{"title":"Atomic force microscopy at ultrasonic frequencies","authors":"U. Rabe, W. Arnold","doi":"10.1117/12.469631","DOIUrl":"https://doi.org/10.1117/12.469631","url":null,"abstract":"We present a new type of near-field Acoustic Microscopy combining Atomic Force Microscopy (AFM) and Acoustic Microscopy. The lateral resolution is given by the probe diameter instead of the acoustic wavelength and can reach atomic scale on flat samples. The ultrasonic vibrations of the AFM cantilever are examined as well as the nonlinear interaction between the AFM tip and the sample surface. An ultrasonic image taken with the new technique is shown","PeriodicalId":394363,"journal":{"name":"1994 Proceedings of IEEE Ultrasonics Symposium","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123901794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Stress sensitivity of electromagnetic resonances in circular dielectric disks","authors":"Pcy Lee, J. S. Yang, A. Ballato","doi":"10.1109/ULTSYM.1994.401737","DOIUrl":"https://doi.org/10.1109/ULTSYM.1994.401737","url":null,"abstract":"By applying a perturbation method to the three-dimensional Maxwell's equations and using the previously obtained two-dimensional closed form solutions as the approximate unperturbed solutions, stress effect on the electromagnetic resonances in a dielectric circular disk embedded in free space are studied. Frequency changes of both the transverse electric and transverse magnetic modes are computed for disks of gallium arsenide and under three cases of loading: (1) A pair of diametral forces, (2) Steady vertical acceleration, and (3) Steady horizontal acceleration. In the latter two cases, the bottom face of the disk is supported by a rigid base","PeriodicalId":394363,"journal":{"name":"1994 Proceedings of IEEE Ultrasonics Symposium","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126901309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"AO intermodulation effects in resonant photoelastic materials","authors":"V. Proklov, V. Chesnokov","doi":"10.1117/12.222750","DOIUrl":"https://doi.org/10.1117/12.222750","url":null,"abstract":"For optically resonant systems the intermodulation amplitudes of the 2nd and 3rd orders in approximation of small diffraction efficiency for the two main AO interaction regimes-“thin” and “thick” gratings are for the first time calculated. It is shown, that the photoelastic nonlinearity causes in general case the complexity of intermodulations. However, under certain conditions, the effect of compensated intermodulation can take place. It yields to the possibility of remarkable growth of the dynamic range value which is a great importance parameter for many AO devices","PeriodicalId":394363,"journal":{"name":"1994 Proceedings of IEEE Ultrasonics Symposium","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123750641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Piel, R. Lewandowski, P. Lorraine, L. Smith, T. Shiota, D. Sahn
{"title":"7.5 MHz pediatric phased-array transesophageal endoscope","authors":"J. Piel, R. Lewandowski, P. Lorraine, L. Smith, T. Shiota, D. Sahn","doi":"10.1109/ULTSYM.1994.401881","DOIUrl":"https://doi.org/10.1109/ULTSYM.1994.401881","url":null,"abstract":"This work extends the clinical benefits of phased array transesophageal echocardiography (TEE) with high detail and contrast resolution to include neonatal patients. We have built several prototype 64 element, 7.5 MHz phased array transducers housed in 6.2 mm endoscope shafts for use with commercially available imaging systems. The acoustic design is standard, but the miniaturized packaging of the electrical connections was quite challenging. The endoscopes demonstrate very good structural resolution and excellent sensitivity for color flow imaging and CW Doppler. They have been used on patients as small as 1.9 kg, frequently as an anatomical guide during catheter based interventions and during congenital-heart surgery. Array test data and representative clinical studies are shown","PeriodicalId":394363,"journal":{"name":"1994 Proceedings of IEEE Ultrasonics Symposium","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130363258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Invasive and non-invasive feedback for ultrasound phased array thermometry","authors":"R. Seip, E. Ebbini","doi":"10.1109/ULTSYM.1994.401944","DOIUrl":"https://doi.org/10.1109/ULTSYM.1994.401944","url":null,"abstract":"The use of high-intensity focused ultrasound for cancer therapy and tissue ablation has been receiving increased attention recently. Currently, fine-wire thermocouple sensors represent the only practical means of feedback for these treatments. Difficulties in placing thermocouples in many clinical situations represent a major limitation on the amount of feedback that can be obtained with these versatile sensors. For this purpose, invasive and non-invasive feedback methods for ultrasound thermotherapy have been developed. Invasive methods for acoustic feedback are based on implantable hydrophone arrays, and non-invasive methods for temperature feedback are based on signal processing of the backscattered diagnostic ultrasound pulse. Experimental results demonstrating quantitative, non-invasive, tissue temperature change measurements are shown. The methods for temperature change estimation presented are independent of the heating modality","PeriodicalId":394363,"journal":{"name":"1994 Proceedings of IEEE Ultrasonics Symposium","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115469783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An optimal image operator design technique for coded excitation ultrasound imaging system","authors":"Jian Shen, Hakan Erdogan, E. Ebbini","doi":"10.1109/ULTSYM.1994.401935","DOIUrl":"https://doi.org/10.1109/ULTSYM.1994.401935","url":null,"abstract":"We have recently proposed a new coded excitation ultrasound imaging system. The system is based on a discretized linear model of the received data from the region of interest (ROI). Thus the system can be characterized by a linear equation with operator G consisting of on-grid impulse responses. The image reconstruction is obtained by solving the equation with a pseudo-inverse image operator (PIO). Since the reconstruction quality of the system is determined by the PIO, an effective design method is necessary to find an optimal PIO (i.e., a PIO has small noise sensitivity and the degradation of its performance caused by off-grid scatterers is well below a pre-specified tolerable level). In this report, an optimal PIO design method is presented with the help of singular value decomposition (SVD) technique. Given specifications imposed on the PIO, the proposed design method provides effective procedures for searching a set of suitable system parameters (such as grid size, codes, transmit channels, etc.). Then, the desirable PIO is evaluated by a method based on the SVD rank reduction technique. Simulation results are given to show the efficiency of the proposed PIO design method","PeriodicalId":394363,"journal":{"name":"1994 Proceedings of IEEE Ultrasonics Symposium","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128995138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. S. Georgides, P. Rinaldi, J. P. Jones, L. R. Price, F. Reines
{"title":"Physiological effects of focused ultrasound pulses on mammalian CNS tissue in an in-vitro preparation","authors":"C. S. Georgides, P. Rinaldi, J. P. Jones, L. R. Price, F. Reines","doi":"10.1109/ULTSYM.1994.401947","DOIUrl":"https://doi.org/10.1109/ULTSYM.1994.401947","url":null,"abstract":"We have investigated the effects of pulsed and highly focused ultrasound on the physiology of 500 micron thick hippocampal slices obtained from 50 male, 120 gram Sprague-Dawley rats. During the study the slices were kept alive in a special in-vitro preparation. We compared the magnitude and latency of the control evoked responses to those of the responses recorded during ultrasound irradiation. Comparisons were made for both the orthodromic and antidromic population responses. For all studies, a highly focused pulsed ultrasonic beam was used with a center frequency of 5 MHz and an intensity (SPTA) of 52 W/cm 2. Significant changes in both the magnitude and the stimulus-response delay were observed. Full recovery was observed when the ultrasound was removed. In addition, temperature effects could be rejected as the sole mechanism producing such changes","PeriodicalId":394363,"journal":{"name":"1994 Proceedings of IEEE Ultrasonics Symposium","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132890224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Real-time dynamic focusing through tissue inhomogeneities during hyperthermia treatments with phased arrays","authors":"P. VanBaren, R. Seip, E. Ebbini","doi":"10.1109/ULTSYM.1994.401943","DOIUrl":"https://doi.org/10.1109/ULTSYM.1994.401943","url":null,"abstract":"A needle probe hydrophone array made of discrete PVDF elements has been designed and fabricated at our laboratory. Such a probe can obtain complex acoustic pressure measurements at or near the tumor site. To extend the region over which these measurements may be used to focus a phased array, a real-time measurement system is needed, along with a method of extrapolating the data to points other than those measured by the probe. We describe such a real-time dynamic focusing algorithm that uses measurements from the full-set of hydrophone array elements in estimating the bearing and range of the elements of the transmitting array. In this way, a measurement of the radius of curvature of the wave front due to an array element is made along the span of the array, which extends the region of reliable refocusing. An outline of the steps of the refocusing algorithm along with simulation and experimental results are given. Finally, we describe the architecture of a real-time system for refocusing currently being designed for this purpose","PeriodicalId":394363,"journal":{"name":"1994 Proceedings of IEEE Ultrasonics Symposium","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116487648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tomographic Schlieren imaging for measurement of beam pressure and intensity","authors":"T. Pitts, J. F. Greenleaf, Jian-yu Lu, R. Kinnick","doi":"10.1109/ULTSYM.1994.401910","DOIUrl":"https://doi.org/10.1109/ULTSYM.1994.401910","url":null,"abstract":"The visualization of ultrasonic fields via acousto-optic interaction is an old technique. Shadowgraph and schlieren imaging produce data representing a line integral related to pressure and time-average intensity, respectively. These “projections” can be used in computed tomography. We have compared the reconstructed pressure distribution in a plane obtained via tomographic inversion with those obtained by mechanically scanning a 0.5 mm calibrated hydrophone through the same plane. Schlieren methods result in the reconstruction of a time average intensity approximation. Shadowgraph methods reconstruct pressure at a given point in time. The advantage of the tomographic methods is that they can be done quickly. A fully automated system could produce a three-dimensional image of an ultrasound beam in a few minutes","PeriodicalId":394363,"journal":{"name":"1994 Proceedings of IEEE Ultrasonics Symposium","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129100260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Sanghvi, R. Hawes, K. Kopecky, F. Gress, S. Ikenberry, O. Cummings, S. Zaidi, C. Hennige
{"title":"High intensity focused ultrasound (HIFU) for the treatment of rectal tumors: a feasibility study","authors":"N. Sanghvi, R. Hawes, K. Kopecky, F. Gress, S. Ikenberry, O. Cummings, S. Zaidi, C. Hennige","doi":"10.1109/ULTSYM.1994.401961","DOIUrl":"https://doi.org/10.1109/ULTSYM.1994.401961","url":null,"abstract":"A rigid ultrasound probe is under development for combined imaging and ablation of rectal tumors with high intensity focused ultrasound (HIFU). To test the device and to assess safety and efficacy of this technology, a canine model was developed by inducing rectal pseudotumors. These animals were imaged by ultrasound and treated with HIFU. The gross pathology and microscopic histology examinations were performed to establish performance of the device. It was observed that HIFU is capable of ablating the tumor tissue while sparing the rectal wall layers and normal surrounding tissue","PeriodicalId":394363,"journal":{"name":"1994 Proceedings of IEEE Ultrasonics Symposium","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132980844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}