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Item Grape yield analysis with 3D cameras and ultrasonic phased arrays : a thesis by publications presented in fulfillment of the requirements for the degree of Doctor of Philosophy in Engineering at Massey University, Albany, New Zealand(Massey University, 2024-01-18) Parr, BadenAccurate and timely estimation of vineyard yield is crucial for the profitability of vineyards. It enables better management of vineyard logistics, precise application of inputs, and optimization of grape quality at harvest for higher returns. However, the traditional manual process of yield estimation is prone to errors and subjectivity. Additionally, the financial burden of this manual process often leads to inadequate sampling, potentially resulting in sub-optimal insights for vineyard management. As such, there is a growing interest in automating yield estimation using computer vision techniques and novel applications of technologies such as ultrasound. Computer vision has seen significant use in viticulture. Current state-of-the-art 2D approaches, powered by advanced object detection models, can accurately identify grape bunches and individual grapes. However, these methods are limited by the physical constraints of the vineyard environment. Challenges such as occlusions caused by foliage, estimating the hidden parts of grape bunches, and determining berry sizes and distributions still lack clear solutions. Capturing 3D information about the spatial size and position of grape berries has been presented as the next step towards addressing these issues. By using 3D information, the size of individual grapes can be estimated, the surface curvature of berries can be used as identifying features, and the position of grape bunches with respect to occlusions can be used to compute alternative perspectives or estimate occlusion ratios. Researchers have demonstrated some of this value with 3D information captured through traditional means, such as photogrammetry and lab-based laser scanners. However, these face challenges in real-world environments due to processing time and cost. Efficiently capturing 3D information is a rapidly evolving field, with recent advancements in real-time 3D camera technologies being a significant driver. This thesis presents a comprehensive analysis of the performance of available 3D camera technologies for grape yield estimation. Of the technologies tested, we determined that individual berries and concave details between neighbouring grapes were better represented by time-of-flight based technologies. Furthermore, they worked well regardless of ambient lighting conditions, including direct sunlight. However, distortions of individual grapes were observed in both ToF and LiDAR 3D scans. This is due to subsurface scattering of the emitted light entering the grapes before returning, changing the propagation time and by extension the measured distance. We exploit these distortions as unique features and present a novel solution, working in synergy with state-of-the-art 2D object detection, to find and reconstruct in 3D, grape bunches scanned in the field by a modern smartphone. An R2 value of 0.946 and an average precision of 0.970 was achieved when comparing our result to manual counts. Furthermore, our novel size estimation algorithm was able accurately to estimate berry sizes when manually compared to matching colour images. This work represents a novel and objective yield estimation tool that can be used on modern smartphones equipped with 3D cameras. Occlusion of grape bunches due to foliage remains a challenge for automating grape yield estimation using computer vision. It is not always practical or possible to move or trim foliage prior to image capture. To this end, research has started investigating alternative techniques to see through foliage-based occlusions. This thesis introduces a novel ultrasonic-based approach that is able to volumetrically visualise grape bunches directly occluded by foliage. It is achieved through the use of a highly directional ultrasonic phased array and novel signal processing techniques to produce 3D convex hulls of foliage and grape bunches. We utilise a novel approach of agitating the foliage to enable spatial variance filtering to remove leaves and highlight specific volumes that may belong to grape bunches. This technique has wide-reaching potential, in viticulture and beyond.Item Morphological effects of pulsed Doppler diagnostic ultrasound on rat adult lung and fetal tissues : a thesis presented in fulfillment of the requirements for the degree of Master of Science in Physiology and Anatomy at Massey University(Massey University, 1999) Dulović, Stanica MilanThis study investigated morphological effects of diagnostic pulsed Doppler ultrasound on adult and fetal rat lungs from 16 to 22 days gestation. A clinical ultrasound machine with two types of focused transducers (3.5 MHz, 5MHz) was used with an adjustment for an experimental animal as small as a rat. Three levels of exposure were represented by a mechanical index (Ml) of 0.5, 0.6 and 1.0. Subpleural multifocal intra-alveolar haemorrhage was found to a significant degree in exposed adult rat lung and less significantly in fetal lung. The threshold for adult lung haemorrhage was considered to be between Ml 0.5 and 0.6. Fetal lungs were microscopically investigated by sectioning through the whole fetal body, which facilitated the discovery of haemorrhage at other sites. The percentage of exposed fetuses with haemorrhage is significant. A threshold for fetal haemorrhage could not be determined because a significant variation due to age within each exposure group affected the results. The oldest 21 and 22 day old fetuses had no lung haemorrhage or significant non-lung haemorrhage. The risk for haemorrhage at all three exposure levels is more than double that of non exposed fetuses. Fetuses with lung in the canalicular stage of development (18-19 day) showed the greatest degree of lung haemorrhage. Following laparotomy of the dam to achieve a precise and uniform exposure, a small number of fetuses within each exposure group was exposed directly. There was no higher degree of haemorrhage in these fetuses than in others indirectly exposed through the dam's abdominal wall. The fetal age dependency of fetal lung haemorrhage found in this study adds complexity to the issue of adult and fetal lung sensitivity to ultrasound and to the question of the pathophysiological role of cavitation in the presence of air. In addition, our result in 21-22day fetuses does not support the hypothesis that fetal haemorrhage is associated with developing bone. The results in this study were achieved using conditions commonly used in echocardiography and obstetrical ultrasound examinations. Therefore, caution is suggested in the medical use of ultrasound.