Position measuring device for endoscope

Abstract: A plurality of arms are successively connected to a fixed arm (2) so that the front end of the connected arms is movable three-dimensionally, a direct-access endoscope (13) is attached to the three-dimensionally movable front end of the arms, and angle sensors (8,9,10,11,12) are provided in the individual arm joints. Changes in angles between the individual arms due to the movement of the front end of the direct-access endoscope are sensed by the angle sensors, and the size and position of the object are numerically determined according to the changes.

Description: This invention relates to a measuring device, comprising: (a) a plurality of arms successively connected to a fixed arm so that a front end of the connected plurality of arms is movable three-dimensionally; (b) angle sensors provided in individual arm joints; and (c) a computer to which the length of the individual arms previously measured and the angles sensed by the angle sensors are inputted. Furthermore, this invention relates to a measuring method, comprising: (a) measuring the length of a plurality of arms successively connected to a fixed arm so that a front end of the connected plurality of arms is movable three-dimensionally; (b) measuring the angles between the individual arms by angle sensors connected to individual joints; and (c) inputting to a computer the length of the individual arms previously measured and the angles sensed by the angle sensors. A measuring device and method of the aforementioned types are described in US-A-4 763 652 using an ultrasonic sensor attached to the free end of the plurality of the connected arms for measuring the position of a kidney stone and the like. Heretofore, various types of endoscopes have been used for observing spaces in the human body, that is, the inner surface of hollow organs and the inside of the thoracic cavity and abdominal cavity. The endoscope plays an important role in diagnosis since it enables visual observation of inside of the body from outside. However, endoscopes, although having advantages of enabling direct visual identification of the presence and shape of an object within the body such as tumors, have had inconveniences in that they cannot numerically measure the size and position of the observed object. For example, the size of a tumor observed by the endoscope is largely affected by the distance between the tumor and the endoscope, and detailed and objective data cannot be obtained. It is a primary object of the present invention to provide a device for observing an object using an endoscope and numerically measuring the size and position of the object. Disclosure of the Invention In accordance with the present invention, there is provided a measuring device of the type mentioned in the beginning, which is characterized in that (1) a direct-access endoscope is connected to the front end of the connected arms; (2) the computer comprises means for storing the length of the direct-access endoscope previously measured; and (3) the computer further comprises means for numerically determining the three-dimensional positions of the front end of the endoscope from the lengths of the individual arms, the angles between the individual arms and the length of the direct-access endoscope and thereby to determine the numerical size and/or position and/or area and/or distance from a specific portion of an object observed by the endoscope. Furthermore, in accordance with the present invention, there is provided a measuring method of the type mentioned in the beginning, which is characterized by (1) measuring the length of a direct-access endoscope connected to the front end of the arms; (2) inputting the length of the direct-access endoscope previously measured to the computer; (3) numerically determining the three-dimensional positions of the front end of the endoscope and/or the numerical size and/or position and/or area and/or distance by the computer from a specific portion of an object observed by the endoscope by: (i) aligning the front end of the endoscope with one portion of the object to be measured and calculating the numerical three-dimensional position of that one portion; (ii) aligning the front end of the endoscope with another portion of the object to be measured or a specific portion and calculating the numerical three-dimensional position of that portion; (iii)possibly repeating the steps (i) and (ii) for measuring the three-dimensional position of further portions of the object to be measured and/or the three-dimensional position of a specific portion; and (iv) calculating the numerical size and/or area and/or position of said object and/or the numerical distance of said object from said specific portion. To make the front end of the arms after connection movable three-dimensionally, the plurality of arms are successively connected to the fixed arm using at least one joint which is rotatable in the horizontal direction relative to the vertical axis of arm and at least one joint which is rotatable in the vertical axial direction. Alternatively, to make the front end of the arms movable three-dimensionally, for example, two rails are individually provided with sliders, the sliders are connected by two rails, a base plate is slidable mounted to the rails connecting the sliders, and a vertically expandable, rotatable arm may be mounted under the base plate. Brief Description of the Drawing Fig.1 is a schematic view of the position measuring device for an endoscope according to the present invention. Best Mode for Practicing the Invention The present invention will now be described in detail with reference to Fig.1 showing an embodiment. In Fig.1, numeral 1 indicates a fixture, numeral 2 indicates a fixed arm, numerals 3, 4, 5, 6, and 7 indicate arms, numerals 8, 9, 10, 11, and 12 indicate angle sensors provided at individual arm joints, numeral 13 indicates a direct-access endoscope, numeral 13a indicates an ocular, and numeral 13b indicates a front end. The fixed arm 2 is mounted to the fixture 1. One end of the arm 3 is connected to the fixed arm 2 so that the arm 3 is rotatable in the horizontal direction relative to the vertical axis of the fixed arm 2. The other end of the arm 3 is connected to one end of the arm 4 so that the arm 4 is rotatable in the vertical axis direction of the arm 3. The other end of the arm 4 is connected to one end of the arm 5 so that the arm 5 is rotatable in the vertical axis direction of the arm 4. The other end of the arm 5 is connected to one end of the arm 6 so that the arm 6 is rotatable in the vertical direction of the arm 5. Furthermore, the other end of the arm 6 is connected to one end of the arm 7 so that the arm 7 is rotatable in the horizontal direction relative to the vertical axis of the arm 6. The rotatable connection is achieved using conventional means known in the art. The direct-access endoscope 13 is vertically attached to the other end of the arm 7, and the angle sensors 8, 9, 10, 11, and 12, which are of a conventional type known in the art, are attached to the individual joints. Since the individual joints between the fixed arm and the arm 3 and between the arm 6 and the arm 7 are rotatable in the horizontal directions relative to the vertical axes of the individual arms, and the individual joints between the arm 3 and the arm 4, between the arm 4 and the arm 5, and between the arm 5 and the arm 6 are rotatable in the vertical axis directions of the individual arms, the direct-access endoscope attached to the front end of the arm 7 is movable in all directions, that is, three-dimensionally. The movement, that is, changes in angle between the individual arms, is sensed and recorded by the individual angle sensors provided in the individual joints. The record is inputted to a computer. This example uses 5 movable arms, and 5 joints and angle sensors. It is preferable to use 5 or more arms and 5 each or more joints and angel sensors in order to achieve free movement of the direct-access endoscope in all directions. However, the relative positions between a joint rotatable in the horizontal direction relative to the vertical axis of an arm and a joint rotatable in the vertical axis direction of an arm are not specifically limited. A measurement method using the inventive measuring device will now be described. Viewing from the ocular 13a of the direct-access endoscope, position of the front end 13b of the direct-access endoscope is aligned with an object to be measured, for example, one end of a tumor. Individual angles between the fixed arm 2 and the arm 3, the arm 3 and the arm 4, the arm 4 and the arm 5, the arm 5 and the arm 6, and the arm 6 and the arm 7 are sensed by the angel sensors, and inputted to the computer to record a three-dimensional position (three-dimensional coordinates) of the front end 13b of the direct-access endoscope. A projection can be attached to the tip of the direct-access endoscope, which is brought in contact with the object to be measured, to achieve simple and precision measurement. Then, the front end 13b of the direct-access endoscope is moved to be aligned with the other end of the tumor. As the front end 13b moves, the individual arms move and angles between the individual arms are changed. The angles after movement are sensed by the angle sensors and inputted to the computer to record a three-dimensional position (three-dimensional coordinates) of the front end 13b of the direct-access endoscope after the movement. The lengths of the individual arms and the length of the direct-access endoscope are previously measured and inputted to the computer. The three-dimensional position (three-dimensional coordinates) of the front end of the direct-access endoscope can be determined from the previously-stored values and the angles between the individual arms. Then, an actual length from one end to the other of the tumor is calculated, using a conventional method known in the art, from the two three-dimensional positions (three-dimensional coordinates) of the front end 13b of the direct-access endoscope before and after the movement. This method can measure not only the size of the tumor but also its area and distance from a specific portion. The endoscope used in the present invention is of a direct-access type which uses a lens to observe an object from outside of the body, but a fiber scope used for observation of digestive canals is not suitable for the purpose. With the position measuring device for an endoscope according to the present invention, for example, a tumor in the human body can be observed for its shape and measured for its size, position, area and the like, and the results are obtained as numerical values.

Claims: A measuring device, comprising: (a) a plurality of arms (3 to 7) successively connected to a fixed arm (2) so that a front end of the connected plurality of arms (3 to 7) is movable three-dimensionally; (b) angle sensors (8 to 12) provided in individual arm joints; and (c) a computer to which the length of the individual arms (3 to 7) previously measured and the angles sensed by the angle sensors (8 to 12) are inputted; characterized in that (1) a direct-access endoscope (13) is connected to the front end of the connected arms (3 to 7); (2) the computer comprises means for storing the length of the direct-access endoscope (13) previously measured; and (3) the computer further comprises means for numerically determining the three-dimensional positions of the front end (13b) of the endoscope (13) from the lengths of the individual arms (3 to 7), the angles between the individual arms (3 to 7) and the length of the direct-access endoscope (13) and thereby to determine the numerical size and/or position and/or area and/or distance from a specific portion of an object observed by the endoscope (13). The measuring device of claim 1, characterized in that said plurality of movable arms (3 to 7) comprises at least five movable arms successively connected to one another. A measuring method, comprising: (a) measuring the length of a plurality of arms (3 to 7) successively connected to a fixed arm (2) so that a front end of the connected plurality of arms (3 to 7) is movable three-dimensionally; (b) measuring the angles between the individual arms by angle sensors (8 to 12) attached to individual joints; and (c) inputting to a computer the length of the individual arms (3 to 7) previously measured and the angles sensed by the angle sensors (8 to 12); characterized by (1) measuring the length of a direct-access endoscope (13) connected to the front end of the arms (3 to 7); (2) inputting the length of the direct-access endoscope (13) previously measured to the computer; (3) numerically determining the three-dimensional positions of the front end (13b) of the endoscope (13) and/or the numerical size and/or position and/or area and/or distance by the computer from a specific portion of an object observed by the endoscope (13) by: (i) aligning the front end (13b) of the endoscope (13) with one portion of the object to be measured and calculating the numerical three-dimensional position of that one portion; (ii) aligning the front end (13b) of the endoscope (13) with another portion of the object to be measured or a specific portion and calculating the numerical three-dimensional position of that portion; (iii)possibly repeating the steps (i) and (ii) for measuring the three-dimensional position of further portions of the object to be measured and/or the three-dimensional position of a specific portion; and (iv) calculating the numerical size and/or area and/or position of said object and/or the numerical distance of said object from said specific portion.

Inventors: HATANO TADASHI, HATANO, TADASHI
Applicants: HATANO TADASHI, HATANO, TADASHI
Application year: 1992
Main classification: A61B1
IPC codes: A61B1, G02B23