Thesis (M.A.)--University of North Carolina at Chapel Hill, 2002. / Includes bibliographical references (leaves 57-59).

M.Tech. (Chiropractic) / Myofascial pain syndrome has become a significant cause of chronic pain and disability in today‟s society. Conditions causing chronic pain can not only cause disability due to pain, but can also lead to other problems such as psychological and behavioural disturbances. Physical deconditioning can also occur due to lack of exercise because of myofascial pain (Rachlin, 1994). The aim of this study was to compare dry needling therapy and ultrasound therapy in the treatment of myofascial trigger points in order to demonstrate any superiority between the two modalities. Participants for this study were recruited by word of mouth and advertisements that were placed around the University of Johannesburg Doornfontein Campus. Thirty people participated in the trial, all of whom conformed to the specific inclusion and exclusion criteria. The participants were randomly placed into two groups. Group A received dry needling therapy, namely the fanning technique, and Group B received ultrasound therapy. Participants in Group A received one treatment per week for four weeks and subjective and objective measurements were taken at each visit. Participants in Group B received two treatments per week for three weeks and measurements were taken at visits one, three, five and seven. Subjective data was obtained through the use of the Visual Analogue Pain Scale, which measured the perception of pain of the participants. Objective data was obtained from pressure algometer readings, which measured pain pressure thresholds of participants, and through the Cervical Range Of Motion (CROM) device. The results of this study indicated that dry needling therapy and ultrasound therapy both significantly benefited participants in terms of the treatment of active myofascial trigger points. Based on the final results, both dry needling therapy and ultrasound therapy are equally effective modalities in the treatment of active myofascial trigger points, with neither modality showing superiority over the other.

This thesis focuses on the design of an ultrasonography compatible implantable sensor platform, as a novel approach that implements a miniaturized, battery-less, real-time trackable parallel biosensing system. In addition to the frontend circuit, a sub-nW fully integrated pH sensor is designed in a way that can be easily integrated with the proposed sonography-compatible sensor platform. Combining the two integrated circuits together, the whole system will be able to map in vivo physiological information acquired from a distributed set of sensors on top of the ultrasound movie, leading to the idea envisioned as “augmented ultrasonography”. Implemented in a 0.18 μm technology, an ultrasound power and data frontend circuit is designed to enable medical sensing implants to operate in an ultrasonography compatible way. When placed within the field of view of an imaging transducer, the frontend circuit harvests the power through a piece of piezo crystal from a minimally modified brightness-mode (B-mode) ultrasound imaging process that is commonly adopted in modern medical practices. The implant can also establish bi-directional data communication channels with the imaging transducer, allowing data to be transmitted in a way synchronized to the frame rate of the B-mode film. The design of the circuit is made possible by a combination of ultra-low-power circuit techniques and novel frontend circuit topologies, as imaging ultrasound waves in the form of short pulses with extremely low duty cycle poses challenges that has not previously seen in other implantable sensor systems. The proposed prototype achieves a total area of 0.6mm² for the integrated circuit (IC), as well as 71mm theoretical maximum implantable depth (up to 40 mm is verified experimentally). These two together give opportunities for this design to become the next generation solution for deep-tissue bio-sensing implants. Realized using the same 0.18 μm technology, the fully integrated pH sensor is designed to deliver accurate pH readouts, at a reasonable speed of 1 sample per second, while consuming only 0.72 nW of power. Using an ion-sensitive field effect transistor (ISFET) and reference field effect transistor pair (REFET), the IC requires minimum additional post fabrication to deliver 10-bit resolution pH readouts at an end-to-end sensitivity of 65.8 LSB/pH. When working as a standalone device, this work advances the state-of-the-art of ISFET based pH sensor design. With an addition of 0.46 mm² of area, it is possible to integrate it with the ultrasound sonography compatible implant platform. This potential integration will further advance the vision of the augmented ultrasonography: real-time display of physiological information in a B-mode film, with the help from a distributed bio-sensor system for deep-tissue physiology monitoring.

No description available.

Diagnoses using images made with non-ionizing ultrasound are based on qualitive criteria and are not more accurate than those made with mammography. Information about tissue state is lost in the processing required to produce ultrasound images, and textural information may not be perceptible to a human observer. This study uses statistical pattern recognition to classify ultrasound A-scans, before any processing other than amplification occurs. A U. I. Octoson was used to collect data from normal, benign, and malignant, in vivo breast tissues. Features based on textural or frequency content of received sound were computed from digitized A-scans. Most textural features have been used previously in image processing, while frequency features assumed differences in frequency-dependent attenuation. Data were collected at the University of Arizona from 17 malignant masses, 8 benign masses, and 7 normal tissues. Univariate and multivariate statistical tests were used to find combinations of features which discriminated best between the classes of tissue. Equal a priori probabilities were used in a Bayesian classifier to classify malignant vs. nonmalignant. Specificity of 76% (13 of 17 malignant masses correct) was found with a sensitivity of 80% (12 of 15 masses correct). A linear combination of one frequency feature and three textural features was used. For malignant vs. benign, sensitivity of 88% (15 of 17 masses) and specificity of 75% (6 of 8 masses) were found. Features used were the same as for classification of malignant vs. nonmalignant, except for modification of one textural feature. The inability to visually detect and gather data from some palpable masses means that further study is needed to determine the effectiveness of applying the method to all breast masses. A set of A-scans from Thomas Jefferson Hospital in Philadelphia was gathered using similar procedures, and analysed with the following results: 18 of 21 (86%) malignant masses, and 45 of 66 (68%) nonmalignant masses were classified correctly, using a linear combination of one textural feature and five frequency features. Confidence limits on the results show that the majority of masses can be classified correctly with this procedure, but success rates are not high enough for breast cancer screening.

No description available.

"Ultrasound has developed from 2D into 3D ultrasound in recent years. 3D ultrasound gives enhanced diagnostic capabilities and can make it easier for less trained people to interpret ultrasound images. In general there are two ways of getting a 3D ultrasound image : By using a 2D array scanner (giving 3D images directly) or by using a series of 2D scans and combine these scans to build a 3D volume. The only practical scanning technique that can be used for portable systems is freehand scanning that combines a series of 2D images. 3D images acquired by using a conventional ultrasound transducer and the freehand scanning technique are, however, often misaligned laterally and have unevenly spacing. These errors can be corrected if the position associated with each 2D image is known. Commercially available positioning systems use magnetic or optical tracking, but these systems are very bulky and not portable. We have proposed another way to get the position by tracking on the skin surface. This is done by obtaining digital images of the surface at a very high rate and then cross correlating each image to reveal the change in position. Accumulating these changes will then give the correct location (in two dimensions) relative to a starting point. Correct volume and surface rendering can therefore be achieved when a scan is done. A custom-made housing was made to mount an optical sensor to the ultrasound transducer. The optical sensor was placed in the housing and the hardware circuit from an optical mouse was used to interface to a USB interface. An implementation with an optical fiber was also made since this could fit easily to the transducer handle. In Windows a custom-made mouse driver was used to extract the position information from the sensor. This driver allowed multiple mouse devices in the system and removed the acceleration of the mouse, giving a correct transfer of the position. A DLL (Dynamic Link Library) was used to interface to a 3D ultrasound software called Sonocubic. Using the DLL and a custom modified version of Sonocubic 3D construction software has allowed a correct compensation of the acquired ultrasound images. To validate the accuracy of the optical sensor an optical mouse was placed in an XY-recorder to compare the acquired position with the actual position. The test revealed that the accuracy of the optical sensor is very high. A 55 mm movement of the sensor gave a deviation of 0.56 mm which is well within the expected result. A computer generated phantom was made to see if the compensation algorithm was working. The test revealed that the compensation algorithm and the software is working perfectly. Next a vessel phantom was scanned to see that the compensation algorithm (lateral compensation) was working in real life. The test showed that a correct lateral compensation was made. Finally 3D phantoms were custom made to test the accuracy of the system by estimation of a known volume. The system was able to estimate the volume in a phantom within an accuracy of 6 %. Performance of the system with direct imaging, using the optical sensor and a lens, was compared to an implementation with an optical fiber, two lenses and the optical sensor. The optical fiber was difficult to implement since the image contrast was degraded severely through the optical fiber and the lenses. This made it difficult for the correlation algorithm to function correctly and tracking could therefore not be done on a skin surface. Code for an FPGA was made in VHDL to extract the actual images from the optical sensor and display them directly on a computer screen. This was necessary to see how well the sensor was in focus. This proved to be a really useful tool for adjusting the optical system for maximal contrast. The optical tracking on a skin surface is a good way to assist a user doing a freehand scanning to get images without geometric distortion. Furthermore, it is the only real positioning system for a portable system. One requirement for this system is, however, that the object being scanned is flat and does not curve or vary vertically. For most applications this is not the case, and we are therefore proposing an implementation with microgyros that is able to give angle information as well. This would give the system a total of up to 5 instead of just 2 degrees of freedom. The status of this is currently that it can be easily implemented in the DLL, but it is not implemented in the 3D reconstruction software, Sonocubic."

"A mobile ultrasound system has been developed, which makes ultrasound examinations possible in harsh environments without reliable power sources, such as ambulances, helicopters, war zones, and disaster sites. The goal of this project was to analyze three different wireless communication technologies that could be integrated into the ultrasound system for possible utilization in remote data applications where medical information may be transmitted from the mobile unit to some centralized base station, such as an emergency room or field hospital. By incorporating wireless telecommunication technology into the design, on site medical personnel can be assisted in diagnostic decisions by remote medical experts. The wireless options that have been tested include the IEEE 802.11g standard, mobile broadband cards on a 3G cellular network, and a mobile satellite terminal. Each technology was tested in two phases. In the first phase, a client/server application was developed to measure and record general information about the quality of each link. Four different types of tests were developed to measure channel properties such as data rate, latency, inter-arrival jitter, and packet loss using various signal strengths, packet sizes, network protocols, and traffic loads. In the second phase of testing, the H.264 Scalable Video Codec (SVC) was used to transmit real-time ultrasound video streams over each of the wireless links to observe the image quality as well as the diagnostic value of the received video stream. The information gathered during both testing phases revealed the abilities and limitations of the different wireless technologies. The results from the performance testing will be valuable in the future for those trying to develop network applications for telemedicine procedures over these wireless telecommunication options. Additionally, the testing demonstrated that the system is currently capable of using H.264 SVC compression to transmit VGA quality ultrasound video at 30 frames per second (fps) over 802.11g while QVGA resolution at frame rates between 10 and 15 fps is possible over 3G and satellite networks."

Over the past 10 years, Compressive Sensing has gained a lot of visibility from the medical imaging research community. The most compelling feature for the use of Compressive Sensing is its ability to perform perfect reconstructions of under-sampled signals using l1-minimization. Of course, that counter-intuitive feature has a cost. The lacking information is compensated for by a priori knowledge of the signal under certain mathematical conditions. This technology is currently used in some commercial MRI scanners to increase the acquisition rate hence decreasing discomfort for the patient while increasing patient turnover. For echography, the applications could go from fast 3D echocardiography to simplified, cheaper echography systems. Real-time ultrasound imaging scanners have been available for nearly 50 years. During these 50 years of existence, much has changed in their architecture, electronics, and technologies. However one component remains present: the beamformer. From analog beamformers to software beamformers, the technology has evolved and brought much diversity to the world of beam formation. Currently, most commercial scanners use several focalized ultrasonic pulses to probe tissue. The time between two consecutive focalized pulses is not compressible, limiting the frame rate. Indeed, one must wait for a pulse to propagate back and forth from the probe to the deepest point imaged before firing a new pulse. In this work, we propose to outline the development of a novel software beamforming technique that uses Compressive Sensing. Time-domain Compressive Beamforming (t-CBF) uses computational models and regularization to reconstruct de-cluttered ultrasound images. One of the main features of t-CBF is its use of only one transmit wave to insonify the tissue. Single-wave imaging brings high frame rates to the modality, for example allowing a physician to see precisely the movements of the heart walls or valves during a heart cycle. t-CBF takes into account the geometry of the probe as well as its physical parameters to improve resolution and attenuate artifacts commonly seen in single-wave imaging such as side lobes. In this thesis, we define a mathematical framework for the beamforming of ultrasonic data compatible with Compressive Sensing. Then, we investigate its capabilities on simple simulations in terms of resolution and super-resolution. Finally, we adapt t-CBF to real-life ultrasonic data. In particular, we reconstruct 2D cardiac images at a frame rate 100-fold higher than typical values.

Modern cancerous tumor diagnostics is nearly impossible without invasive methods, such as biopsy, that may require involved surgical procedures. In recent years some work has been done to develop alternative non-invasive methods of medical diagnostics. For this purpose, the data obtained from an ultrasound image of the body crosssection, has been analyzed using statistical models, including Rayleigh, Rice, Nakagami, and K statistical distributions. The homodyned-K (H-K) distribution has been found to be a good statistical tool to analyze the envelope and/or the intensity of backscattered signal in ultrasound tissue characterization. However, its use has usually been limited due to the fact that its probability density function (PDF) is not available in closed-form. In this work we present a novel closed-form representation for the H-K distribution. In addition, we propose using the first order approximation of the H-K distribution, the I-K distribution that has a closed-form, for the ultrasound tissue characterization applications. More specifically, we show that some tissue conditions that cause the backscattered signal to have low effective density values, can be successfully modeled by the I-K PDF. We introduce the concept of using H-K PDF-based and I-K PDF-based entropies as additional tools for characterization of ultrasonic breast tissue images. The entropy may be used as a goodness of fit measure that allows to select a better-fitting statistical model for a specific data set. In addition, the values of the entropies as well as the values of the statistical distribution parameters, allow for more accurate classification of tumors. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection