KR20030046787A - Digital stroboscope with continuous light source - Google Patents

Abstract

The present invention relates to an image inspector for visually observing an image of an object performing periodic motion at high speed through a displayed screen.

To replace a strobe light source that emits intermittently with a continuous light source to provide a smaller and cheaper device,

Light emitting means for providing a continuous light source; A CCD camera for acquiring the corresponding optical signal as an analog image signal by the light obtained from the light source of said light emitting means; A computer comprising a video capturing board synchronized with the CCD camera and converting an analog video signal transmitted from the CCD camera into a digital video signal, and a program for adjusting shutter time and sampling speed of the CCD camera; And by providing a digital stroboscope using a continuous light source, characterized in that consisting of a monitor for outputting a digital image signal processed by the computer on the screen for the examiner to recognize,

Compared to conventional stroboscopes, the construction is simpler and the volume and weight are smaller, which is economically advantageous and can be used in many fields and in medical or industrial applications.

Description

DIGITAL STROBOSCOPE WITH CONTINUOUS LIGHT SOURCE}

The present invention relates to an apparatus for visually observing an image of an object performing periodic movements such as rotation and vibration at high speed by providing a continuous light source instead of an intermittently emitting strobe light source. For example, in vivo, the gates of the larynx can open and close about 100-250 times per second during vocalization to accurately observe the tremors of the gates without using a stroboscope using a strobe light source according to the prior art. In this regard, the present invention relates to a digital stroboscope capable of observing glottal motion and the like without using an intermittent strobe light source by using a light emitting means that provides a continuous light source in a field requiring a stroboscope.

In general, when the observation object performs a periodic motion such as rotation or vibration at high speed, the shape and motion of the object cannot be recognized by the naked eye. This is because the movements are continuously superimposed by the afterimage effect of the eyes. It is also due to this afterimage effect that an object appearing on the screen moves through a device in which still images are continuously projected.

However, due to the afterimage effect as described above, when the object performs the periodical movement at high speed, the object cannot be clearly recognized by the naked eye. It is because of this effect that you cannot see the wheels of the car or the wings of the fan that rotates at high speed.

The stroboscope according to the prior art can observe the motion of an object by continuously imaging a plurality of sequential still images obtained by illuminating intermittent light on an object that performs periodic motion at such a high speed.

In this case, an aliasing phenomenon occurs due to a difference between the actual movement speed of the object and the movement speed of the object through a continuous still image. It is also due to the aliasing phenomenon that the fan blades appear to rotate in the forward or reverse direction at low speed under the fluorescent lamp.

When the frequency of light intermittently emitted from the stroboscope is synchronized with the frequency of the object performing periodic motion, the object provided through the image is observed as if it is stationary. At this time, when a small change is made in the frequency of intermittent light, that is, the frequency of the stroboscope, it is observed through the image that the object performs periodic motion in the forward or reverse direction at low speed.

Stroboscopes with this principle can be used in all fields and are actually used, for example, to observe the laryngeal gates in vivo. The application examples in which the stroboscope according to the related art is used for observing the laryngeal gate of the body in vivo are described below.

In general, the human body has a very admirable biostructure, which is difficult to cure or heal when abnormalities occur in the tissue because the composition or tissue is very fine, and also during the treatment process It may be more important to prevent the degree of damage or functional abnormalities in advance.

The vocal fold of the human body is a vocal organ for communication through language, and the laryngeal gates vibrate about 100 to 250 times per second along the air flow of exhaled breath. In disease states such as voice changes, the movements of these gates become irregular, asymmetrical or do not vibrate at all or in part of the vocal cords.

In other words, air inhaled into the airways during vocalization is converted to pressure by the vocal cords closed in the sub-glottalarea, and when the pressure becomes greater than the resistance of the vocal cords, it is present at the inferior margin of the vocal cords. A mucosal wave is directed towards the superior margin. The speed and intensity of the mucous waves affect the auditory properties of the air through the vocal cords to determine the quality of the voice.

That is, the vocal cords are rapidly symmetrically oscillating at tens to hundreds of Hz, and convert the hydrodynamic energy generated in the subglottic region, that is, sub-glottal pressure, into sound energy. However, when there are vocal cord paralysis or vocal cord nodules, the symmetry of the mucosal waves is lowered, which makes it impossible to convert energy effectively, resulting in abnormal voice.

Therefore, it is essential to understand the motion of the larynx of the larynx when examining the abnormalities of the voice, and the methods currently used for this use a stroboscope, and the stroboscope cycles at a high speed of 100 to 250 times per second. You can observe the movement of the laryngeal gates at low speed.

The stroboscope uses the principle that the gate shows the least movement when the frequency of the stroboscope is synchronized with the frequency of the periodic motion of the gate. In other words, by measuring the vibration period of the vocal cords by using a microphone or electro-glottography, a stroboscope light source with a repetitive and intermittent light having a slightly smaller period is applied to the vocal cords to slow the vibration of the vocal cords. This allows the observation of changes in vibration patterns and the overall asymmetry of the vocal cord movement in various frequency bands.

At this time, the stroboscope essentially requires a light source, the strobe light shines intermittently rather than continuous to the moving object at high speed. The CCD camera acquires an image only while the light source is turned on and displays it on the monitor. At this time, if the strobe light source is controlled, the image of the moving object can be obtained at a low speed.

However, the conventional stroboscope has a problem that the light source device for producing an intermittent light emitting strobe light source has a large volume and weight, consumes a lot of power and is expensive in equipment.

In addition, the conventional stroboscope has a problem in that when the strobe light source is not synchronized with the sampling speed of the camera, the image becomes dark and the object cannot be clearly observed.

The present invention has been made to solve the problems described above, and by using a light source that emits continuously instead of a strobe light source that intermittently emits light to visually observe an image of an object performing periodic movements at high speed, Its purpose is to provide a more compact device and to provide a more economical device by consuming less power during operation, and to provide a more economical view of the object.

1 shows an example of waveforms of periodic motion of an actual object.

Figure 2 is an example showing the waveform of the periodic motion of the object obtained as a still image through the digital stroboscope according to the present invention

3 is an exemplary configuration diagram of a digital stroboscope according to the present invention.

4 is an exemplary operation diagram of a digital stroboscope according to the present invention.

The present invention for achieving the above object

An apparatus for observing periodic motion of an object;

Light emitting means for providing a continuous light source;

A CCD camera for acquiring the corresponding optical signal as an analog image signal by the light obtained from the light source of said light emitting means;

A computer comprising a video capturing board synchronized with the CCD camera and converting an analog video signal transmitted from the CCD camera into a digital video signal, and a program for adjusting shutter time and sampling speed of the CCD camera; And

The present invention provides a digital stroboscope using a continuous light source, characterized in that the monitor is configured to output a digital image signal processed by the computer to the screen for the examiner to recognize.

The above object and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

A digital stroboscope using a continuous light source according to the present invention observes a low-speed image of an object that periodically cycles at high speed by artificially generating an aliasing phenomenon like a conventional stroboscope.

As described above, in order to observe an object moving at high speed, a sequential still image must be continuously imaged. Such still images can be obtained by shortening the time that the shutter of the camera is opened (hereinafter referred to as shutter time).

The digital stroboscope uses this principle, and includes a light emitting means that provides a continuous light source for observing an object moving at high speed, and a camera having an adjustable shutter time and imaging speed (hereinafter, referred to as a sampling speed). Thus, the shutter time of the camera is set at least equal to 0.5 cycles (more preferably less than 0.1 cycles), and the sampling speed of the object to be subjected to the periodic movement. By adjusting to synchronize with a period, a still image can be obtained continuously, and in this state, a low-speed image of an object that performs periodic movement in the forward or reverse direction can be obtained by changing the sampling speed small or large. At this time, the frame grabber mounted on the PC receives the synchronized image from the camera, and the program embedded in the hardware of the PC is set to adjust the shutter time and the sampling speed of the camera. The image from the camera is digitized in a computer and output on a monitor.

It is preferable that the light emitting means and the camera be integrally manufactured in terms of construction.

Figure 1 is a representation of the actual movement of the physical waveform as a waveform, Figure 2 is a digital stroboscope according to the present invention by capturing the object with a CCD (Charged Coupled Device) camera is synchronized according to the trigger signal of the computer The periodic motion of an object expressed as a still image is illustrated as a waveform.

As shown in FIG. 1, the trigonometric signal for the periodic motion of the actual object is 2048 data sampled from 100sin (16 * π / 512), and the contents shown in FIG. 2 are attached to the actual object. By sampling the periodic motion of the object with the digital stroboscope according to the present invention is extracted 33 data extracted at 62 intervals from the original signal.

Therefore, by sampling the periodic motion of the repetitive object at a suitable low speed, one periodic component of the repeated motion can be extracted completely. In other words, if the data of the graph shown in FIG. 1 is sampled at 2048 speeds per second to obtain a waveform corresponding to 32 cycles, the data of the graph shown in FIG. Even at speed, a waveform corresponding to one cycle signal can be obtained.

In this case, the smaller the shutter time of the CCD camera is, the higher the shutter time is, one image is obtained as a continuous image rather than a still image, and the observer cannot clearly observe the state of periodic movement of the object. Therefore, to observe an object performing 32 cycles per second, the shutter time of the CCD camera should be adjustable to at least 1/64 seconds or less.

As mentioned above, the present invention can be used in medicine, engineering, and the like. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the contents described below will be described in more detail with reference to the accompanying drawings.

FIG. 3 shows a configuration of a digital stroboscope using a continuous light source according to the present invention, which processes images of the laryngeal gate of a periodic cycle at high speed, and obtains desired information from the processed images using a computer. An endoscope (not shown) having light emitting means for providing a continuous light source for observing the laryngeal motion of the laryngeal to be observed by performing a program for outputting the result; A CCD camera (200) for acquiring the corresponding optical signal as an analog image signal by the light obtained from the light source of said light emitting means; The image capture board 410 and the image capture board 410 which are synchronized with the CCD camera 200 and perform actual data processing for converting an analog image signal transmitted from the CCD camera 200 into a digital image signal. A computer 400 having a program 420 for adjusting the shutter time and the sampling speed of the CCD camera 200 to observe the voice movement of the larynx from the collected image information; And a monitor 300 that outputs the digital video signal processed by the computer 400 to a screen so that an examiner can recognize the digital video signal.

In this case, in the computer 400, an image input under the control of the program 420 is output on the monitor 300 as a still image and an image moving at a low speed, and the CCD camera 200 is connected to the computer 400. According to the shutter time and the sampling speed adjusted by the program of the image of the glottal motion is transmitted to the image processing board 410.

As described above, the image processing board 410 digitizes the analog image transmitted and synchronized with the CCD camera 200. In this case, the endoscope and the CCD camera are preferably integrated.

The program 420 running on the computer 400 may also be set to display the digitized image on the monitor 300 and to store it as a file for repeated playback. It can be reproduced and observed every time.

Therefore, the digital stroboscope according to the present invention has the same function as a conventional stroboscope while using a continuous light source, and when the strobe light source is not synchronized with the sampling speed of the camera during operation of the conventional stroboscope, the image becomes dark and Although it may not be clearly observed, the digital stroboscope according to the present invention does not occur by using a continuous light source, so that the object can be clearly observed at all times, which is more advantageous in terms of performance.

In addition, the CCD camera 200 may adjust the shutter time according to the brightness of the light source, and transmits the image synchronized with the trigger signal of the computer 400. The capture board 410 digitizes an image signal transmitted from the CCD camera 200 and outputs it to the monitor 300 and stores it in a storage device of the computer 400. As mentioned above, the stored image can later be recalled for repeated playback.

A brief description of how this system works is as follows.

The image of the CCD camera 200 through the endoscope is shown on the screen of the monitor 300 through the image capture board 410. At this time, if the sampling speed of the camera 200 is adjusted by the program 420, it can move at high speed so that the motion of the laryngeal gate, which cannot be observed only by the naked eye, can be seen as a slow motion image or a still image. have. That is, you can observe whether the larynx closes and opens correctly. CCD camera 200 of the component should be able to adjust the shutter time and the sampling (taking) speed and the image capture board 410 should be synchronized with the camera 200 to obtain an image.

4 is a flowchart illustrating an operation of the digital stroboscope in accordance with the present invention. Image acquisition in which the image captured by the CCD camera 200 is converted into a digital signal that can be analyzed by the computer 400 and collected. Process; A data storing step of storing image data converted into the digital signal; A gated motion output process of visualizing and outputting image data on a screen of a monitor; And adjusting the shutter time or the sampling speed of the CCD camera to observe the clear glottal motion from the output glottal motion.

This is explained in more detail.

First, the collection of the image required for analysis is converted to an image signal based on the light source provided by the endoscope using the CCD camera 200 and then collected.

The entire field of the image obtained by the CCD camera 200 as described above is A / D-converted by the image capturing board 410 and stored in main memory through an internal bus of the computer 400.

Once the image data is transferred to the memory, the image data acquired by the program 420 is visualized and output to the screen of the monitor.

In the collection operation of the image using the CCD camera 200, the gate of the larynx is normally opened and closed about 100 to 250 times per second during speech, so that the shutter time of the CCD camera 200 is at least 0.5 cycles or less when analyzing the gate movement of the larynx. It is adjusted to have a time interval corresponding to (more preferably 0.1 cycles or less), and adjusts the sampling speed so that it can accurately observe the glottal movement output to the screen.

Thereafter, the CCD camera 200 visualizes the glottal motion and transmits it to the image capturing board 410 according to the shutter time and the sampling speed adjusted by the program of the computer 400. The process of sequentially outputting a still image on the screen of the monitor is repeated.

While the invention has been shown and described in connection with specific embodiments thereof, it is well known in the art that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the claims. Anyone who owns it can easily find out.

As described above, the digital stroboscope according to the present invention is configured with smaller volume and weight to provide a compact and portable device at low cost, and to provide a more economical device by consuming less power during operation. By using a conventional light source, the object can be clearly observed, thereby providing an improved device.

Claims (3)

An apparatus for observing periodic motion of an object; Light emitting means for providing a continuous light source; A CCD camera for acquiring the corresponding optical signal as an analog image signal by the light obtained from the light source of said light emitting means; A computer comprising a video capturing board synchronized with the CCD camera and converting an analog video signal transmitted from the CCD camera into a digital video signal, and a program for adjusting shutter time and sampling speed of the CCD camera; And And a monitor for outputting a digital image signal processed by the computer to a screen so that an examiner can recognize the digital image signal. The method of claim 1, And said light emitting means and a CCD camera are integral. The method according to claim 1 or 2, A digital stroboscope using a continuous light source, characterized in that it is used to observe the glottis of the larynx in vivo with an endoscope manufactured integrally with the CCD camera.