Ph.D. University of Illinois Champaign-Urbana, 1996
Associate Professor of Bioengineering
219 Hallowell Building
Tel: (814) 865-8087
Fax: (814) 863-0490
Email: nbs@engr.psu.edu
For more information, please link to:Ultrasound
Therapeutic Applications Laboratory
The research of Dr. Smith focuses on therapeutic applications
of ultrasound and its combination with diagnostic magnetic resonance
imaging (MRI). Therapeutic applications include the design and
construction of focused ultrasound arrays to non-invasively ablate
tissue which has potential for localized treatment of benign or
cancerous tumors. This research has also shown for the first time
the feasibility of using focused ultrasound for transmyocardial
revascularization in vivo. Additionally, ultrasound offers an attractive
means of non-invasive localized hyperthermia treatment of tumors
in the prostate. Because it is easily accessible via intracavitary
(transrectal) applicators, the prostate can be heated with minimal
heating of normal tissue. Intracavitary ultrasound arrays allow
deep localized heating with fine power control and are capable
of generating sufficient power for hyperthermia. Currently, this
hyperthermia array is used for treatment of prostate cancer at
Dana-Farber Cancer Institute in Boston, MA. Traditionally, invasive
thermometry (thermocouples) has been used to measure temperatures
in the target region. Yet thermocouples may bypass the regions
of greatest temperature elevation.
MRI offers a means to locate both the desired area for thermal
therapy and the location of the applicator relative to the target,
as well as potential for non-invasive temperature measurement.
Non-invasive MR thermometry results have been obtained using proton
resonance frequency shift. This method relies on frequency changes
resulting from temperature-dependent variations in the molecular
shielding constant of the water molecule. MRI is a promising modality
for non-invasive guidance, monitoring, and control of thermal therapies
because it provides good spatial localization, temperature sensitivity,
and a level of tissue contrast that allows for accurate target
identification in ultrasound thermal therapy. Current research
utilizes the facilities of the Harvard Medical School / Brigham
and Women's Hospital and the Pennsylvania State University Center
for Transducer Engineering. Continuing research will use the MR
facilities at the Hershey Medical Center.
(a) Sagittal view of a T2-weighted image, a 16-element ultrasound array heating
a rabbit thigh along with the region of interest (ROI-box) used for the
in vivo magnetic resonance (MR) temperature mapping. Click for 300DPI version.
(b) Elements located in the center of the array are powered at 2.5W for 30
minutes. The MR spatial temperature map shows temperature rise contours
(as indicated by the "+" for each contour) ranging from 1 to
6 degrees C, with some artifact due to fat. Click for 300DPI version.
Representative Publications
Sun L.,. Collins C. M, Schiano, J. and Smith, N.B "Adaptive
control for MRI-guided ultrasound hyperthermia treatment for prostate
disease: in vivo and ex vivo results" Mag Res Engineering,
2005, in-press.
Saleh, K. and N.B. Smith, "A 63 element 1.75 dimensional
ultrasound phased array for the treatment of benign prostatic hyperplasia",
BioMedical Engineering OnLine, , 4:39, 2005.
Lee, S, Nayak V, Dodds J, Pisko M and Smith NB, "Ultrasonic
Mediated Glucose Measurements in vivo using the Cymbal Array",
Ultrasound in Medicine and Biology, 31(7), pp 971-977, 2005.
Snyder, B., Lee, S, Newnham, R. and Smith, N.B., "Application
of the Cymbal Transducer Towards Noninvasive Transdermal Insulin
Delivery", Journal of Materials Science -Frontiers of Research
in Ferroelectricity - Special Issue 2005, in press.
Lee, S, Snyder, B., Newnham, R. and Smith, N.B.,"Noninvasive
Ultrasonic Transdermal Insulin Delivery in Rabbits Using the Light
Weight Cymbal Array," Diabetes Technology & Therapeutics,
Volume 6 / Issue 6, December 2004.
Saleh, K. and N.B. Smith, Design and evaluation of a 3 x 21 element
1.75 dimensional tapered ultrasound phased array for the treatment
of prostate disease, Materials Research Innovation, 8, (2) 2004,
pp 121-124.
Lee, S, Newnham, R., Smith, N.B., Short Ultrasound Exposure Times
for Noninvasive Insulin Delivery in Rats using the Light Weight
Cymbal Array, IEEE Transactions on Ultrasonics, Ferroelectrics
and Frequency Control, 51 (2), pp 176-180, (2004) .
Al-Bataineh, O.M., D. Markly, R.J. Meyer, R.E. Newnham, and N.B.
Smith. Feasibility of miniature high-frequency piezoelectric ceramic
hollow spheres for exposimetry and tissue ablation. Materials Research
Innovation, 8, (2) 2004, pp 78-83.
N.B. Smith, M.T. Buchanan, and K. Hynynen, Transrectal ultrasound
applicator for prostate heating monitored using MRI thermometry, Int.
J. Radiation Oncology Biol.Phys., 43, pp. 217-225, (1999).
N.B. Smith and K. Hynynen, The feasibility of using focused ultrasound
for transmyocardial revascularization, Ultrasound Med.Biol.,
24, pp. 1045-1054, (1998).
N.B. Smith, M.T. Buchanan, and K. Hynynen, MRI Compatible Ultrasound
Array for Induction of Hyperthermia in Prostate, in "Proc.,
ISMRM, 7th Annual Meeting, Sydney, NSW, Australia, April 1998",
p. 1998. |
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