An apparatus, comprising: a cannula , comprising: a body extending between a first end and a second end , the body having a first side and an opposite second side ; and a leading edge formed by the first end, the leading edge extending along a first plane, the first plane extending between the first side and second side, the first plane forming a leading edge angle between the intersection of the first side and the first plane; a mandrel , comprising: a body extending between a first end and a second end along a central longitudinal axis; a notch formed by the body, the notch forming a bed extending between the first end and the second end; a first sample region formed by the bed, the first sample region, comprising: a first plurality of ridges , wherein each of the first plurality of ridges comprises: a flank extending from the bed toward the mandrel body second end, the flank terminating at a crest ; and a concave slope descending from the crest; a second sample region formed by the bed, the second sample region comprising: a second plurality of ridges , wherein each of the second plurality of ridges comprises: a flank extending from the bed toward the mandrel body second end, the flank terminating in a crest ; and a concave slope descending from the crest; a deck disposed between the first plurality of ridges and the second plurality of ridges. a cannula , comprising: a body extending between a first end and a second end , the body having a first side and an opposite second side ; and a leading edge formed by the first end, the leading edge extending along a first plane, the first plane extending between the first side and second side, the first plane forming a leading edge angle between the intersection of the first side and the first plane; a body extending between a first end and a second end , the body having a first side and an opposite second side ; and a leading edge formed by the first end, the leading edge extending along a first plane, the first plane extending between the first side and second side, the first plane forming a leading edge angle between the intersection of the first side and the first plane; a mandrel , comprising: a body extending between a first end and a second end along a central longitudinal axis; a notch formed by the body, the notch forming a bed extending between the first end and the second end; a body extending between a first end and a second end along a central longitudinal axis; a notch formed by the body, the notch forming a bed extending between the first end and the second end; a first sample region formed by the bed, the first sample region, comprising: a first plurality of ridges , wherein each of the first plurality of ridges comprises: a flank extending from the bed toward the mandrel body second end, the flank terminating at a crest ; and a concave slope descending from the crest; a second sample region formed by the bed, the second sample region comprising: a second plurality of ridges , wherein each of the second plurality of ridges comprises: a flank extending from the bed toward the mandrel body second end, the flank terminating in a crest ; and a concave slope descending from the crest; a second plurality of ridges , wherein each of the second plurality of ridges comprises: a flank extending from the bed toward the mandrel body second end, the flank terminating in a crest ; and a concave slope descending from the crest; a deck disposed between the first plurality of ridges and the second plurality of ridges. <EOS>