Patent ID: 8852156

Claim:
A stylet capable of being inserted into a catheter, the catheter having a catheter lumen, a tip, and a plurality of side holes, wherein the side holes are located in a working area of the catheter, the stylet comprising: a shaft having a proximal end and a distal end; and a lumen blocking portion at the proximal end of the shaft, wherein the lumen blocking portion has an outer surface approximately flush with the catheter lumen in the working area of the catheter, wherein the outer surface of the lumen blocking portion has a first effective stylet diameter that is 90-99% of the catheter lumen diameter, wherein the lumen blocking portion has a length capable of covering at least one side hole in the plurality of side holes when the catheter is inserted through a specified volume of tissue, and wherein the covering of at least one side hole is capable of reducing tissue accumulation in a side hole in the plurality of side holes when the catheter is inserted through the specified volume of tissue; wherein the shaft has a second effective stylet diameter distal to the lumen blocking portion, and wherein the second effective stylet diameter is less than the first effective stylet diameter, and wherein the shaft has a rigidity which enables the catheter to penetrate the specified volume of tissue; wherein the tissue is live tissue chosen from the group consisting of the brain, central nervous system, fat, muscle, connective tissue, lung, liver, pancreas, uterus, trachea, esophagus, stomach, intestines, colon, pleura, chest wall, and kidneys.