An Ultrasonic Catheter for Intravascular Measurement of Blood Flow: Technical Details

Martin, Roy W.; Watkins, Dennis

doi:10.1109/t-su.1980.31191

Cited by 12 publications

(5 citation statements)

References 10 publications

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“…Another development was by Martin and Watldns [11] who used a transducer consisting of six radial crystals at a catheter tip to generate a crude estimate of cross-sectional area of the pulmonary artery as part of a cardiac output monitor.…”

Section: Early Developmentsmentioning

confidence: 99%

Intravascular real-time, two-dimensional echocardiography

et al. 1989

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Contrast arteriography is currently the principal method for assessment of the presence and severity of both peripheral and coronary vascular anatomy. With the rapid progress in interventional radiology and cardiology, there is an increasing need for more specific information on vascular pathology and better understanding of its pathophysiology. Noninvasive ultrasound imaging may allow cross-sectional visualization of certain but limited portions of the peripheral arterial system [1, 2] but has serious limitations for imaging the coronary arteries [3,4]. The intraoperative epicoronary application of highfrequency transducers has confirmed the abnormal findings of earlier pathologic studies and further corroborated the insensitivity of coronary arteriography in appraising the extent and distribution of atherosclerotic wall disease [5]. Fiberoptic angioscopy allows visualization of the inner surface of the arterial wall and has significantly added to our understanding of acute ischemic syndromes. The method, however, has practical limitations and no information on the vessel wall under the endothelium is obtained [6].Clearly, there is a need for an imaging method allowing the study of the vessel wall and both the characterization and quantification of its pathology. Ultrasonic real-time intravascular echography allows cross-sectional i.e. circumferential imaging providing information on the arterial wall under the endothelial surface [7]. This technique has unique and fundamental advantages over presently available techniques. In this contribution we will describe the principles of intravascular real-time, two-dimensional echocardiography and give a perspective of the potential applications of this exciting new method.

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Section: Early Developmentsmentioning

confidence: 99%

Intravascular real-time, two-dimensional echocardiography

et al. 1989

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“…The total angle of deflection will be the summation of the deflections produced by equations 18 and 20: 3 Otav = Ots-~" 2 0 i_l a = i=n 3 (28.65/GI) E (aiTis + ciTisa) [22] i-n Therefore, the rotational torque and twisting an-…”

Section: ] I=nmentioning

confidence: 99%

“…One of the authors has employed three different wire configurations in various miniature ultrasonic probes. The most elegant and costly type is a microcoax with 0.203 mm (0.008") outside diameter and 50f~ characteristic impedance [22]. Two styles were used, UT-8 and UT-8S, both manufactured by Micro-coax Components, Inc., Collegeville, PA.…”

Section: Electrical Wire For Connecting the Transducermentioning

confidence: 99%

Design characteristics for intravascular ultrasonic catheters

Martin

Johnson

1989

Int J Cardiac Imag

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Several factors are important in the design of intracoronary ultrasonic imaging catheters. The mechanical considerations are first discussed and equations are developed for calculating the forces affecting catheter passage in a blood vessel. These equations are applied to the problem of Judkins (transfemoral) coronary artery catheterization, using previously described anatomical information and catheter moduli values. The introduction force is calculated for each position along the vessel for both a high and low value of estimated catheter-wall friction (coefficient values of 0.04 and 0.2, respectively). Next, the problem of catheter or transducer rotation is analytically described. The advantages of spiral drive cables with high torsional rigidity and low bending stiffness are numerically shown. Finally, several methods and considerations are given for electrical connection to the transducer. These results and equations should facilitate the design of intracoronary ultrasound imaging devices in the future.

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“…A pulsed ultrasonic Doppler probe was constructed from 20 mHz piezoelectric ceramic material according to the design recommendations of Martin and Watkins. 19 The probe was used to monitor cardiac output as measured over the right brachiocephalic artery. The ultrasonic Doppler probe was connected to a 20 mHz directional Doppler system.…”

Section: Otolaryngology-head and Neck Surgerymentioning

confidence: 99%

Measuring Cochlear Blood Flow by Laser Doppler Spectroscopy

Short

Goodwin

Kaplan

et al. 1985

Otolaryngol.--head neck surg.

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Cochlear blood flow (CBF) was studied with a commercially available laser Doppler system in 20 guinea pigs. The cochlea was exposed to permit placement of the laser Doppler probe over the intact lateral wall of the basal turn. Ketamine and xylazine were used for anesthesia, and blood pressure was monitored from the femoral artery. In some cases, skin blood flow was monitored with a second laser Doppler system, and cardiac output was monitored with an ultrasonic Doppler system placed over the right brachiocephalic artery. We found that the laser Doppler signal is composed primarily of blood flow supplied by the internal auditory artery. Local pressure on the contents of the internal auditory canal after occipital craniotomy was found to reduce CBF to 15% of its original value in a reversible fashion. There was no change in CBF after bilateral occlusion of the common carotid arteries. There appears to be a mechanism governing CBF that stabilizes its value in the face of changes in blood pressure and cardiac output. This is similar to the vascular behavior of the central nervous system. Through the use of positive airway pressure and blood removal at different rates, cardiac output could be depressed to varying degrees. The magnitude of decrease in CBF was clearly related to the rate at which cardiac output and blood pressure dropped. This was confirmed when intravenous phenylephrine was given in sequential and increasing doses. CBF increased as blood viscosity decreased, as expected according to the vascular behavior of the central nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)

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An Ultrasonic Catheter for Intravascular Measurement of Blood Flow: Technical Details

Cited by 12 publications

References 10 publications

Intravascular real-time, two-dimensional echocardiography

Intravascular real-time, two-dimensional echocardiography

Design characteristics for intravascular ultrasonic catheters

Measuring Cochlear Blood Flow by Laser Doppler Spectroscopy

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