Brain ventricle cannula

Claim 1

A CANNULA FOR INSERTION INTO THE VENTRICLES OF THE BRAIN, THERE TO REMAIN AND PROVIDE FOR CONSTANT ACCESS WITHOUT ADDITIONAL TRAUMA, COMPRISING: A FLEXIBLE TUBE OF SUFFICIENT LENGTH TO EXTEND FROM THE SCALP INTO A LATERAL VENTRICLE OF THE BRAIN AND HAVING A UNIFORM INSIDE AND OUTSIDE DIAMETER IN ITS RELAXED CONDITION AND NOT ADAPTED TO BE CHANGED IN EITHER DIAMETER WHEN INSTALLED IN SITU, SAID TUBE BEING MADE MATERIAL PHYSICALLY AND CHEMICALLY COMPATIBLE WITH THE TISSUES OF THE BRAIN, SAID TUBE HAVING AN AXIS, A CLOSED FIRST END, A CLOSED CIRCUMFERENTIAL WALL, AN OPEN SECOND END, AN AXIAL PASSAGE CONNECTING THE ENDS, AND A PERFORATION THROUGH THE TUBE ADJACENT TO THE FIRST END AND CONNECTING THE PASSAGE WITH THE OUTSIDE OF THE TUBE; A DISK INTEGRAL WITH THE TUBE ADJACENT TO THE SECOND END THEREOF, WHICH DISK HAS A THICKNESS GREATER THAN THE WALL THICKNESS OF THE TUBE OVER A SUBSTANTIAL AREA ADJACENT TO ITS INTERSECTION WITH THE TUBE, WHEREBY TO PROVIDE A SUBSTANTIAL ABUTMENT MEANS TO LIMIT THE AXIAL MOVEMENT OF THE TUBE, SAID DISK BEING ADAPTED TO BEAR AND ABUT AGAINST THE SKIN ON THE OUTSIDE OF THE SKULL AND TO BE RETAINED THERETO SO AS TO DEFINE THE AXIS POSITION OF THE TUBE INSIDE THE SKULL; A RECESSED PLUG SEAT IN THE DISK SURROUNDING THE AXIAL PASSAGE ADJACENT TO THE SECOND END SAID SEAT HAVING A GREATER DIAMETER THAN THE INSIDE DIAMETER OF THE PASSAGE; AND A PLUG FLEXIBLY CONNECTED TO THE DISK AND ADAPTED TO SEAT UPON AND SEAL WITH THE PLUG SEAT SO AS TO CLOSE THE PASSAGE, SAID PLUG BEING REMOVABLE TO OPEN THE SAME.