Please note that there is no callback for when a pushbutton is released, only for when it is pushed
Normally you would keep track of your objects somehow (such as with a "handles" structure using guidata(), the way that GUIDE does), or you would set the Tag field for each uicontrol to something unique so that you can locate them:
currentfig = ancestor(gcbo,'figure');
eta9_handle = findobj(currentfig, 'tag', 'Eta_9'); %to locate the one you tagged with Eta_9
If you just want them all and will determine an order afterwards then:
currentfig = ancestor(gcbo,'figure');
object_handles = findobj(currentfig, 'type', 'uicontrol');
or you can look for a particular variety:
currentfig = ancestor(gcbo, 'figure');
push_handles = findobj(currentfig, 'type', 'uicontrol', 'style', 'pushbutton');
