# Catheter System for Opening and Closing Body Passages > This 1980 patent describes a medical catheter system with a guide catheter and a special dilatation catheter that can expand to open or close body passages, like blood vessels. - **Patent:** US 4195637 - **Original title:** Catheter arrangement, method of catheterization, and method of manufacturing a dilatation element - **Owner:** Schneider Medintag AG - **Granted:** 1980 - **Status:** Public domain (expired) - **Times cited:** 256 - **Field:** medical_devices, biotech, pharmaceutical ## What it does This patent details a medical device system for procedures like angioplasty. It involves two main parts: a guide catheter and a dilatation catheter. The dilatation catheter has a special expandable tip, called a dilatation element, which has two separate internal channels (lumens). One channel is for injecting fluid to open up a passage or cavity, and the other is for inflating the dilatation element itself to a specific size. The guide catheter is designed to be stiff and allow for twisting (torsional forces) to help steer it. The dilatation element is described as having a foldable wall that can expand to a predetermined shape and diameter when pressurized. An example use would be to insert this system into a narrowed blood vessel, position the dilatation element at the blockage, and then inflate it to widen the vessel. ## What it does NOT cover - Catheter systems where the dilatation element is not foldable or pre-shaped. - Catheter systems that do not have two distinct lumens within the dilatation element. - Catheter systems where one lumen is not used for inflating the dilatation element. - Catheter systems where the guide catheter cannot transmit torsional forces. - Catheter systems without a marking element for X-ray localization. ## The clever bit The innovation lies in the dual-lumen design of the dilatation element, allowing simultaneous inflation of the balloon and delivery of fluid to the target site, all guided by a specially reinforced catheter for better control during complex navigation. ## Real-world examples 1. Balloon angioplasty catheters 2. Percutaneous transluminal coronary angioplasty (PTCA) devices ## Why it matters This patent is foundational for minimally invasive cardiovascular procedures, particularly angioplasty. It describes the core components and mechanism for balloon catheters used to open blocked arteries, a technique that revolutionized cardiac care and continues to be a cornerstone of treating heart disease. ## Frequently asked questions ### What does Catheter System for Opening and Closing Body Passages cover? This 1980 patent describes a medical catheter system with a guide catheter and a special dilatation catheter that can expand to open or close body passages, like blood vessels. ### Who owns patent US 4195637? Schneider Medintag AG owns this patent, granted in 1980. ### When does this patent expire? This patent has expired and is now in the public domain — anyone can use the invention freely. ### What is patent US 4195637 cited by? This patent has been cited by 256 later patents that build on its ideas. ### What problem does this patent solve? This patent is foundational for minimally invasive cardiovascular procedures, particularly angioplasty. It describes the core components and mechanism for balloon catheters used to open blocked arteries, a technique that revolutionized cardiac care and continues to be a cornerstone of treating heart disease. ### What does this patent NOT cover? Catheter systems where the dilatation element is not foldable or pre-shaped. **Full plain-English explainer:** https://patentbrief.org/patent/us/4195637/balloon-angioplasty-catheter-gruentzig **Original patent:** https://patents.google.com/patent/US4195637 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How Doctors Implant a Permanent Stent Using a Balloon](https://patentbrief.org/patent/us/4733665/palmaz-balloon-expandable-stent) — This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open. - [How Early CT Scans Created Detailed Body Images](https://patentbrief.org/patent/us/3778614/ct-scanner-hounsfield) — This 1973 patent describes a method for using X-rays from many angles to build a detailed 2D image of the inside of a body, like a slice of a CT scan. - [How Auto-Injectors Adjust Their Dose Using a Simple Spacer](https://patentbrief.org/patent/us/4031893/epipen-autoinjector-kaplan) — A 1977 invention for auto-injectors that uses a physical spacer to adjust the amount of medicine inside the device before it is fired. - [Leonarde Keeler's Early Mechanical Blood Pressure Recorder](https://patentbrief.org/patent/us/1788434/polygraph-lie-detector-keeler) — A 1925 invention by Leonarde Keeler designed to mechanically record a patient's arterial blood pressure over time. - [How the First Heart-Lung Machine Oxygenated Blood](https://patentbrief.org/patent/us/2702035/heart-lung-machine-gibbon) — A 1955 invention that allowed surgeons to oxygenate a patient's blood outside the body, enabling the first successful open-heart surgeries.