Tip adjustable stylet

A stylet configured to be inserted inside of a tubular structure and to be pushed out a tubular structure distal aperture to form one or more curves comprising:

• (a) a rod, wherein the rod comprises a proximal segment and a distal segment, wherein the distal segment comprises a bendable segment and a tip segment, wherein the proximal segment has a proximal segment end and a proximal segment distal end, wherein the bendable segment has a bendable segment proximal end and a bendable segment distal end, wherein the proximal segment distal connects with the bendable segment proximal end and forms a first bendable junction, wherein the first bendable junction is configured to bend when a bending force is applied, and wherein said bendable junction being pushed outside of the tubular structure distal aperture is configured to be bend readily, wherein the tip segment having a tip segment proximal end and a tip distal curved region distally, wherein right or left side the tip segment is coupled to the bendable segment by a bendable side connection, wherein said bendable side connection is configured to be bend under a force;
• (b) a retracting string, wherein the retracting string is configured as the coiled-like or spring-like or wave-like extensible and compressible structure which is extensible under an external force and has a retracting string proximal end and a retracting string distal end;
• wherein the retracting string distal end is coupled to the distal end or near the distal end of the bendable segment of the rod, wherein at the proximal end of the retracting string includes a string hook, wherein the string hook is configured to couple to the retracting string proximal end and configured to engage the proximal opening of the tubular structure when the rod is moved distally, wherein the retracting string is configured to generate a retracting force when the retracting string is tauten and elongated and therefore to hold the bendable segment of the rod backward when the rod is being pushing forward, and thereby forming one or more curves along the bendable segment of the rod;
• (c) a second retracting string, wherein the second retracting string is a short segment string and has a second string's first end and a second string distal end, wherein the second string distal end couples to the tip segment proximal end, wherein the second string first end couples to the retracting string and divides the retracting string as string distal filament and a string proximal filament, therefore when the string proximal filament is being pulled the pulling force can be transmitted to the second string to pull the tip segment proximal end.

The stylet to be inserted inside of a tubular structure and to be pushed out a tubular structure distal aperture comprising:

• (a) a rod comprising a proximal segment and a distal segment, wherein the distal segment includes a bendable segment and a tip segment, wherein the proximal segment includes a proximal end and a distal end, wherein the bendable segment has a bendable segment proximal end and a bendable segment distal end, wherein the distal end of the proximal segment connects with the bendable segment proximal end and forms a first bendable junction, wherein the first bendable junction is configured to be able to bend when a bending force applied, and wherein the bendable segment is configured to be pushed further out of the tubular structure distal aperture, and wherein said first bendable junction upon being pushed outside of the tubular structure distal aperture is configured to be bent readily, wherein the bendable segment distal end connects to the tip segment and forms a wave like shaped the distal segment of the rod;
• (b) a retracting string configured as the coiled-like or spring-like or wave-like extensible and compressible structure which is extensible under an external force, wherein the retracting string has a retracting string proximal end and a retracting string distal end;
• wherein the retracting string distal end of the retracting string is configured to attach to the tip segment of the rod, wherein at the retracting string proximal end includes a docking device, wherein the docking device is configured in such way to couple the retracting string proximal end to the proximal aperture of the tubular structure when the bendable member is moving distally, wherein the retracting string is configured to generate a retracting force when the retracting string is tauten and elongated therefore pulls the tip segment down when the rod is pushing forward and thereby forming curvatures along the bendable segment of the rod.