# US 2019/0167907 A1 · Syringe for administering foam > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0167907 A1 - Document ID: US20190167907A1 - Status: Published application - Kind: A1 - Application number: 16/320,599 - Filed: 2017-07-20 - Published: 2019-06-06 - Earliest claimed: 2016-07-26 - Assignees: Provensis Limited - Applicants: Provensis Limited - Inventors: David FAULKNER; Daniel ISLER - Web page: https://patentgrep.com/patent/US20190167907A1 ## CPC - A61M 5/315: Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod {or piston}; Appliances on the rod for facilitating dosing {; Dosing mechanisms} - A61B 17/00491: {Surgical glue applicators} - A61B 17/12181: {formed by fluidized, gelatinous or cellular remodelable materials, e.g. embolic liquids, foams or extracellular matrices} - A61M 5/178: Syringes - A61M 5/1782: {Devices aiding filling of syringes in situ (combination of a vial and a syringe for transferring or mixing their contents A61J1/2096, filling of medical containers in general B65B3/003)} - A61M 5/3129: {Syringe barrels (A61M5/3205, A61M5/50 take precedence)} - A61M 5/3148: {Means for causing or aiding aspiration or plunger retraction} - A61M 5/34: Constructions for connecting the needle {, e.g. to syringe nozzle or needle hub (connecting catheter tubes to hubs A61M25/0014)} - A61M 2005/3114: {Filling or refilling} - A61M 2005/3123: {having air entrapping or venting means, e.g. purging channels in pistons} - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract Syringes which are suitable for dispensing and injecting medical foams for sclerotherapy are described and claimed. The syringes of the invention comprise a syringe barrel having a nozzle and a bore to receive a syringe plunger; a syringe plunger defined by a front end and a rear end connected by a tubular walls and having an internal hollow duct between the front end and the rear end, and through which foam can flow; and an injectate chamber formed by insertion of the front end of the plunger into the barrel. The syringes comprise a flow-disruptor arranged to modify the flow of foam as it enters the injectate chamber. In certain embodiments the syringes comprise waste chambers which capture and retain poor quality foam. The syringes are particularly useful for dispensing foams made with little or no nitrogen content and are configured to reduce the risk of air contamination during dispensing the foam. Kits comprising the syringes together with a suitable source of foam and methods of dispensing foam form further aspects of the invention. ## Claims ### Claim 1 A syringe for dispensing injectable foam comprising: a syringe barrel having a nozzle and a bore to receive a syringe plunger; a syringe plunger defined by a front end and a rear end connected by a tubular walls and having an internal hollow duct between the front end and the rear end, and through which foam can flow; and an injectate chamber formed by insertion of the front end of the plunger into the barrel, and which comprises a flow-disruptor arranged to modify the flow of foam as it enters the injectate chamber. ### Claim 2 (depends on 1) The syringe according to claim 1 wherein the flow disruptor is a panel arranged to divert flow of foam radially outwards from the point at which it enters the injectate chamber. ### Claim 3 (depends on 2) The syringe according to claim 2 wherein the panel is disc shaped and is a baffle, a diffuser, a duck-bill valve or an umbrella valve. ### Claim 4 (depends on 1) The syringe according to claim 1 wherein the syringe is provided with the plunger partially withdrawn from the barrel to create an injectate chamber of a volume that corresponds to the maximum volume of foam to be injected. ### Claim 5 (depends on 1) The syringe according to claim 1 wherein the internal hollow duct comprises a one-way valve, which prevents foam from travelling out of the aperture in the rear end of the plunger. ### Claim 6 (depends on 1) The syringe according to claim 1 wherein the front end of the plunger has tapered edges which extend radially outwards from the aperture and axially towards the syringe nozzle. ### Claim 7 (depends on 1) The syringe according to claim 1 further comprising a vented waste chamber which allow air to pass through but retains foam. ### Claim 8 (depends on 7) The syringe according to claim 7 wherein the waste chamber comprises a transparent window which becomes opaque when the waste chamber is full of foam. ### Claim 9 (depends on 7) The syringe according to claim 7 wherein the waste chamber is external to the syringe but connected through the nozzle such that the syringe is filled with foam through the rear end of the plunger to displace air through the waste chamber and fill the injectate chamber after the waste chamber has been filled with foam. ### Claim 10 (depends on 7) The syringe according to 8 claim 7 wherein the waste chamber is present within the internal hollow duct of the syringe plunger such that the syringe in filled with foam through the syringe nozzle. ### Claim 11 (depends on 1) A kit for dispensing medical grade injectable foam comprising a syringe according to claim 1 and a source of foam. ### Claim 12 (depends on 11) The kit according to claim 11 wherein the source of foam is a pressurised canister containing liquid sclerosing agent and gas under pressure. ### Claim 13 (depends on 1) A method of dispensing foam comprising: connecting the syringe according to claim 1 to a source of foam; and dispensing a continuous flow of foam into the syringe from the source, whereby the flow of foam displaces air through the waste chamber, fills or substantially fills the waste chamber with foam and fills the injectate chamber after the waste chamber has been filled. ### Claim 14 (depends on 2) The syringe according to claim 2 wherein the syringe is provided with the plunger partially withdrawn from the barrel to create an injectate chamber of a volume that corresponds to the maximum volume of foam to be injected. ### Claim 15 (depends on 3) The syringe according to claim 3 wherein the syringe is provided with the plunger partially withdrawn from the barrel to create an injectate chamber of a volume that corresponds to the maximum volume of foam to be injected. ### Claim 16 (depends on 8) The syringe according to claim 8 wherein the waste chamber is external to the syringe but connected through the nozzle such that the syringe is filled with foam through the rear end of the plunger to displace air through the waste chamber and fill the injectate chamber after the waste chamber has been filled with foam. ### Claim 17 (depends on 8) The syringe according to claim 8 wherein the waste chamber is present within the internal hollow duct of the syringe plunger such that the syringe in filled with foam through the syringe nozzle.