KR20170105383A - Accidents notification device and notification system using the device - Google Patents

Accidents notification device and notification system using the device Download PDF

Info

Publication number
KR20170105383A
KR20170105383A KR1020160028532A KR20160028532A KR20170105383A KR 20170105383 A KR20170105383 A KR 20170105383A KR 1020160028532 A KR1020160028532 A KR 1020160028532A KR 20160028532 A KR20160028532 A KR 20160028532A KR 20170105383 A KR20170105383 A KR 20170105383A
Authority
KR
South Korea
Prior art keywords
heart rate
safety accident
wearer
signal
ear
Prior art date
Application number
KR1020160028532A
Other languages
Korean (ko)
Inventor
김동성
박성재
허성필
문창배
Original Assignee
금오공과대학교 산학협력단
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 금오공과대학교 산학협력단 filed Critical 금오공과대학교 산학협력단
Priority to KR1020160028532A priority Critical patent/KR20170105383A/en
Publication of KR20170105383A publication Critical patent/KR20170105383A/en

Links

Images

Classifications

    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B21/00Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
    • G08B21/02Alarms for ensuring the safety of persons
    • G08B21/0202Child monitoring systems using a transmitter-receiver system carried by the parent and the child
    • G08B21/0205Specific application combined with child monitoring using a transmitter-receiver system
    • G08B21/0211Combination with medical sensor, e.g. for measuring heart rate, temperature
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/02Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/024Detecting, measuring or recording pulse rate or heart rate
    • A61B5/02405Determining heart rate variability
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/02Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/024Detecting, measuring or recording pulse rate or heart rate
    • A61B5/0245Detecting, measuring or recording pulse rate or heart rate by using sensing means generating electric signals, i.e. ECG signals
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00Measuring for diagnostic purposes; Identification of persons
    • A61B5/72Signal processing specially adapted for physiological signals or for diagnostic purposes
    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B21/00Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
    • G08B21/02Alarms for ensuring the safety of persons
    • G08B21/0202Child monitoring systems using a transmitter-receiver system carried by the parent and the child
    • G08B21/028Communication between parent and child units via remote transmission means, e.g. satellite network
    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B21/00Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
    • G08B21/18Status alarms
    • G08B21/182Level alarms, e.g. alarms responsive to variables exceeding a threshold
    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B25/00Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
    • G08B25/01Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium
    • G08B25/10Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium using wireless transmission systems
    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B3/00Audible signalling systems; Audible personal calling systems
    • G08B3/10Audible signalling systems; Audible personal calling systems using electric transmission; using electromagnetic transmission
    • GPHYSICS
    • G08SIGNALLING
    • G08CTRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
    • G08C17/00Arrangements for transmitting signals characterised by the use of a wireless electrical link
    • G08C17/02Arrangements for transmitting signals characterised by the use of a wireless electrical link using a radio link
    • GPHYSICS
    • G08SIGNALLING
    • G08CTRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
    • G08C2201/00Transmission systems of control signals via wireless link
    • G08C2201/40Remote control systems using repeaters, converters, gateways

Landscapes

  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Cardiology (AREA)
  • General Physics & Mathematics (AREA)
  • Emergency Management (AREA)
  • Business, Economics & Management (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Child & Adolescent Psychology (AREA)
  • Animal Behavior & Ethology (AREA)
  • Surgery (AREA)
  • Physiology (AREA)
  • Veterinary Medicine (AREA)
  • Biophysics (AREA)
  • Pathology (AREA)
  • Biomedical Technology (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Public Health (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Electromagnetism (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Psychiatry (AREA)
  • Alarm Systems (AREA)

Abstract

The present invention relates to a safety accident notification device and a notification system using the same and includes a band part 100 to be worn on the wrist and a ear plug part 200 to be partially inserted into the ear, An accident detection unit 110 for detecting a heart rate and outputting a radio signal if an abnormality is detected and a band 120 for allowing the accident detection unit 110 to be closely fixed to the wearer's wrist, The case 200 includes a case 220 having an outer shape and a part of which is partially inserted into the ear of the wearer so as to partially block the external noise and a case 220 housed in the case 220, And an alarm generating unit 210 for generating an alarm.

Description

Technical Field [0001] The present invention relates to a safety accident notification device and a notification system using the same,

The present invention relates to a safety accident occurrence notification device and a notification system using the same, and more particularly, to a safety accident occurrence notification device and a notification system using the safety accident occurrence notification device for propagating to a surrounding area when a safety accident occurs.

Generally, in a noisy industrial field, ear plugs are usually worn to protect the hearing of workers. Ear plugs reduce external noise to prevent damage to the hearing, but it becomes difficult to hear the sounds of nearby workers.

Therefore, there is a problem that when the worker is engaged in the work, the surrounding worker is not easily noticed in case of a safety accident.

One of the prior arts in the same technical field as the present invention is Registered Patent No. 10-1448809 (registered October 01, 2014). In the above-mentioned Patent No. 10-1448809, the distances to other workers are checked at the cutting site where the operation noise occurs, and when there are other workers within the danger radius, the alarm is recognized using the alarm sound or the lamp.

Such a conventional technique can prevent workers from being located within a critical radius from each other in a logging site, thereby preventing the occurrence of a safety accident.

However, when the other workers are outside the risk radius, even if the worker has a safety accident, the neighboring worker can not recognize the safety of the worker, and thus the worker who has been subjected to the safety accident can not take any measures .

In order to solve the above-mentioned problems, an object of the present invention is to provide a safety accident occurrence notification device and a safety accident occurrence notification device, which enable other workers to quickly recognize the occurrence of a safety accident when a safety accident occurs in a nearby industrial workplace in a noisy environment. And to provide a safety accident notification system.

It is another object of the present invention to provide a safety accident occurrence notification device and a safety accident occurrence notification system which can easily recognize occurrence of a safety accident while partially blocking noise in an industrial site with a high noise level.

In order to solve the above-mentioned problems, the safety accident notification device of the present invention includes a band part 100 to be worn on the wrist and a ear plug part 200 to be partially inserted into the ear, An accident detection unit 110 for detecting a heart rate and outputting a radio signal if an abnormality is detected and a band 120 for allowing the accident detection unit 110 to be closely fixed to the wearer's wrist, The case 200 includes a case 220 having an outer shape and a part of which is partially inserted into the ear of the wearer so as to partially block the external noise and a case 220 housed in the case 220, And an alarm generating unit 210 for generating an alarm.

The accident occurrence detecting unit 110 includes a heart rate measuring sensor 111 for measuring the heart rate of the wearer, a controller 112 for comparing the heart rate detected by the heart rate measuring sensor 111 with a reference heart rate, 112 for outputting a promised radio signal through the antenna 114 when the heart rate detected by the heart rate measuring sensor 111 is higher or lower than a reference heart rate.

The alarm generating unit 210 includes a short range wireless communication module 212 for receiving an external signal through an antenna 211 and a speaker 214 for receiving a sound when a signal is received through the wireless communication module 212. [ And a sound generating unit 213 for outputting the sound signal through the speaker.

When it is determined that a safety accident has occurred, the accident occurrence detecting unit 110 transmits a ZigBee type wireless signal, and the alarm generating unit 210 can receive a Zigbee type wireless signal and propagate a safety accident occurrence .

(2) for receiving and relaying signals of the safety-accident notification devices (1) within a set communication area, each of which can be identified with safety-accident notification devices (1) And transmits a radio signal to the safety accident notification devices (1) in the communication area of the relay device (2) when the radio signal of the safety accident notification device (1) is received through the control server 3).

The communication area of the relay device 2 may be wider than the communication area of the safety accident notification device 1. [

A radio signal relayed through the repeater 2 may use a ZigBee type signal.

The safety accident notification device of the present invention includes a band unit for detecting a heart rate by wearing on an operator's cuff and transmitting a radio signal according to the presence or absence of the heart rate, And an earplug part that partially blocks the external noise. When a worker is caught in a safety accident and a change occurs in his / her heart rate, he / she perceives that there is another worker who is caught in a safety accident around a certain worker, So that the user can take action.

In addition, the notification system using the safety accident notification device according to the present invention includes a plurality of relay devices and a control server, and a safety accident occurring in the communication area of the relay device It is possible to quickly perform the safety accident process.

1 is a configuration diagram of a safety accident occurrence notification device according to a preferred embodiment of the present invention.
2 is a block diagram of a safety accident occurrence notification device according to a preferred embodiment of the present invention.
3 is a configuration diagram of a notification system using a safety accident notification device according to a preferred embodiment of the present invention.

The safety accident notification device of the present invention and a notification system using the same will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a safety accident occurrence notification device according to a preferred embodiment of the present invention, and FIG. 2 is a block diagram of FIG.

Referring to FIGS. 1 and 2, a safety accident notification device according to a preferred embodiment of the present invention is divided into two parts, a band part 100 to be worn on the wrist, and a ear plug part 200 to be partially inserted into the ear Lt; / RTI >

The band unit 100 includes an accident detection unit 110 for detecting a wearer's heart rate and outputting a radio signal when there is an abnormality, a band 120 for allowing the accident detection unit 110 to be closely fixed to the wearer's wrist, And,

The earplug part 200 includes a case part 220 having an outer shape and partially inserted into the ear of the wearer to partially block external noise, And an alarm generating unit 210 for generating an alarm to the wearer when the alarm is received.

The accident occurrence detecting unit 110 includes a heart rate measuring sensor 111 for detecting a heart rate of a wearer and a controller 112 for comparing the heart rate measured by the heart rate measuring sensor 111 with a predetermined reference heart rate And a short range wireless communication module 113 for outputting a radio signal set through the antenna 114 according to the comparison result of the controller 112.

The alarm generating unit 210 of the ear plug unit 200 includes a short range wireless communication module 212 for receiving an external wireless signal through an antenna 211 and a short range wireless communication module 212 for receiving a wireless signal from the short range wireless communication module 212 A speaker 214 for converting the sound signal of the sound generator 213 into sound and recognizing the sound signal by the wearer.

The case part 220 of the ear plug part 200 is located in the ear of a wearer of the speaker 214 and the antenna 211 is located at the outermost position and protrudes from the ear. So as to have a sound insulation effect that cuts off external noise.

Further, the portion where the antenna 211 is housed is protruded to the outside so that it is possible to easily confirm whether the work instruction or the field supervisor is worn.

Hereinafter, the configuration and operation of the safety accident notification device according to the preferred embodiment of the present invention will be described in detail.

The band part 100 is worn on the wrist of a worker who is working in a place with a lot of noises and the ear part 200 is connected to the ear part It is worn with a part of it inserted into the ear.

The band part 100 can be used regardless of its position if it can be worn at a specific position of a human body capable of measuring heart rate, but it is most appropriate to wear it on the wrist when considering convenience.

The heartbeat measurement sensor 111 provided in the failure detection unit 110 of the band unit 100 measures the heart rate of the wearer in real time.

The wearer's heart rate measured by the heart rate sensor 111 is transmitted to the controller 112. The controller 112 calculates the heart rate during the set time and compares the heart rate with a preset reference heart rate.

The controller 112 may set the set time to one minute, but it may be set to 15 seconds, 30 seconds, etc., if necessary, and the heart rate of the wearer can be checked by converting it to one minute.

Also, the reference heart rate is an average heart rate range, and it is determined that a safety accident occurs when the measured heart rate of the wearer exceeds or falls below the reference heart rate range.

Then, the control unit 112 outputs a control signal to the short range wireless communication module 113 only when the detected heart rate of the wearer is greater than or less than the reference heart rate, To be transmitted.

The short-range wireless communication module 113 may output a zigbee signal, and may use various short-range wireless communication methods such as Bluetooth.

However, if a large number of workers are working on a large workshop, ZigBee-style short-range communication is the most suitable.

In such a configuration, when a safety accident occurs to a specific user (wearer), the heart rate increases when the wearer is surprised by the occurrence of a safety accident, and the heart rate is remarkably slowed when the wearer is close to the cardiac arrest by accident At this time, the accident detection unit 110 of the band unit 100 transmits the predetermined radio signal described above.

The radio signal transmitted from the accident detection unit 110 is received by the antenna 211 of the ear plug unit 200 of all the wearers within the communication range. The signal received through the antenna 211 is transmitted to the sound generator 213 through the short range wireless communication unit 212. The sound generator 213 outputs an acoustic signal as an analog signal, So that the wearer can recognize it.

A wearer who hears a promised sound through the speaker 214 can check whether a safety accident has occurred in the vicinity, and can treat other wearers who have experienced a safety accident first-aid.

As described above, the safety accident notification device of the present invention can detect the occurrence of a safety accident by detecting the heart rate of the wearer and can automatically propagate the occurrence of a safety accident around the occurrence of a safety accident, So that it can be performed quickly.

3 is a configuration diagram of a notification system using a safety accident notification device according to a preferred embodiment of the present invention.

Referring to FIG. 3, a notification system using a safety accident notification device according to a preferred embodiment of the present invention includes an accident occurrence detection unit 110 for detecting a heart rate of a wearer and outputting a radio signal when an abnormality occurs, A band part 100 including a band 120 for fixing the sensing part 110 to the wearer's wrist and a casing part 220 formed in an outer shape and partially inserted into the ear of the wearer to partially block external noise, And an ear generating unit 210 for receiving an external radio signal received in the case 220 and generating an alarm to the wearer when the external radio signal is received, (1), a plurality of repeaters (2) each having a predetermined communication area defined therein for relaying radio signals, and a plurality of repeaters (2) for relaying the received radio signals medium Transmitting a wireless signal to the device 2 comprises a control server (3) that controls to transmit a radio signal to the alarm generating section 210 which is located in the communication area of the relay (2).

Hereinafter, the configuration and operation of the notification system using the safety accident notification device according to the preferred embodiment of the present invention will be described in detail.

First, the technical configuration shown in FIG. 3 can be understood to spatially expand the function of the safety accident notification device shown in FIGS. 1 and 2.

In other words, by using one control server (3) in a large workplace, it is possible to recognize that all wearers in the workplace have a safety accident in the vicinity, and to be able to quickly dispatch emergency personnel or an ambulance to the position will be.

To this end, the repeater 2 having IDs that can be distinguished from one another is arranged as far as possible without overlapping communication areas.

3, the following description will be made on the basis of the relay device 2 covering the communication area A. Assuming that one of the wearers located in the communication area A is subjected to a safety accident, The accident detection unit 110 of the band unit 100 worn on the wrist detects that there is an abnormality in the heart rate of the wearer and transmits a radio signal.

In this case, if the communication area of the accident detection unit 110 is the area B and the area B does not have the other wearers, the wearer perceives the occurrence of the safety accident in the configuration described above with reference to FIGS. 1 and 2 The radio signal is received by the relay station 2 having the area A as a communication area and transmitted to the control server 3.

When a wireless signal indicating that a safety accident has occurred is received through the repeater 2 having the area A as a communication area, the control server 3 transmits a wireless signal to the repeater 2 having the area A as a communication area , A radio signal indicating that a safety accident has occurred is received in the alarm generator 210 of all the wearers in the area A which is the communication area of the relay device 2.

Therefore, the wearer in the area A can find the wearer who has an unstable heart rate due to a safety accident and can perform first aid treatment. In the control server (3), a safety accident occurs in the area A so that the emergency structure can be performed.

As described above, according to the present invention, even if there is no other wearer within the communication range of the safety accident notification device 1, the relay device 2 can be transmitted around the safety accident occurrence, The control server 3 relayed is informed of the occurrence of a safety accident to the wearer in the communication area of the relay device 2 and can take a life preserver so that a wider range and more wearers can be managed simultaneously .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention will be.

100: band part 110: accident detection part
111: heart rate measuring sensor 112:
113: short-range wireless communication module 114: antenna
120: Band 200: Ear plug section
210: an alarm generating unit 211: an antenna
212: short range wireless communication unit 213: sound generating unit
214: Speaker 1: Safety incident notification device
2: Repeater 3: Control server

Claims (7)

A band portion 100 to be worn on the wrist, and a ear plug portion 200 to be partially inserted into the ear,
The band unit 100 includes an accident detection unit 110 for detecting a wearer's heart rate and outputting a radio signal when there is an abnormality, a band 120 for allowing the accident detection unit 110 to be closely fixed to the wearer's wrist, ≪ / RTI >
The earplug part 200 includes a case part 220 having an outer shape and partially inserted into the ear of the wearer to partially block external noise, And an alarm generating unit (210) for generating an alarm to the wearer when it is received.
The method according to claim 1,
The accident detection unit 110 detects the occurrence of an accident,
A heart rate measuring sensor 111 for measuring the wearer's heart rate,
A controller 112 for comparing the heart rate detected by the heart rate sensor 111 with a reference heart rate,
And a short range wireless communication module 113 for outputting a promised wireless signal through the antenna 114 when the heart rate detected by the heart rate measuring sensor 111 is higher or lower than the reference heart rate as a result of the comparison by the controller 112 Wherein said safety accident notification device comprises:
The method according to claim 1,
The alarm generating unit 210 generates the alarm-
A short range wireless communication module 212 for receiving an external signal through an antenna 211,
And an acoustic generator (213) for outputting the sound through the speaker (214) when a signal is received through the wireless communication module (212).
The method according to claim 2 or 3,
When it is determined that a safety accident has occurred, the accident detection unit 110 transmits a Zigbee type wireless signal,
Wherein the alarm generating unit (210) receives a Zigbee type wireless signal and propagates a safety accident occurrence.
A safety accident notification device (1) according to any one of claims 1 to 3;
(2) capable of identifying each of them and receiving and relaying signals of the safety accident notification devices (1) in a set communication area; And
When a wireless signal of the safety accident notification device 1 is received through the relay device 2, a wireless signal is transmitted to the safety accident notification devices 1 in the communication area of the relay device 2, And a control server (3) for propagating the safety accident notification signal.
6. The method of claim 5,
Wherein the communication area of the relay device (2) is wider than the communication area of the safety accident notification device (1).
6. The method of claim 5,
Wherein the wireless signal relayed through the relay device (2) is a ZigBee type signal.
KR1020160028532A 2016-03-09 2016-03-09 Accidents notification device and notification system using the device KR20170105383A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020160028532A KR20170105383A (en) 2016-03-09 2016-03-09 Accidents notification device and notification system using the device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020160028532A KR20170105383A (en) 2016-03-09 2016-03-09 Accidents notification device and notification system using the device

Publications (1)

Publication Number Publication Date
KR20170105383A true KR20170105383A (en) 2017-09-19

Family

ID=60033633

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020160028532A KR20170105383A (en) 2016-03-09 2016-03-09 Accidents notification device and notification system using the device

Country Status (1)

Country Link
KR (1) KR20170105383A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210034179A (en) * 2019-09-20 2021-03-30 백우민 Employee health status determination system by using sensor processed information combination

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210034179A (en) * 2019-09-20 2021-03-30 백우민 Employee health status determination system by using sensor processed information combination

Similar Documents

Publication Publication Date Title
US10896667B2 (en) Distributed network of communicatively coupled noise monitoring and mapping devices
US5045839A (en) Personnel monitoring man-down alarm and location system
KR20180037209A (en) Automation systems and processes to provide personal safety
KR101309747B1 (en) System for rescuing distress of human life by collapse and fire
KR101581353B1 (en) Safety helmet
KR20120123404A (en) Protective compliance systems
KR101920537B1 (en) smart band system for detecting emergency patients emergency patient information providing method
KR102140829B1 (en) System for monitoring a emergent situation using a smart helmet and the method thereof
JP5382453B2 (en) Contact accident prevention system between construction machines and workers
JP7441436B2 (en) Alarm sound detection device and alarm sound detection program
US11857339B2 (en) Headgear-type device for hazardous air quality warning and air quality improvement
KR20170105383A (en) Accidents notification device and notification system using the device
KR20160074435A (en) Wearable apparatus and method for danger area guiding
KR20190106214A (en) User crisis notification system and method thereof
KR102025379B1 (en) Wearable apparatus for safety supervisory of construction field workers
KR101751960B1 (en) Personal alert safety system for fireman
KR101858995B1 (en) Safety accident prevention system
TWM563246U (en) Personnel monitoring system for rescue sites
KR20080088217A (en) Pulse-sensing earphone with alarm
US20210264762A1 (en) Improved Arboriculture Safety System
JP7055193B2 (en) Emergency evacuation warning device and emergency evacuation warning system for wearing helmets
KR101680836B1 (en) User emergency situation detecting device
KR20190068894A (en) bluetooth safety alarm device
CN220511200U (en) Voice intercom communication system under complex working condition
CN220511199U (en) Voice intercom communication system under complex working condition

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E601 Decision to refuse application