PVP and PVA as in vivo biocompatible acoustic coupling medium
An vivo biocompatible and bio-excretable lubricant and ultrasound coupling fluid or gel comprising polyvinylpyrrolidone (PVP) and/or polyvinyl alcohol (PVA). The inventive couplant fluid or gel comprises polyvinylpyrrolidone and/or polyvinyl alcohol solutions in water to which humectants such as alkylene glycols and/or polyalkylene glycols are added to achieve desired tactile and drying characteristics. Additionally, such fluids and gels may be prepared by addition of organic and inorganic cross-linkers.
1 . An in vivo biocompatible ultrasound acoustic couplant or lubricant comprising:
at least one of 3-30 wt. % polyvinylpyrrolidone and 6-25 wt. % polyvinyl alcohol;
at least one of (alkylene glycol, polyalkylene glycol, and fats and esters thereof in an amount of 1-80 wt. %; and,
the balance water.
2 . The couplant or lubricant of claim 1 wherein said at least one of (alkylene glycol, polyalkylene glycol, and fats and esters thereof is included in an amount of 10-70 wt. %.
3 . The couplant or lubricant of claim 1 wherein said at least one of (alkylene glycol, polyalkylene glycol, and fats and esters thereof is included in an amount of 20-60 wt. %.
4 . The couplant or lubricant of claim 1 wherein the molecular weight of polyvinylpyrrolidone is in the range of 360,000-1,500,000 daltons.
5 . The couplant or lubricant of claim 1 wherein polyvinylpyrrolidone is included in an amount of 10-20 wt. %.
6 . The couplant or lubricant of claim 1 wherein polyvinylpyrrolidone is included in an amount of 10-12 wt. %.
7 . The couplant or lubricant of claim 1 wherein polyvinyl alcohol is included in an amount of 9-15 wt. %.
8 . The couplant or lubricant of claim 1 wherein said alkylene glycol comprises propylene glycol.
9 . The couplant or lubricant of claim 1 wherein said polyalkylene glycol comprises polyethylene glycol.
10 . The couplant or lubricant of claim 1 wherein the polyethylene glycol has a molecular weight of 300.
11 . The couplant or lubricant of claim 1 wherein said at least one of (alkylene glycol, polyalkylene glycol, and fats and esters thereof comprises two or more carbon atoms.
12 . The couplant or lubricant of claim 11 wherein said at least one of (alkylene glycol, polyalkylene glycol, and fats and esters thereof comprises 2-6 carbon atoms.
13 . The couplant or lubricant of claim 1 comprising:
15 wt. % polyvinyl alcohol;
20 wt. % propylene glycol; and,
the balance water.
14 . The couplant or lubricant of claim 1 comprising:
12 wt. % polyvinylpyrrolidone;
55 wt. % propylene glycol;
5 wt. % polyethylene glycol;
the balance water.
15 . The couplant or lubricant of claim 1 comprising:
10 wt. % polyvinylpyrrolidone;
55 wt. % propylene glycol;
5 wt. % polyethylene glycol;
the balance water.
16 . The couplant or lubricant of claim 1 comprising:
9 wt. % polyvinyl alcohol
3 wt. % polyvinylpyrrolidone;
20 wt. % propylene glycol;
the balance water.
17 . The couplant or lubricant of claim 1 being non cross-linked.
18 . The couplant or lubricant of claim 1 being sterilized.
19 . The couplant or lubricant of claim 1 being in the form of a liquid or gel.
20 . The couplant or lubricant of claim 1 wherein said water is pyrogen free water.
21 . The couplant or lubricant of claim 1 wherein the molecular weight of polyvinylpyrrolidone is in the range of 40,000-54,000 daltons.