《An Introduction to Ultrasound Equipment and Knobology》.pdf

An Introduction to Ultrasound Equipment and Knobology J. Luis Enriquez, MDa,*, Teresa S. Wu, MDb KEYWORDS Ultrasound Equipment Knobology Probes Transducers Doppler B-mode M-mode KEY POINTS The use of ultrasonography in medical practice has evolved dramatically over the last few decades and will continue to improve as technological advances are incorporated into daily medical practice. Although ultrasound machine size and equipment have evolved, the basic principles and fundamental functions have remained essentially the same. Becoming familiar with the machine and the controls used for image generation optimizes the scans being performed and enhances the use of ultrasound in patient care. INTRODUCTION The use of ultrasonography in medical practice has evolved dramatically over the last few decades and will continue to improve as technological advances are incorporated into daily medical practice. Although ultrasound (US) machine size and equipment have changed over time, the basic principles and fundamental functions have remained essentially the same. This article reviews the general US apparatus design, the most common probe types available, and the system controls used to manipulate the images obtained. A detailed discussion of the physics involved in medical ultraso- nography is presented elsewhere in this issue of Critical Care Clinics. US MACHINES The fundamental principle of ultrasonography can be traced to approximately 200 years ago when Lazzaro Spallanzani, an Italian biologist, theorized that bats used echolocation to hunt in the dark.1 During the late 1800s, the concept of sound The authors have no conflicts of interest or disclosures. a Department of Emergency Medicine, Maricopa Medical Center, 2601 East Roosevelt Street, Phoenix, AZ 85008, USA; b EM Residency Program, Emergency Medicin