# US 5,700,252 A · Lumen-seeking nasogastric tube and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,700,252 A - Document ID: US5700252A - Status: Granted - Kind: A - Application number: 08/551,453 - Filed: 1995-11-01 - Granted: 1997-12-23 - Earliest claimed: 1995-11-01 - Inventors: Ralph James Klingenstein - Web page: https://patentgrep.com/patent/US5700252A ## CPC - A61M 25/0068: {Static characteristics of the catheter tip, e.g. shape, atraumatic tip, curved tip or tip structure} - A61J 15/0003: {Nasal or oral feeding-tubes, e.g. tube entering body through nose or mouth} - A61J 15/0026: {Parts, details or accessories for feeding-tubes (external tubes from medical containers to a connector outside of the body A61M39/08)} - A61M 25/008: {Strength or flexibility characteristics of the catheter tip} - A61J 15/0073: {Multi-lumen tubes} - A61M 25/0052: {Localized reinforcement, e.g. where only a specific part of the catheter is reinforced, for rapid exchange guidewire port} - A61M 25/0053: {having a variable stiffness along the longitudinal axis, e.g. by varying the pitch of the coil or braid} - A61M 2025/0081: {Soft tip} - 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)} - A61J: CONTAINERS SPECIALLY ADAPTED FOR MEDICAL OR PHARMACEUTICAL PURPOSES; DEVICES OR METHODS SPECIALLY ADAPTED FOR BRINGING PHARMACEUTICAL PRODUCTS INTO PARTICULAR PHYSICAL OR ADMINISTERING FORMS; DEVICES FOR ADMINISTERING FOOD OR MEDICINES ORALLY; BABY COMFORTERS; DEVICES FOR RECEIVING SPITTLE ## Abstract Disclosed is an improved nasogastric tube having a coupled or integrally formed flexible tip which facilitates insertion and advancement of the tube through a nasopharynx and into a stomach of a patient while reducing the risk of trauma to the nasal cavity and perforation of the esophagus and other soft tissue. Geometry and material of the tip and tube body are selected so that the tip preferentially buckles before the tube body upon meeting body structure during advancement of the tube. Buckling of the tip passively steers the tip and tube body through the nasal cavity along the esophageal lumen, unlike conventional nasogastric tubes which tend to displace or perforate proximate body structure. Tip geometries include those which are cylindrical, frustoconical, tapered, bulbous, pleated and necked. Tips may be hollow or solid, symmetrical or asymmetrical, and may include a reinforcement member to modify the column strength thereof. One or more transition zones may be provided to transition between tube structures having differing column strengths. ## Claims ### Claim 1 A nasogastric tube for insertion into a digestive system of a patient via a nasal cavity comprising: a flexible tube body configured to provide a first column strength, said tube body comprising: a sidewall defining a lumen; and a distal end portion; a tip coupled to said distal end portion along a transition zone, said tip configured to provide a second column strength, wherein said first column strength is greater than said second column strength so that said tip preferentially buckles before said tube body upon encountering body structure during insertion of said nasogastric tube to provide a lumen seeking function; and an aperture transecting at least one of said sidewall and said tip, said aperture being in fluid communication with said lumen. ### Claim 2 (depends on 1) The invention according to claim 1 wherein said tip comprises a member selected from the group consisting of cylindrical, frustoconical, tapered, bulbous, pleated, necked, solid, hollow, symmetric and asymmetric members and combinations thereof. ### Claim 3 (depends on 1) The invention according to claim 1 wherein said tip includes an end selected from the group consisting of radiused, truncated and spherical ends and combinations thereof. ### Claim 4 (depends on 1) The invention according to claim 1 wherein at least one of said first column strength and said second column strength varies respectively as a function of position along said tube body and said tip. ### Claim 5 (depends on 1) The invention according to claim 1 wherein said tip comprises at least two adjacent tip members, each member configured to provide a respective column strength and coupled to an adjacent member along a tip transition zone. ### Claim 6 (depends on 5) The invention according to claim 5 wherein said coupling of adjacent tip members comprises a male/female connection. ### Claim 7 (depends on 1) The invention according to claim 1 wherein said coupling of said tip to said body distal end portion comprises a male/female connection. ### Claim 8 (depends on 1) The invention according to claim 1 wherein said coupling of said tip to said body distal end portion comprises an inseparable assembly. ### Claim 9 (depends on 1) The invention according to claim 1 wherein said nasogastric tube further includes a reinforcement member disposed along said tip. ### Claim 10 (depends on 9) The invention according to claim 9 wherein said reinforcement member comprises a coiled wire. ### Claim 11 (depends on 9) The invention according to claim 9 wherein said reinforcement member is anchored in said sidewall. ### Claim 12 (depends on 1) The invention according to claim 1 wherein said nasogastric tube has a smoothly contoured external configuration along said transition zone. ### Claim 13 (depends on 1) The invention according to claim 1 wherein said tip is formed integrally with said body distal end portion. ### Claim 14 (depends on 1) The invention according to claim 1 wherein said tube body has a minimum external diameter of about 6 Fr. ### Claim 15 (depends on 1) The invention according to claim 1 wherein said nasogastric tube further includes a radiopaque marker. ### Claim 16 (depends on 15) The invention according to claim 15 wherein said radiopaque marker is disposed at least in said tip. ### Claim 17 (depends on 1) The invention according to claim 1 wherein said lumen is transected by a septum, along at least a portion thereof, said lumen being thereby divided into multiple lumens. ### Claim 18 (depends on 1) The invention according to claim 1 wherein said tube body further comprises at least two adjacent tube body sections, each section configured to provide a respective column strength and coupled to an adjacent section along a body transition zone. ### Claim 19 (depends on 18) The invention according to claim 18 wherein said coupling of adjacent sections comprises a male/female connection. ### Claim 20 (depends on 19) The invention according to claim 19 wherein said lumen passes through said male/female connection. ### Claim 21 A method for providing fluidic communication with a digestive system of a patient comprising the steps of: 1) providing a nasogastric tube comprising: a flexible tube body configured to provide a first column strength, said tube body comprising: a sidewall defining a lumen; and a distal end portion; a tip coupled to said distal end portion along a transition zone, said tip configured to provide a second column strength, wherein said first column strength is greater than said second column strength so that said tip preferentially buckles before said tube body upon encountering body structure during insertion of said nasogastric tube to provide a lumen seeking function; and an aperture transecting at least one of said sidewall and said tip, said aperture being in fluid communication with said lumen; 2) inserting said tip into a nostril of the patient; and 3) passively steering said tip into the digestive system by: a) advancing said nasogastric tube until said tip buckles upon encountering body structure; b) manipulating said nasogastric tube to bypass said body structure; and c) repeating substeps a) and b) until said aperture is disposed in a desired location in the digestive system. ### Claim 22 (depends on 21) The invention according to claim 21 wherein said tube manipulating substep includes a motion from the group consisting of advancing, retracting, dithering, and twisting motions and combinations thereof. ### Claim 23 A tip for coupling to a nasogastric tube body having a first column strength for insertion into a digestive system of a patient via a nasal cavity, said tip comprising: a flexible member configured to provide a second column strength less than said first column strength so that said flexible member preferentially buckles before said tube body upon encountering body structure during insertion to provide a lumen seeking function.