Light imaging elements in the bottom of {HEAD ~ the fluid channel} may be used to image {TAIL ~ the object} 
Light imaging elements in the bottom of { HEAD ~ the fluid channel } may be used to image { TAIL ~ the object }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL