3.1.2 Ozone disinfection and sterilization is fast. UV irradiation requires a long action time for sterilization—generally more than 6 hours—whereas ozone at the standard-compliant concentration only needs the machine to run for 1 hour.

　　3.1.3 Ozone disinfection works better under high humidity. When the ambient relative humidity reaches above 60%, the disinfection effect of UV irradiation drops sharply, and at humidity above 80% it can instead induce bacterial revival. Ozone is the opposite: the higher the humidity, the better the sterilization effect. This is because cell membranes swell and thin under high humidity, making their structure easier for ozone to destroy.

　　3.1.4 Ozone disinfection has a low-concentration maintenance function. During UV irradiation, production personnel must leave the site, and after irradiation low-power UV cannot be used for ongoing cleanliness maintenance; during ozone disinfection, production personnel must leave the site, but after disinfection the ozone output can be turned down, using low-concentration ozone that meets national hygiene standards to keep the production workshop air clean.

　　3.1.5 Ozone disinfection has an excellent deodorizing and purifying effect: relying on its strong oxidizing properties, ozone can quickly decompose odor-producing and other odorous organic or inorganic substances to achieve deodorization, breaking the odor source substances down into harmless substances.

3.2 Selecting an Ozone Sterilizer by Installation Location

　　3.2.1 Split-type or mobile units placed in individual rooms

　　3.2.2 Assembled into the air-conditioning unit

　　3.2.3 In the main supply air duct

　　3.2.4 In the main return air duct

　　3.2.5 Separately installed, with only the ozone outlet inserted into the supply (return) air duct—the fifth method is now used: one ozone generator produces ozone that can serve multiple rooms simultaneously.

　　The process is as follows: air compressor – oxygen concentrator – ozone generator – main air-conditioning supply duct – each clean zone.

　　The ozone generated by the ozone generator is led via a nylon tube directly into the main supply air duct; using the pressurized air source produced by the purification fan of the air-conditioning system, it diffuses throughout the entire controlled clean area. This installation method is suitable for both newly built and renovated plants. For rooms without an air-conditioning system, ozone can be fed directly into the room and diffused throughout the room by internal circulation—equally feasible.

Section 9 Medical Laboratory Information System

　　The Medical Laboratory Information System (Laboratory Information System, abbreviated LIS) is an important component of the HIS system; its main functions are the management and transmission of laboratory data. Judging from current applications, LIS has become an indispensable part of modern hospital management.

I. Basic Functions and Requirements of LIS

　　Although developers differ in approach and style, current domestic LIS systems generally have the following functions:

Data acquisition: automatically collects and receives test data sent by analytical instruments and matches it with patient information entered at the front desk to form a database.

　　Data entry: includes entry and editing of basic patient information and entry and editing of manually measured results.

　　Report printing: implements Chinese localization of English reports and prints various test report forms in a unified, fixed format. It can provide complete patient information, specimen status, results, units, reference values (automatically applying reference ranges for different sexes and age groups), and flags for values exceeding the reference range.

　　Statistical processing: performs certain statistical processing of test data, such as computing the Patient Data Mean (PDM) for a batch of results of certain items to observe whether serious systematic errors exist.

　　Real-time monitoring: the measurement results of any instrument in the system can be monitored in real time at any workstation, facilitating problem detection and timely handling.

　　Electronic query of results: using SQL query technology, fuzzy queries of test results can be performed with a single condition or a combination of multiple conditions—fast, accurate, and convenient.

　　Quality control system: can automatically receive or manually enter quality control data, and display and print quality control charts according to the corresponding rules.

　　Automatic billing: automatically bills for completed examination items, avoiding missed or incorrect charges.

　　Statistical reports: can generate at any time various reports on workload, charges, equipment usage, reagent consumption, etc., strengthening departmental management.

　　Comparison of historical patient result data: when reviewing a report, the system can automatically retrieve the same patient's most recent results or all historical results for comparative observation, alerting the reviewer—are discrepancies due to changes in the condition or other causes?—reducing the occurrence of errors.

　　Dynamic charts of patient results: can provide dynamic trend charts of a patient's consecutive measurement results.

　　Long-term storage of results: patient information and results can be stored long-term; storage is limited only by hard disk capacity, and when full, a new hard disk can be installed or data can even be burned onto optical discs for storage.

　　Real-time data sharing: with an LIS built on 10/100 Mbps Ethernet cards, each workstation can enter, view, edit, query, and print the same patient's information and results, achieving real-time data sharing.

　　Management functions: continuously improving departmental personnel, reagent, and instrument/equipment management functions.

　　Electronic attendance system: each operator can sign in at any workstation with an ID number and password, making it convenient for the department director to know staff status at any time.

　　Automatic identification system: bar-code management of specimens, achieving automatic recognition of specimen information.

　　Networking with wards: connected to the Hospital Information System (HIS) of wards or outpatient clinics; all HIS clients can share LIS information in real time. See Fig. 6-61.

[Figure: Fig. 6-61 LIS system working diagram. Both the LIS system and the HIS system are dual-machine systems, connected via LAN and labeled "UIT CDP real-time data replication"; the backup server connects down to UIT BL2000; two fiber-channel switches connect down to UIT BL2900; the dashed box on the right is the disaster recovery center, containing LAN, disaster recovery site, and UIT BL3200; the figure labels fiber cables, backup data flow, CDP data flow, and network cables.]

II. LIS Workflow

　　(1) Test order (laboratory order): the test items that a doctor prescribes for treating a patient's illness—such as blood routine, urine routine, liver function, hepatitis B panel, glucose tolerance, etc.—which may be a single item or a combination of items. (2) Electronic test order: to enable patient billing, the nurse enters the test orders from the medical record into the computer system, thereby forming electronic test orders that are standardized according to billing units and stored in the computer system. (3) Test requisition: the voucher written and issued by the doctor, used by the nurse as the basis for sampling, and finally provided to the laboratory technician for performing the test. The test requisition has a unique serial number and contains the patient information and the test items the patient is to undergo. (4) Electronic test requisition: the test requisition stored in the LIS or HIS system. It can be formed in several ways: A) completed by the LIS system alone; B) completed jointly by the LIS and HIS systems, with the LIS then automatically converting the electronic test orders in the HIS system into electronic test requisitions according to set rules (manual adjustment allowed). (5) Test sample: a patient sample collected by the nurse and provided to the laboratory department for testing, such as blood, urine, feces, cerebrospinal fluid, etc.; one sample corresponds to one test requisition—a one-to-one relationship. (6) Test report: the written report containing test results that the laboratory issues to the clinical department after accepting the test requisition, completing the sample testing, and reviewing the results. (7) Electronic test report: a unified test report provided through the LIS system, which can be conveniently retrieved for reading, printing, etc.

A network system capable of realizing the electronic management of test information and the automation of test information management. A state-of-the-art laboratory information system should have important features such as two-way communication with physician orders, bar-code management, automatic financial billing, and two-way instrument control. See Fig. 6-62.

[Figure: LIS system diagram — at the top is the hospital HIS system (including the management information system: outpatient management, drug management, inpatient management, nurse workstation, medical technology management, surgery management, materials management, equipment management, financial management, director's query, medical insurance interface, touch-screen guidance; and the clinical information system: outpatient doctor workstation, inpatient doctor workstation, nursing information system, electronic medical record), connected via three HIS interfaces respectively to the LIS system (laboratory server — bidirectional communication interface — laboratory instruments), the PACS system (image server — DICOM gateway — CT, color ultrasound, X-ray machine), and the OA system (office automation, Internet, personnel management, archive management, logistics management, library management); on the left vertically is the administrator maintenance center]

Fig. 6-62 LIS System Diagram

III. Application of LIS

　　Functions and applications of the Medical Laboratory Information System (LIS): test data output by laboratory instruments is analyzed to generate test reports, which are stored in a database via the network, enabling doctors to view patients' test results conveniently and promptly. It is an information management system designed specifically for hospital laboratories: it networks laboratory instruments with computers, enabling intelligent, automated, and standardized management of complicated operational processes such as patient sample login, experimental data access, report review, printing and distribution, and statistical analysis of experimental data. It helps improve the laboratory's overall management level, reduce loopholes, and improve testing quality. See Fig. 6-63.

[Figure: LIS workflow diagram — in the top row are three instruments, "biochemistry analyzer," "hematology analyzer," and "urine analyzer," which feed via red lines down into the "workstation"; the workstation connects right to the "LIS server," and then via the network to the "HIS server"]

Fig. 6-63 LIS Workflow Diagram

IV. Development Direction of LIS

　　Development toward intelligence: flagging results outside the reference range and giving warnings in different colors (already achieved) or even by sound.

　　Automatically determining erroneous results caused by various reasons—such as negative values, component values not adding up to the total, or simultaneous positive results for both antigen and antibody of the same virus—giving a warning and prohibiting printing of the result, thereby avoiding the issuance of erroneous reports.

　　Making judgments based on the patient's microbiological examination and identification results, drug susceptibility tests, infection rates, and other data to guide clinical medication.

　　Establishing expert systems: based on measurement results and comprehensive analysis of patient data, proposing the most probable diagnostic opinions for the reference of clinicians.

　　Internet connection: connecting to the Internet to achieve social sharing of laboratory information resources. However, patient information shall be subject to identity verification to protect personal privacy. See Fig. 6-64.

[Figure: Information quick-connect laboratory system solution diagram — with the "Lan" bus as the backbone, three "office network PCs" attached above; below the bus are attached in sequence six servers—HIS, HIS, LIS, LIS, EMR, EMR—plus servers for "cost accounting," "physical examination," "electronic medical record," "electronic medical record," etc.; on the left, six servers connect downward through two switches in a cross connection to "DS 4800 (storage)" and "DS 3400 (backup)", and connect to the "Veritas NetBackup" backup device; on the right, two EMR servers connect via two switches to the "DS4800" storage device]

Fig. 6-64 Information Quick-Connect Laboratory System Solution Diagram