Make Interface for EOG

[jennichrni]

Hello everyone, introduce my name is Jenni Chaerani. I just learned Labview as the interface for my TA project.

I want to make an interface for the Eyeball Movement Reading by Electrooculography Sensor. The movement is divided into four, namely looking up, down, left and right. I tried to design when moving my eyeballs, the LED indicator will light up according to the eye movements made.

I tried to make a program with threshold and polarity detection of the signal.

Where when Ch1 <Th2 & ch2 <th2 is defined as above.

then when ch1> th1 & ch2> th1 ==> down

It's just that I'm constrained because the signal produced in the form of two waves, so when I look up the eye will automatically go back down so that the resulting signal becomes up and down. Signal indicators become inaccurate.

So what I want to ask is if the view can call a function like coding a text program? when condition A is called function A, etc.

Or is there a solution and other LabVIEW features that can facilitate the reading of this signal?

because when I'm confused and don't know the right keywords for this problem

thank you

[jennichrni]

Hallo semuanya, perkenalkan nama saya Jenni Chaerani. Saya baru mempelajari Labview sebagai antarmuka proyek TA saya.

Saya ingin membuat antarmuka untuk Pembacaan Gerakan Bola mata oleh Sensor Electrooculography. Gerakannya terbagi empat yaitu melihat ke atas, bawah, kiri dan kanan. Saya memcoba mendesain ketika menggerakkan bola mata, indikator Led akan menyala sesuai dengan gerakan mata yang dilakukan.

Saya mencoba membuat program dengan threshold dan deteksi polaritas dari sinyal.

Dimana ketika Ch1< Th2 & ch2 < th2 didefinisikan sebagai atas.

lalu ketika ch1>th1 & ch2> th1 ==> bawah

Hanya saja saya terkendala karena sinyal yang dihasilkan berupa dua gelombang, jadi ketika saya melihat ke atas otomatis mata akan kembali ke bawah sehingga sinyal yang dihasilkan menjadi atas dan bawah. Indikator sinyal menjadi tidak akurat.

Jadi yang ingin saya tanyakan apakah dilabview bisa memanggil fungsi seperti coding program teks? ketika kondisi A maka akan dipanggil fungsi A dsb.

Atau apakah ada solusi dan fitur labview lainnya yang bisa mempermudah pembacaan sinyal ini?

karena ketika saya bingung dan tidak tau kata kunci yang tepat untuk permasalahan ini

Terima kasih

wassalam

Jenni

[GerdW · Accepted solution]

Hi Jenni,

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@jennichrni wrote:

I tried to make a program with threshold and polarity detection of the signal.

Where when Ch1 <Th2 & ch2 <th2 is defined as above.

then when ch1> th1 & ch2> th1 ==> down

---

There are simple comparison functions you can use:

Simple comparison: no need for ExpressVIs, no need for IndexArray&ArraySize, no need for FOR loops!

But:

In your VI you are reading 2000 samples from DAQAssistent, at a sample rate of 1kS/s. This gives you data for 2s: how do you want to handle "up" in the first 0.5s and "down" in the last 0.5s of the same data block?

You really should not use the ExpressVIs and the DDT wires, better use plain LabVIEW and DAQmx functions. This way you are much more safe about your DATAFLOW! You need to know, what kind of data is flowing through those wires at which time…

You don't need the sequence structure in your ("direction…") VI. Adding an additional delay next to DAQmx functions most often gives problems. Lots of other quirks in the VI…

[jennichrni · Accepted solution]

I have made that block diagram, but I need the specific threshold, so it can't be ch1<0.

if i dont use the sequence, so how can i manage the signal reading one by one?

[GerdW · Accepted solution]

Hi jennichmi,

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@jennichrni wrote:

I have made that block diagram, but I need the specific threshold, so it can't be ch1<0.

if i dont use the sequence, so how can i manage the signal reading one by one?

---

If I remember right I tool the "<0" comparison from your VI.

You don't need sequences once you "THINK DATAFLOW!"…