Patent EA-002041-B1 (EA)
Title: Continuous ligation kit
Inventor: HIGUMA MASATO
IPC: A61B17/12
Filed: 1999-08-20
Abstract: 1. A successive ligation instrument for ligating a lesion by charging a fluid into a distal device attached to an endoscope to apply pressure in order to push forward and separate two or more ligating rings attached to the distal device, the ligation instrument comprising: a pressure applying means for charging the fluid into the distal device; a fluid circuit arranged between the distal device and the pressurizing device; a controller connected to the fluid circuit to control the movement of the ligating ring, wherein the controller senses a pressure drop that occurs in the distal device when one or a plural number of the ligating rings are separated from the distal device, and wherein the movement of the ligating rings is stopped in accordance with the pressure drop so that a certain number of the ligating rings are separated. 2. The successive ligation instrument according to claim 1, wherein the pressure applying means is either a manual pressure applying means or an automatic pressure applying means. 3. The successive ligation instrument according to any one of claims 1 and 2, comprising one of a pressure releasing valve for selectively opening and closing a portion between the interior and exterior of the fluid circuit in accordance with an electric control signal and a pressure blocking valve for selectively opening and closing a portion between the interior of the fluid circuit and the pressure applying means in accordance with an electric control signal, wherein the pressure in the fluid circuit is decreased by controlling one of the pressure releasing valve and the pressure blocking valve to stop the movement of the ligating rings. 4. The successive ligation instrument according to claim 3, wherein the pressure releasing valve and the pressure blocking means is formed by an electromagnetic valve or a pinch valve. 5. The successive ligation instrument according to any one of claims 1 to 4, wherein the fluid is a liquid. 6. The successive ligation instrument according to any one of claims 1 to 5, wherein the distal device includes an inner tube for guiding the movement of the ligating rings. 7. The successive ligation instrument according to claim 6, wherein a slightly projected portion is arranged on the peripheral surface at the distal portion of the inner tube of the distal device to provide resistance to the movement of the ligating rings. 8. The successive ligation instrument according to claim 7, wherein the slightly projected portion is ring-like. 9. The successive ligation instrument according to any one of claims 6 to 8, wherein the distal portion of the inner tube of the distal device has a tapered hood. 10. The successive ligation instrument according to any one of claims 1 to 9, wherein the controller includes a sensing means for sensing a pressure drop in the fluid circuit. 11. The successive ligation instrument according to claim 10, wherein the sensing means includes a balloon expanded and contracted in accordance with the pressure in the fluid circuit, and wherein a pressure drop is sensed by measuring an interior pressure fluctuation of the balloon. 12. The successive ligation instrument according to claim 11, wherein the balloon has a connecting portion for connection with the fluid circuit, and wherein the connecting portion is funnel-like. 13. The successive ligation instrument according to claim 10, wherein the sensing means includes a hermetic chamber connected to the fluid circuit and a piston body moved in accordance with the pressure in the hermetic chamber, and wherein an interior pressure fluctuation of the hermetic chamber is measured based on the movement of the piston body. 14. The successive ligation instrument according to claim 10, wherein the sensing means includes a pressure sensor connected to the fluid circuit. 15. The successive ligation instrument according to any one of claims 1 to 14, wherein the controller includes a waveform processing portion having a differentiating circuit and a comparator circuit for converting the sensed pressure drop to an electric signal. 16. The successive ligation instrument according to any one of claims 1 to 15, wherein the controller includes a calculating means for processing the sensed pressure drop within a predetermined time in accordance with the timing of the successive separations of the ligating rings.