Viscosity and stability modified ultrasound gel

Abstract

An ultrasound gel is provided for use with internal ultrasound imaging and/or therapy. The gel can have acoustic properties that can closely match a soft tissue to be imaged/treated and can be of a high viscosity that is maintained at body temperature. In some embodiments, the gel can act as a lubricant and, although water based, can be hydrophobic and not dissolve in bodily fluids. In some embodiments, the gel can be sterile, safe for ingestion, safe for application over mucous membranes, and include a preservative. In order to achieve sterility while maintaining a desired viscosity range, the gel can include a viscosity stabilising agent such as a viscosity protection agent for protection from radiation induced breakdown. In some embodiments, methods of altering or maintaining the viscosity of a gel is provided.

1 . An internal gel comprising:
 water;   a thickening agent for thickening the water into a gel;   a neutralizer for setting the gel viscosity and adjusting a pH level of the gel;   a viscosity agent for reducing changes of gel viscosity due to radiation exposure; and   a preservative for preserving the gel;   wherein the gel has an acoustic impedance similar to soft tissue and can be safely used internally or orally.   
     
     
         2 . The gel of  claim 1  wherein i, the viscosity agent comprises nanoparticles. 
     
     
         3 . The gel of  claim 1  wherein in the viscosity agent comprises CNC. 
     
     
         4 . The gel of  claim 1  wherein the viscosity agent comprises glycerin. 
     
     
         5 . The gel of  claim 1  wherein the thickening agent comprises a carbomer. 
     
     
         6 . (canceled) 
     
     
         7 . The gel of  claim 5  wherein the carbomer comprises carbomer homopolymer Type B. 
     
     
         8 . The gel of  claim 1  wherein the neutralizer comprises a base selected from the group consisting of potassium hydroxide, sodium hydroxide, and triethanolamine. 
     
     
         9 . The gel of  claim 1  wherein the pH level of the gel is between 5.8 and 6.4. 
     
     
         10 . The gel of  claim 1  wherein the preservative comprises a food grade preservative. 
     
     
         11 . The gel of  claim 1  wherein the preservative comprises potassium sorbate. 
     
     
         12 . The gel of  claim 1  further comprising a dental agent for inhibiting growth of dental microorganisms. 
     
     
         13 . The gel of  claim 12  wherein the dental agent is a sugar alcohol. 
     
     
         14 . The gel of  claim 13  wherein the sugar alcohol is xylitol. 
     
     
         15 . The gel of  claim 1  further comprising a colourant for colouring the gel. 
     
     
         16 . (canceled) 
     
     
         17 . A method of treating a tissue with ultrasound, the method comprising:
 providing an ultrasound treatment apparatus, the apparatus comprising a transducer for emitting ultrasound;   applying the gel of  claim 1  between the transducer and the tissue to be treated;   positioning the transducer proximate the tissue to be treated; and   emitting ultrasound through the gel to treat the tissue.   
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . The method of  claim 17  wherein the viscosity agent comprises nanoparticles. 
     
     
         21 . The method of  claim 20  wherein the viscosity agent comprises CNC. 
     
     
         22 . The method of  claim 17  wherein the viscosity agent comprises glycerin. 
     
     
         23 - 29 . (canceled) 
     
     
         30 . A use of the gel of  claim 1  to alleviate symptoms of dry mouth. 
     
     
         31 . The method of  claim 17  wherein the thickening agent comprises a carbomer.