Removing periodic spike noise from ECG signal The signal shown in the following figure is collected from a ECG sensor. The spike noise that is observed with a periodicity of 30 seconds was traced to the periodic blip of the LED as it draws current.

 

The following is one instance of the spike noise after zooming in,



Frequency domain filters are not effective in this case because the frequency domain characteristics of the LED blip artifact is similar to the heart beat signal(QRS). 

Is there any effective way to remove this artifact..? I was think of using the blip as a mother wavelet and performing a multi-scale correlation with the ECG signal to detect the spikes. Is this the procedure for wavelet denoising? Is there any other effective way of denoising for this case?
In the first place I would suggest you to look for some electrical methods of avoiding those spikes... If it's impossible to do so, then you must find a close enough mathematical model of your noise generation process from which you may decide to choose an adequate method of noise removal...Provided you can do so...