Computer Systems Basics—Hardware


2


Computer Systems Basics—Hardware



Mary L. McHugh



INTRODUCTION



This chapter covers various aspects of computer hardware: the components and their functions which allow computers to do their work, and the various classes of computers and their characteristics. Basic computer concepts, and devices and media used to communicate, store, and process data are addressed. To understand how a computer processes data, it is necessary to examine the component parts and devices that comprise computer hardware.


A computer is a machine that uses electronic components and instructions to the components to perform calculations and repetitive and complex procedures, process text, and manipulate data and signals. Today, computer processors are encountered in most areas of people’s lives. From the grocery store to a community’s power grid, from nuclear power plants to a State’s voting machines, from infusion pumps to physiological monitors, and from patient record systems to radiology machines and other diagnostic devices, computer processors are employed so widely that today’s society could not function without them.


In fact, so dependent has society become on computer processing that a major concern of national agencies focused on combatting terrorism is the vulnerability of American society’s infrastructure (Derene, 2019). Not only are power grids (that control the flow of electricity to all communities in the country) controlled largely by computer systems, but also are water, sewage treatment facilities, financial networks, gas and oil pipelines, much of the military (including nuclear warhead targeting), and virtually all American industry, including healthcare facilities. Perhaps the best example of the influence of computers on our lives is the deep concern many have expressed that foreign countries could use—or may have already used—intrusions into voting machines to affect elections in the United States. Given the essential nature of computers in maintaining society, nurses today should know the basics of computer parts and how they work.


HARDWARE COMPONENTS



Computer hardware is defined as all of the physical components of a computer. The basic hardware of a computer composes the computer’s architecture, and includes the electronic circuits, microchips, processors, random access memory (RAM), read-only memory (ROM), the BIOS chip, and graphic and sound cards. These are attached to a component called a motherboard. The motherboard is the “guts” of a computer. It is a square or rectangular board made of a nonconducting material such as fiberglass or heat-resistant plastic. The motherboard consists of layers of the material that have been sealed together with resin and “printed” with copper tracts (Oettinger, 2016; Padilla, 2019). The copper tracts look a bit like threads and are/interconnected so that electric impulses can be sent throughout the motherboard. The threads of copper create a system of circuits (routes for the impulses to travel) which maximize the speed with which electric impulses can be carried to various components that are soldered onto the motherboard.


Devices that may be inside the computer case but are not part of the architecture include the main storage device which is usually an internal hard drive, optical drive or solid state drive, the cooling system (including heatsinks and fans), a modem, Ethernet connectors, universal serial bus (USB) connectors, and multi-format media card readers. In addition, devices attached or linked to a computer that are peripheral to (outside) the main computer box are part of the system’s hardware. These include input and output devices including the keyboard, monitor (with or without a touch screen), mouse, printer, scanner, and Fax. They also include storage components such as external data storage devices, thumb drives, floppy drives, and tape drives. Most personal computer systems also have sound and video systems, including microphones, speakers, subwoofers, earphones, and a video camera. Typically, computer systems are composed of many different component parts that enable the user to communicate with the computer, and with other computers to produce work. The group of required and optional hardware items that are linked together to make up a computer system is called its configuration. When computers are sold, many of the key components are placed inside a rigid plastic housing or case, which is called the box. What can typically be seen from the outside is the box (Fig. 2.1) containing the internal components, and the peripherals such as a keyboard, mouse, speakers, monitor, and printer.


Images


• FIGURE 2.1. Desktop Computer.


Computer hardware advances during the later 1900s and continuing now in this century have made possible many changes to the healthcare industry. The first business processes to be modified consisted of special administrative functions such as finance, payroll, and billing. Later, computers and associated software programs were developed to assist with hospital bed assignment, nurse staffing and scheduling support, and computer-based charting. Today, many of the hospital’s communication processes are computer based, including programs that support patient communication with the system (often called patient portals), ordering from labs, radiology, pharmacy, and dietary, and all the other services that are ordered to support patient care.


Major advances in the fields of miniaturization and computer imaging allowed incredible changes in the department of radiology, allowing noninvasive visualization not only of internal structures, but even of metabolic and movement functions (Cammilleri et al., 2019; Falke et al., 2013; Gropler, 2013; Hess, Ofori, Akbar, Okun, & Vaillancourt, 2013; Ishii, Fujimori, Kaneko, & Kikuta, 2013; Modesti, 2018; O’Neill et al., 2018; Suff & Waddington, 2017). Computer-enhanced surgical instruments enabled surgeons to insert endoscopy tools that allow for both visualization and precise removal of diseased tissues, leaving healthy tissues minimally damaged and the patient unscarred (Botta et al., 2013; Gumbs et al., 2009; Roner et al., 2019; Vilmann et al., 2019). Virtual reality programs and robotics in surgery have greatly enhanced the scope and complexity of surgeries that are now amenable to much less invasive surgeries (Quero et al., 2019). As a result, massive damage to skin, subcutaneous tissues, muscles, and organs have been eliminated from many procedures. Today, millions of patients who formerly would have needed weeks in the hospital for recovery from major surgery to organs and bones are now able to be released from the hospital the day of their surgery, or in a day or two more at most.


Computers are pervasive throughout the healthcare industry. Their applications are expected to continue to expand and thereby improve the quality of healthcare while at the same time reducing some costs. Most important, the applications of computers to healthcare will greatly expand the diagnostic and therapeutic abilities of practitioners and broaden the diagnostic and treatment options available to recipients of health care. Computers allow for distance visualization and communication with patients in remote areas. Telemedicine is now being used to reduce the impact of distance and location on accessibility and availability of healthcare (Baroi, McNamara, McKenzie, Gandevia, & Brodi, 2018; Evans, Medina, & Dwyer, 2018; Raikhelkar & Raikhelkar, 2019). And during the Corona Virus-19 epidemic, patient and healthcare provider safety has been enhanced through telemedicine medical appointments when the patient did not have to be physically in the presence of the provider. None of these changes could have happened without tremendous advances in the hardware of computers.


REQUIRED HARDWARE COMPONENTS OF A COMPUTER



The heart of any computer is the motherboard (Fig. 2.2), a thin, flat sheet made of a firm or flexible nonconducting material on which the internal components—printed circuits, chips, slots, and so on—of the computer are mounted. The motherboard is made of a nonconducting plastic or fiberglass material. Copper (or other metal) conducting lines (circuits) are embedded into the board. The motherboard has holes or perforations through which components can be affixed so they can transmit data across the circuits (Fig. 2.3). Typically, one side looks like a maze of soldered metal trails with sharp projections (which are the attachments for the chips and other components affixed to the motherboard). The motherboard contains the microchips (including the CPU), and the wiring, and slots for adding components. The specific design of the components on the motherboard—especially the central processing unit (CPU) and other microprocessors— composes the foundation of the computer’s architecture.


Images


• FIGURE 2.2. Motherboard.


Images


• FIGURE 2.3. Circuit Board.


A key component of a computer is called the BIOS chip, short for Basic Input/Output System. The BIOS itself is a computer program stored on a permanent (nonvolatile) memory chip on the motherboard, and is called the BIOS chip. This chip controls several essential operations of a computer, including start-up, performing a self-test of the system to ensure the operating system can function, and communication with input and output devices. If it malfunctions, the computer will not even “start up” so that the user can enter commands. It might show some kinds of error messages, but the computer will not function because the BIOS is what loads the operating system, and without the operating system, the computer doesn’t function at all.


A computer has four basic components, although most have many more add-on components. At its most basic, a computer must consist of communication buses of the printed circuits and slots on the motherboard, a CPU, the input and output controllers, and storage media. The motherboard’s storage media is called memory. Memory includes the locations of the computer’s internal or main working storage. Memory consists of registers (a small number of very high speed memory locations), RAM, which is the main storage area in which the computer places the programs and data it is working on, and cache (a small memory storage area holding recently accessed data).


Memory


Memory refers to the electronic storage devices or chips on the motherboard of a computer. There are three key types of memory in a computer. They are random access memory (RAM), read-only memory (ROM), and cache.


Random Access Memory Random access memory (RAM) refers to working memory used for primary storage. It is used as temporary storage by the CPU and other processors for holding data and commands the processors are actively using. Also known as main memory, RAM can be accessed, used, changed, and written on repeatedly. RAM is the work area available to the CPU for all processing applications. When a user clicks on a program icon, such as a word processing program, the computer loads all or part of the program into RAM where it can be accessed very quickly. It saves work done by the user’s programs until the user either saves the work on permanent storage or discards it. RAM is a permanent part of the computer. Because everything in RAM unloads (is lost) when the computer is turned off, RAM is called volatile memory. The computer programs that users install on their computers to do work or play games are stored on media such as on the hard drive. They are not components of the computer itself and may be replaced by users if desired. Running programs from the hard drive would be a very slow process, so parts of the programs are loaded and unloaded as needed from the much faster RAM. They are unloaded when the user closes the program or turns off the computer. The contents of RAM are erased whenever the power to the computer is turned off. Thus, RAM is made ready for new programs when the computer is turned on again.


Read-Only Memory Read-only memory (ROM) is a form of permanent storage in the computer. It carries instructions that allow the computer to be booted (started), and other essential machine instructions. Its programming is stored on the ROM chip by the manufacturer and cannot be changed by the user. This means that data and programs in ROM can only be read by the computer and cannot be erased or altered by users. As a result, ROM chips are called firmware (as opposed to software that can be changed by programmers). ROM generally contains the programs used by the control unit of the CPU to oversee computer functions. In microcomputers, this may also include the software programs used to translate the computer’s high-level programming languages into machine language (binary code). ROM storage is never erased.


Cache Cache is a smaller form of RAM. Its purpose is to speed up processing by storing frequently called (used) data and commands in a small, rapid access memory location. To understand how cache works, think of a surgical nursing unit. Prior to the 1980s, many hospitals did not have many volumetric pumps on the nursing unit. The pumps were usually kept in the Central Supply (CS) department—usually far away in the basement. Whenever a nurse needed a pump (which at that time was used only for especially dangerous IV medication infusions), the nurse had to go to the CS department and fetch it. When no longer needed for that patient, the pump was to be returned to the CS department. This slow process is analogous to a system with no cache. This was a good system when pumps were seldom used on any unit because storage space is always limited. Now, however, changes in practice and patient acuity have led to the need for one or more volumetric pumps used for every patient. The new plan is to have at least one at every bed and extra volumetric pumps in a storage area in the nursing unit so there are always machines nearby. This system is much more efficient for the nurses. Having pumps at the bedside (and a space to store the pumps nearby) greatly reduces the time needed for nurses to get a pump whenever needed. Rarely used equipment is still often kept in the CS department, but frequently needed items must be kept in a nearby storeroom for quick and efficient retrieval. This is similar to cache. Prior to the development of cache, all information had to be fetched from the hard drive or even from a floppy disc and then stored in RAM. To handle all the work, the processor had to move information into and out of RAM (and back to the hard drive) in order to manage all the data from programs and their output. Given that RAM is large, it takes the computer more time to search RAM to find just the pieces needed. Cache is much smaller than RAM, and thus fetching from cache takes much less time than from RAM. Keeping information that will be used frequently in cache greatly reduces the amount of time needed to move data around among the memory locations. It is a relatively inexpensive way to increase the speed of the computer.


Input and Output


To do work, the computer must have a way of receiving commands and data from the outside and a way of reporting out its work. The motherboard itself cannot communicate with users. However, it has slots and circuit boards that allow the CPU to communicate with the outside world. Input and output devices are wired to a controller that is plugged into the slots or circuit boards of the computer. Some devices can serve as both input and output devices to receive and store information as well as send their programs to the computer itself.


Input Devices


These devices allow the computer to receive information from the outside world. The most common input devices are the keyboard and mouse. Others commonly seen on nursing workstations include the touch screen, light pen, microphone, and scanner. A touch screen is actually both an input and output device combined. Electronics allow the computer to “sense” when a particular part of the screen is pressed or touched. In this way, users input information into the computer. The touch screen displays information back to the user, just as does any computer monitor. A light pen is a device attached to the computer that has special software that allows the computer to sense when the light pen is focused on a designated part of the screen. It allows smaller screen location discriminations than does a touch screen. For both the touch screen and light pen, software interprets the meaning of the useridentified screen location to the program. Many other input devices exist. Some devices are used for security and can detect users’ fingerprints, retinal prints, voiceprints, or other personally unique physical characteristics that identify users who have clearance to use the system.


In healthcare computing, many medical devices serve as input devices. For example, the electrodes placed on a patient’s body provide input into the computerized physiologic monitors. The oximetry device placed on a patient’s finger uses light waves to detect impulses which are sent to a computer and then interpreted as oxygen levels in the blood. Voice systems allow the nurse to speak into a microphone (which is the input device) to record data, submit laboratory orders, or request information from the computer. In radiology, most machines today input digital images from the X-Ray machines to a computer rather than storing them on radiographic film. In fact, the most advanced imaging machines, such as computerized axial tomography (CAT) scans and medical resonance imaging (MRI) machines, could not exist without computer technology.


Output Devices These devices allow the computer to report its results to the external world. Output devices are defined as any equipment that translates the computer information into something usable by people or other machines. Output can be in the form of text, data files, sound, graphics, or signals to other devices. The most obvious output devices are the monitor (display screen) and printer. Other commonly used output devices include storage devices such as the USB drive (also known as flash or thumb drive) and optical media. In healthcare settings, a variety of medical devices serve as output devices. Heart monitors are output devices recording and displaying heart rhythm patterns and initiating alarms when certain conditions are met. Volumetric infusion pump outputs includes both fluids infused into the patient’s body and images displayed on a screen. The pump delivers a specific volume of IV fluids based on commands that the nurse enters so the ordered fluid volume will be infused in the correct time period.


Storage Media


Storage includes the main memory but also external devices on which programs and data are stored. The most common storage device is the computer’s hard drive. Other common media include external hard drives, flash drives, and read/write digital versatile disks (DVDs), and compact disks (CDs). The hard drive and diskettes are magnetic storage media. DVDs and CD-ROMs are a form of optical storage. Optical media are read by a laser “eye” rather than a magnet.


Hard Drive The hard drive is a peripheral component that has very high speed and high density (Fig. 2.4). That is, it is a very fast means of storing and retrieving data as well as having a large storage capacity in comparison with some other types of storage. The hard drive is the main storage device of many personal computers and is typically inside the case or box that houses other internal hardware. Internal hard drives are not portable; they are plugged directly into the motherboard. The storage capacity of hard drives has increased and continues to increase exponentially every few years. In 2014, most personal computers (PCs) were sold with between 500 gigabytes (GB) and up to about a terabyte of storage; in 1990 the PCs had about 500 megabytes (MB) capacity (Table 2.1). That is approximately a 1000% to 2100% increase. On the biggest computers, storage is measured in petabytes (see Table 2.1), which is an almost unimaginably huge number.


Images


• FIGURE 2.4. Hard Drive.



TABLE 2.1. Meaning of Storage Size Terms


Images


USB Flash Drive with the rise in demands for higher and higher density transportable storage, the popularity of the USB drive has also risen. A USB flash drive is actually a form of a small, erasable, programmable, read-only memory (EPROM), a bit like the ROM chips in a computer. It functions a bit like a removable hard drive that is inserted into the USB port of the computer. There are many names for it, including pen drive, jump drive, thistle drive, pocket drive, and so forth. This is a device that can store 4 gigabytes (GB) for about $10. Flash drives can be very tiny, only about ½ in. by 1 in. in some cases. They can also be much bigger and can hold 128 GB or more.


The flash drive is highly reliable and small enough to transport comfortably in a pants pocket or on a lanyard as a necklace, or on one’s keychain. The device plugs into one of the computer’s USB ports and instead of saving content to the hard drive or CD-ROM or disk, the user simply saves to the flash drive. Since the flash drive can store so much data in a package so much smaller than a CD or DVD, the convenience makes it worth the slightly higher price to many users. Of course, as its popularity increases, prices drop.


It should be noted that flash drives are not really used in clinical settings, at least not for business or patient care purposes. However, they are often carried by personnel who may plug them into the hospital’s computer to do personal work. There is a danger that these devices can end up being used to compromise patient or company confidentiality. Nurses should not save confidential patient or company information onto their personal flash drive (or any other personal storage devices). It is too easy to lose the drive itself, and then confidential information could end up anywhere! While working with hard copy medical records, a person had to laboriously copy confidential information onto a piece of paper to create a major risk to confidentiality. With electronic media, it is perilously easy to copy confidential information and breach the security of that information. All nurses are responsible for protecting confidential patient and company information because of personal and company policies and the Health Insurance Portability and Accountability Act (HIPAA) Privacy Rule (www.hhs.gov/hipaa/for-professionals/privacy/index.html).


Optical Media Optical media include compact disks, digital versatile disks, and Blu-Ray. CD-ROMs and DVDs are rigid disks that hold a higher density of information and have higher speed. Until the late 1990s, CD-ROMs were strictly input devices. They were designed to store sound and data, held about 737 MB of information (see Table 2.1), and large laser writers were required to store data on them. Thus, they were read-only media. However, technology developed in the 1980s by Philips Corporation permitted the development of a new type of CD that could be written on by the user. Those are called CD-RW for Compact Disc Read-Write. As technology advanced and people wanted to store motion pictures on computer-readable media, DVDs were developed and held approximately 4.3 GB of information, which handled a regular 2 h movie. They were originally too limited to handle high definition movies and movies longer than 2 hours, and thus media moved to the even higher storage capacity of Blu-Ray discs. Double-layer Blu-Ray discs can store 54 GB or 4.5 h of highdefinition motion picture media. But the technology has advanced to four-layer discs storing 128 GB of media. The name is derived from the blue color of the laser that writes on the media and ray for the optical ray that reads the media.


Other Storage Device As computers became more standard in offices during the 1990s, more and more corporate and individual information was stored solely on computers. Even when a hard copy backups was kept, loss of information on the hard drive was usually inconvenient at the least and a disaster at worst. Diskettes could not store large amounts of data, so people began to search for economical and speedy ways to back up the information on their hard drive. Zip drives, which were mini magnetic tape devices, were a form of relatively fast (in their time) backup storage for people’s data. Thumb (USB) and external hard drives were faster than tape media and replaced it as the backup media of choice. Today, many people purchase services that allow them to back up their data online, which means it gets stored on commercial computers that themselves have backup facilities.


Cloud Storage An extension of the online storage service offered by individual vendors is cloud storage. Data stored “in the Cloud” is still stored on commercial computers called servers. However, “cloud” refers to a distributed system of many commercial, networked servers that communicate through the Internet and work together so closely that they can essentially function as one large system. Enormous numbers of servers that store data are physically located in many warehouse-sized buildings (Fig. 2.5). These data storage sites are called data centers. Multiple data centers are linked together to create cloud storage. The advantage to the customer is safety of the stored data. All personally owned storage devices will fail at some point and it is difficult for people to remember to regularly back up their data. As a result, many people have suffered loss of valued personal data. The cloud storage solution provides greater data security because of multiple security and backup facilities.


Images


• FIGURE 2.5. Cloud Storage Center.


A key factor in cloud storage is redundancy. The storage vendors must maintain multiple copies of the data they store. If one server in a data center fails (becomes inoperable), copies of the data on that server are stored elsewhere and thus the data are not lost. They can be retrieved from another server. There are quite a few vendors who offer individuals free cloud storage space for their customers’ personal files, such as photos, music, and the like. They may also offer storage for a modest monthly or yearly fee. Some continuously back up data, others back up data at specified times, and typically the user can order files to be backed up whenever he or she wishes. Cloud storage is far more secure and reliable than a personal hard drive or backup drives.


Most users of smartphones, tablet computers, and other portable devices store their data in the Cloud, not only because of the security of the data, but also because storage in small devices is somewhat limited. The Cloud allows more data storage than most individuals need for personal use.


MAJOR TYPES OF COMPUTERS



The computers discussed so far are general purpose machines, because the user can program them to process all types of problems and can solve any problem that can be broken down into a set of logical sequential instructions. Special purpose machines designed to do only a very few different types of tasks have also been developed. A category of special purpose computers includes the tablet computers, personal digital assistants (PDAs), and smartphones.


Today, five basic types of computers are generally recognized. Each type of computer was developed as the computer industry evolved and for a different purpose. The basic types of computers include the supercomputer, the mainframe, the microcomputer, the handheld, and PDAs. They differ in size, composition, memory and storage capacity, processing time, and cost. They generally have different applications and are found in many different locations in the healthcare industry.


Supercomputers


The largest type of computer is the supercomputer (Fig 2.6). First developed by Semour Cray in 1972, the early supercomputer research, development, and production were carried out by Cray Corporation or one of its affiliates (Cray Corp, 2014). A supercomputer is a computational-oriented computer specially designed for scientific applications requiring a gigantic amount of calculations which, to be useful, must be processed at superfast speeds. The supercomputer is truly a world-class “number cruncher.” Designed primarily for analysis of scientific and engineering problems and for tasks requiring millions or billions of computational operations and calculations, they are huge and expensive. Supercomputers are used primarily in such work as defense and weaponry, weather forecasting, advanced engineering and physics, and other mathematically intensive scientific research applications. The supercomputer also provides computing power for the high-performance computing and communication (HPCC) environment.


Images


• FIGURE 2.6. Supercomputer Mainframe.


Mainframes


The mainframe computer is the most common fast, large, and expensive type of computer used in large businesses (including hospitals and other large healthcare facilities) for processing, storing, and retrieving data. It is a large multiuser central computer that meets the computing needs of largeand medium-sized public and private organizations. Virtually all largeand medium-sized hospitals (300 beds and up) rely on mainframe computers to handle their business office operations. They may have the hospital’s electronic medical record (EMR) on that computer as well, or they may subcontract mainframe computing from a professional computer system support vendor.


Mainframes are used for processing the large amount of repetitive calculations involved in handling billing, payroll, inventory control, and business operations computing. For example, large volume sales businesses like grocery store chains and the “big box” stores have mainframe computers tracking all sales transactions. In fact, the machines and software that process transactions in high-volume businesses are known as transaction processing systems (TPS). The information nurses chart on patients in inpatient care facilities can be viewed as transactions. For example, every time a nurse charts a medication, that charting records use of one or more drugs. That charting in turn is transmitted to the pharmacy so that one item of that drug in inventory can be decreased. Typically, when the count of remaining inventory drops to a certain level, the TPS automatically initiates an order to a pharmacy supply house for more of the drug. Operations such as charting a patient’s vital signs goes into that person’s medical record and might trigger a warning to the nurse should any of the vital signs be out of range for that patient. For example, if the blood pressure is too high or too low, the system might be programmed to signal a warning alert so the nurse is advised to assess the patient and take appropriate action. Given the number of these kinds of “transactions” in clinical facilities, a powerful computer is needed to handle them all, and therefore, the hospital’s EMR and other clinical applications are often handled through a mainframe computer.


Mainframes always have very high processing speeds (calculated in millions of processes per second, or MIPS, or in floating point operations per second, or FLOPS). In earlier times (prior to the year 2000), mainframes were often defined almost entirely by their high processing speed. However, computer processing speed changes so rapidly that today’s mainframes are more defined by the following characteristics than merely processing speed:


1.   Extensive input and output capabilities to support their multi-user environment


2.   Complex engineering to support long-term stability with high reliability, allowing these machines to run uninterrupted for decades


3.   Ability to process the massive throughput needed for high-volume business transactions and business office operations.


In hospitals, mainframe computers are often used to support the entire Hospital Information Technology (HIT) system, also known as the Hospital Information System (HIS), purchased from one of the large HIT vendors. The HIT not only includes business and nursing operations components, but also supports many clinical systems. As previously mentioned, the applications nurses use in hospitals and other large healthcare facilities to document patient care, obtain laboratory and radiology results, record medication orders and administration records, and perform many other nursing record-keeping and information retrieval tasks typically involve use of a hospital mainframe computer.


Virtually all general hospital departments need large amounts of computer support. A partial listing of departments that typically have their systems on the hospital’s mainframe computer includes the laboratory and radiology systems, the dietary department, the admissions department and its patient location system, the pharmacy department, and the central supply department’s inventory control system. Sometimes clinical monitoring systems such as cardiac and fetal monitors, and surgery information systems may be housed on the mainframe, although these systems may reside on their own separate computer hardware.


Today the average sized or large acute care hospital has a HIT system with hardware configuration of a mainframe that may be located on-site (physically located at the hospital) or it might be located somewhere else. In some cases, the mainframe is not owned by the hospital but by a computer service vendor who provides mainframe computing power to multiple customers. In that case, the hospital’s information is processed and stored on the vendor’s computer systems.


A mainframe is capable of processing and accessing billions (GB) of characters of data or mathematical calculations per second. Mainframes can serve a large number (thousands) of users at the same time. In some settings, hundreds of workstations (input and output devices that may or may not have any processing power of their own) are wired directly to the mainframe for processing and communication speeds faster than can be achieved with wireless communications. Typically, there are also wireless and telephone linkages into the computer so that remote users can gain access to the mainframe. As compared with a desktop PC, a mainframe has an extremely large memory capacity, fast operating and processing time, and it can process a large number of functions (multiprocessing) at one time.


Microcomputers (Personal Computers or PCs)


While mainframe computers provide critical service to the healthcare industry, much smaller computers are also an essential part of healthcare computing systems. Computers designed to support a single user are called microcomputers or personal computers (PCs). Much smaller and less powerful than a mainframe, PCs were designed to be used by one person at a time.


In hospitals, PCs are used for an increasing number of independent applications as well as serving as an intelligent link to the programs of the mainframe. Hospital nursing departments use PCs to process specific applications such as patient classification, nurse staffing and scheduling, and personnel management applications. Microcomputers are also found in educational and research settings, where they are used to conduct a multitude of special educational and scientific functions. Desktops are replacing many of the mainframe attributes. Desktops can serve as stand-alone workstations and can be linked to a network system to increase their capabilities. This is advantageous, since software multiuser licensing fees are usually less expensive per user than having each user purchase his or her own copy. Computer size has steadily decreased since their invention, while at the same time power has grown exponentially. The components of desktop computers are typically housed in a hard case. While the size of the case can vary considerably, one common size is 2 feet long by 6 to 10 in. wide. The case is most typically connected via wire or wireless technology to a network, keyboard, monitor, mouse, and printer.


Microcomputers are also available as portable or laptop computers, notebooks, tablets, and handheld computers. Laptop computers are highly portable because they are much smaller than the standard desktop microcomputer. Many are less than 2 in. deep. There is huge variation in the length and width, but if a 15 in. viewing screen is used, the case is usually about 16 in. by 12 in. Notebook computers are a bit smaller and lighter, although the line between a laptop and a notebook computer is thin. Notebooks tend to have a bit less computing power and are about 12 in. by 8.5 in. and very light.


Desktop and laptop computer systems with wireless connectivity to the hospital’s computer network are often placed on a rolling cart for use of the nursing staff in recording nursing notes, ordering tests and treatments, looking up medications, and other computer work in inpatient and clinic settings. These computers on carts are often referred to as “WOWs” for workstation on wheels, or “CABs” for computer at bedsides. Many nurses find these rolling workstations to be much more useful than fixed computers at patient bedsides for a variety of reasons. Additionally, one workstation can be assigned to a nurse to use with his or her assigned patients, thus eliminating the need for a separate computer for every bed. This solution allows nurses to adjust screen height and location of the mouse on the WOW for their physical comfort that day rather than having to readjust a separate computer at every bedside (Box 2.1).


Only gold members can continue reading. Log In or Register to continue

Jul 29, 2021 | Posted by in NURSING | Comments Off on Computer Systems Basics—Hardware
Premium Wordpress Themes by UFO Themes