Subretinal injection is a delicate and complex microsurgery. The main surgical difficulties come from the surgeon's hand tremor, dexterous motion, and insufficient visual feedback. In order to begin addressing these challenges, this article presents a robot system for subretinal insertion integrated with intraoperative optical coherence tomography (OCT). The surgical workflow using this system consists of two main parts. The first part is the manual robot control, which aims the target before approaching the retinal surface, while considering the remote center of motion (RCM) constraint. When the injection area has been located precisely, needle is inserted into retina. To ensure surgical safety, needle insertion depth is estimated using OCT images on a continuous basis. A soft RCM control method is designed and integrated for the controller of our hybrid parallel-serial surgical robot. Safety and accuracy performance evaluation with a 15-ms control loop shows that the worst-case RCM deviation error is within 1 mm. Experimental results demonstrated that the proposed system has the ability to improve surgical outcomes by surgeons overcoming their physical limitations in order to enable a better dexterous motion, and furthermore enhancing their visual feedback for a better intraocular perception.

Abstract:Scientific reasoning is commonly regarded as the core problem in science studies. This paper suggests that model-based reasoning is an important part of scientific creativity. I approach this problem from the standpoint of the origin of human thinking and genetic epistemology to understand representative practices of scientists. I also argue that objective similarity in the world is what makes model-based reasoning a powerful tool. 1. THE OCCURRENCE OF THE PROBLEMScientific reasoning has been commonly considered to be the central problem in studies of scientific methodology. Scientific reasoning includes aspects of both discovering and proving. This domain was studied two thousand years ago, beginning with Aristotle. This continued with modern science through four hundred years since Bacon, but it still has yet not been given an answer that is entirely satisfactory. In the XX century the rise of logical positivism excluded scientific discovery from considerations of scientific method. Since the seventies and eighties of the past century the circles of philosophy of science inside and out~ide China have attached importance to studies of the methods of scientific discovery about, providing analyses of typical cases and suggesting some discovery patterns from these cases.Conventional viewpoints of philosophy about reasoning in science are limited and do not accord with scientists' practices. These viewpoints limit reasoning to induction and deduction, applied to linguistic or formulaic representations. This is not in accord with scientific practices exhibited in the

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