A ring applied to the surface of the tissue stabilizes {HEAD ~ the tissue} to {TAIL ~ the optics} and localizes a portion of the tissue surface through an aperture in the ring 
to
A ring applied to the surface of the tissue stabilizes { HEAD ~ the tissue } to { TAIL ~ the optics } and localizes a portion of the tissue surface through an aperture in the ring
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH