Medical Catheter with a Balloon Embedded in a Head

A medical catheter with a balloon (2) embedded in a head, comprising a catheter head (11), a catheter middle portion (12), a catheter tail (13);

• and
• a balloon (2) which consists of a balloon connecting portion (21) and a balloon free portion (22);
• wherein the catheter head (11) has a head recess (H110) for receiving the balloon free portion (22), and a head sidewall (H112) surrounding the head recess (H110);
• the balloon connecting portion (21) is sealed to the catheter head (11), the balloon (2) has an inner surface (23), an outer surface (24), a balloon chamber area (1103) enclosed by the outer surface (24), and a farthest endpoint (A);
• at least one part of the balloon free portion (22) is inserted into the head recess (H110), and the farthest endpoint (A) of the balloon free portion (22) is located in the head recess (H110);
• a lower gap (1102) is defined between the inner surface (23) of the balloon free portion (22) and the head sidewall (H112), a lower gap fluid passage (1105) communicates with the lower gap (1102);
• the balloon chamber area (1103), located in the head recess (H110) for containing a drug (D), is bag-like and has an opening (1106) toward an outside of the head recess (H110);
• when an external fluid enters the lower gap fluid passage (1105) and then enters the lower gap (1102), a volume of the lower gap (1102) will increase, and the external fluid will squeeze the inner surface (23) to decrease a volume of the balloon chamber area (1103);
• and, under the squeezing of the external fluid, the balloon chamber area (1103) disappears when the balloon free portion (22) completely bulges out from the head recess (H110) so as to release the drug (D) contained in the balloon chamber area (1103).