Nursing Informatics

Nursing Informatics Self Study: the Computer System Part 1

Computers are used to make complex repetitive calculations, store information, and speed data processing. Within the medical field, computers were first used only in the areas of billing, payroll, and scheduling. They are now used in nearly every aspect of medical care. The application of computer systems into healthcare setting continuously help to improve the quality of healthcare while at the same time reduce some costs, more important, the application of computer systems made telemedicine available and accessible.

Components of Computers

Computers contain physical parts known as hardware. Hardware of the computer includes the electronic circuits, microchips, processors, and the motherboard are housing inside the computer. In addition, devices that peripheral to the main computer including the keyboard, mouse, speaker, printer, fax, monitor, storage devices, and other input and output devices.

The motherboard is a thin, flat piece of non-conducting plastic onto which the computer’s circuits are printed. The motherboard also has areas where chips are mounted and slots are placed which allow the addition of other pieces of hardware.

Memory of a Computer Consists of:

  1. Random access memory (RAM), which is the main storage area in which the computer places the programs and data it is working on, and cache. RAM can be accessed, used, changed, and written on repeatedly. They are loaded when needed and they can be altered. The contents of RAM are lost whenever the power to the computer is turned off.
  2. Read-only memory (ROM), is a form of permanent storage, in which the memory can only read by the computer and cannot be erased or altered. ROM generally contains the programs, called firmware, used by the control unit of the CPU to oversee computer functions. The contents of ROM is not erased when the computer is turned off, and is the first part of the computer to function when the system is turned on.

Input and Output Devices: a way of receiving and reporting data/ information

  1. Input devices: in which the way of information delivered to a computer.
    • Examples of commonly used input devices including:
      • Keycoard: allows data to be typed into a computer by the user
      • Mouse
    • Other examples including:
      • Scanner
      • Touch screen
      • Light pen
      • Human voice
      • Security scanners for fingerprints,
      • Retinal prints
      • Voiceprints
      • Electrodes
      • Optical scanners
      • Magnetic-ink character recognition readers
      • MRIs, CAT scans, and etc..
  2. Output devices:
    • Information that is provided from the computer flows through output devices to the external world.
    • Output devices send this information to where it can be seen or heard.
    • Examples:
      • Monitor
      • Printer
      • Speakers,
    •  Additionally, the computer can send various signals to receiving units to allow for status checks, abnormal conditions, or security breeches.
  3. Some peripherals can be used for both input and output, for example: floppy disks, CD-ROMs, DVDs, and USB drives.


Meaning of Computer Storage Size: Bits VS. Bytes

  1. A bit (binary digit) is a unit of data in the binary numbering system
    • Binary means two, so a bit can assume one of two positions
    • A bit is an ON/OFF switch
      • ON equals the value of 1 and OFF equals 0
    • Bits are grouped into collections of 8, and 8 bits function as a unit-> Byte
  2. A byte is made up of 8 bits


Other Storage Size Terms:

1 kilobyte = 1024 Bytes

1 megabyte (MB)= 1 million bytes

1 igabyte (GB) = 1 billion bytes

1 terabyte (TB) = 1 trillion bytes

Petabyte (PB), Exabyte (EB), Zettabyte (ZB), Yottabyte (YB), and etc.


Computer Speed 

The basic operations of the computer central processing unit (CPU) are called cycles, and each cycle contains fetch, decode, execute, and store.

  • Fetch is the process of retrieving information from storage.
  • Decode is the process of making that information useable.
  • Execute is the process of sending the decoded information to the arithmetic and logic unit.
  • Store is the process of putting the resulting information into the computer’s memory.

The computer speed is measured in time to perform such cycles, and measured by cycles per second which called the clock speed of the computer.

  • Computer Speed Terms:
    • 1 million cycles per second is called 1 megahertz (MHz)
    • 1 billion cycles per second is called 1 gigahertz (GHz)


Computer Software VS Hardware: 

  1. Software is the general term applied to their instructions that direct the computer’s hardware to perform work.
  2. Software consists of instructions communicated electronically to the hardware, in which hardware consists of physical components.
  3. Why needs software
    • Computers only recognizes binary numbers
    • Computers do not directly understand human languages
    • Software is pre-program, packaged, and stored as a tool in needed to make the computer usable based on consumers’ needs.

Examples of software in the health care systems:

  • Hospital information system (HIS)
  • Medication administration record (MAR)
  • Computerized physician order entry (CPOE)
  • Clinical decision support systems (CDSSs)






Saba, V. K. & McCormick, K. A. (2011) Essentials of nursing informatics. (fifth ed).

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