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A robot-assisted orthopedic telesurgery system, named HIT-RAOTS, has been developed according to Chinese conventional operation method. Its main function includes obtaining images with information of position and orientation of fracture, providing fracture information for doctors, assisting the doctors to complete the reposition of fracture and locking operation of intramedullary nail. In this system,...
Ophthalmic viscoelastic devices play a crucial role in cataract surgery today by protecting corneal endothelium, structures of anterior chamber and maintaining space inside the eye for safe manipulation during surgical treatment. Many factors likely affect the corneal endothelium during phacoemulsification procedure. These can be divided into 3 groups: 1) direct mechanical trauma including inadvertent...
The objective of this study was to simulate clamping of the aorta. It is computationally demanding and involves contact between clamp and aorta, large deformations, and fluid-structure interactions (FSI). Models of the aortic root and clamp were created and solve in ADINA, a finite element analysis package. The tissue model was created using a non-linear material. Fluid-structure interactions (FSI)...
A new thermal system for tumor treatment was designed to enhance the curative effects while minimizing invasion to the surrounding healthy tissue. This system includes LN2 cryosurgery and RF ablation, which can be used separately or simultaneously. A heat transfer model describing the thermal field during treatments was established. The SAR distribution was assumed to be resulted from an infinite...
A novel liquid nitrogen cryoprobe is developed in the present study. The inlet, handle, the vapor-liquid separator and the heat transfer segment of the cryoprobe are designed to be detachable. This flexible construction provides many distinct features, such as good maneuverability, high safety and low cost. A new vapor-liquid separator is made to ensure the free flow of the liquid nitrogen and increase...
For accurate predictions of the tissue temperature distribution during cryosurgery a thermal model should incorporate the individual impact of large blood vessels. In presence of large vessel, configuring cryoprobe becomes very important because misplacement of cryoprobes may result in either inadequate cooling temperatures in the target tissue due to the heating nature of large vessels or undesired...
Idealized geometries of bypass grafts have been constructed to analyze the blood flow in an aorto-coronary bypass graft system. In this paper we discuss the influence of the realistic bypass graft geometry for the in-plane and out-of-plane aorto-left bypass graft models on the wall shear stress distribution. In the in-plane aorto-left coronary bypass graft model we have the centerlines of the aorta,...
This paper presents a study on investigating the role of three-dimensional visualization (3-D displays) in surgical planning of treating lung cancer. Contrasting to the minor role of 3-D displays in learning anatomy, this study discovered a significant role of 3-D displays in this surgical planning. The study proved the concept that 3-D displays of lung cavities are feasible and have distinctive advantages...
Recent advances in tissue-engineered cartilage open the door to new clinical treatments of joint lesions. Common to all therapies with in-vitro engineered autografts is the need for optimal fit of the construct, to allow screwless implantation and optimal integration into the live joint. Computer assisted surgery techniques are prime candidates to ensure the required accuracy while at the same time...
There is a novel method for creating a 2-d parameterized finite element model of the human femur with matching artificial hip joint based on X-ray image before the hip joint replacement surgery. It can help us to evaluate the selected appropriate hip joint prosthesis
This study describes the autonomic nervous system (ANS) response before, during and after a percutaneous transluminal coronary angioplasty (PTCA). The study population consisted of 37 patients undergoing PTCA from Staff-3 Database. Classical heart rate variability (HRV) parameters: RR mean, SD, rMSSD, LF, HF, LF/HF and LF/(HF+LF) were extracted and a multiple factorial analysis (MFA) was carried out...
Venox is a propriety venous oximetry system, capable of measuring peripheral venous oximetry. In this ongoing study, Venox is being compared against mixed central venous oximetry during human cardiac surgery, with fibre optic reflectance spectrophotometry being used as the gold standard, placed in the pulmonary artery. A background review of the pulse oximetry, current venous oximetry techniques and...
A stereo far-infrared (FIR) system based on the trigonometric parallax is presented in this paper for locating the distal arterial tree from the coronary artery bypass graft. The system can obtain the wide angle-of-view range information in the near distance by changing the optical path of one fixed uncooled FIR camera. Meanwhile, the speed of pixel movement on the FIR imaging plane is discussed for...
Telesurgery systems have long been suffering variable and unpredictable Internet commutation time delay, operation fatigue, and other drawbacks. Based on virtual reality technology, a teleprogramming scheme combined with semi-autonomous control is introduced to guarantee the robustness and efficiency of teleoperation of HIT-RAOS, a robot-assisted orthopedic surgery system. In this system, without...
The per presents a new telementoring system incorporating audio-video communication and remote robotic control. The system was developed around an off the shelf ISDN video conferencing system enhanced with video annotation and remote robot control features. The user can remotely control a robot to perform needle alignment and insertion in a percutaneous access procedure. Particular attention was devoted...
We have been proposing novel thermal balloon angioplasty, photo-thermo dynamic balloon angioplasty (PT-DBA). PTDBA realized <10s short term heating that can prevent surrounding tissue thermal injury and low pressure dilatation that can prevent restenosis in chronic phase. We aim to determine the most efficient heating condition suit to individual symptom with pre-operation thermal simulation. We...
This paper presents the design and initial experimental results of a flexure-based parallel manipulator that is actuated by three piezoelectric stacks. The manipulator is for an active handheld tremor canceling device for microsurgery. By using flexures to approximate pin and ball joints, errors due to friction, backlash, and imperfect assemblies have been eliminated. The results show that the manipulator...
Impedance spectroscopy has been proposed as a method of monitoring mucosal injury due to hypoperfusion and ischemia in the critically ill. The present study evaluates spectral differences in elective cardiovascular surgery patients compared with the impedance spectra of the gastric mucosa in healthy adults. An impedance spectroscopy probe and nasogastric tube (ISP/NGT) was placed into the stomach...
A new approach of registration in multimodal imaging has been developed. Modalities involved are digital subtracted angiography (DSA, 2D) and magnetic resonance angiography (MRA, 3D). Our approach is an hybrid one, mixing feature and intensity based approaches. This approach is based on the extraction of a anatomical referential common to both MRA and DSA. The results obtained prove the methods efficiency...
The primary goal in this study was to investigate 3-D dose distribution, near the areas of tissue inhomogeneities, in Gamma Knife radiosurgery with the gel dosimetry. The spherical glass balloon of a diameter of 16 cm filled with the gel forms the homogeneous phantom; and an identical balloon with two corks placed on each side to represent the air cavities forms the inhomogeneous phantom. Dose calibration...
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