squares: 10, blue: red • Bands: 10,white:black,horiz • Q1: Squares • Q2: Bands • Q3: Blank • Q4: Blank

11. Steps programming • The way to define a step: • Patterns used • Duration (frequency) • D.C. • Example: • Pattern1, Pattern2

12. Example of a program • Program1: • Pattern:P1 • Squares: 10, blue: red • Bands: 10,white:black,horiz • Q1: Squares • Q2: Bands • Q3: Blank • Q4: Blank • Pattern:P2 • … • Step:S1 • P1:30%, P2:70% • Frequency: 5Hz • Duration = 2sec

13. Development Timeframes • All major problems must be solved not later than in 2 weeks. • The FRS must be completed not later than in 3 weeks • The FRS should contain solutions and decisions for all issues mentioned in “Risks & Problems” on the following slides

14. Project Blocks Diagram • The below is relevant only if the FRS is finished as stated above Programmable Module Electrical pulse Interface Video Interface Arbiter – Main Application Module Uni-Tests QA System Tests

15. Major Risks & Problems • Is the synchronization accuracy of 1ms correct? • The delay of the video card is unknown • It takes the screen (5 – 10)ms (? – refresh rate) to draw the image. What should be the synchronization point ??? • We have to catch a beginning of a Vertical Sync. of the image we sent. • Verify the delay of an output port is constant and short enough.

16. Major Risks & Problems cont. • Supposed the application is written in Windows we have the following problems: • There might be a Context Switch between 2 commands… • Does the Kernel run if the process’s priority is Real-Time • Video Card buffer’s delay is unknown (32 Mb) • Any HW access requires a device driver • Supposed the application is written in DOS we have the following issues & problems: • Is direct writing to the Video memory possible? • Is the data sent to video card un-buffered? • Are video paging switches possible? How much time it takes to switch paging?

17. Gathered Information • Maximum Refresh Rate: 200Hz • ECP: output takes ~ 1microsecond • There is a driver API allowing to block the application till the next Vertical Blank (Windows - DirectDraw)