What do the x- and y-axes of this pulse oximeter signal represent?

What do the x-Coordinate and y-Coordinate mean? And what is the range of y?

[Azzi Abdelmalek]

How are we supposed to know?

[yihui]

i mean,the signal is on oscilloscope,is it Definitely that x represent time,y represent voltage?

Answer 1

[Azzi Abdelmalek]

You can read about Pulse_oximetry

the range of y depends on your Pulse_oximetry, you have to read its characteristics.y is a voltage which is related to Molecular oxygen concentration, this relation is also is given in your Pulse_oximetry characteristics

[yihui]

i have read it,but because the poor understanding,still can not find the range.my teacher just draw the picture as i show before,and then ask me to find what x means,y means,and the range of y.i have collect the pulse oximeter data once,but i'm not sure,is it the correct data,so teacher ask me to find the range.if my data is belonging to the range,then i can tell whether my data is true~so sad~~~

[yihui]

http://www.ufiservingscience.com/datasheets/1020manual.pdf this is the one i use for my lab~

[Azzi Abdelmalek]

Ok, have you read the specifications in page 7, it says the output range is 5-50mV

[yihui]

so that means when i collect data,the data is 5-50mv?is it the normal pulse oximeter data for people too?

Answer 2

[Image Analyst]

x is most likely time. If it's an oscilloscope, the y is voltage but if it's a custom program, y could represent "percent oxygen" or something else.

[yihui]

so can i ask what is the range of y? are u Familiar with pulse oximeter?

[Image Analyst]

How are you collecting data? Do you have an oscilloscope hooked up to the thing? Do you have any kind of calibration factor that converts voltage into percent oxygen?

[yihui]

yeah,i use oscilloscope to see the signal,and use one device that is provided by my teacher to store the data,and the data i think is just represent the voltage~

[Image Analyst]

Well to convert to %O you're going to need a calibration factor to convert your voltage into %O. Consult your manual or teacher for assistance.