12,040 research outputs found
Ergonomics of the Operative Field in Paediatric Minimal Access Surgery
Imperial Users onl
3D haptic needle insertion simulator utilising an agent based spherical voxel model
This paper describes a technique for the real-time modeling of deformable tissue. Specifically geared towards needle insertion simulation, the low computational requirements of the model enable highly accurate haptic feedback to a user without introducing noticeable time delay or buzzing generally associated with haptic surgery simulation. Using a spherical voxel array combined with aspects of computational geometry and agent communication and interaction principals, the model is capable of providing haptic update rates of over 1000Hz with real-time visual feedback. Iterating through over 1000 voxels per millisecond to determine collision and haptic response while making use of Vieta’s Theorem for extraneous force culling. <br /
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Specialist Monitoring Technology and Skills for the Critically Ill Woman
Haptics in Robot-Assisted Surgery: Challenges and Benefits
Robotic surgery is transforming the current surgical practice, not only by improving the conventional surgical methods but also by introducing innovative robot-enhanced approaches that broaden the capabilities of clinicians. Being mainly of man-machine collaborative type, surgical robots are seen as media that transfer pre- and intra-operative information to the operator and reproduce his/her motion, with appropriate filtering, scaling, or limitation, to physically interact with the patient. The field, however, is far from maturity and, more critically, is still a subject of controversy in medical communities. Limited or absent haptic feedback is reputed to be among reasons that impede further spread of surgical robots. In this paper objectives and challenges of deploying haptic technologies in surgical robotics is discussed and a systematic review is performed on works that have studied the effects of providing haptic information to the users in major branches of robotic surgery. It has been tried to encompass both classical works and the state of the art approaches, aiming at delivering a comprehensive and balanced survey both for researchers starting their work in this field and for the experts
Factors of Micromanipulation Accuracy and Learning
Micromanipulation refers to the manipulation under a microscope in order to
perform delicate procedures. It is difficult for humans to manipulate objects
accurately under a microscope due to tremor and imperfect perception, limiting
performance. This project seeks to understand factors affecting accuracy in
micromanipulation, and to propose strategies for learning improving accuracy.
Psychomotor experiments were conducted using computer-controlled setups to
determine how various feedback modalities and learning methods can influence
micromanipulation performance. In a first experiment, static and motion accuracy
of surgeons, medical students and non-medical students under different
magniification levels and grip force settings were compared. A second experiment
investigated whether the non-dominant hand placed close to the target can contribute
to accurate pointing of the dominant hand. A third experiment tested a
training strategy for micromanipulation using unstable dynamics to magnify motion
error, a strategy shown to be decreasing deviation in large arm movements.
Two virtual reality (VR) modules were then developed to train needle grasping
and needle insertion tasks, two primitive tasks in a microsurgery suturing
procedure. The modules provided the trainee with a visual display in stereoscopic
view and information on their grip, tool position and angles. Using the
VR module, a study examining effects of visual cues was conducted to train tool
orientation. Results from these studies suggested that it is possible to learn and
improve accuracy in micromanipulation using appropriate sensorimotor feedback
and training
Southwest Research Institute assistance to NASA in biomedical areas of the technology
Significant applications of aerospace technology were achieved. These applications include: a miniaturized, noninvasive system to telemeter electrocardiographic signals of heart transplant patients during their recuperative period as graded situations are introduced; and economical vital signs monitor for use in nursing homes and rehabilitation hospitals to indicate the onset of respiratory arrest; an implantable telemetry system to indicate the onset of the rejection phenomenon in animals undergoing cardiac transplants; an exceptionally accurate current proportional temperature controller for pollution studies; an automatic, atraumatic blood pressure measurement device; materials for protecting burned areas in contact with joint bender splints; a detector to signal the passage of animals by a given point during ecology studies; and special cushioning for use with below-knee amputees to protect the integrity of the skin at the stump/prosthesis interface
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