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Chapter 6: Biomedical Science

SURG 111: Surgical Technique

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Key Terms

• Active Electrode• Cartesian coordinate• Geometry• Central Processing Unit• CPU• Circuit• Degrees of Freedom

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Key Terms

• Electrons• Free Electrons• Generator• Grounding Pad• Insulators• Load

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Key Terms

• Mass• Modem• Monitor• Mouse• Neutrons• Patient Return Electrode

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Key Terms

• Plasma• Power• Pressure• Protons• Switch

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Objectives

• After studying this chapter, you will be able to:– Recognize basic components of a computer

system– Demonstrate basic word processing, Internet,

and e-mail functions– Apply computer knowledge to safe patient

care– Apply electrical safety precautions

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Objectives (cont’d.)– Cite the basic principles of electricity and their

application in the operating room (OR)– Interpret the basic concepts of robotics– Analyze the geometrical concepts of robotics

and the mechanisms of the robotic system– Apply the principles of robotics to safe patient

care practices in the OR– Demonstrate principles of sterile technique

during robotic surgical procedures

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Introduction

• This chapter provides a broad base of knowledge for entry-level surgical technologists– Areas: computers, electricity, and robotics

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Computers

• Hardware– Overall term used to describe the components of

a computer• Central processing unit (CPU), monitor, modem, and

memory storage devices

– Using the computer: switch on, start-up, and login– Desktop: first to pop up on monitor screen

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Computers (cont’d.)

• Software – Programs that operate the computer system,

individual hardware components, and user’s programs

– Available on CD-ROMs or the Internet – Many varieties

• Word processing– Creating a document

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Internet Basics

• Internet – Gigantic international network connected via

millions of servers• World Wide Web

– User-friendly format for browsing Internet pages • Addresses

– Usually contain: http://, www., and .com

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Internet Basics (cont’d.)

• Accessing the Internet– Requires Internet service provider account– Surfing the Internet refers to looking at many

different web pages and jumping from one to another

• Favorites and history features– Archive website addresses for easy referencing

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Internet Basics (cont’d.)

• Forward and back buttons– Used to move back and forth among pages of a

website– Access very recently viewed websites

• Importing images from the Internet– Photographs and drawings can be imported into a

document from the Internet– General steps: refer to text

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Internet Basics (cont’d.)

• Internet research– Conducted through a search engine– Biggest challenge: helping the search engine

understand what exactly to look for• Using e-mail

– E-mail program functions: saving a message and replying to, forwarding, printing, or deleting it

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Surgical Applications

• Scheduling surgical patients – Streamlined because of computer technology– Communication via e-mail or fax instantly provides

necessary patient information– Surgery schedule can be scanned, saved, and sent

as an e-mail attachment• Surgeon’s preference card

– Now developed and saved electronically

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Surgical Applications (cont’d.)

• Patient charts– Electronic charts are easily accessible to confirm

results or other information• Surgical records

– Computers are helpful for interdepartmental communication

• Sterile processing– Computers have substantially reduced paperwork

in sterile processing department

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Electricity• Basic principles of electricity

– Electron theory: principles that govern the behavior of electrons

• Atoms, electrons, and matter– Matter is anything that has mass and occupies

space– All matter consists of atoms– Atoms are composed of small particles: protons,

electrons, and neutrons

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Electricity (cont’d.)

• Insulators– Materials that inhibit the flow of electrons

• Electrical charges – Negative or positive – Too many or too few electrons on an atom,

respectively– Law of electric charges: like charges repel each

other; unlike charges attract each other

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Electricity (cont’d.)

• Electric current – Movement of the electrical charge

• Magnetism and electricity– Magnetic fields: created by electrons as they orbit

the nucleus – Electromagnets: metals that become magnetic

when a conductor is wrapped around it

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Electricity (cont’d.)

• Volt – Defines electrical potential– Voltage: potential energy of electrons (or the

electric charge) at any given time between two points

• Current – Measured in amperes (amps)– Flow of electric charge or rate of flow of electrons

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Electricity (cont’d.)

• Power, load, and switch– Power: rate at which work is done– Load: device that uses electricity to perform some

type of function– Switch: device used to open or close a circuit and

controls the flow of electricity• Wall outlets

– Usually 110 volts– Three prongs: positive, negative, and ground

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Electricity (cont’d.)

• Direct current and alternating current– Direct current (DC): electrical current that flows in

one direction from the negative pole to the positive pole

– Alternating current (AC): flow of current that reverses direction periodically

• Radiofrequency– Frequency: number of wave cycles per second

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Electricity (cont’d.)

• Isolated circuit– Protection against shock: access prevention or

insulation barrier • Electrosurgery

– Application of electrical current through tissue to coagulate or cut tissue

• ESU circuit– Components: generator, active electrode, patient, and dispersive electrode

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Monopolar Electrosurgical Units

• Monopolar mode components– Generator– Active electrode– Dispersive electrode

• Pathway of the monopolar current – Refer to Figure 6-6

• General safety and patient considerations – Refer to text

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Bipolar Electrosurgical Units

• Bipolar electrocautery – Same basic components as monopolar mode,

except in a different configuration• Bipolar current

– Current flows from generator to the active electrode

– Active electrode delivers coagulating current – Electrical current passes through the tissue – Current returns to the generator

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Accessories to Electrosurgery

• Argon gas – Used to enhance the effectiveness of the

electrosurgical current– Inert and incapable of combustion, allowing

electric current to pass safely through the gas• Harmonic scalpel

– Uses ultrasonic energy to cut and coagulate tissue at the point of impact

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Advantages of Electrosurgery

• Reduces blood loss – Bleeding is quickly controlled

• Saves time – Faster to use

• Cutting current burns tissue as it is divided– Reduces need to stop and control bleeding

• Cutting current seals small spaces in the tissue and lymphatic vessels – Would normally ooze fluid postoperatively.

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Hazards to the Patient and Surgical Team

• Causes of electrical burns– RF capacitive coupling: an alternating current travels

from the active electrode, across intact insulation, and into the skin

– Dielectric breakdown: high voltage breaks down some insulating material

• Vaporized tissue plume– Formed when tissue is thermally destroyed and

vaporized through the use of the ESU, laser, or other surgical devices

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Surgical Applications

• Electricity is used in numerous ways in the OR environment– X-ray machine– Endoscopes– Robotics– Lasers

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Surgical Applications (cont’d)

• Four interactions of laser with tissue– Absorption– Transmission– Reflection– Scattering

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Surgical Applications (cont’d)

• Laser parts– Energy pump or excitation source– Laser head– Ancillary (auxiliary) components– Control panel– Delivery system

• CO2 laser – Permits precise cutting and coagulating due to absorption of energy by cellular water content

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Surgical Applications (cont’d)

• Nd:YAG laser– Wavelength is located in the near-infrared region

of the electromagnetic spectrum– Consists of an yttrium–aluminum–garnet solid

crystal that is laced with neodymium• Holmium:YAG laser

– Discharges a pulsed beam– Laser energy travels to the tissue through a flexible fiber

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Surgical Applications (cont’d)

• Krypton laser – Gas laser– Electrical current activates the krypton medium to

create the laser energy• Excimer laser

– Uses gases and halogens as the active medium– Laser beam is ultraviolet in color

• Is absorbed by protein with minimal thermal spread

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Surgical Applications (cont’d)

• Argon laser – Produces a blue light or green light– Plasma tube contains the argon

• Lasers in endoscopy– Gastrointestinal endoscopy– Laser microlaryngoscopy and bronchoscopy– Stereotactic laser endoscopy – Arthroscopy– Endoscopic transurethral prostatectomy

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Surgical Robots

• Robot(s)– Sophisticated machine developed to perform

specific tasks– Features some degree of mobility and, once

programmed, operates automatically and performs a large variety of tasks

– Classified by generations: first-, second-, third-, and fourth-generation

– Improve surgical patient care – Help control the cost of health care

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Terminology

• Robotic “language”– Articulated– Binaural hearing– Cartesian coordinate geometry– Cylindrical coordinate geometry– Degrees of freedom– Degrees of rotation– Expert systems– Manipulators

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Terminology (cont’d.)

– Resolution– Revolute geometry– Sensitivity– Telechir– Telepresence

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da Vinci® Robotic System

• One of the most frequently used surgical robots – Refer to Figures 6-9 and 6-10

• Components– Console– Patient-side cart – Four manipulators– High-definition three-dimensional vision system

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da Vinci® Robotic System (cont’d.)

• Surgical technologists involved with robotic surgery – Must have a thorough understanding of the

robotic system• Positioning the system • Connecting electrical cords and equipment• Testing the system• Loading and switching out surgical instruments on

manipulators• Troubleshooting

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Advantages of Remote Manipulation

• Eliminates hand tremor – More precise surgical technique

• Allows the surgeon to effectively perform complex interventions – Within a confined space

• Better visualization of the operative site– Three-dimensional imaging

• Fosters telesurgery– Benefit to small rural hospitals

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Manipulators

• Characteristics of manipulators– Categorized by geometrical design– Joints are referred to as shoulders, elbow, and

wrist – Definite number of degrees of freedom and

rotation– Geometry designs: Cartesian coordinate geometry,

cylindrical coordinate geometry, and revolute geometry

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Voice-Activated Control System, Hearing and Vision

• Master control unit – Activated by the surgeon’s hand or voice via a

headset and microphone– Controls the manipulator and other surgical

applications– Programmed to ignore casual conversation– Hearing is analogous to human hearing– Important concepts: sensitivity and resolution

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Decontamination and Sterilization of Robotic Components

• Sterile instruments and endoscope – Cleaned and sterilized in the same way as any

other minimally invasive components• Manipulators of the robot that hold the

endoscope and instruments – Not sterilized– Covered with special sterile sleeves

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Summary

• This chapter reviewed:– Basic computer system components– Computer knowledge as it relates to safe patient

care– Electrical safety precautions– Basic principles of electricity – Basic concepts of robotics– Principles of sterile technique

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Homework Assignment