JP2006280638A - Travelling capsule - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small travelling capsule which can stably advance and also can smoothly move by shaping a waveform input to a coil. <P>SOLUTION: The travelling capsule is constituted in such a way that a permanent magnet is arranged in the capsule so that the magnet can reciprocate like a piston, AC current is made to flow through the coil arranged surrounding the magnet to cause the magnet to perform piston action, and the capsule travels in a fixed direction utilizing inertia reaction generated by the piston action. In this travelling capsule, output of the positive side and output of the negative side of the AC current to input to the coil is varied using a power operation amplifier. Thus, force of pushing the magnet out is adjusted to be strong and force of pulling the magnet back into the coil is adjusted to be weak. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an elongated tube having a curved portion, for example, a capsule that can freely run inside a human digestive tract.

  Since the human digestive tract is a flexible, curved, elongated tubular body, it is very difficult to observe the inside from the mouth or anus using an endoscope or a sonde scope. For this purpose, a self-propelled device with an independent moving mechanism in the main body and a device with a method of operating the moving means provided in the main body from the outside have been proposed, and so far it has been displaced in different directions. The two movable legs that move, the vibration generating member that can expand and contract in the direction of the moving axis, and the main body move forward and backward in the direction of the moving axis, and one of the two movable legs comes into contact with the vagina wall An automatic traveling capsule device including a blocking member and a driving unit for preventing (see Patent Document 1), a capsule endoscope device including an imaging unit for observing the inside of a body and a power supply unit for supplying energy, a part of which A fixing means for fixing the inside of the body cavity, the imaging means being connected to the imaging means by a flexible cable so that the imaging means can move forward and backward with respect to the fixing portion in the body cavity (see Patent Document 2), Movable in the lumen A medical device including a traveling device and a treatment path connected to the self-propelled device so that at least a part of the lumen can be accessed from outside the patient's body via the self-propelled device (see Patent Document 3) ) Etc. are known.

  On the other hand, as an example of a micromechanism device operated from the outside, two mechanical vibration means having different resonance frequencies and acoustic energy having the same frequency as any one of these resonance frequencies are sequentially emitted from the outside. A micro-mechanism device (see Patent Document 4) is known that resonates and excites independent vibration displacements, determines the direction and speed of self-running, and moves by remote control.

  However, each of these devices has a complicated structure, and it cannot be recognized that sufficient consideration has been given to downsizing of the device. Therefore, many of these devices must be further solved in practical use. There is a problem.

JP-A-5-212093 (Claims and others) JP-A-7-289504 (Claims and others) JP 2003-299613 A (Claims and others) JP-A-6-154191 (Claims and others)

  The inventors of the present invention applied a sinusoidal alternating current to a coil previously fixed in a capsule, a dry reaction force when a permanent magnet arranged in the coil performs a piston motion, an impact force on an inner wall, a running surface, A traveling capsule that travels with a combination of frictional forces between the outer surfaces of the capsule has been developed, and various studies have been conducted to further reduce the size of the capsule. In connection with this, it was found that the waveform during amplification was disturbed and the progress of the capsule was unstable.

  An object of the present invention is to provide a small traveling capsule that shapes the input waveform to such a coil, stabilizes the progress of the capsule, and further facilitates the movement of the capsule.

  The present inventors arrange a permanent magnet in a capsule so that the piston can reciprocate, cause an alternating current to flow through a coil arranged around the capsule, perform a piston motion, and use the generated inertial reaction force in a certain direction. As a result of various studies on the miniaturization of the traveling capsule to be driven, the amplification performed after the waveform was output by the function synthesizer was performed using a personal computer speaker until now, but this output waveform was confirmed by an oscilloscope. However, while it was remarkably disturbed, by using a power operational amplifier, it becomes a normal waveform, and by changing the output on the plus side and the output on the minus side, the force with which the magnet is pushed out is increased, and the coil By adjusting the force withdrawn back weakly, even if the traveling capsule is downsized, it can move smoothly. Headings, leading to completion of the present invention based on this finding.

  That is, according to the present invention, a permanent magnet is disposed in a capsule so that the piston can reciprocate, an alternating current is caused to flow through a coil disposed around the capsule, and a piston motion is performed. In a traveling capsule that travels to a coil, the AC current input to the coil is changed by using a power operational amplifier, and by changing the output on the positive side and the output on the negative side, the force with which the magnet is pushed out is increased, and the force that is pulled back into the coil A small traveling capsule characterized by being adjusted weakly is provided.

Next, the structure of the traveling capsule of the present invention will be described according to the attached drawings.
FIG. 1 is a cross-sectional view showing an example of the traveling capsule of the present invention, in which a cylinder 3 around which a coil 2 constituting an electromagnet is wound inside a capsule container 1 and a piston-shaped permanent magnet 4 reciprocating inside thereof. Is housed.

  In the space on the opposite side of the coil cylinder in the capsule, there is a space where the piston of the permanent magnet moves left and right, and a stopper is installed at the end. A cable for supplying power to the coil exits from one end of the capsule. The capsule is preferably formed so that its outer surface can move smoothly without causing friction with the contact surface.

  In order to run in the pipe using this device, an alternating current is passed from the cable so that the electromagnet and the permanent magnet interact with each other. Then, the permanent magnet reciprocates and the capsule travels with its inertial reaction force.

  In the case of an internal structure that is subject to right and left, the capsule also simply reciprocates, and on average, the displacement remains zero. However, because the internal structure is asymmetrical, the displacement caused by vibration is forward and backward. Differently, it proceeds in one direction due to these differences.

The capsule moving speed S at this time can be calculated by the following equation.
S = C _S・ K _S
C _S = [(2n + 1) − (n + 1) f] / {2 (n + 1) √ [(n + 1) f−1]}
K _S = √ [(a · f _r ) / 2M]
n = M / m
f = f _m / f _r
However,
S: Capsule moving speed C _S : Speed coefficient K _S : Capsule shape factor n: Capsule mass ratio M: Mass of capsule shell m: Mass of permanent magnet a: Magnet movable range f: Force acting on capsule Ratio f _m : Electromagnetic force due to magnet and coil f _r : Friction force generated between capsule and sample considered to be close to digestive tract

  In the traveling capsule of the present invention, the input waveform to the amplifier is used to increase the force by which the magnet is pushed out and to weaken the force pulled back into the coil by changing the output on the plus side and the minus side of the amplifier that amplifies the output. The positive side voltage and the negative side voltage can be changed, for example, by changing the positive side voltage of the input waveform to the amplifier to 4 V and the negative side voltage to -2 V, or by changing the application time of both.

  According to the present invention, it is possible to obtain a traveling capsule in which the smallest traveling capsule (30 mm in length) has been reduced to about a half.

  Next, the best mode for carrying out the present invention will be described by way of examples, but the present invention is not limited by these.

In the structure shown in FIG. 1, a traveling capsule having a diameter of 4 mm and a length of 15 mm was manufactured using a coil produced by winding a small magnet (φ: 1 mm, l: 6 mm) and a copper wire of φ0.05 mm 200 times. A power operational amplifier (TOSHIBA TA8407P) manufactured by Toshiba was used as an amplifier that amplifies the output waveform.
The result of observing this output waveform with an oscilloscope is shown in FIG. For comparison, an output waveform when amplified using a conventional personal computer speaker is shown in FIG.
Thus, the output waveform of the traveling capsule of the present invention shows a normal waveform, whereas the output waveform of the conventional traveling capsule is significantly disturbed.
Next, different pulse voltages are applied between 0 and 7V, and the measured travel distance is shown in FIG.

  Using the same amplifier as in Example 1, 4V on the positive side, 2V on the negative side under the conditions of 4V and 15Hz, so that the time to flow the duty ratio to the positive side and the time to flow to the negative side will be a ratio of 1: 3. When the travel capsule of Example 1 was moved, the speed was increased efficiently and stable travel was demonstrated.

  Since the running capsule of the present invention is small, it is useful, for example, for insertion into a human digestive tract and diagnosis and treatment.

Sectional drawing of an example of this invention traveling capsule. The output waveform figure from amplifier of this invention travel capsule. The output waveform figure from the amplifier of the conventional traveling capsule. The graph which shows the travel distance in the pulse voltage 0-7V of this invention travel capsule.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capsule container 2 Coil 3 Coiled cylinder 4 Piston-shaped permanent magnet

Claims (2)

  In a traveling capsule in which a permanent magnet is disposed in a capsule so that the piston can reciprocate, an alternating current is passed through a coil arranged around the permanent magnet to cause the piston to move, and the inertial reaction force is used to travel in a certain direction. By using a power operational amplifier to change the AC current input to the coil, the positive output and the negative output are changed to adjust the force with which the magnet is pushed out and the force withdrawn back into the coil. A small traveling capsule. The small traveling capsule according to claim 1, wherein the outer surface of the capsule is formed so as to be able to move smoothly without causing friction with the contact surface.

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