JP2587463B2 - Rotation measurement device for micro rotating body - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotation measuring device for a minute rotating body. More particularly, the present invention relates to a rotation measuring device for a microrotator, which measures and records the rotational motion of a microparticle such as a bacterium in a tethered cell state with good spatial and temporal resolution.

(Background Art) Bacteria move by rotating flagella by a so-called flagellar motor, and tethered cells (tethered cells) are a powerful system for examining the characteristics of the flagellar motor.
cell) is known.

As shown in FIG. 5, the tethered cell is obtained by fixing the flagella (a) of bacteria (a) to a glass plate (c). When the flagella are fixed in this manner, the bacteria (A) themselves rotate due to the torque of the flagellar motor, so that the characteristics of the flagellar motor can be examined by measuring the rotational movement.

In this case, as a device for measuring the rotational movement,
Micro bacteria (a) with a diameter of about 1 μm
It must be accurate enough to observe and record movements in Hz changing the direction of rotation from time to time. Further, it is required that the environment such as the temperature, brightness, and the holding solution of the bacteria (A) can be freely set. Conventionally, as a measuring device for such a minute rotating body, for example, a tracking microscope has been used.
There is known a device to which is applied.

This tracking microscope detects the position of the specimen and adjusts the positional relationship between the specimen and the microscope so that the enlarged image is always at the center of the field of view of the microscope even if the specimen moves. It was done. In a measuring device for a micro rotating body to which this is applied, the position of the bacteria (A) can be detected as follows. For example, as shown in FIG. 6, four optical sensors (a) to (d) are associated with a coordinate system of + X, -X, + Y, and -Y at a position where a real image (d) of a bacterium is obtained by a microscope. And detects the intensity of light incident on each optical sensor. Then, the relationship between the light intensity Ix, Iy in X or Y and the time t as shown in FIG. 7 is obtained, the rotation speed of the bacteria is obtained from the cycle, and the rotation fragrance can be obtained from the phase. .

As another rotation measuring device for a minute rotating body, a microscope image of bacteria (A) is taken on a video monitor, and the video signal is decomposed in X and Y directions using a mask with a gradient, and the same as above. In some cases, the rotational speed of bacteria is determined from the cycle of signals in the X and Y directions, and the rotational direction is determined from the phase.

However, in any of these conventional rotation measuring devices, there is a problem that the rotation direction cannot be determined unless the bacteria (a) rotate about half a turn, and the detection accuracy of the rotation position is low. Furthermore, in a rotation measuring device using a mask with a gradient, a signal passed through a video is processed, and the actual time resolution is as low as 1/30 to 1/60 sec.

(Object of the Invention) The present invention has been made in view of the above-described circumstances, improves the disadvantages of the conventional measuring device, and reduces the rotational motion of a micro-rotary body such as a tethered cell in a small rotation angle. It is an object of the present invention to provide a new rotation measuring device for a minute rotating body which can detect a position with high accuracy and with a superior time resolution.

(Disclosure of the Invention) In order to achieve the above object, the present invention has a light detection unit including a large number of optical fibers arranged in a circular shape and detecting a microscopic image of a minute rotating body, and a phase contrast microscope, Provided is a rotation measuring device for a minute rotating body, characterized in that the position is measured from the output value.

Hereinafter, the present invention will be specifically described with reference to the accompanying drawings.

Taking the position detection of the bacteria in the tethered cell as an example, as shown in FIG. 1, a large number of optical fibers (3) are arranged around the rotation center (2) of the real image (1) when the bacteria are enlarged by a microscope. ) Is disposed, and a microscopic image of bacteria is detected by each optical fiber (3).

In this case, 4 + 4n (0 <N) optical fibers (3) are arranged on the circumference as much as possible. As shown in FIG. 2, in this case, an end face (4) of the optical fiber (3) is used as a light receiving surface, and the received light is connected to the other end of the optical fiber (3). Can be used.

The number of optical fibers (3) is determined according to the required rotational angular resolution of the bacterium. By setting the number to, for example, 32, it becomes possible to achieve a remarkably superior resolution as compared with a device using a conventional tracking microscope. .

According to the present invention, for example, the rotational movement of bacteria is measured by using the optical fiber (3) group arranged as described above, and an enlarged image of the bacteria (1) is detected by a microscope for detection by the optical fiber (3). Or the method of calculating and recording the rotational movement from the value detected by the optical fiber (3) can be implemented by, for example, an apparatus configured as shown in the block diagram of FIG.

In the apparatus constructed according to the block diagram of FIG. 3, a magnified real image of the tethered cell using a microscope (1)
To form At this time, a phase contrast microscope is used as a microscope. In addition, it is preferable that the tethered cell installed in the phase contrast microscope be a flow set that allows the temperature and brightness of the chamber to be adjusted and allows the holding solution to be exchanged.

Next, with respect to the enlarged real image (1) of the bacterium, the XY stage is adjusted so that the rotation center of the bacterium image is located at the center of the detection unit composed of the optical fibers (3) arranged in a circumference. . Then, it is confirmed by an optical splitter, a video camera, a video deck, and a monitor that the position of the rotation center is exactly at a predetermined position. FIG. 4 shows a more specific arrangement. That is, a half mirror (8) is provided as an optical splitter between the optical path between the zoom lens (7) following the phase contrast microscope (6) and the light receiving surface of the optical fiber (3). Light from the light receiving surface of (3) is converted to a video camera (9)
The light is reflected in the direction, and the monitor (10) monitors the positional relationship between the enlarged real image of the bacteria and the optical fiber (3). Thus, in the case of only the phase contrast microscope (6), the chain line A
The bacterial image (1) observed as in (1) is observed as in the chain line B on the monitor (10).

The zoom lens (7) is used to match the size of the bacteria image with the size of the circle of the optical fiber (3) group. An intermediate variable power device that changes stepwise may be used.

The rotational movement of the bacteria is detected by using a large number of optical fibers (3) arranged in a circle in this manner. This detection signal is sent to the signal recording processor through the amplifier shown in FIG.

A personal computer or the like is used as the signal recording processing device, and the rotation speed and the rotation direction are calculated based on the period and the phase of the detection value from each of the plurality of optical fibers (3). Then, the display device displays the rotation speed, the rotation direction, or the current position.

There is no particular limitation on the time required for measuring the rotational movement of the bacteria and the sampling period of the detection signal of the movement. For example, the sampling period is 1 ms.
By setting c as the measurement time for 10 minutes, the rotation speed or rotation direction of the bacteria can be known with extremely high accuracy.

Of course, the present invention is not limited to bacteria, and can be applied to any micro rotating body.

(Effect of the Invention) According to the rotation measuring device of the present invention, as described in detail above, for example, a magnified real image of a microrotor such as bacteria in a tethered cell state is formed by a microscope, and the magnified real image is circumferentially formed. Since the detection is performed by a large number of optical fibers disposed, the rotational movement of the bacteria in the tethered cell state can be measured with high accuracy and high resolution even at a small rotation angle. Furthermore, the time resolution can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating the positional relationship between an optical fiber and a microscopic image of bacteria in the rotation measuring device of the present invention. FIG. 2 is a perspective view illustrating a light detection unit used in the present invention. FIG. 3 is a configuration block diagram showing an example of the rotation measuring device of the present invention. FIG. 4 is a main part configuration diagram showing the vicinity of the optical splitter of the rotation measuring device of the present invention. FIG. 5 is a side view showing the tethered cell. FIG. 6 is a plan view showing a positional relationship between a light sensor and a microscopic image of bacteria in a conventional rotation measuring device, and FIG. 7 is a graph showing the relationship between the light intensity detected by the light sensor and time. FIG. DESCRIPTION OF SYMBOLS 1 ... Real bacteria image 2 ... Rotation center 3 ... Optical fiber 4 ... Optical fiber end face 5 ... Photoelectric exchange element 6 ... Phase contrast microscope 7 ... Zoom lens 8 ... Half mirror 9 ... Video camera , 10 ... Monitor

Claims (2)

(57) [Claims] The present invention is characterized in that it has a light detecting section comprising a large number of optical fibers arranged circumferentially for detecting a microscopic image of a minute rotating body and a phase contrast microscope, and the position is measured from an output value thereof. A rotation measuring device for micro rotating bodies. 2. The rotation measuring device for a micro rotating body according to claim 1, wherein the micro rotating body is a bacterium in a tethered cell state.