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Full-Text Articles in Engineering
Real-Time Membrane Puncture Detection Using Force Sensors For Micro-Injections In Phantoms, Szymon Kowal
Real-Time Membrane Puncture Detection Using Force Sensors For Micro-Injections In Phantoms, Szymon Kowal
Electronic Thesis and Dissertation Repository
Micro-manipulators provide tools for researchers to improve workflow in common preclinical and clinical applications. Following drug delivery injections where drugs did not reach their target will squander research time, experimental animals and other resources. An ultrasound-guided robot developed at Robarts Research Institute was revised to implement closed-loop force feedback to compensate for tissue deformation during micro-interventions. Force sensors can detect puncture events as the needle penetrates tissue membranes, thereby reducing damage to surrounding tissues by preventing the needle from overshooting its target. Changing the angle of injection determined that the range of detectable forces during injections into tissue-mimicking phantoms suggests …
Ultra-High Field Strength Mr Image-Guided Robotic Needle Delivery Device For In-Bore Small Animal Interventions, Matthew J. Gravett
Ultra-High Field Strength Mr Image-Guided Robotic Needle Delivery Device For In-Bore Small Animal Interventions, Matthew J. Gravett
Electronic Thesis and Dissertation Repository
Current methods of accurate soft tissue injections in small animals are prone to many sources of error. Although efforts have been made to improve the accuracy of needle deliveries, none of the efforts have provided accurate soft tissue references. An MR image-guided robot was designed to function inside the bore of a 9.4T MR scanner to accurately deliver needles to locations within the mouse brain. The robot was designed to have no noticeable negative effects on the image quality and was localized in the MR images through the use of an MR image visible fiducial. The robot was mechanically calibrated …
Ultrasound-Guided Mechatronic System For Targeted Delivery Of Cell-Based Cancer Vaccine Immunotherapy In Preclinical Models, Adem Nadjib Hadj Boussaad
Ultrasound-Guided Mechatronic System For Targeted Delivery Of Cell-Based Cancer Vaccine Immunotherapy In Preclinical Models, Adem Nadjib Hadj Boussaad
Electronic Thesis and Dissertation Repository
Injection of dendritic cell (DC) vaccines into lymph nodes (LN) is a promising strategy for eliciting immune responses against cancer, but these injections in mouse cancer models are challenging due to the small target scale (~ 1 mm × 2 mm). Direct manual intranodal injection is difficult and can cause architectural damage to the LN, potentially disrupting crucial interactions between DC and T cells. Therefore, a second-generation ultrasound-guided mechatronic device has been developed to perform this intervention. A targeting accuracy of < 500 μm will enable targeted delivery of the DCs specifically to a LN subcapsular space. The device was redesigned from its original CT-guided edition, which used a remote centre of motion architecture, to be easily integrated onto a commercially available VisualSonics imaging rail system. Subtle modifications were made to ensure simple workflow that allows for live-animal interventions that fall within the knockout periods stated in study protocols. Several calibration and registration techniques were developed in order to achieve an overall targeting accuracy appropriate for the intended application. A variety of methods to quantify the positioning accuracy of the device were investigated. The method chosen involved validating a guided injection into a tissue-mimicking phantom using ultrasound imaging post-operatively to localize the end-point position of the needle tip in the track left behind by the needle. Ultrasound-guided injections into a tissue-mimicking phantom revealed a targeting accuracy of 285 ± 94 μm for the developed robot compared to 508 ± 166 μm for a commercial-available manually-actuated injection device from VisuailSonics. The utility of the robot was also demonstrated by performing in vivo injections into the lymph nodes of mice.