Parks 915-BL, Operating & Service Manual

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A therosclerosis of the peripheral vessels is
extremely common in our society and is
responsible for significant morbidity and
mortality. It is therefore imperative that the
physician who first encounters patients with
vascular complaints recognizes the disease and
begins proper treatment. Until recently, the
diagnosis of arteriosclerosis obliterans has been
dependent upon the clinical history and physical
examination. As a result, the disease has only
been detectable in a relatively far advanced stage.
Since the introduction of the Doppler ultrasonic
velocity detector in 1959, more sensitive and
objective methods of evaluation have been
available to the clinician.
1-4
The use of these
technics, however, has been restricted to a
relatively small number of specialists and
investigators. Although they are extremely simple
to do, these examinations have not been widely
used by primary care physicians.
The purpose of this paper is to familiarize
clinicians with three simple office technics for
detecting atherosclerotic occlusive disease and
t o p r e s e n t t h r e e c a s e s t h a t i l l u s t r a t e t h e
efficiency of these technics.
*Read before the Section on Surgery, Southern Medical Association,
S i x t y - s e v e n t h A n n u a l S c i e n t i f i c M e e t i n g , S a n A n t o n i o , Te x .
†From the Department of Surgery, Vascular Surgery Service, Wilford
H a l l U S A F M e d i c a l C e n t e r, L a c k l a n d A i r F o r c e B a s e , Te x .
R e p r i n t r e q u e s t s t o C M R # 8 , B o x 3 6 9 5 0 1 , L a c k l a n d A F B ,
Tex 78236 (Dr. Hagood).
Material and Technics
The Doppler ultrasonic velocity detector has
become a familiar tool used by obstetricians
and vascular surgeons alike.
5 The instrument
uses two piezoelectric crystals. One crystal, when
stimulated by an electric voltage, e m i t s a
continuous wave of ultrasonic energy at a
frequency of 5 to 10 MHz, which is transmitted
through the skin. If this sound wave is reflected
back from stationary tissue interfaces, the
frequency of the returned signal received by the
second crystal will be the same as the transmitted
frequency. If the sound wave strikes moving
red cells, the returned signal will be a different
frequency from the transmitted signal. The
difference is directly proportional to the velocity
of the blood, according to the Doppler principle.
The transmitted and received frequencies are
compared electronically and the difference
between the two, the Doppler shift frequency, is
amplified. S i n c e t h i s f r e q u e n c y i s i n t h e
a u d i b l e r a n g e , it can be perceived with
earphones or a loudspeaker. For most clinical
purposes, the audible signal is all that is
necessary. Ultrasonic energy transmitted by
these instruments has been tested both in the
laboratory and clinically and has been found to
be non-destructive to tissue.
6
Examination can
thus be carried out at frequent intervals without
fear of over-exposure.
Practical Office Technics for
Physiologic Vascular Testing
*
COL CLYDE 0. HAGOOD, JR., MC, USAF, LTC DAVID J.
MOZERSKY, MC, USAF, and SSGT RANDAL N. TUMBLIN, BS, USAF, †
Lackland AFB, Tex
Abstract: The development of the Doppler ultrasonic flow velocity detector
has improved diagnostic accuracy in peripheral arterial occlusive disease.
Survey of the peripheral vessels with the Doppler ultrasonic flow velocity
detector, measurement of systolic arterial blood pressure at the ankle and
arm, and exercise testing are three easily done tests which may be readily
c a r r i e d o u t i n t h e d o c t o r ’ s o f f i c e a n d w h i c h p r o v i d e u s e f u l
information. Noninvasive vascular testing should be in the
armamentarium of all primary care physicians.
SOUTHERN MEDICAL JOURNAL, Vol 68, No. 1 17