[Summary]Electrical construction in hospital operating rooms requires an effective fusion of functionality and safety to better serve their purpose and patients. In this article, the author will discuss this topic from five aspects: determining the load level, designing the power distribution system, designing lighting fixtures, installing and setting up automatic doors, and equipotential bonding connections. The author will provide personal views and suggestions on the electrical construction plan.
Keywords:Hospital; Operating Room; Electrical Construction; Medical IT Systems
1. Introduction
The operating room is a crucial medical facility within a hospital, thus its electrical design and construction must be highly aligned with the room's functional and safety specifications. It should enable the normal operation of various electrical medical equipment while also meeting the basic treatment needs of patients. Through personal experience and by drawing on the ideas and experiences of other electrical designers, the author has compiled an electrical construction plan for hospital operating rooms, based on existing national regulations and design requirements, for the reference and use of the wider design and construction community.
Determination of Load Grades
As the national emphasis on healthcare reform intensifies and related measures are implemented, the medical environment and standards between urban and rural areas are continuously evolving. Even at second-level and below medical facilities, such as village and town clinics, there is a possibility of conducting independent surgeries. Therefore, the author believes that the determination of hospital load levels should include second-level and below hospitals as well.
Design of the power distribution system
During power outages, electrical designs typically opt for fast-starting diesel generators as backup power sources, or they may use EPS systems with shorter switchover times.
Firstly, if an IT system is used in the operating room, the isolation transformer used for the internal medical equipment's circuit becomes the main power source. Secondly, if there is an insulation failure in the electrical equipment within the operating room, the fault current is confined within the system, a relatively small capacitance current fault, which ensures surgery can be performed without cutting off power, and also guarantees patient safety. Furthermore, the local IT system requires the installation of residual current detection devices to promptly identify and rectify faults, preventing ground fault situations. Fourthly, the domestic medical market already has complete sets of medical IP supply equipment, with each operating room requiring a separate distribution box with a capacity not less than 8KV.A. Typically, the operating room distribution box is installed on the wall of an outdoor corridor, allowing maintenance personnel to complete their work without entering the operating room, maintaining the cleanliness of the environment and reducing any external dust and bacteria. Lastly, the alarm display device should be installed in easily accessible and observable locations in the operating room and control center, usually at a height of 1.5 meters from the ground, for wall mounting.
4 Lighting Fixtures Arrangement
Operating room lighting typically includes general and localized illumination. According to the basic requirements of the "Building Illumination Design Standard," the lighting power density of operating rooms should not exceed 30W/m², with a color rendering index over 90. Therefore, based on the performance and level of lighting products available on the market, T5 fluorescent lamps can be used as clean light source strips. On the other hand, a set of viewing lights is required on the wall opposite the operating surgeon, with the number of lamps being 3 for small operating rooms, 4 for medium-sized operating rooms, and 6 for large operating rooms, all to be executed strictly in accordance with relevant requirements. Generally, during the electrical design process, since the doctor's position is not confirmed, dedicated viewing light power sources are pre-installed on both walls of the operating bed.
The setup of the operation lights must comply with the requirements of the "Civil Regulations," but due to the uncertainty of specific surgical projects in each department during the preliminary design phase, the power supply预留 for the operation lights only needs to reach the control box.
Installation and Configuration of 5 Automatic Doors
The operating rooms typically use automatic doors, with "Operating" signs above the door frames. As a complementary product to the automatic doors, they usually only require basic power supply for the doors. If automatic doors are not used, the signs on the door frames would need separate power arrangements, and the control switches would need to be positioned on the side wall inside the operating room.
In addition, if a diesel generator is chosen as the backup power source, emergency lighting that can be used during power outages must be installed in the operating room to ensure it meets the lighting needs during extraordinary times.
6-way equipotential bonding
In compliance with the requirements of the "Civil Code," local equipotential bonding is necessary for surgical operations. Page 19 of the National Standard Atlas "Installation of Equipotential Bonding" explains the primary methods for local potential bonding in hospital operating rooms. Generally, copper conductors with a cross-sectional area of 16mm² or more are used to connect the local equipotential grounding terminal board and the PE line of the isolation transformer system in the operating room's power distribution box.
Firstly, all conductive items within a 2.5m radius in the operating room, such as metal windows and doors, operating tables, water pipes, electrical outlet boxes' PE lines, and the building's reinforcing steel, are connected in a radial manner to LEB boards using copper wiring. Additionally, the resistance on each connection must be ensured not to exceed 0.2 ohms, and any potential difference that could lead to conduction must be kept below 10MV. This allows for a unified connection of the TN-S system before the IT system's isolation transformer and the system's grounding device, eliminating the need for separate grounding equipment. This ensures that the power systems of medical equipment maintain consistent protection grounding, equipotential grounding, and lightning protection grounding to prevent electric shock accidents. However, during actual construction and design, as various facilities in the operating room cannot be installed at once, this naturally presents certain difficulties and challenges for the construction of radial potential connections.
Secondly, as most electronic equipment in hospitals are high-frequency devices, formula analysis indicates that for these devices to meet all application requirements, the grounding of high-frequency equipment must be as short as possible. Therefore, first, a 0.6mm thick copper tape should be used for exposed installation under the suspended ceiling, forming a equipotential metal grid which is connected to the local equipotential bonding (LEB); second, in addition to grounding the medical equipment through the PE line of the distribution box, the grounding wire of the equipment should also be connected to the grid with the shortest possible distance. Moreover, within the operating room, any conductive part within a height range of no more than 2.5 meters can be connected to the grid using the shortest distance principle—after applying equipotential bonding measures, it can reduce the occurrence of high-frequency interference in medical electrical equipment; third, during actual construction and application, careful handling is required for the equipment added for equipotential bonding, and maintenance and repairs should be conducted on the finished surfaces.
In summary, the electrical design and construction of hospital operating rooms, beyond the content mentioned above, also involves the power distribution system and low-voltage systems. The low-voltage systems specifically include video surveillance systems, network communication systems, fire protection systems, and more. Although the author does not delve into the details of the low-voltage systems in this document, this is a part that will require in-depth research and discussion in the electrical construction plans for hospital operating rooms for a considerable period of time in the future.
Selection and Application of 7 Medical Isolation Power Supply Monitoring Systems
7.1 Overview
As electronic medical devices are widely used in hospitals, the threat of leakage current to patients is increasingly significant, especially in critical areas where patients are under surgery or anesthesia. Various electrodes and sensors are directly inserted into the human body, and even the smallest leakage current can potentially cause electrocution and death. Additionally, some medical equipment is used to sustain the lives of critically ill patients, and power outages can also pose a threat to their lives. Therefore, electrical design for this special medical environment should be strictly in accordance with national standards and regulations. Ankorui's medical IT system insulation monitoring and fault location device and system are suitable for critical areas such as operating rooms and ICU (CCU) monitoring wards in hospitals, providing a safe, continuous, and reliable power supply solution for such locations.
7.2 Application Scenarios
Remote monitoring and automation of medical isolation power systems suitable for operating rooms, various intensive care units, emergency rooms, endoscopy rooms, and angiography rooms, among other second-class medical facilities.
7.3 System Architecture
7.4 System Features
The Ankorri IT Distribution Monitoring System is designed with touch screen software, featuring various functions such as remote measurement, remote parameter setting, and remote self-check. It provides a robust system integration tool for centralized monitoring of IT distribution systems in various locations. The primary functions of the software include:
A graphic and an on-site distribution display
The system features a single image and on-site distribution map display function, enabling a clear understanding and timely identification of alarm locations or areas in the IT power supply system, thereby facilitating professionals in reaching the scene promptly for troubleshooting.
Real-time Data Collection and Display
Utilizing insulation monitoring instruments and insulation fault locating instruments installed in various IT power distribution systems, parameters of each isolated power supply system are collected. The collected data is displayed in real-time on the monitoring system interface, including insulation resistance of the IT system to ground, transformer load current, transformer winding temperature, and insulation fault loops, among others.
Fault Alert
Our IT power distribution systems are equipped with a unified processing and recording system for various faults, such as insulation faults, overload faults, overheating faults, and wiring breakage faults. This system can directly pop up on the display interface with fault types, monitoring values, fault locations, and occurrence times. Additionally, the monitoring system's audio-visual alarm system is activated to promptly remind relevant personnel of fault handling. The audio alarm signal can be manually canceled.
Remote Parameter Settings and Queries
Through the system, various alarm parameter thresholds of insulation monitoring instruments in all IT power distribution systems can be remotely adjusted and set according to requirements, and these alarm parameter values can also be freely viewed. Parameters include insulation alarm values, load current alarm values, and isolation transformer temperature alarm values, among others.
Graphics Display Feature
The system can display the insulation and load conditions of various IT power distribution systems, as well as the temperature rise of isolation transformers, in a curve format. This allows facility managers to understand and analyze the operating changes of each power system, enabling targeted maintenance and care for specific systems.
7.5 Ampcree Product Features and Technical Specifications
Reference:
Zhang Lian. Discussion on Key Points of Electrical Engineering Construction in Clean Operating Rooms of Hospitals[J]. Great Science & Technology, 2020(8): 227~228.
Liang Chongjing, Chen Fusheng. Full-process Management of Hospital Operating Room Renovation [J]. China Hospital Construction and Equipment, 2020(4): 72-74.
[3] Summer Cool. Discussion on Electrical Construction Plans for Hospital Operating Rooms
Ankorree Enterprise Microgrid Design and Application Manual, 2022.05 Edition
