VIETNAM NATIONAL UNIVERSITY – HOCHIMINH CITY
INTERNATIONAL UNIVERSITY
SCHOOL OF BIOMEDICAL ENGINEERING
Lab 1A - Biomedical Instrumentations
BM050IU
Lab Report: MEDICAL DEVICES SESSION
ULTRASOUND
Prepared by
Nguyen Thuy Vy - BEBEIU20162
Nguyen Quynh Nhung - BEBEIU20227
Nguyen Thi Hong Chau - BEBEIU20132
Vuong Hong Kim Chau - BEBEIU20188
Date Submitted:
Course Instruction :
6/12/2021
Dr. Nguyen Thanh Qua
TABLE OF CONTENTS
1.
INTRODUCTION ................................................................................................................... 1
2.
WORKING PRINCIPLE ......................................................................................................... 2
3.
4.
2.1.
Block diagram of these devices ...................................................................................... 2
2.2.
The principle of components .......................................................................................... 6
2.3.
The operation of these devices ........................................................................................ 7
CLINICAL APPLICATION ................................................................................................... 8
3.1.
Main purposes ................................................................................................................. 8
3.2.
How does it work? .......................................................................................................... 9
3.3.
Diagnosis and Treatment ................................................................................................ 9
THE LATEST ADVANCEMENT ........................................................................................ 10
4.1.
The latest technology .................................................................................................... 10
4.2.
Functions - How can it help people?............................................................................. 11
4.3.
The future development trends ..................................................................................... 11
5.
CONCLUSION ...................................................................................................................... 12
6.
REFERENCES ...................................................................................................................... 12
International University
Lab 1A – Biomedical Instrumentations
i
BM050IU
1.
INTRODUCTION
Today's lecture has provided an overview of a medical device which is the
Ultrasound. Besides, we have learned some fundamental knowledge about this device
such as their history, the basic structures, main functions, clinical applications. The
Ultrasound machine are very useful in the biomedical application field. Over
centuries, these devices have been completed day by day, allowing people to reach the
latest devices, bring new changes for health improvement.
The course not only introduces the device but also mentions the operation of those
instruments in life. It lays out some different methods, applications used for diagnosis
and treatment. Moreover, we have learned about medical machine processing, block
diagram, and the principle of each component in these devices, which are directly
related to our major.
a. Background information:
What is an Ultrasound device?
Ultrasound encompasses both diagnostic
(mostly imaging) and therapeutic (mostly
therapeutic) ultrasound uses. It's used in
diagnostics to build an image of internal
body structures including tendons,
muscles, joints, blood vessels, and
internal organs, as well as to quantify
specific properties (such distances and
velocities) and provide an informative
auditory sound. Its goal is usually to
locate a disease source or rule out
pathology. Obstetric ultrasonography was a forerunner of clinical ultrasonography,
and it involves utilizing ultrasound to examine pregnant women.
Ultrasound is made up of sound waves with frequencies that are far higher than the
human hearing range (>20,000 Hz).[1] Ultrasonic images, often known as sonograms,
are made by utilizing a probe to emit ultrasound pulses into tissue. Ultrasound pulses
reverberate off tissues with varying reflection characteristics and are returned to the
probe, which records and shows the image.
In medicine, a procedure known as transonography is commonly utilized.
Ultrasound can be used to guide diagnostic and therapeutic operations such as
biopsies and fluid draining. Sonographers are medical practitioners who perform scans
that are traditionally analyzed by radiologists, or cardiologists in the case of cardiac
ultrasonography, who are specialists in the application and interpretation of medical
imaging modalities (echocardiography). Ultrasound is increasingly being used in
office and hospital practice by physicians and other healthcare providers who provide
direct patient care (point-of-care ultrasound).[2]
International University
Lab 1A – Biomedical Instrumentations
1
BM050IU
b. History:[3]
 Lazzaro Spallanzani, a biologist, professor, and priest, is credited for laying the
fundamental groundwork for the use of ultrasonography in 1794.
 In 1877, the piezoelectric effect was established by Pierre and Jacques Curie,
and it was later used to build ultrasonic transducers.
 During World War I, Paul Langevin and an engineer called Chilowski
developed the "Sonar," which was designed to detect submarines by detecting
their reflection of ultrasonic waves. The invention benefited from Pierre and
Jacques Curie's piezoelectricity research. The Florisson-Langevin probe, their
first transducer, was a mosaic of quartz plates bonded between two steel foils.
 Ultrasound was formerly thought to be a cure-all in the 1940s. Everything from
arthritic symptoms to gastric ulcers and eczema were treated with it.
 By measuring the transmission of an ultrasonic beam through the skull, Karl
Dussik and his brother Freiderich, a physicist, attempted to find brain tumors
and cerebral ventricles. "They coined the term "hyperphonography" to describe
their method.
 During his time at the Naval Medical Research Institute in Maryland in the late
1940s, George Ludwig employed ultrasonography to identify gallstones.
 In 1948, Douglas Howry, a University of Colorado radiologist who focused on
the creation of B-mode equipment that linked cross-sectional anatomy to gross
pathology, is another ultrasound pioneer.
 John Reid and John Wild, who designed a linear, handheld, B-mode equipment
for breast cancers in 1950 and Joseph Holmes, who, with Howry and other
engineers, created the first 2D B-mode linear compound scanner in 1951.
 Inge Edler and Hellmuth Hertz are regarded the "fathers" of echocardiography,
while Wolf D. Keidel was the first to use ultrasound on the heart. In early
1953, Hertz was a physicist when he met Edler, a cardiologist, by chance over
lunch.
 In 1966 Don Baker, Dennis Watkins and John Reis invented the Doppler
ultrasound machine to help display images of blood flowing in blood vessels.
 Kazunori Baba of the University of Tokyo pioneered 3D ultrasound technology
in the 1980s, and the first 3D ultrasound photos of the fetus were recorded in
1986.
 In 1989, Professor Daniel Litchtenstein began to combine ultrasound in general
and lung ultrasound into diagnosis and treatment.
2.
2.1.
WORKING PRINCIPLE
Block diagram of these devices
The Ultrasound device is divided into 6 types, including:[4]
 Endoscopic Ultrasound
International University
Lab 1A – Biomedical Instrumentations
2
BM050IU





Doppler Ultrasound
Color Ultrasound
Duplex Ultrasound
Triplex Ultrasound
Transvaginal Ultrasound
The Endoscopic Ultrasound is the main
purpose of this type of ultrasound is related
to the biopsy procedure. This procedure
has a crucial effect on the patients’
therapeutic by obtaining a definite tissue
diagnosis for lesions gained by
endosonographic. This method is not at all
limited to any organs of the body, from
gastroenterology to various anatomical
regions associated with pulmonology,
thoracic, gynecology and endocrinology.[5]
Equipment of the Endoscopic Ultrasound:
 Endoscopic
 Micromotor driver circuit
 Delay generator
 US pulser – receiver
 CPU
The Endoscopic probe has:[6]






Stiff steel needle (the core of this instrument)
Handle piston (controling the needle)
Means of button (locking and unlocking handle piston)
Luer-lock (connecting handle and the endoscope)
Metalspiral (avoiding damage in endoscope instrument)
Elevator (positioning the needle)
The Doppler Ultrasound is a non-invasive test can be used to estimate the blood flow
through the blood vessels by reflecting ultrasound from circulating red blood cells,
using high-frequency sound waves to create images, but cannot show blood flow.[7]
There are 2 types of Doppler Ultrasound: Continuous Wave (CW) Doppler Ultrasound and
Pulse Wave (PW) Doppler Ultrasound.
Continuous Wave (CW) Doppler Ultrasound: measuring mainly the velocity of moving blood.
International University
Lab 1A – Biomedical Instrumentations
3
BM050IU
Equipment of the CW Doppler
Ultrasound:
 Relatively narrow-band high-Q
transducer, including transmitter
and receiver: preserving velocity
information.
 Amplifier: amplifying ultrasound
signals to an audible sound level
(Beat)
 Wall Filter: removing low
frequencies.
 Headphones/Speakers: hearing
Beat.
 Spectrum analyser: displaying
output.
Pulse Wave (PW) Doppler Ultrasound: obtaining both velocity and depth information.
Equipment of the PW Doppler
Ultrasound:
 Sample volumn
 Electronic range gate: receiving
echoes
 Transducer: sending and
receiving signals
 Amplifier
 Sample-and-hold operation:
constructing a staircase signal
 Spectrum Analyzer
 Headphones/Speakers
The Color Ultrasound: Color (flow) scanning involves displaying Colour Doppler
data on real-time (B-mode) grayscale images. The superimposition is such that
tissue volumes containing no detectable flow are displayed in grayscale and motion
is in color (usually red for toward the transducer and blue for away from the
transducer). The Color Ultrasound is useful in imaging the heart and major blood
vessels in applications for which mean flow velocity is a diagnostically useful
parameter. It is also used to recognize and localize vessels and vascular blockage.[7]
International University
Lab 1A – Biomedical Instrumentations
4
BM050IU
Equipment of the Color
Ultrasound:
 Transducer
 Transmitter & Receiver
 Scanner
 TGC & ADC
The Duplex Ultrasound: is a ultrasound
allows using high-frequency sound
waves to estimate the blood flow velocity
directly from the Doppler shift frequency
and leg vein structures. The term
“duplex” means using the two modes of
ultrasound, including a Doppler type
(evaluating the speed and direction of
blood flow in the vessel) and 2D B-mode
imaging (obtaining vessel images).[8]
Equipment of the Duplex Ultrasound:[9]
 Probe with piezoelectric crystals
 Linear array transducer
 Low frequency transducer
 Ultrawide bandwidth/ harmonic imaging transducer
 Two-dimensional transducer
 Color-flow Doppler display
 Grayscale B-mode
The Triplex Ultrasound: is the combination of the 3 methods: B-Scale greyscale,
Color Doppler and Spectral Doppler to simplify the explanation of the ultrasound data
due to using the different colors to designate the blood flow direction. Vessels in which
blood is flowing are colored red for flow in one direction and blue for flow in the other,
with a color scale reflecting the flow velocity.[7]
(Block diagram of the Triplex Ultrasound)
International University
Lab 1A – Biomedical Instrumentations
5
BM050IU
Equipment of the Triplex Ultrasound:[10]
 Electromagnetic position sensor
 Electric gyro attached to the probe
 2D/3D transducer
 Ultrasound scanner
 ROI mask
 Video capture card
The Transvaginal Ultrasound: By inserting the wand-shaped transducers into the
vagina, this type of ultrasound allow obtaining images of pelvic organs, including
ovaries when the transducer emits sound waves.[11]
Equipment of the
Transvaginal
Ultrasound:
 Wand-shaped
transducer
 Transmitter
 Beam former
 Microprocessor
 Signal processor
 Scanner
 Display
2.2.
The principle of components
The Central Processing Unit (CPU): the CPU plays an instrument in controlling and
processing the majority of the ultrasound system functions. It is responsible for the
input of the other components, as well as receiving and analyzing electronic input from
the transducer ultimately to construct the image. It also provides the tools for estimating
and obtaining quantitative measurements from the images. Besides, the CPU is cited as
the temporary storage image system.[12]
Transducer: being considered as the “working arm” of an ultrasound system, the
transducer creates the sound waves and receives reflected sound waves. Sound waves
produced by piezoelectric crystals in transducers are focused into a beam and
International University
Lab 1A – Biomedical Instrumentations
6
BM050IU
transmitted through the soft tissues of the body and target organ. After that, the
transducer pauses for a short term to receive the reflected sound waves. The transducer
also includes a sound-absorbing material to minimize back reflections from itself, as
well as an acoustic lens to assist concentrate the generated sound waves.[12]
Transducer pulse controls: the transducer pulse controls allow the user to select and
adjust the frequency and length of the ultrasonic pulses, as well as the machine's scan
mode. The operator's orders are converted into varying electric currents that are applied
to the piezoelectric crystals in the transducer.
Image storage system: the image storage systems differ significantly amongst
ultrasound systems. Recent systems allow to save a limited number of digital images;
nevertheless, the images must still be transmitted to another computer system, such as
a workstation, or stored on magneto-optical diskettes. The method of digital image
storage and archiving enables simpler picture retrieval and analysis while avoiding the
loss of resolution that occurs when images are saved on videotape. Picture analysis can
be conducted utilizing the ultrasound machine or a suitable workstation with digital
image storage.
Monitor: after reflected sound waves interact with the transducer’s piezoelectric
crystals to generate a small current, the CPU processes these electrical impulses, and
the image is created and presented on a monitor. Depending on the model of the
ultrasound machine, the data on the monitor can be black-and-white or color.
2.3.
The operation of these devices
A transducer, which can both emit and detect ultrasonic echoes reflected back, generates
ultrasound waves. The active parts in most ultrasonic transducers are comprised of
unique ceramic crystal materials known as piezoelectrics. When an electric field is
given to certain materials, they can create sound waves, but they can also act in reverse,
creating an electric field when a sound wave strikes them. The transducer in an
ultrasonic scanner emits a beam of sound waves into the body.[13] Sound waves are
International University
Lab 1A – Biomedical Instrumentations
7
BM050IU
reflected back to the transducer by tissue boundaries along the beam's course (e.g. the
boundary between the fluid and soft tissue or tissue and bone).
When these echoes strike the transducer, electrical impulses are generated and
transferred to the ultrasound scanner. The scanner then determines the distance from
the transducer to the tissue border by using the speed of sound and the duration of each
echo's return. These signals are converted by the CPU into images viewed on a monitor
and stored in the image storage system.
Control knobs, buttons, and other command features on the CPU of ultrasound scanners
let the sonographer make changes, store photos, and conduct other operations.
3.
CLINICAL APPLICATION
Ultrasound is a popular method of detecting sickness that is safe, non-invasive, and
does not use radiation. Ultrasound findings are defined by sound waves that are then
used to create images of the inside of the body.[14]
3.1.
Main purposes
Ultrasound is used to detect:
 The source of discomfort
 The infections in the internal organs
 The case of prenatal ultrasound to inspect an unborn child
 The diagnosis of cardiac disorders
 The assessment of damage following a heart attack.
There is a kind of ultrasound that allows doctors to detect and evaluate the blood
supply through arteries and veins, which is Doppler Ultrasound.
It also helps evaluate the movement of materials in your body.
Doppler Ultrasound consists of three types:
Color Doppler: display the speed and direction of blood flow through a blood vessel
by an array of colors.
Power Doppler: unlike color doppler because without the ability of direction's
determination of blood flow. However, it helps provide accurate and more details
about the blood flow when it is maximal or minimal volume.
Spectral Doppler: rather than a color image, it presents blood flow measurements
graphically, in terms of distance traveled per unit of time. It may also translate
information about blood flow into a unique sound (heard with each heartbeat)
Doppler ultrasound helps detect:
 Blockages to blood flow, blood clotting
 Narrowing the valve
 Heart valve defects and congenital heart disease
International University
Lab 1A – Biomedical Instrumentations
8
BM050IU
 Reduced blood flow to various organs
 Increased blood flow, which may be a sign of infection
3.2.
How does it work?
Ultrasound is used for detecting alterations in the appearance of organs, tissues, and
arteries, as well as abnormal structures such as tumors.
In an ultrasound exam, a transducer delivers and records sound waves in the body.
These waves are measured by a computer as real-time images on a monitor
Doctors can also insert a probe into a body cavity to collect images of the organs
These tests include the following:
 Transesophageal echo (TEE) test: this is a type of echo that uses a long, thin,
tube (endoscope) to guide the ultrasound transducer down the esophagus. This
lets the doctor see pictures of the heart without the ribs or lungs getting in the
way.[15]
 Ultrasound through transrectal (endorectal ultrasound, ERUS): A
procedure in which a probe that sends out high-energy sound waves is inserted
into the rectum. Transrectal ultrasound is used to look for abnormalities in the
rectum and nearby structures, including the prostate.
 Transvaginal ultrasound (Ultrasound of the cervix): Transvaginal means
across or through the vagina. The ultrasound probe will be placed inside the
vagina during the test to check a woman's uterus, ovaries, tubes, cervix and
pelvic area.[16]
3.3.
Diagnosis and Treatment
It can be used for specific purposes in CLINICAL CASES[17]
A prenatal ultrasound to:
+ Examine the unborn child’s size and location.
+ Examine the back of the baby’s neck for symptoms of Down syndrome, the brain,
spinal cord, heart, and other sections of the body for birth abnormalities.
+Examine the amount of amniotic fluid.
Diagnostic ultrasound may be used to evaluate heart conditions:
+ Checking the blood flow is running normally and at a normal level.
+ See if there is a problem with your heart’s structure
In some other clinical cases:
Although ultrasonic waves are interrupted by air or gas, making them unsuitable for
imaging air-filled lungs, they can be utilized to identify fluid surrounding or within
the lungs. Similarly, ultrasonography cannot enter bone but can be used to image bone
fractures or infections that surround a bone.
International University
Lab 1A – Biomedical Instrumentations
9
BM050IU
4.
4.1.
THE LATEST ADVANCEMENT
The latest technology
Ultrasound technology has significantly improved and developed over the past several
decades, both technically and visually, making ultrasound more accessible than ever.
Help doctors easily, higher accuracy rate in diagnosing the patient's medical condition
and health. It contributes to the creation of better, safer and more economical patient
care pathways than traditional imaging.[18]
Here are some additional products to consider:
Artificial Intelligence in Ultrasound:[19]

AI in ultrasound is a transformative new technology that enables healthcare
practitioners – even those with no prior ultrasound experience – to quickly
perform ultrasound exams. and accuracy, by providing expert guidance,
automatic quality assessment and intelligent interpretation.

Artificial intelligence (AI) uses data and algorithms to draw conclusions as
good or even better than those drawn by humans.

It can be used to diagnose cancer, classify important findings in medical
imaging, flag acute abnormalities, provide radiologists with help in
prioritizing cases. life-threatening conditions, diagnose cardiac arrhythmias,
predict stroke outcomes, and help manage chronic diseases.
Pocket-sized ultrasound machines:[20]
It's ideal for rapid and easy evaluations in cardiac imaging and other body sections. Its
application in imaging other body parts, however, has yet to be determined. Image
quality is exceptional, and it meets the needs of clinical ultrasound. Its small size and
light weight make it perfect for usage at the point of care. Wirelessly connected, it can
be used in surgery without the need for cords.
Volumetric Ultrasound
They can be used to detect cancers, assess cardiac function, and many other things. The
capacity of this type of ultrasound to provide images with more apparent volume, rather
than a flat shape, that closely mimic the actual shape of organs and systems, earned it
the name. These ultrasounds can make diagnosing a lot easier in some circumstances.
GE Vivid iq is an example of the pocket ultrasound.
The Vivid iq System is a digital cardiovascular and shared-service ultrasound system
that supports cardiac, transesophageal, intraoperative, peripheral vascular, adult
cephalic, neonatal cephalic, musculoskeletal conventional, musculoskeletal superficial,
transcranial, and transvaginal 2D clinical applications.
The Vivid iq System is ultraportable, making it easy to transfer and promote scanning
at the patient's location. Without an AC power supply, battery operation extends
scanning time and allows for speedy boot-up from sleep mode
International University
Lab 1A – Biomedical Instrumentations
10
BM050IU
4.2.
Functions - How can it help people?
 Ultrasound can be used to check up on the fetus, detect a disorder, or
guide a surgeon through a process.[21]
 If a problem affects pelvic pain, irregular periods, cysts, or other
disorders involving the female reproductive system, a pelvic ultrasound
scan may be performed.
 Musculoskeletal scans (to assess areas like shoulders, hips, and elbows)
and breast scans are two further advantages (e.g., to further investigate
abnormalities picked up during a physical exam or mammogram).
4.3.
The future development trends
Ultrasound machines will most likely become quicker and have more
memory to store data in the future. To obtain better images of inside
organs, transducer probes may be made smaller and more insertable probes
may be designed. 3D ultrasound will almost certainly improve and become
more common. For field application, entire ultrasound equipment will most
likely be smaller, possibly even portable (e.g. paramedics, battlefield
setting). The development of ultrasound imaging mixed with virtual
reality/virtual reality-style displays, which will allow the doctor to "see"
inside you while performing minimally invasive or non-invasive
treatments such as amniocentesis or biopsies, is an intriguing new area of
research. [22]
- Fewer drop-down menus, fewer keystrokes, faster processing times, and
measurement automation are all features of next-generation ultrasound
devices. These may appear to be minor adjustments, but they pile up over
time. More time is spent with patients when less time is spent clicking
buttons and scrolling through dropdowns. They are given better care, and
technicians are able to do their tasks more quickly. More features will not
be added in the future; instead, redundant buttons will be removed and
speed will be increased.
-
International University
Lab 1A – Biomedical Instrumentations
11
BM050IU
5.
CONCLUSION
Our session presented an introduction of a medical devices – The Ultrasound. Aside
from that, the lecture has provided some basic information regarding device, such as
their history, basic architecture, key functions, and therapeutic uses. Ultrasound
machines is extremely valuable in biological applications. This technology has been
finished day by day throughout millennia, allowing individuals to attain the latest
devices, bringing fresh advances for health enhancement.
The course not only introduces the gadgets but also discusses how they work in real
life. It describes many approaches and applications for diagnosis and therapy. In
addition, we learnt about medical machine processing, block diagrams, and the
principles of each component in these devices, all of which are directly relevant to our
major.
6. REFERENCES
1. Aldrich JE. Basic physics of ultrasound imaging. Crit Care Med. 2007 May;35(5
Suppl):S131-7. doi: 10.1097/01.CCM.0000260624.99430.22. PMID 17446771.
2. Amaral CB, Ralston DC, Becker TK. Prehospital point-of-care ultrasound: A
transformative technology. SAGE Open Med. 2020 Jul 26;8:2050312120932706. doi:
10.1177/2050312120932706. PMID 32782792; PMCID: PMC7383635.
3. Ultrasound History By Beth W. Orenstein Radiology Today Vol. 9 No. 24 P. 28
4. Types of Ultrasounds. (n.d.). Atlantic Medical Imaging. Retrieved December 6, 2021,
from https://www.atlanticmedicalimaging.com/radiology-services/ultrasound/typesof-ultrasounds/
5. Peter Vilmann. (2006, February 20). Endoscopic ultrasound guided fine needle
aspiration
biopsy:
Equipment
and
technique.
Medtronic.
https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1440-1746.2006.04475.x
6. Yang, Joon-Mo & Favazza, Christopher & Chen, Ruimin & Yao, Junjie & Cai, Xin
& Li, Chiye & Maslov, Konstantin & Zhou, Qifa & Shung, K. & Wang, Lihong. (2013).
Photoacoustic endoscopic imaging of the rabbit mediastinum. Progress in Biomedical
Optics and Imaging - Proceedings of SPIE. 8581. 10.1117/12.2004980.
7. Victor Ekpo. (2017, March 20). MSc Medical Physics Programme, College of
Medicine,
University
of
Lagos,
2017.
Doppler
Effect.
https://www.slideshare.net/VictorEkpo2/doppler-effect-ultrasound
8. Procedures. (2019, December 18). Stanford Health Care.
https://stanfordhealthcare.org/medical-tests/u/ultrasound/procedures.html
9. Maureen E. Cheung; Vikramjeet Singh; Michael S. Firstenberg. (n.d.). NCBI WWW Error Blocked Diagnostic. NCBI. Retrieved September 18, 2021, from
https://www.ncbi.nlm.nih.gov/books/NBK459266/
International University
Lab 1A – Biomedical Instrumentations
12
BM050IU
10. Armin Schneider, Hubertus Feussner, Chapter 5 - Diagnostic Procedures,
Biomedical Engineering in Gastrointestinal Surgery, Academic Press, 2017, Pages 87220, ISBN 9780128032305, https://doi.org/10.1016/B978-0-12-803230-5.00005-1.
11. Bonitto Daley. (2018, February 10). Your Doctor Prescribed a Transvaginal
Ultrasound: Here’s What You Should Know. Radiology Affiliates Imaging.
https://4rai.com/blog/has-your-doctor-prescribed-a-transvaginal-ultrasound-hereswhat-you-should-know
12. G. Andreonia , M. Mazzolaa , S. Matteolib , S. D’Onofrioc , L. Forzonic. (2015).
Ultrasound system typologies, user interfaces and probes design: a review. Elsevier.
https://www.sciencedirect.com/
13. Parmley, L. (2018, January 3). How Does an Ultrasound Machine Work? •.
Ultrasound
Technician.
https://www.ultrasoundtechniciancenter.org/ultrasoundknowledge/how-ultrasound-machines-work.html
14. Acr, R. A. (2020, April 21). General Ultrasound. Radiologyinfo.Org.
https://www.radiologyinfo.org/en/info/genus
15. Transesophageal Echocardiogram (TEE). (2019, July 16). Cleveland Clinic.
https://my.clevelandclinic.org/health/diagnostics/4992-echocardiogramtransesophageal
16. John D. Jacobson. (2020, March 31). Transvaginal ultrasound. MedlinePlus.
https://medlineplus.gov/ency/article/003779.htm#:%7E:text=Transvaginal%20ultraso
und%20is%20a%20test,the%20vagina%20during%20the%20test.
17. NCI Dictionary of Cancer Terms. (n.d.). National Cancer Institute.
https://www.cancer.gov/publications/dictionaries/cancer-terms/def/transrectalultrasound
18. Jeff Zagoudis And Dave Fornell. (2016, February 12). The Latest in Ultrasound
Technology.
DAIC.
Retrieved
October
1,
2021,
from
https://www.dicardiology.com/article/latest-ultrasound-technology
19. Latest Advancements in Ultrasound Imaging Technology. (2019, May 7). Peconic
Bay
Medical
Center.
https://www.pbmchealth.org/news-events/blog/latestadvancements-ultrasound-imaging-technology
20. GE Vivid iq Ultra Edition Portable Ultrasound. (n.d.). Davis Medical Electronics.
https://www.davismedical.com/Products/GE-Vivid-iq-Ultra-Edition-PortableUltrasound__GEN-ULT-VIVIDIQ.aspx
21. Ka Hei Tse. (2014, June). NCBI - WWW Error Blocked Diagnostic. PMC.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4294060/
22. Craig C. Freudenrich, Ph.D. (n.d.). How Ultrasound Works. Howstuffwworks?
http://electronics.howstuffworks.com/ultrasound.htm
International University
Lab 1A – Biomedical Instrumentations
13
BM050IU