JP3216949B2 - Power supply circuit for medical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply circuit of a medical device for performing in vivo diagnosis and the like.

[0002]

2. Description of the Related Art In recent years, adequate measures against EMC (general problem of electromagnetic interference (EMI) and problem of electromagnetic interference (EMS)) have been taken sufficiently for electrical equipment used in hospitals. Is in an increasingly desired situation.

Conventionally, a primary power supply of a medical diagnostic apparatus is composed of an electric component including a power inlet, a breaker, a line filter, a power switch, a terminal board, and an insulating transformer, and a cable connecting the electric components. The terminal board is fixed to another member or one member.

However, depending on the arrangement of the line filter and the terminal board, a cable for connecting the line filter and the breaker (hereinafter referred to as an input side cable), a cable for connecting the terminal board to a transformer, and a power switch for connecting the terminal board to the power switch. Cables (hereinafter referred to as output-side cables) are considerably close to or in contact with each other.

[0005] In addition to the power from the external power supply, noise unnecessary for the device is superimposed on the input side cable. Therefore, the output side cable that transmits the noise-removed power through the line filter is connected to the input side cable. Noise is radiated from the input side cable. This noise may be mixed with the video signal of the ultrasonic diagnostic apparatus to lower the quality of the ultrasonic image, or may be mixed with the control signal and cause a malfunction.

On the other hand, noise is radiated from an output-side cable that picks up noise generated in the device to an input-side cable. This noise may cause malfunction of other devices.

[0007] As a countermeasure against these problems, in the conventional medical diagnostic apparatus, the cable routing on the input side and the output side is devised so that the cables do not come too close to each other, or a line filter and a terminal board are provided between the input side and the output side cables. In addition, a plate was provided separately from the member for fixing the plate to shield it.

Japanese Utility Model Application Laid-Open No. 55-76523 discloses a device in which a connection terminal on the power input side is provided in a cover for covering the noise filter body.

[0009]

When a cable is routed so that the cables on the input and output sides of the line filter do not come too close to each other, variations in the routing may occur depending on the operator. It has been difficult to suppress the radiation of noise from the side cable to the output cable and the radiation of noise from the output cable to the input cable of the line filter. In addition, when shielding plates are separately provided between the input side and the output side cables, there is a problem that the number of components increases.

The present invention has been made in view of such problems, and radiates noise from the input cable of the line filter to the output cable and noise from the output cable of the line filter to the input cable. An object of the present invention is to provide a power supply circuit of a medical device capable of reliably suppressing radiation without increasing the number of components.

[0011]

SUMMARY OF THE INVENTION In a power supply circuit of a medical device for supplying power necessary for operating an electric circuit forming the medical device, a power supply inlet for receiving power from an external power supply, and a breaker. A line filter that removes noise superimposed on an external power supply and noise that goes out of the device, a power switch that turns on and off the power, an insulating transformer, and a primary power supply path to a power inlet and an insulating transformer. A line, a terminal board for relaying a primary line between the power switch and the insulating transformer, a line filter, a fixed plate having a surface for attaching the terminal board and electrically isolating an input line and an output line of the line filter. Noise radiation from the input side cable to the output side cable of the line filter and the line filter. Only radiation of noise from other output cable to the input cable without increasing the component so that it is possible to suppress the reliably.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. 1 and 2 relate to a first embodiment of the present invention. FIG. 1 shows an overall configuration of an ultrasonic diagnostic apparatus having the first embodiment, and FIG. 2 shows a fixing structure of a line filter.

An ultrasonic diagnostic apparatus 1 having a first embodiment of the present invention shown in FIG. 1 is inserted into a living body to perform ultrasonic diagnostics, an ultrasonic endoscope 2, and transmission and reception of ultrasonic waves. An ultrasonic observation device 3 for processing a signal, and a TV monitor 4 for displaying a video signal processed by the ultrasonic observation device 3
And a keyboard 5 connected to the ultrasonic observation apparatus 3 for inputting data such as comments on the ultrasonic image displayed on the TV monitor 4.

The ultrasonic endoscope 2 is provided with a probe section 6a containing a transducer for transmitting and receiving ultrasonic waves at the tip of an insertion section 6 to be inserted into a living body. An illumination optical system and an observation optical system are provided in a portion adjacent to the probe unit 6a, and illumination light is supplied by connecting the light guide connector 2a at the end of the light guide cable to a light source device (not shown).

The ultrasonic connector 2c at the end of the ultrasonic cable 2b extending from the ultrasonic endoscope 2 can be detachably connected to the transmission / reception connector 12 of the ultrasonic observation apparatus 3.

The ultrasonic observation apparatus 3 includes a primary power supply unit 7, a secondary / patient power supply unit 8, a fan 9 for cooling the inside of a housing, a transmission circuit 10 for driving a vibrator, and amplifying and detecting a signal received by the vibrator. A receiving circuit 11, a connector 12 for transmitting and receiving an ultrasonic wave, which is a connection unit with the ultrasonic endoscope 2, a CPU unit 13 for controlling the timing of transmitting and receiving the ultrasonic wave, and a DSC 14 for performing image processing on a received signal of the ultrasonic wave. Consists of

The primary power supply 7 forming the first embodiment is a power supply circuit for supplying power required for the operation to the secondary / patient power supply 8 side, and is connected to an external commercial power supply via a power cord (not shown). Power supply inlet 15, breaker 16, line filter 17 for removing power line noise, power switch 18, terminal board 1
9. An insulating transformer 20 for insulating the primary side and the secondary / patient power supply side, and the power supply inlet 15 is connected to a breaker 16 via a cable. The breaker 16 is connected to a line filter 17 via a cable.

The line filter 17 is connected to a power switch 18 via a cable. Power switch 1
Reference numeral 8 is connected to a terminal board 19 via a cable. The terminal board 19 is connected to an insulating transformer 20 via a cable.

The secondary / patient power supply section 8 supplies a power to a part of the receiving circuit 11 and the transmitting circuit 10;
It comprises a secondary power supply for supplying power to the U section 13, the DSC 14, and the like. The patient power supply and the secondary power supply are connected to the insulating transformer 20 via a cable.

The transmission circuit 10 is connected to a secondary
The secondary / patient power supply 8 is connected to the patient power supply 8 and supplies power required for operation. The transmitting circuit 10 is connected to the DSC 14 and the connector 12 for transmitting and receiving ultrasonic waves. The receiving circuit 11 is connected to the DSC 1 via a cable.
4. Connected to the connector 12 for transmitting and receiving ultrasonic waves.

The DSC 14 is connected to the transmission circuit 10 and the reception circuit 11 as described above, and is also connected to the CPU 13. The DSC 14 is an ultrasonic observation device 3
Is connected to a rear connector 22 fixed to the rear panel 21 of the first embodiment. 2A and 2B are views showing a fixing structure of the line filter 17 in the primary power supply unit 7 according to the first embodiment of the present invention. FIG. 2A is a top view, and FIG. 2B is a side view of a main part. is there.

The power inlet 15 and the breaker 16 are fixed to the back panel 21. The line filter 17 is screw-fixed from below to a fixed plate 24 via an insulating plate 23. The terminal board 19 is fixed to the fixing plate 24 with screws from above. The fixing plate 24 has isolation surfaces 26 and 27 for isolating the line filter 17 from the insulating transformer 20 and the chassis 25.

The breaker 16 and the line filter 17
Cables 28a, 28b connecting the power switch 18 and the terminal board 19 to each other.
An insulating surface 26 of the fixing plate 24 on the side of the insulating transformer 20 extends in a vertical direction so as to electrically isolate the cables 30a and 30b connecting the insulating transformer 20 with the insulating plate 9b and the terminal board 19. An L-shaped plate 31 is welded to the terminal board 19 mounting surface.

A cover 34 is provided on the upper side of the terminal board 19.
Is attached to prevent noise radiated from the input side cable 28a into the inside of the apparatus from leaking to other areas in the apparatus or outside. The line filter 17 and the power switch 18 are connected by cables 35a and 35b.

Next, the operation of this embodiment will be described. When the power switch 18 is turned on, power is supplied from an external power supply to the apparatus via the power supply inlet 15. In some cases, this power is superimposed with noise unnecessary for the apparatus. This noise is generated by, for example, a line filter input cable 28 connecting the line filter 17 and the breaker 16.
a and 28b are radiated into the apparatus.

However, the isolation surface 26 of the fixed plate 24 on the transformer 20 side, the L-shaped plate 31, the back panel 21, the chassis 2
5, the bottom part 32, the side part 33, and the cover 34
The above-described input side cables 28a, 28b, etc., and the cables 29a, 29 connecting the power switch 18 and the terminal board 19
b, since the cables 30a and 30b connecting the terminal board 19 and the insulating transformer 20 are electrically isolated,
9a, 29b, cables 30a, 30b, cable 35 for connecting line filter 17 and power switch 18
No noise is radiated to a and 35b.

Since the noise superimposed on the power supplied from the external power supply into the apparatus is removed by the line filter 17, the noise is not superimposed on the cables 35a and 35b connected to the line filter 17. Therefore,
Noise is not superimposed on the cables 29a and 29b and the cables 30a and 30b.

On the other hand, even when high-frequency noise is radiated from a board on which an IC driven at a high-frequency clock frequency is mounted, such as the CPU section 13, or a cable connected to the board, the transformer 20 of the fixed plate 24 can be used. Side isolation surface 2
6, input side cables 28a, 28b, etc. are isolated from the area where noise is radiated by the L-shaped plate 31, the rear panel 21, the bottom surface 32 and the side surface 33 of the chassis 25, and the cover 34. Side cables 28a, 28
b and the like are not radiated.

Even if noise is superimposed on the cables 29a and 29b, the cables 30a and 30b, and the cables 35a and 35b due to the radiated noise, the noise is removed by the line filter 17, so that the input side cables 28a and No noise is superimposed on 28b and the like. Therefore, no noise is emitted outside the device via the power cord connected to the power inlet 15.

This embodiment has the following effects. A fixing plate 24 for fixing the line filter 17 and the terminal board 19 is composed of cables 28a and 28b on the input side and cables 29a, 29b, 30a, 30b and 3 on the output side of the line filter 17.
5a and 35b are isolated from each other, so that the noise superimposed on the power supplied from the external power supply into the device is
It is not radiated and superimposed on the cable on the line filter output side.

Even when noise is radiated from the board in the apparatus or the cable connected to the board, the noise is not radiated and superimposed on the cables 28a and 28b on the line filter input side. No noise.

Since the noise countermeasures are determined by the shape of the fixing plate 24 on which the line filter 17 and the terminal board 19 are mounted, the noise countermeasures can be reliably performed irrespective of the manner in which the cable is routed by the worker.

In this embodiment, the line filter 17,
Although the L-shaped plate 31 is welded to the fixing plate 24 for fixing the terminal board 19, it goes without saying that the entire plate may be integrated.

Next, a second embodiment of the present invention will be described. FIG.
Is a ferrite core 40 for removing noise through a cable 39 connecting the transmitting / receiving connector 12 and the transmitting circuit 10 or the like.
3 (a) is a top view and FIG. 3 (b) is a side view.

The ferrite core 40 is a core for a split type flat cable, and a rubber member 41 is attached to an outer periphery thereof, and a cable 39 is inserted through an inner periphery thereof. An L-shaped plate 42 is attached to the chassis 25 of the apparatus. A bush 43 made of an insulating material is inserted and fixed to the L-shaped plate 42. A band 44 covering the outer periphery of the ferrite core 40 is inserted into a band hole 45 of the bush 43 to fix the ferrite core 40 to the bush 43.

The other structure is the same as that of the first embodiment.
Next, the operation will be described. Split type ferrite core 40
Will be described with reference to FIG. First, the band 44
Is inserted into the band hole 45 of the bush 43 attached to the L-shaped plate 42 to form a loop.

Next, the transmitting / receiving connector 12 and the transmitting circuit 1
Cables 39 connecting the two ferrite cores 4
Cover with 0. A rubber member 41 with double-sided adhesive paper is attached to the ferrite core 40. After the ferrite core 40 is passed through the inside of the ring of the band 44, the band 44 is pulled to make the ring smaller, the rubber member 41 attached to the ferrite core 40 is deformed, and the ferrite core 40 is fixed to the L-shaped plate 42. I do.

This embodiment has the following effects. As described above, since the ferrite core 40 is fixed by the band 44, the mounting space for the ferrite core 40 is reduced.

As shown in FIG. 3C, a concave portion 46 may be provided in the rubber member 41a attached to the ferrite core 40a. In this way, by attaching the concave portion 46 to the band 44, the work of pulling the band 44 and fixing the ferrite core 40a can be performed easily.

Next, a third embodiment of the present invention will be described. FIG.
FIG. 3 is a diagram illustrating a structure of a shield case 50 that shields the transmission circuit 10. The transmission circuit 10 includes the capacitor 5
1. A circuit in which electric components such as a pulse transformer 52 and a photocoupler 53 are mounted, and outputs a signal for causing a vibrator to vibrate and transmit an ultrasonic wave.

The transmission circuit 10 is fixed to the chassis 25 via a spacer 54 made of an insulating material. A shield case 50 is fixed to the chassis 25 with a screw fixing portion 56 so as to surround the transmission circuit 10. An opening (not shown) is provided in the cable lead-out portion of the shield case 50, and this opening is as small as possible.

The other parts of the shield case 50 are in a state where the gap between the shield case 50 and the chassis 25 is small. The shield case 50 and the transmission circuit 10 are fixed to the chassis 25 at a distance defined by, for example, IEC 601-1 to ensure electrical safety. As described with reference to FIG. 3, the cable 39 connecting the transmitting circuit 10 and the transmitting / receiving connector 12 is provided.
Is provided with a ferrite core 40. Other configurations are the same as in the first embodiment.

Next, the operation will be described. The transmission circuit 10 is connected to the ultrasonic endoscope 2 via a transmission / reception connector 12, and a vibrator that oscillates ultrasonic waves toward a living body is provided at a distal end of the ultrasonic endoscope 2. Have been. Therefore, when noise is radiated to the transmission circuit 10 from a circuit other than the transmission circuit 10 in the device, the noise is radiated out of the device together with the ultrasonic signal from the transducer at the distal end of the ultrasonic endoscope 2. It is necessary to take noise countermeasures.

In FIG. 4, when noise is radiated from a circuit other than the transmission circuit 10 in the device, the shield case 5
Since the gap between the chassis 0 and the chassis 25 is small, noise cannot enter the inside 55 of the shield case 50. Therefore, no noise is radiated to the transmission circuit 10. Most of the noise hitting the shield case 50 is absorbed by the shield case 50, becomes a small current, and flows on the surface of the shield case 50. Since the shield case 50 and the chassis 25 are connected by the screw fixing portion 56 of the shield case 50, current flows to the chassis 25 via the screw fixing portion 56 of the shield case 50.

For example, when noise is radiated from the transmission circuit 10, the noise is not radiated to the outside 57 of the shield case 50 because the gap between the shield case 50 and the chassis 25 is small.

Further, when noise radiated from the transmission circuit 10 hits the shield case 50, most of the noise becomes a small current, flows on the surface of the shield case 50, and passes through the screw fixing portion 56 of the shield case 50. Flow to 25.

As described with reference to FIG. 3, the cable 39 connecting the transmission circuit 10 and the transmission / reception connector 12 is provided with the ferrite core 40 for removing the noise of the cable 39. Noise is not radiated from the vibrator at the tip of the endoscope 2.

This embodiment has the following effects. By fixing the shield case 50 surrounding the transmission circuit 10 to the chassis 25 with screws as described above, even if noise is radiated from a circuit other than the transmission circuit 10 in the device, the noise is not radiated to the transmission circuit 10. Even if noise is radiated from the transmission circuit 10, noise is not radiated to circuits other than the transmission circuit 10 in the device.

Further, since the cable 39 connected to the transmission circuit 10 is provided with the ferrite core 40, noise is radiated from the vibrator at the tip of the ultrasonic endoscope 2 to the outside of the apparatus together with the ultrasonic signal. Not done. Accordingly, the transmission circuit 10 can be reliably shielded.

Next, four embodiments of the present invention will be described. FIG.
Are shield cases 60 for shielding the receiving circuit 11,
FIG. 61 is a diagram showing a configuration of a first embodiment. The receiving circuit 11 is fixed to the front panel 64 with screws via spacers 62 and 63 made of an electrically conductive material such as metal. Shield cases 60 and 61 are fastened together on the upper and lower sides of the receiving circuit 11 by a spacer 63 so as to cover the receiving circuit 11.

The spacers 62 and 63, the contact portions, the shield cases 60 and 61, and the contact surface of the receiving circuit 11 are GND lands.

A cable 65 connected to the transmitting / receiving connector 12 is connected to the left side of the receiving circuit 11. A cable 66 connected to the DSC 14 is connected to the right side of the receiving circuit 11. The cables 65 and 66 are provided with ferrite cores 67a and 67b for removing noise.

An opening 68 is provided in the cable lead-out portion of the shield case 60, and the opening 68 is as small as possible. Other portions of the shield case 60 are in a state in which a gap with the shield case 61 is small. Other configurations are the same as in the first embodiment.

Next, the operation will be described. The receiving circuit 11 is a circuit that amplifies and detects a signal received by the vibrator, and processes a weak received signal. Therefore, when noise is radiated, the noise is superimposed on an image signal to be subjected to processing such as amplification. Causes noise on the image, which is not preferable for diagnosis. Therefore, it is necessary to take measures against noise.

In FIG. 5, when noise is radiated from a circuit other than the receiving circuit 11 in the device, the shield case 6
The gap between the shield case 60 and the shield case 61 is small.
No noise can enter the 9,70. Therefore, the receiving circuit 1
No. 1 does not radiate noise.

Most of the noise hitting the shield case 60 and the shield case 61
It is absorbed by 0, 61 and becomes a small current, and the shielding case 6
It flows on the surface of 1,61. Since the shield cases 60 and 61 are fastened together at the spacer 63, and the spacer 63 and the front panel 64 are connected, current flows to the front panel 64 via the spacer 63 and connects the chassis 25 (not shown). It flows to the chassis 25 through the section.

For example, when noise is radiated from the receiving circuit 11, the shield case 60 and the shield case 6
Since there is little gap between the shield cases 60 and 61, noise is not radiated to the outside of the shield cases 60 and 61.

Further, when noise radiated from the receiving circuit 11 hits the shield cases 60 and 61, most of the noise becomes a small current, and
The current flows through the surface of the front panel 64 through the spacer 63 where the shield case 60 and the shield case 61 are fastened together.
And flows to the chassis 25 via a connection portion of the chassis 25 (not shown).

A ferrite core 6 for removing noise is provided on a cable 66 connecting the receiving circuit 11 and the DSC 14 and a cable 65 connecting the transmitting / receiving connector 12.
Since there are provided 7a and 67b, there is no superposition of noise via the cables 65 and 66 connected to the receiving circuit 11.

The effects of this embodiment are as follows. Shield case 6 surrounding reception circuit 11 as described above
0, 61 are connected to a front panel 64 by spacers 62,
By tightening together at 63, even if noise is radiated from circuits other than the receiving circuit 11 in the device, the receiving circuit 1
No. 1 does not radiate noise.

Even if noise is radiated from the receiving circuit 11, no noise is radiated to circuits other than the receiving circuit 11 in the apparatus. Further, the cable 6 connected to the receiving circuit 11
Since the ferrite cores 67a and 67b are provided on the wires 5 and 66, there is no superposition of noise via the cables 65 and 66. Therefore, the shield of the receiving circuit 11 can be reliably performed.

Although the ultrasonic diagnostic apparatus has been described as a medical apparatus in the above-described embodiment, the present invention can be similarly applied to other medical apparatuses, and the power supply circuit in the case of the medical apparatus is also applicable. The same applies.

[0063]

As described above, according to the present invention, the radiation of noise from the input cable of the line filter to the output cable and the radiation of noise from the output cable of the line filter to the input cable are controlled. , And can be reliably suppressed without increasing the number.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an ultrasonic diagnostic apparatus including a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration near a line filter in the ultrasonic observation apparatus.

FIG. 3 is a diagram showing a mounting structure of a ferrite core according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a structure near a shield case for shielding a transmission circuit according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a structure near a shield case for shielding a receiving circuit according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic diagnostic apparatus 2 ... Ultrasound endoscope 3 ... Ultrasonic observation apparatus 4 ... TV monitor 5 ... Keyboard 6 ... Insertion part 7 ... Primary power supply part 8 ... Secondary / patient power supply part 10 ... Transmission circuit 11 ... Reception Circuit 12 ... Transmitter / receiver connector 13 ... CPU unit 14 ... DSC 15 ... Power inlet 16 ... Breaker 17 ... Line filter 18 ... Power switch 19 ... Terminal board 20 ... Insulation transformer 21 ... Back panel 24 ... Fixing plate 25 ... Chassis 26, 27 ... Isolation surface 28a, 28b ... Input side cable 29a, 29b, 30a, 30b, 35a, 35b ... Cable 31 ... L-shaped plate

Claims (1)

(57) [Claims] 1. A power supply circuit for a medical device, which supplies power required to operate an electric circuit forming the medical device, comprising: a power supply inlet for receiving power from an external power supply; a breaker; and an external power supply. A line filter that removes superimposed noise and noise that goes out of the device, a power switch that turns on and off the power, an isolation transformer, a primary line that serves as a power supply path to the power inlet and the isolation transformer, and a power switch. A terminal board for relaying a primary line between the insulating transformers, a line filter, and a fixing plate for attaching the terminal board and having a surface for electrically isolating an input side line and an output side line of the line filter are provided. Power supply circuit of medical equipment.