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Calculating SpO2 in pulse oximetre, 16F877A PIC

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spraga

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Hi I have just built a pulse oximetre circuit and tested it and it is working fine. My problem now is to calculate the SpO2. I am using a 16F877A PIC and need help with the code. Can anyone pls help me. thanks
 

Calculating SpO2 in pulse oximetre

hi, spraga,

i just come into this topic and my focus is the algorithm design for pulse oximeters. i have reviewed some algorithms and now tried to assess them. how about you send some signal samples of your pulse oximeter to me and i test your samples then send the code to you?
 
Last edited by a moderator:
Hi

Search Freescale site - you will find some nice application note on Pulse oximeter and how to use it

All the best

Bobi


The microcontroller specialist
 
hello
i m an electronic engineer. sand me all of ur data i wll read ths and wll help u according to ur circuit.. i had worked recently on ths. i m very good in programming
 
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SpO2 circuit: how to determine the suitable clock pulse for LED?

Hi!
Please share your knowledge upon my simple question here.
What are the criteria needed in selecting suitable clock frequency to driven my LEDs?
I have two LEDs, red and infrared. I want to design the digital LED driver; where the clock pulse is driven from the LabVIEW software. I'm using DAQPad 6016 which has 200kHz/scan but since this DAQ board is a multiplex one, so per channel it can only scan for 25kHz since I want to use up to 8 channels.
So;
1. should the clock frequency less than 25kHz or more?
2. what is the suitable time delay for the second LED (IR)?

Many thanks in advance!
 
Re: SpO2 circuit: how to determine the suitable clock pulse for LED?

nafn said:
Hi!
Please share your knowledge upon my simple question here.
What are the criteria needed in selecting suitable clock frequency to driven my LEDs?
I have two LEDs, red and infrared. I want to design the digital LED driver; where the clock pulse is driven from the LabVIEW software. I'm using DAQPad 6016 which has 200kHz/scan but since this DAQ board is a multiplex one, so per channel it can only scan for 25kHz since I want to use up to 8 channels.
So;
1. should the clock frequency less than 25kHz or more?
2. what is the suitable time delay for the second LED (IR)?

Many thanks in advance!
Click to expand...

The heart rate is 0.5Hz - 5 Hz. Sampling frequency should be at least 2x more (The Nyquist Sampling Rate). Ive been working on Spo2 reading, led changing frequency is 1kHz (1 ms) => 1ms IR LED ON, 1ms R LED ON.
 
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    vik424

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Pulse Oximeter Design Enquiry Please

Hello Everyone,
Currently as part of my group's graduation project im responsible for understanding the pulse oximeter , i've some questions if you dont mind :) ;

1. whats the purpose of the calibration curve and how did we get the polynomial Spo2 function Equation ?
2. whats the difference between SaO2 and SpO2 and which one are we going to use ?

Thanks In Advance
Omar Sultan
 

Re: Pulse Oximeter Design Enquiry Please

1. The equation for SpO2 calculation is theoretical formula from Lambert-Ber law. In biological object the light consumption is differ from Lambert-Ber law because the light is scattered. For correction formula for SpO2 equation the designers adds calibration curve. This curve is based on experimental data from CO-oximeter.
2. SaO2 - is theoretical parameter is saturation hemoglobin of oxygen and SpO2 - is the value, which measure pulse oximeter. Additional pulse oximeter can not determine other hemoglobin (methemoglobin and so on) and pulse oximeter can measure partial value.
 
Re: Pulse Oximeter Design Enquiry Please

Thank You MaxG For Your Help , can u please give me some information on how we derived the polynomial equation ?

Much Appreciated :)
kastella
 

Re: Pulse Oximeter Design Enquiry Please

Thanks Alot :D ,
I Found This Book Here In The Forums Will LookUp Into It ASAP :D

Regards
kastella
 

Can you help me i have the same pic ,but i need the code source ...
 

hi guyz
i am just starting to build an SPO2 monitor but I got no glue of wer to start.
plz help with anything you can...plz
 


Re: Pulse Oximeter Design Enquiry Please

plz help me I wanna dsign an SPO2 monitor wer to start.

---------- Post added at 12:44 ---------- Previous post was at 12:30 ----------

[/COLOR]hi ,i am more interest for now on the design of the probe,i got the leds, but the led only got 2 wires, and is 2 type of led so i dont have a ground fo switch it on.plz help with the probe design.
 
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thx very much will have a look at it
hope it help

---------- Post added at 12:49 ---------- Previous post was at 12:40 ----------

hey please I have those note already i am more concern about the design of the probe .I got the LED that i am supose to use but i only have 2 wires while its 2 led on it so i m confuse on how will i switch the leds without a ground or how can i do it.
thx alot
 

Re: SpO2 circuit: how to determine the suitable clock pulse for LED?

plz can i have the design circuit of the spo2 probe?I m seriously desperate .just start to design a SPO2 monitor but stuck just at the begining because the led that i m supose to use only got 2 wire while is 2 led it need a ground.pls help with anything.
 

djomgoue said:
thx very much will have a look at it
hope it help

---------- Post added at 12:49 ---------- Previous post was at 12:40 ----------

hey please I have those note already i am more concern about the design of the probe .I got the LED that i am supose to use but i only have 2 wires while its 2 led on it so i m confuse on how will i switch the leds without a ground or how can i do it.
thx alot
Click to expand...

to under stand types of sensor please check out this thread

https://www.edaboard.com/threads/10910/

regards
Fragrance
 

here is complete project for pulse oximeter with PCB design and source code for pic micro

Regards
Fragrance
 

Attachments

  • pulse oximeter.7z
    1.6 MB · Views: 390

@ Fragrance :

Thanks for the docs , can you tell me why using +12 , -12 in the circuit ?!
cant we just use +5 , GND instead ?!
 

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