JPH05168588A - Electronic endoscope - Google Patents

Abstract

PURPOSE:To provide an electronic endoscope apparatus which allows the performing of a proper treatment immediately when an electronic trouble occurs by monitoring the presence of electrical troubles an endoscope. CONSTITUTION:A monitoring mechanism which contains current sensor circuits 10 and 13, current limiter circuits 11 and 14 and current (signal) shielding circuits 12 and 15 is provided to detect abnormality monitoring states in the supply of power to a CCD module 2 and in the transmission of signals thereto Wide an endoscope 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus for picking up an image of a subject with a solid-state image pickup device such as a CCD mounted on the tip of an endoscope and displaying the picked-up contents on a monitor.

[0002]

2. Description of the Related Art As is well known, an endoscope in an electronic endoscope apparatus of this type has an electric circuit such as a CCD image pickup device in a portion to be inserted into a body cavity of a patient. Therefore, if a failure such as a short circuit or a low resistance occurs in the electric circuit, that portion may generate heat and may harm the subject. Further, if the electric circuit is broken or the resistance becomes large, normal operation may be lost and the image may disappear. Further, a power supply circuit for supplying electric power to the electric circuit of the portion inserted into the body cavity of the endoscope or a driver capable of sufficiently supplying current is generally provided so that it can be stably supplied against load fluctuations. However, since the state is maintained as it is when the above-mentioned short circuit, low resistance state, disconnection or high resistance state is maintained, it has been possible in the past to create a dangerous state for the subject.

[0003]

However, in the case of the conventional electronic endoscope apparatus of this type, it is necessary to completely know the above-mentioned short circuit or low resistance state, disconnection or high resistance state during operation of the endoscope. Therefore, there was the above-mentioned problem, that is, the following problem.

(1) There is a possibility of damaging a patient due to the failure of the portion inserted into the body cavity.

(2) Even if a failure occurs, it cannot be detected and the operator does not notice that it is dangerous.

(3) Even if the operator notices the failure,
Unless the operator turns off the power, the situation remains the same and it is dangerous.

The present invention has been made by paying attention to the above-mentioned circumstances, and an object thereof is to monitor the presence or absence of electrical failure of an endoscope and to take an appropriate countermeasure immediately when the failure occurs. An object is to provide an endoscopic device.

[0008]

In order to achieve the above object, the present invention monitors each state of power supply to an electric circuit inside an endoscope and signal transmission in the electric circuit to detect an abnormality. A monitoring mechanism is provided.

[0009]

With the configuration of the electronic endoscope apparatus according to the present invention,
When an abnormality occurs in at least one of each state of power supply to the electric circuit inside the endoscope scope and signal transmission in the electric circuit, the abnormality is detected by the monitoring mechanism, and immediate action to avoid the abnormality can be taken. ..

[0010]

1 is a block diagram showing the configuration of an electronic endoscope apparatus according to a first embodiment of the present invention. Although the processor is provided with a current detection mechanism in this embodiment,
This may be provided in the endoscope scope.

The electronic endoscope apparatus according to the first embodiment is shown in FIG.
Scope tip 1 of the endoscope 100 as shown in FIG.
00a is provided with a CCD module 2 including a CCD image pickup device 1 and a buffer amplifier 3 for a signal (OS signal) from the CCD image pickup device 1 in the relationship shown in FIG. Such a scope tip 100a is inserted into the body cavity of a patient. For this reason, if some failure occurs in the CCD module 2, the electric circuit inside the scope is short-circuited or short-circuited due to low resistance, and an abnormal overcurrent flows and heat is generated, there is a risk of injuring a patient. ..

The CCD module 2 has a power source, C
The DC power supply 4 is supplied for the DC bias of the CD, the bias of the buffer amplifier 3, and the like. At the same time, the CCD image pickup device 1 is supplied with a vertical clock 5 and a horizontal clock 6 for scanning pixels. These are signals that may cause an overcurrent due to a short circuit or the like. Furthermore, since the video output signal (OS signal) 7 from the CCD module 2 is supplied from the buffer amplifier 3, if a short circuit accident occurs in the CCD module 2, the bias current of the buffer amplifier 3 becomes an overcurrent.

Therefore, in the present embodiment, the DC power supply 4 for supplying power to the CCD module 2 and the vertical clock 5 for supplying to the CCD module 2 are made by the processor 28 of the apparatus main body (not shown), and the horizontal clock 6 is internally provided. While making with the horizontal clock driver 29 in the endoscope 100,
Multiple power supply currents 8 supplied to the endoscope 100
And the vertical clock driver 16 inside the processor 28
A plurality of supply currents 9 to the current sensor circuits 10 and 13
The endoscope scope 100 can be monitored by using
It is assumed that the overcurrent generated in the above is detected. Although only one power supply current 8 and one supply current 9 are shown in FIG. 1, there are actually only necessary power supplies. For example, the power supply to the vertical clock driver 16 is +15
Three of V, + 5V, -7, + to the endoscope scope 100
There are two, 15V and + 9V.

The DC power source applied to the CCD image pickup device 1 operates as follows.

The current from the power supply 17 is the current sensor circuit 1
0, the current limiter circuit 11, and the current cutoff circuit 12 are supplied to the scope. Although only one set is shown in FIG. 1, they are provided for each of a plurality of DC voltages.

The power source of the CCD image pickup device 1 is + 15V, and normally only about 15 mA flows. Therefore, the current sensor circuit 10 takes into consideration variations in parts, noise, etc., and increases the current by 50% when a current of 23 mA or more flows.
Is to be output. When this signal 10a is detected by the controller 21, the controller 21 writes a warning indicating that the overcurrent is flowing in the graphic memory 23. The output of the graphic memory 23 is added to the video signal by the adding circuit 25, and a warning is displayed on the display device 24. On the other hand, the overcurrent signal is sent to the video signal processing circuit
It is also connected to. When there is an overcurrent signal, the video signal processing circuit 22 switches the built-in color processing circuit to change the color of the image on the display device 24 so as to be apparently abnormal. This makes it possible for the operator to know that an abnormality has occurred even if the controller 21 or the graphic memory 23 is abnormal.

On the other hand, when the overcurrent is detected, the timer 19 operates. This is provided in order to continue to output an image even if an image is output, although an overcurrent is generated due to an abnormality in the CCD module 2. In endoscopy, it is dangerous to see the image immediately because surgery is performed. Therefore, if the image appears, I want to continue to produce it. Normally, the timer 19 is set to 30 seconds because it can be removed from the body in about 30 seconds. While the timer 19 is working, a warning is displayed on the display image, and the color has changed so that it can be clearly seen that there is an abnormality. Then, the endoscope scope 100 is removed from the body.

When the set time of the timer 19 is reached, the timer 19 activates the current cutoff circuit 12 to cut off all power to the CCD module 2. As a result, the operator can get out of the situation that may pose a danger to the patient without the operation of removing the endoscope 100.

In the above cases, the module is not short-circuited, but has a low resistance, and the temperature rise at the tip of the scope is gentle, and images continue to appear. However, a short circuit with almost no resistance can be considered. In this case, if a short circuit occurs at the tip of the scope, the temperature at the tip of the scope will rise rapidly. In this example, the current limiter 11 is used as a countermeasure. The current limiter 11 does not work up to a constant current, but when a current more than a preset current is about to flow, the voltage is reduced so that only the set current flows. Experimentally, if the temperature of the tip of the scope is about 100 mA, the dangerous temperature will not be reached within 30 seconds, so in this example, 100 mA is set as the limiter setting value. Therefore, even if the load is short-circuited and the resistance becomes small, the current does not exceed 100 mA. Also at this time, the current sensor circuit 10 detects the overcurrent, so that there is a warning display as described above,
All powers off in 30 seconds.

In this way, the DC power source applied to the CCD image pickup device 1 is monitored, and when an abnormality is detected, the power source is cut off. This also applies to vertical clocks and horizontal clocks. But for the clock,
The energy that causes heat generation is a temporal average value. Since this is just the power supply current supplied to the clock driver, the vertical clock driver 1 is used in this embodiment as in the case of the DC power supply described above.
The current supplied to 6 is monitored by the current sensor circuit 13, the controller 21 detects that an overcurrent signal 13a has occurred in the current sensor circuit 13, and a warning indicating that the overcurrent has flown to the graphic memory 23 is issued. A warning is displayed on the writing / display device 24.
Further, the timer 20 is activated by the detection of overcurrent, and after a lapse of a certain time, the signal cutoff circuit 15 is activated to stop the supply of the vertical clock signal to the CCD module 2 or the current limiter circuit 14 suppresses the signal supply. There is. It should be noted that the horizontal clock is adapted to the cutoff of the DC power supply.

Next, shutting off when the illumination system is abnormal will be described.

The endoscope must illuminate the inside of the body. Generally, the light of a powerful lamp 102 inside the processor is guided to the tip by a light guide 101 made of an optical fiber to illuminate it. From lamp 102 to light guide 101
It is possible to change the intensity of the lighting by providing a diaphragm etc. CCD1 in normal operation
The intensity of this illumination is changed so that the brightness of the video signal output from the device is within a certain range. The mechanism is ALC (auto
matic light contrller) 26. The problem here is that the illumination is so intense that heat is generated.
At the tip of the scope, illumination is performed from the light guide 101 through an illumination lens (not shown), but it is difficult to reduce the loss of light between the glass and the air because of the size restriction. Therefore, when illuminated, the loss becomes heat.

In normal observation, the light amount is rarely the maximum, so heat generation is not a problem. But CCD
If module 2 fails and no image appears, ALC2
In the case of No. 6, the amount of light is maximized, and the heat is generated at the distal end of the scope, which causes a dangerous state.

As a countermeasure, the controller 2 is used in this embodiment.
When 1 detects an abnormality, the lamp controller 27 is instructed to turn off the lamp 102 after a lapse of a certain time. This time is set to be a little longer than the time when the power is cut off due to overcurrent, so that the image is continuously output as much as possible while the image is displayed.

Next, each embodiment will be described with respect to an overcurrent detection circuit including a combination of a current sensor circuit, a timer and a current limiter.

FIG. 3 is a circuit diagram showing the configuration of the first embodiment of the overcurrent detection cutoff circuit. The operation is shown below.

The detection of overcurrent is composed of a resistor 201 and a transistor 202. As the current flowing to the load increases, the voltage drop across the resistor 201 increases. When this voltage exceeds the emitter-base voltage (VBE) of the transistor 202, the transistor 202 turns on. As a result, the transistor 203 is turned on, and the output of the gate 204 is H.
Becomes For example, when a silicon transistor is used as the transistor 202, VBE is about 0.6 V. Therefore, in order to set the detection current to 25 mA, the resistance 201 may be set to 24Ω.

The current limiter is composed of the transistor 205 and the transistor 206, and the current cutoff is performed by the transistor 2
06 and the transistor 209. When the current is less than the limit value, the voltage drop of the resistor 210 does not turn on the transistor 205, and the transistor 205 is not related to the operation. At that time, when the output of the gate 208 becomes H, the transistor 209 turns on, the base current of the transistor 206 flows, and the transistor 206 turns on. Gate 20
When the output of 8 becomes L, the base current stops flowing, so that the transistor 206 is turned off and the current can be cut off.

When the transistor 209 is in the ON state and a current is flowing, the voltage drop of the resistor 210 increases as the current increases, and the collector current of the transistor 205 starts to flow when VBE of the transistor 205 is reached.
Then, the voltage drop across the resistor 211 increases and the base current of the transistor 206 decreases. Since the base current of the transistor 206 is reduced, the current to the load is limited and acts as a current limiter. Limit current about 100mA
To achieve this, the resistance 210 may be set to 6Ω so that the voltage drop of the resistance 210 becomes 0.6V.

Since these use the VBE of the transistor, they are affected by temperature changes, but since there is a margin in both overcurrent detection and current limit, no problematic error occurs in the operating temperature range.

FIG. 4 is a circuit diagram showing the configuration of the second embodiment of the overcurrent detection cutoff circuit. This allows the CPU to change the set voltage. In operation, when the CPU writes voltage data to be set in the register 301 through the data bus, the D / A converter 302 outputs a voltage corresponding to it. The DC amplifier amplifies this voltage and outputs it. 303 is an operational amplifier, and transistors 304 and 3
05 together with a DC amplifier. The load current flows from the power supply through the route of the resistor 306, the resistor 307, and the transistor 308. The overcurrent is detected by the resistor 306 and the transistor 309 as in the first embodiment.

Here, the capacitor 310 forms a time constant with the resistor 311. Normally, a capacitor is included in the load to prevent noise. Therefore, the current required to charge the capacitor flows at the moment when the set voltage is increased. Since this current is instantaneous, it is not related to heat generation, but is detected by the overcurrent detection circuit. Therefore, the capacitor 31
The output is output only when the overcurrent continues for a certain time or more with the time constant of 0 and the resistance 311. In this example, the time is determined by the capacitor and the resistor, but if a digital circuit is used, such as counting a constant clock with a counter, the accuracy will be improved.

In FIG. 3, the current is cut off by setting the output voltage to 0V. The CPU may set 0V, but it is desirable to be able to set 0V by hardware in order to improve reliability.
In this example, the reset (clear) signal of the register 301 is used. When this signal becomes L, the outputs of the registers are all L and the D / A converter 302 outputs 0V. This cuts off the current.

In each of the above-described embodiments of the present invention, only the overcurrent can be detected, but when the current value is smaller than the specified value, a failure such as disconnection can be considered. In this case, the possibility of harm due to heat generation is less than overcurrent, but it is still a failure, and abnormality detection is still important.

Therefore, in the electronic endoscope apparatus of the second embodiment of the present invention, as shown in FIG. 5, a current sensor 401 for detecting the current by the amount of magnetism generated around the electric wire is used as the current sensor. .. The output of the current sensor 401 is amplified by the amplifier 402, digitized by the A / D converter 403, and transmitted to the CPU.

The CPU performs the processing shown in FIG.
This process can be dealt with whenever an abnormality occurs by constantly performing the process at regular intervals using, for example, a timer interrupt.

First, in step ST1, the current sensor is read. Next, in step ST2, it is determined whether this value is within the normal range. If it is between IMIN and IMAX1, it is normal, so the process exits without doing anything. If the current is too large or too small, the process branches at this point, the timer process of step ST3 waits for T1, and then the current sensor is read again in step ST4. This timer process eliminates any transient overcurrent such as inrush current, and waits, for example, several tens of milliseconds.

The value obtained by reading the current sensor again is IMAX.
When it is larger than 2, the process branches at step ST5. This value should be a value at which the current should be immediately cut off due to a short circuit or the like. For example, about 200 mA. If the current is more than this, it is displayed in step ST8, and the output is immediately cut off in step ST13. At the same time, the illumination lamp is turned off in step ST14. The endoscope apparatus according to the first embodiment shown in FIG. 1 has performed only this, but it is dangerous even if the operator is upset and continues to supply air, for example.
At T15, the air supply pump is also turned off.

Even if the current value does not exceed IMAX2, I
When it exceeds MAX1, the process branches at step ST6. Although this value is abnormal, it does not cause dangerous fever immediately and the image appears, so I want to continue to output the image for a while. Therefore, at the same time that the warning is displayed in step ST9, the timer process in step ST10 waits for the time T2. For example, this IMAX1 can be 25 mA and T2 can be 30 seconds. It should be noted that the warning display in step ST9 indicates that the image should be removed in 30 seconds, so that the user should immediately remove it from the body. After T2, the output is similarly cut off (step ST13), the lamp is turned off (step ST14),
Stop the pump (step ST15).

Next, when the current is smaller than IMIN, the process branches at step ST7. In this case, it is not immediately dangerous, but it is a failure. Therefore, step ST
It issues a warning at 11 and waits for T3. This time may be longer than T2, but if it is too long, there is a possibility that the failure may spread, so it is set to, for example, about 1 minute. In this case also, the output is cut off as in the previous two examples.

When the above three abnormalities are detected, step ST16 is followed. This is used to indicate that there was an anomaly in the past when the scope was connected to the processor by writing in the history management memory of the anomaly to indicate that the anomaly was not available. This memory uses a non-volatile memory such as an EEPROM. The memory may be inside the processor, but by having the memory inside the scope, it can be used as data for repair.

[0042]

As described above, according to the present invention,
The monitoring mechanism can detect a failure of an electric circuit inside the endoscope and inform the operator of the failure, and can automatically perform a processing operation so as to be safe. Along with this, the reliability of the electronic endoscope apparatus is significantly improved as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an electronic endoscope apparatus of a first embodiment to which the present invention is applied.

FIG. 2 is a perspective view showing the appearance of an endoscope.

FIG. 3 is a circuit diagram showing a configuration of a first embodiment of an overcurrent detection circuit.

FIG. 4 is a circuit diagram showing a configuration of a second embodiment of an overcurrent detection circuit.

FIG. 5 is a circuit diagram showing a main part of a monitoring mechanism in an electronic endoscope apparatus according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing a processing operation of a monitoring mechanism in the electronic endoscope apparatus according to the second embodiment of the present invention.

[Explanation of symbols]

 1 CCD image sensor 2 CCD module 3 Buffer amplifier 4 DC power supply 5 Vertical clock 7 Video output signal 8 Power supply current supplied to the endoscope scope 9 Current supplied to the vertical clock driver 10 Current sensor circuit 11 Current limiter circuit 12 Current cutoff circuit 13 current sensor circuit 14 current limiter circuit 15 signal cutoff circuit 16 vertical clock driver 17 power supply 18 timing generator 19 timer 20 timer 21 controller 22 video signal processing circuit 23 graphic memory 24 display device 25 adder circuit 26 ALC 27 lamp controller 28 processor 29 horizontal Clock driver 100 Endoscope scope 101 Light guide 102 Lamp

Claims (12)

[Claims] 1. An electronic endoscope apparatus, comprising: a monitoring mechanism for monitoring each state of power supply to an electric circuit inside the endoscope scope and signal transmission in the electric circuit to detect an abnormality. .. 2. The electronic endoscope apparatus according to claim 1, wherein the processor has the monitoring mechanism. 3. The electronic endoscope apparatus according to claim 1, wherein the endoscope has the monitoring mechanism. 4. The electronic endoscope apparatus according to claim 1, wherein the monitoring mechanism is provided in both the endoscope and the processor. 5. The electronic device according to claim 1, wherein the monitoring mechanism measures a consumption current for monitoring a power supply state to the electric circuit and compares the measurement result with a normal range to detect an abnormality. Endoscopic device. 6. The monitoring mechanism measures power consumption of a signal drive circuit for monitoring a signal transmission state in the electric circuit, and compares the measurement result with a normal range to detect an abnormality. Item 2. The electronic endoscope apparatus according to item 1. 7. The electronic device according to claim 1, wherein the monitoring mechanism detects an abnormality by comparing a drive waveform of the signal drive circuit with a normal range for monitoring a signal transmission state in the electric circuit. Endoscope device. 8. The electronic endoscope apparatus according to claim 5, further comprising means for displaying abnormality detection information on a display screen when an abnormality is detected by the monitoring mechanism. 9. The electronic endoscope apparatus according to claim 5, further comprising means for executing abnormality avoidance processing when an abnormality is detected by the monitoring mechanism. 10. When the target of the abnormality avoidance processing is an overcurrent, and when a short circuit is apparently compared with a normal range, the power is immediately turned off, and when it is an overcurrent but not a short circuit, after a certain period of time elapses. The electronic endoscope apparatus according to claim 9, further comprising means for turning off a power source. 11. The electronic endoscope apparatus according to claim 1, further comprising means for turning off a power source after a lapse of a predetermined time when the target of the abnormality avoidance process is a current decrease. 12. The electronic endoscope apparatus according to claim 10, wherein the means for turning off the power supply has a function of turning off the illumination lamp.