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Sample records for aided surgery patient-specific

  1. Orbital and Maxillofacial Computer Aided Surgery: Patient-Specific Finite Element Models To Predict Surgical Outcomes

    CERN Document Server

    Luboz, V; Swider, P; Payan, Y; Luboz, Vincent; Chabanas, Matthieu; Swider, Pascal; Payan, Yohan

    2005-01-01

    This paper addresses an important issue raised for the clinical relevance of Computer-Assisted Surgical applications, namely the methodology used to automatically build patient-specific Finite Element (FE) models of anatomical structures. From this perspective, a method is proposed, based on a technique called the Mesh-Matching method, followed by a process that corrects mesh irregularities. The Mesh-Matching algorithm generates patient-specific volume meshes from an existing generic model. The mesh regularization process is based on the Jacobian matrix transform related to the FE reference element and the current element. This method for generating patient-specific FE models is first applied to Computer-Assisted maxillofacial surgery, and more precisely to the FE elastic modelling of patient facial soft tissues. For each patient, the planned bone osteotomies (mandible, maxilla, chin) are used as boundary conditions to deform the FE face model, in order to predict the aesthetic outcome of the surgery. Seven F...

  2. Patient-Specific Simulation of Implant Placement and Function for Cochlear Implantation Surgery Planning

    DEFF Research Database (Denmark)

    Ceresa, Mario; Mangado Lopez, Nerea; Dejea Velardo, Hector;

    2014-01-01

    We present a framework for patient specific electrical stimulation of the cochlea, that allows to perform in-silico analysis of implant placement and function before surgery. A Statistical Shape Model (SSM) is created from high-resolution human μCT data to capture important anatomical details...

  3. A Numerical Multiscale Framework for Modeling Patient-Specific Coronary Artery Bypass Surgeries

    Science.gov (United States)

    Ramachandra, Abhay B.; Kahn, Andrew; Marsden, Alison

    2014-11-01

    Coronary artery bypass graft (CABG) surgery is performed to revascularize diseased coronary arteries, using arterial, venous or synthetic grafts. Vein grafts, used in more than 70% of procedures, have failure rates as high as 50% in less than 10 years. Hemodynamics is known to play a key role in the mechano-biological response of vein grafts, but current non-invasive imaging techniques cannot fully characterize the hemodynamic and biomechanical environment. We numerically compute hemodynamics and wall mechanics in patient-specific 3D CABG geometries using stabilized finite element methods. The 3D patient-specific domain is coupled to a 0D lumped parameter circulatory model and parameters are tuned to match patient-specific blood pressures, stroke volumes, heart rates and heuristic flow-split values. We quantify differences in hemodynamics between arterial and venous grafts and discuss possible correlations to graft failure. Extension to a deformable wall approximation will also be discussed. The quantification of wall mechanics and hemodynamics is a necessary step towards coupling continuum models in solid and fluid mechanics with the cellular and sub-cellular responses of grafts, which in turn, should lead to a more accurate prediction of the long term outcome of CABG surgeries, including predictions of growth and remodeling.

  4. Splintless orthognathic surgery: a novel technique using patient-specific implants (PSI).

    Science.gov (United States)

    Gander, Thomas; Bredell, Marius; Eliades, Theodore; Rücker, Martin; Essig, Harald

    2015-04-01

    In the past few years, advances in three-dimensional imaging have conducted to breakthrough in the diagnosis, treatment planning and result assessment in orthognathic surgery. Hereby error-prone and time-consuming planning steps, like model surgery and transfer of the face bow, can be eluded. Numerous positioning devices, in order to transfer the three-dimensional treatment plan to the intraoperative site, have been described. Nevertheless the use of positioning devices and intraoperative splints are failure-prone and time-consuming steps, which have to be performed during the operation and during general anesthesia of the patient. We describe a novel time-sparing and failsafe technique using patient-specific implants (PSI) as positioning guides and concurrently as rigid fixation of the maxilla in the planned position. This technique avoids elaborate positioning and removal of manufactured positioning devices and allows maxillary positioning without the use of occlusal splints.

  5. Patient-Specific Biomechanical Modeling for Guidance During Minimally-Invasive Hepatic Surgery.

    Science.gov (United States)

    Plantefève, Rosalie; Peterlik, Igor; Haouchine, Nazim; Cotin, Stéphane

    2016-01-01

    During the minimally-invasive liver surgery, only the partial surface view of the liver is usually provided to the surgeon via the laparoscopic camera. Therefore, it is necessary to estimate the actual position of the internal structures such as tumors and vessels from the pre-operative images. Nevertheless, such task can be highly challenging since during the intervention, the abdominal organs undergo important deformations due to the pneumoperitoneum, respiratory and cardiac motion and the interaction with the surgical tools. Therefore, a reliable automatic system for intra-operative guidance requires fast and reliable registration of the pre- and intra-operative data. In this paper we present a complete pipeline for the registration of pre-operative patient-specific image data to the sparse and incomplete intra-operative data. While the intra-operative data is represented by a point cloud extracted from the stereo-endoscopic images, the pre-operative data is used to reconstruct a biomechanical model which is necessary for accurate estimation of the position of the internal structures, considering the actual deformations. This model takes into account the patient-specific liver anatomy composed of parenchyma, vascularization and capsule, and is enriched with anatomical boundary conditions transferred from an atlas. The registration process employs the iterative closest point technique together with a penalty-based method. We perform a quantitative assessment based on the evaluation of the target registration error on synthetic data as well as a qualitative assessment on real patient data. We demonstrate that the proposed registration method provides good results in terms of both accuracy and robustness w.r.t. the quality of the intra-operative data.

  6. Patient specific finite element model of the face soft tissues for computer-assisted maxillofacial surgery.

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    Chabanas, Matthieu; Luboz, Vincent; Payan, Yohan

    2003-06-01

    This paper addresses the prediction of face soft tissue deformations resulting from bone repositioning in maxillofacial surgery. A generic 3D Finite Element model of the face soft tissues was developed. Face muscles are defined in the mesh as embedded structures, with different mechanical properties (transverse isotropy, stiffness depending on muscle contraction). Simulations of face deformations under muscle actions can thus be performed. In the context of maxillofacial surgery, this generic soft-tissue model is automatically conformed to patient morphology by elastic registration, using skin and skull surfaces segmented from a CT scan. Some elements of the patient mesh could be geometrically distorted during the registration, which disables Finite Element analysis. Irregular elements are thus detected and automatically regularized. This semi-automatic patient model generation is robust, fast and easy to use. Therefore it seems compatible with clinical use. Six patient models were successfully built, and simulations of soft tissue deformations resulting from bone displacements performed on two patient models. Both the adequation of the models to the patient morphologies and the simulations of post-operative aspects were qualitatively validated by five surgeons. Their conclusions are that the models fit the morphologies of the patients, and that the predicted soft tissue modifications are coherent with what they would expect.

  7. Patient-specific finite-element simulation of the human cornea: a clinical validation study on cataract surgery.

    Science.gov (United States)

    Studer, Harald P; Riedwyl, Hansjörg; Amstutz, Christoph A; Hanson, James V M; Büchler, Philippe

    2013-02-22

    The planning of refractive surgical interventions is a challenging task. Numerical modeling has been proposed as a solution to support surgical intervention and predict the visual acuity, but validation on patient specific intervention is missing. The purpose of this study was to validate the numerical predictions of the post-operative corneal topography induced by the incisions required for cataract surgery. The corneal topography of 13 patients was assessed preoperatively and postoperatively (1-day and 30-day follow-up) with a Pentacam tomography device. The preoperatively acquired geometric corneal topography - anterior, posterior and pachymetry data - was used to build patient-specific finite element models. For each patient, the effects of the cataract incisions were simulated numerically and the resulting corneal surfaces were compared to the clinical postoperative measurements at one day and at 30-days follow up. Results showed that the model was able to reproduce experimental measurements with an error on the surgically induced sphere of 0.38D one day postoperatively and 0.19D 30 days postoperatively. The standard deviation of the surgically induced cylinder was 0.54D at the first postoperative day and 0.38D 30 days postoperatively. The prediction errors in surface elevation and curvature were below the topography measurement device accuracy of ±5μm and ±0.25D after the 30-day follow-up. The results showed that finite element simulations of corneal biomechanics are able to predict post cataract surgery within topography measurement device accuracy. We can conclude that the numerical simulation can become a valuable tool to plan corneal incisions in cataract surgery and other ophthalmosurgical procedures in order to optimize patients' refractive outcome and visual function.

  8. Patient-specific port placement for laparoscopic surgery using atlas-based registration

    Science.gov (United States)

    Enquobahrie, Andinet; Shivaprabhu, Vikas; Aylward, Stephen; Finet, Julien; Cleary, Kevin; Alterovitz, Ron

    2013-03-01

    Laparoscopic surgery is a minimally invasive surgical approach, in which abdominal surgical procedures are performed through trocars via small incisions. Patients benefit by reduced postoperative pain, shortened hospital stays, improved cosmetic results, and faster recovery times. Optimal port placement can improve surgeon dexterity and avoid the need to move the trocars, which would cause unnecessary trauma to the patient. We are building an intuitive open source visualization system to help surgeons identify ports. Our methodology is based on an intuitive port placement visualization module and atlas-based registration algorithm to transfer port locations to individual patients. The methodology follows three steps:1) Use a port placement visualization module to manually place ports in an abdominal organ atlas. This step generates port-augmented abdominal atlas. This is done only once for a given patient population. 2) Register the atlas data with the patient CT data, to transfer the prescribed ports to the individual patient 3) Review and adjust the transferred port locations using the port placement visualization module. Tool maneuverability and target reachability can be tested using the visualization system. Our methodology would decrease the amount of physician input necessary to optimize port placement for each patient case. In a follow up work, we plan to use the transferred ports as starting point for further optimization of the port locations by formulating a cost function that will take into account factors such as tool dexterity and likelihood of collision between instruments.

  9. Real-time surgery simulation of intracranial aneurysm clipping with patient-specific geometries and haptic feedback

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    Fenz, Wolfgang; Dirnberger, Johannes

    2015-03-01

    Providing suitable training for aspiring neurosurgeons is becoming more and more problematic. The increasing popularity of the endovascular treatment of intracranial aneurysms leads to a lack of simple surgical situations for clipping operations, leaving mainly the complex cases, which present even experienced surgeons with a challenge. To alleviate this situation, we have developed a training simulator with haptic interaction allowing trainees to practice virtual clipping surgeries on real patient-specific vessel geometries. By using specialized finite element (FEM) algorithms (fast finite element method, matrix condensation) combined with GPU acceleration, we can achieve the necessary frame rate for smooth real-time interaction with the detailed models needed for a realistic simulation of the vessel wall deformation caused by the clamping with surgical clips. Vessel wall geometries for typical training scenarios were obtained from 3D-reconstructed medical image data, while for the instruments (clipping forceps, various types of clips, suction tubes) we use models provided by manufacturer Aesculap AG. Collisions between vessel and instruments have to be continuously detected and transformed into corresponding boundary conditions and feedback forces, calculated using a contact plane method. After a training, the achieved result can be assessed based on various criteria, including a simulation of the residual blood flow into the aneurysm. Rigid models of the surgical access and surrounding brain tissue, plus coupling a real forceps to the haptic input device further increase the realism of the simulation.

  10. Comparative Evaluation of Handheld Robot-Aided Intraocular Laser Surgery

    Science.gov (United States)

    Yang, Sungwook; MacLachlan, Robert A.; Martel, Joseph N.; Lobes, Louis A.; Riviere, Cameron N.

    2015-01-01

    This paper presents robot-aided intraocular laser surgery using a handheld robot known as Micron. The micromanipulator incorporated in Micron enables visual servoing of a laser probe, while maintaining a constant distance of the tool tip from the retinal surface. The comparative study was conducted with various control methods for evaluation of robot-aided intraocular laser surgery. PMID:27019653

  11. 3D Rapid Prototyping for Otolaryngology-Head and Neck Surgery: Applications in Image-Guidance, Surgical Simulation and Patient-Specific Modeling.

    Directory of Open Access Journals (Sweden)

    Harley H L Chan

    Full Text Available The aim of this study was to demonstrate the role of advanced fabrication technology across a broad spectrum of head and neck surgical procedures, including applications in endoscopic sinus surgery, skull base surgery, and maxillofacial reconstruction. The initial case studies demonstrated three applications of rapid prototyping technology are in head and neck surgery: i a mono-material paranasal sinus phantom for endoscopy training ii a multi-material skull base simulator and iii 3D patient-specific mandible templates. Digital processing of these phantoms is based on real patient or cadaveric 3D images such as CT or MRI data. Three endoscopic sinus surgeons examined the realism of the endoscopist training phantom. One experienced endoscopic skull base surgeon conducted advanced sinus procedures on the high-fidelity multi-material skull base simulator. Ten patients participated in a prospective clinical study examining patient-specific modeling for mandibular reconstructive surgery. Qualitative feedback to assess the realism of the endoscopy training phantom and high-fidelity multi-material phantom was acquired. Conformance comparisons using assessments from the blinded reconstructive surgeons measured the geometric performance between intra-operative and pre-operative reconstruction mandible plates. Both the endoscopy training phantom and the high-fidelity multi-material phantom received positive feedback on the realistic structure of the phantom models. Results suggested further improvement on the soft tissue structure of the phantom models is necessary. In the patient-specific mandible template study, the pre-operative plates were judged by two blinded surgeons as providing optimal conformance in 7 out of 10 cases. No statistical differences were found in plate fabrication time and conformance, with pre-operative plating providing the advantage of reducing time spent in the operation room. The applicability of common model design and

  12. 9th Asian Conference on Computer-Aided Surgery

    CERN Document Server

    2016-01-01

    This book presents the latest research advances in the theory, design, control, and application of robot systems intended for a variety of purposes such as manipulation, manufacturing, automation, surgery, locomotion, and biomechanics. Several chapters deal with fundamental kinematics in nature, including synthesis, calibration, redundancy, force control, dexterity, inverse and forward kinematics, kinematic singularities, and over-constrained systems. This book is a compilation of the extended versions of the very best papers selected from the many that were presented at the Asian Conference on Computer-Aided Surgery held September 16–18, 2013, in Tokyo, Japan (ACCAS 2013).

  13. Image-guided installation of 3D-printed patient-specific implant and its application in pelvic tumor resection and reconstruction surgery.

    Science.gov (United States)

    Chen, Xiaojun; Xu, Lu; Wang, Yiping; Hao, Yongqiang; Wang, Liao

    2016-03-01

    Nowadays, the diagnosis and treatment of pelvic sarcoma pose a major surgical challenge for reconstruction in orthopedics. With the development of manufacturing technology, the metal 3D-printed customized implants have brought revolution for the limb-salvage resection and reconstruction surgery. However, the tumor resection is not without risk and the precise implant placement is very difficult due to the anatomic intricacies of the pelvis. In this study, a surgical navigation system including the implant calibration algorithm has been developed, so that the surgical instruments and the 3D-printed customized implant can be tracked and rendered on the computer screen in real time, minimizing the risks and improving the precision of the surgery. Both the phantom experiment and the pilot clinical case study presented the feasibility of our computer-aided surgical navigation system. According to the accuracy evaluation experiment, the precision of customized implant installation can be improved three to five times (TRE: 0.75±0.18 mm) compared with the non-navigated implant installation after the guided osteotomy (TRE: 3.13±1.28 mm), which means it is sufficient to meet the clinical requirements of the pelvic reconstruction. However, more clinical trials will be conducted in the future work for the validation of the reliability and efficiency of our navigation system.

  14. In-vivo measurement of the human soft tissues constitutive laws. Applications to Computer Aided Surgery

    CERN Document Server

    Schiavone, Patrick; Ohayon, J; Payan, Y

    2007-01-01

    In the 80's, biomechanicians were asked to work on Computer Aided Surgery applications since orthopaedic surgeons were looking for numerical tools able to predict risks of fractures. More recently, biomechanicians started to address soft tissues arguing that most of the human body is made of such tissues that can move as well as deform during surgical gestures [1]. An intra-operative use of a continuous Finite Element (FE) Model of a given tissue mainly faces two problems: (1) the numerical simulations have to be "interactive", i.e. sufficiently fast to provide results during surgery (which can be a strong issue in the context of hyperelastic models for example) and (2) during the intervention, the surgeon needs a device that can be used to provide to the model an estimation of the patient-specific constitutive behaviour of the soft tissues. This work proposes an answer to the second point, with the design of a new aspiration device aiming at characterizing the in vivo constitutive laws of human soft tissues....

  15. Decision aiding in plastic surgery: a multicriteria analysis

    Directory of Open Access Journals (Sweden)

    Luiz Flávio Autran Monteiro Gomes

    2012-08-01

    Full Text Available The aim of this article is to present, through a real case, a practical way, based on Multicriteria Decision Aiding, to support decision making in Plastic Surgery. The case studied was a Caucasian woman of 36 years of age with mammarian hypertrophia with ptosis and abdominal lipodystrophy, making it necessary to select the most adequate techniques for the best aesthetic result. For this purpose, the multicriteria methods Even Swaps and PrOACT were used. Three plastic surgeons working in the city of Rio de Janeiro with equivalent professional experience were consulted as decision agents. In order to define the objectives to be achieved, the criteria relevant to the making of the decision and the alternatives which could be used were identified. Throughout this identification and in the later analysis the surgeons participated in the application of the methods, which contributed towards facilitating their acceptance of the multicriteria analysis in their decision making. It was confirmed, in this case study, that the use of Multicriteria Decision Aiding tends to make the medical decision more wide ranging and, above all, transparent. The plastic surgeons themselves validated the analysis, considering it fully consistent with their professional experience.

  16. Assessment of patient-specific surgery effect based on weighted estimation and propensity scoring in the re-analysis of the sciatica trial.

    Directory of Open Access Journals (Sweden)

    Bart J A Mertens

    Full Text Available We consider a re-analysis of the wait-and-see (control arm of a recent clinical trial on sciatica. While the original randomised trial was designed to evaluate the public policy effect of a conservative wait-and-see approach versus early surgery, we investigate the impact of surgery at the individual patient level in a re-analysis of the wait-and-see group data. Both marginal structural model re-weighted estimates as well as propensity score adjusted analyses are presented. Results indicate that patients with high propensity to receive surgery may have beneficial effects at 2 years from delayed disc surgery.

  17. Biomechanics applied to computer-aided diagnosis: examples of orbital and maxillofacial surgeries

    CERN Document Server

    Payan, Y; Chabanas, M; Swider, P; Marecaux, C; Boutault, F; Payan, Yohan; Luboz, Vincent; Chabanas, Matthieu; Swider, Pascal; Marecaux, Christophe; Boutault, Franck

    2005-01-01

    This paper introduces the methodology proposed by our group to model the biological soft tissues deformations and to couple these models with Computer-Assisted Surgical (CAS) applications. After designing CAS protocols that mainly focused on bony structures, the Computer Aided Medical Imaging group of Laboratory TIMC (CNRS, France) now tries to take into account the behaviour of soft tissues in the CAS context. For this, a methodology, originally published under the name of the Mesh-Matching method, has been proposed to elaborate patient specific models. Starting from an elaborate manually-built "generic" Finite Element (FE) model of a given anatomical structure, models adapted to the geometries of each new patient ("patient specific" FE models) are automatically generated through a non-linear elastic registration algorithm. This paper presents the general methodology of the Mesh-Matching method and illustrates this process with two clinical applications, namely the orbital and the maxillofacial computer-assi...

  18. Electromagnetic tracking for abdominal interventions in computer aided surgery.

    Science.gov (United States)

    Zhang, Hui; Banovac, Filip; Lin, Ralph; Glossop, Neil; Wood, Bradford J; Lindisch, David; Levy, Elliot; Cleary, Kevin

    2006-05-01

    Electromagnetic tracking has great potential for assisting physicians in precision placement of instruments during minimally invasive interventions in the abdomen, since electromagnetic tracking is not limited by the line-of-sight restrictions of optical tracking. A new generation of electromagnetic tracking has recently become available, with sensors small enough to be included in the tips of instruments. To fully exploit the potential of this technology, our research group has been developing a computer aided, image-guided system that uses electromagnetic tracking for visualization of the internal anatomy during abdominal interventions. As registration is a critical component in developing an accurate image-guided system, we present three registration techniques: 1) enhanced paired-point registration (time-stamp match registration and dynamic registration); 2) orientation-based registration; and 3) needle shape-based registration. Respiration compensation is another important issue, particularly in the abdomen, where respiratory motion can make precise targeting difficult. To address this problem, we propose reference tracking and affine transformation methods. Finally, we present our prototype navigation system, which integrates the registration, segmentation, path-planning and navigation functions to provide real-time image guidance in the clinical environment. The methods presented here have been tested with a respiratory phantom specially designed by our group and in swine animal studies under approved protocols. Based on these tests, we conclude that our system can provide quick and accurate localization of tracked instruments in abdominal interventions, and that it offers a user-friendly display for the physician.

  19. Does computer-aided surgical simulation improve efficiency in bimaxillary orthognathic surgery?

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    Schwartz, H C

    2014-05-01

    The purpose of this study was to compare the efficiency of bimaxillary orthognathic surgery using computer-aided surgical simulation (CASS), with cases planned using traditional methods. Total doctor time was used to measure efficiency. While costs vary widely in different localities and in different health schemes, time is a valuable and limited resource everywhere. For this reason, total doctor time is a more useful measure of efficiency than is cost. Even though we use CASS primarily for planning more complex cases at the present time, this study showed an average saving of 60min for each case. In the context of a department that performs 200 bimaxillary cases each year, this would represent a saving of 25 days of doctor time, if applied to every case. It is concluded that CASS offers great potential for improving efficiency when used in the planning of bimaxillary orthognathic surgery. It saves significant doctor time that can be applied to additional surgical work.

  20. Patient-Specific Computational Modeling

    CERN Document Server

    Peña, Estefanía

    2012-01-01

    This book addresses patient-specific modeling. It integrates computational modeling, experimental procedures, imagine clinical segmentation and mesh generation with the finite element method (FEM) to solve problems in computational biomedicine and bioengineering. Specific areas of interest include cardiovascular problems, ocular and muscular systems and soft tissue modeling. Patient-specific modeling has been the subject of serious research over the last seven years and interest in the area is continually growing and this area is expected to further develop in the near future.

  1. Using a smart phone for information rendering in Computer-Aided Surgery

    CERN Document Server

    Gael, Le Bellego; Bricault, Ivan; Troccaz, Jocelyne

    2011-01-01

    Computer-aided surgery intensively uses the concept of navigation: after having collected CT data from a patient and transferred them to the operating room coordinate system, the surgical instrument (a puncture needle for instance) is localized and its position is visualized with respect to the patient organs which are not directly visible. This approach is very similar to the GPS paradigm. Traditionally, three orthogonal slices in the patient data are presented on a distant screen. Sometimes a 3D representation is also added. In this study we evaluated the potential of adding a smart phone as a man-machine interaction device. Different experiments involving operators puncturing a phantom are reported in this paper.

  2. Evaluation of three-dimensional position change of the condylar head after orthognathic surgery using computer-aided design/computer-aided manufacturing-made condyle positioning jig.

    Science.gov (United States)

    Kim, Hyung-Mo; Baek, Seung-Hak; Kim, Tae-Yun; Choi, Jin-Young

    2014-11-01

    This study was performed to evaluate the efficacy of computer-aided design/computer-aided manufacturing (CAM/CAD)-made condyle positioning jig in orthognathic surgery. The sample consisted of 40 mandibular condyles of 20 patients with class III malocclusion who underwent bilateral sagittal split ramus osteotomy with semirigid fixation (6 men and 14 women; mean age, 25 y; mean amount of mandibular setback, 5.8 mm). Exclusion criteria were patients who needed surgical correction of the frontal ramal inclination and had signs and symptoms of the temporomandibular disorder before surgery. Three-dimensional computed tomograms were taken 1 month before the surgery (T1) and 1 day after the surgery (T2). The condylar position was evaluated at the T1 and T2 stages on the axial, frontal, and sagittal aspects in the three-dimensional coordinates. The linear change of the posterior border of the proximal segment of the ramus between T1 and T2 was also evaluated in 30 condyles (15 patients), with the exception of 10 condyles of 5 patients who received mandibular angle reduction surgery. There was no significant difference in the condylar position in the frontal and sagittal aspects (P > 0.05). Although there was a significant difference in the condylar position in the axial aspect (P < 0.01), the amount of difference was less than 1 mm and 1 degree; it can be considered clinically nonsignificant. In the linear change of the posterior border of the proximal segment of the ramus, the mean change was 1.4 mm and 60% of the samples showed a minimal change of less than 1 mm. The results of this study suggest that CAD/CAM-made condyle positioning jig is easy to install and reliable to use in orthognathic surgery.

  3. AIDS

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/000594.htm HIV/AIDS To use the sharing features on this page, ... immunodeficiency virus (HIV) is the virus that causes AIDS. When a person becomes infected with HIV, the ...

  4. Development of a computer-aided design software for dental splint in orthognathic surgery

    Science.gov (United States)

    Chen, Xiaojun; Li, Xing; Xu, Lu; Sun, Yi; Politis, Constantinus; Egger, Jan

    2016-12-01

    In the orthognathic surgery, dental splints are important and necessary to help the surgeon reposition the maxilla or mandible. However, the traditional methods of manual design of dental splints are difficult and time-consuming. The research on computer-aided design software for dental splints is rarely reported. Our purpose is to develop a novel special software named EasySplint to design the dental splints conveniently and efficiently. The design can be divided into two steps, which are the generation of initial splint base and the Boolean operation between it and the maxilla-mandibular model. The initial splint base is formed by ruled surfaces reconstructed using the manually picked points. Then, a method to accomplish Boolean operation based on the distance filed of two meshes is proposed. The interference elimination can be conducted on the basis of marching cubes algorithm and Boolean operation. The accuracy of the dental splint can be guaranteed since the original mesh is utilized to form the result surface. Using EasySplint, the dental splints can be designed in about 10 minutes and saved as a stereo lithography (STL) file for 3D printing in clinical applications. Three phantom experiments were conducted and the efficiency of our method was demonstrated.

  5. Virtual Reality Aided Positioning of Mobile C-Arms for Image-Guided Surgery

    Directory of Open Access Journals (Sweden)

    Zhenzhou Shao

    2014-06-01

    Full Text Available For the image-guided surgery, the positioning of mobile C-arms is a key technique to take X-ray images in a desired pose for the confirmation of current surgical outcome. Unfortunately, surgeons and patient often suffer the radiation exposure due to the repeated imaging when the X-ray image is of poor quality or not captured at a good projection view. In this paper, a virtual reality (VR aided positioning method for the mobile C-arm is proposed by the alignment of 3D surface model of region of interest and preoperative anatomy, so that a reference pose of the mobile C-arm with respect to the inside anatomy can be figured out from outside view. It allows a one-time imaging from the outside view to greatly reduce the additional radiation exposure. To control the mobile C-arm to the desired pose, the mobile C-arm is modeled as a robotic arm with a movable base. Experiments were conducted to evaluate the accuracy of appearance model and precision of mobile C-arm positioning. The appearance model was reconstructed with the average error of 2.16 mm. One-time imaging of mobile C-arm was achieved, and new modeling of mobile C-arm with 8 DoFs enlarges the working space in the operating room.

  6. Microscope-integrated optical coherence tomography for image-aided positioning of glaucoma surgery

    Science.gov (United States)

    Li, Xiqi; Wei, Ling; Dong, Xuechuan; Huang, Ping; Zhang, Chun; He, Yi; Shi, Guohua; Zhang, Yudong

    2015-07-01

    Most glaucoma surgeries involve creating new aqueous outflow pathways with the use of a small surgical instrument. This article reported a microscope-integrated, real-time, high-speed, swept-source optical coherence tomography system (SS-OCT) with a 1310-nm light source for glaucoma surgery. A special mechanism was designed to produce an adjustable system suitable for use in surgery. A two-graphic processing unit architecture was used to speed up the data processing and real-time volumetric rendering. The position of the surgical instrument can be monitored and measured using the microscope and a grid-inserted image of the SS-OCT. Finally, experiments were simulated to assess the effectiveness of this integrated system. Experimental results show that this system is a suitable positioning tool for glaucoma surgery.

  7. A 3D computer-aided design system applied to diagnosis and treatment planning in orthodontics and orthognathic surgery.

    Science.gov (United States)

    Motohashi, N; Kuroda, T

    1999-06-01

    The purpose of this article is to describe a newly developed 3D computer-aided design (CAD) system for the diagnostic set-up of casts in orthodontic diagnosis and treatment planning, and its preliminary clinical applications. The system comprises a measuring unit which obtains 3D information from the dental model using laser scanning, and a personal computer to generate the 3D graphics. When measuring the 3D shape of the model, to minimize blind sectors, the model is scanned from two different directions with the slit-ray laser beam by rotating the mounting angle of the model on the measuring device. For computed simulation of tooth movement, the representative planes, defined by the anatomical reference points, are formed for each individual tooth and are arranged along a guideline descriptive of the individual arch form. Subsequently, the 3D shape is imparted to each of the teeth arranged on the representative plane to form an arrangement of the 3D profile. When necessary, orthognathic surgery can be simulated by moving the mandibular dental arch three-dimensionally to establish the optimum occlusal relationship. Compared with hand-made set-up models, the computed diagnostic cast has advantages such as high-speed processing and quantitative evaluation on the amount of 3D movement of the individual tooth relative to the craniofacial plane. Trial clinical applications demonstrated that the use of this system facilitated the otherwise complicated and time-consuming mock surgery for treatment planning in orthognathic surgery.

  8. Implantable and semi-implantable hearing AIDS: a review of history, indications, and surgery.

    Science.gov (United States)

    Bittencourt, Aline Gomes; Burke, Patrick Rademaker; Jardim, Isabela de Souza; Brito, Rubens de; Tsuji, Robinson Koji; Fonseca, Anna Carolina de Oliveira; Bento, Ricardo Ferreira

    2014-07-01

    Introduction The complaints associated with the use of conventional amplifying hearing aids prompted research at several centers worldwide that ultimately led to the development of implantable devices for aural rehabilitation. Objectives To review the history, indications, and surgical aspects of the implantable middle ear hearing devices. Data Synthesis Implantable hearing aids, such as the Vibrant Soundbridge system (Med-El Corporation, Innsbruck, Austria), the Maxum system (Ototronix LLC, Houston, Texas, United States), the fourth-generation of Carina prosthesis (Otologics LLC, Boulder, Colorado, United States), and the Esteem device (Envoy Medical Corporation - Minnesota, United States), have their own peculiarities on candidacy and surgical procedure. Conclusion Implantable hearing aids, which are currently in the early stages of development, will unquestionably be the major drivers of advancement in otologic practice in the 21st century, improving the quality of life of an increasingly aged population, which will consequently require increased levels of hearing support.

  9. Implantable and Semi-Implantable Hearing Aids: A Review of History, Indications, and Surgery

    Directory of Open Access Journals (Sweden)

    Bittencourt, Aline Gomes

    2014-04-01

    Full Text Available Introduction The complaints associated with the use of conventional amplifying hearing aids prompted research at several centers worldwide that ultimately led to the development of implantable devices for aural rehabilitation. Objectives To review the history, indications, and surgical aspects of the implantable middle ear hearing devices. Data Synthesis Implantable hearing aids, such as the Vibrant Soundbridge system (Med-El Corporation, Innsbruck, Austria, the Maxum system (Ototronix LLC, Houston, Texas, United States, the fourth-generation of Carina prosthesis (Otologics LLC, Boulder, Colorado, United States, and the Esteem device (Envoy Medical Corporation - Minnesota, United States, have their own peculiarities on candidacy and surgical procedure. Conclusion Implantable hearing aids, which are currently in the early stages of development, will unquestionably be the major drivers of advancement in otologic practice in the 21st century, improving the quality of life of an increasingly aged population, which will consequently require increased levels of hearing support.

  10. Observation in Laparoscopic Surgery: Overview of Impeding Effects and Supporting Aids

    NARCIS (Netherlands)

    Breedveld, P.; Stassen, H.G.; Meijer, D.W.; Jakimowicz, J.J.

    2000-01-01

    Within a Dutch research program on minimally invasive surgery, a large literature survey has been carried out. This article describes the state of the art in research on observation in laparoscopy. It gives an overview of factors impeding the surgeon and technical developments designed to overcome t

  11. Surgery

    Science.gov (United States)

    ... the hospital, sometimes in an intensive care unit (ICU). Direct discharge home A person being sent home ... from surgery should occur gradually. Some people need rehabilitation , which involves special exercises and activities, to improve ...

  12. Patient-Specific Modeling in Tomorrow's Medicine

    CERN Document Server

    2012-01-01

    This book reviews the frontier of research and clinical applications of Patient Specific Modeling, and provides a state-of-the-art update as well as perspectives on future directions in this exciting field. The book is useful for medical physicists, biomedical engineers and other engineers who are interested in the science and technology aspects of Patient Specific Modeling, as well as for radiologists and other medical specialists who wish to be updated about the state of implementation.

  13. A web-based computer aided system for liver surgery planning: initial implementation on RayPlus

    Science.gov (United States)

    Luo, Ming; Yuan, Rong; Sun, Zhi; Li, Tianhong; Xie, Qingguo

    2016-03-01

    At present, computer aided systems for liver surgery design and risk evaluation are widely used in clinical all over the world. However, most systems are local applications that run on high-performance workstations, and the images have to processed offline. Compared with local applications, a web-based system is accessible anywhere and for a range of regardless of relative processing power or operating system. RayPlus (http://rayplus.life.hust.edu.cn), a B/S platform for medical image processing, was developed to give a jump start on web-based medical image processing. In this paper, we implement a computer aided system for liver surgery planning on the architecture of RayPlus. The system consists of a series of processing to CT images including filtering, segmentation, visualization and analyzing. Each processing is packaged into an executable program and runs on the server side. CT images in DICOM format are processed step by to interactive modeling on browser with zero-installation and server-side computing. The system supports users to semi-automatically segment the liver, intrahepatic vessel and tumor from the pre-processed images. Then, surface and volume models are built to analyze the vessel structure and the relative position between adjacent organs. The results show that the initial implementation meets satisfactorily its first-order objectives and provide an accurate 3D delineation of the liver anatomy. Vessel labeling and resection simulation are planned to add in the future. The system is available on Internet at the link mentioned above and an open username for testing is offered.

  14. 3D reconstruction of patient-specific femurs using Coherent Point Drift

    Directory of Open Access Journals (Sweden)

    Shaobin Sun

    2013-02-01

    Full Text Available This paper dealt with the problem that the overlapping digital radiographs couldn`t reflect the 3D space information of the patient-specific femur in the orthopaedic surgery diagnosis. A 2D-3D non-rigid registration method based on Coherent Point Drift was proposed to realize the 3D reconstruction of the patient-specific femur before the surgery, which used biplanar digital radiographs of the patient-specific femur and the CT volume data of a generic femur. With the advantages of low cost, fast imaging speed and little radiation to the patients and doctors, this method provided more effective 3D imaging information for the femur diagnosis and preoperative plans. The registration experiments showed that the proposed method recovered the 3D model and the pose of the patient-specific femur effectively with a fast, accurate and robust registration result, which had satisfied the needs of clinical application.

  15. 3D-printed patient-specific applications in orthopedics

    Directory of Open Access Journals (Sweden)

    Wong KC

    2016-10-01

    Full Text Available Kwok Chuen Wong Department of Orthopedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong Abstract: With advances in both medical imaging and computer programming, two-dimensional axial images can be processed into other reformatted views (sagittal and coronal and three-dimensional (3D virtual models that represent a patients’ own anatomy. This processed digital information can be analyzed in detail by orthopedic surgeons to perform patient-specific orthopedic procedures. The use of 3D printing is rising and has become more prevalent in medical applications over the last decade as surgeons and researchers are increasingly utilizing the technology’s flexibility in manufacturing objects. 3D printing is a type of manufacturing process in which materials such as plastic or metal are deposited in layers to create a 3D object from a digital model. This additive manufacturing method has the advantage of fabricating objects with complex freeform geometry, which is impossible using traditional subtractive manufacturing methods. Specifically in surgical applications, the 3D printing techniques can not only generate models that give a better understanding of the complex anatomy and pathology of the patients and aid in education and surgical training, but can also produce patient-specific surgical guides or even custom implants that are tailor-made to the surgical requirements. As the clinical workflow of the 3D printing technology continues to evolve, orthopedic surgeons should embrace the latest knowledge of the technology and incorporate it into their clinical practice for patient-specific orthopedic applications. This paper is written to help orthopedic surgeons stay up-to-date on the emerging 3D technology, starting from the acquisition of clinical imaging to 3D printing for patient-specific applications in orthopedics. It 1 presents the necessary steps to prepare the medical images that are

  16. Simulated surgery on computed tomography and magnetic resonance images: an aid for intraoperative radiotherapy.

    Science.gov (United States)

    Desco, M; López, J; Calvo, F A; Santos, A; Santos, J A; del Pozo, F; García-Barreno, P

    1997-01-01

    Intraoperative radiotherapy (IORT) is a relatively new technique in which irradiation with electrons is performed during an open surgery procedure. This approach poses significant problems in obtaining accurate dosimetry, since neither the pre- nor the postoperative patient images actually matches the irradiation field. Our objective was to implement a software tool able to provide an estimate of the dose distribution, overcoming the problem of the geometrical mismatch between the images and the surgical field during the irradiation. The program was developed in the C programming language, on a noncommercial version of a Philips EasyVision workstation. The application allows to create a new data set by manipulating the preoperative computed tomography and magnetic resonance images in order to simulate the final geometry of the surgical area during the IORT procedure. The exact dose distribution can then be calculated by transferring these new images to a standard radiotherapy planning system. Also an approximate dose distribution can be quickly displayed by superimposing isodose curves obtained from a water phantom. The proposed approach introduces a helpful tool for dosimetry and planning in IORT protocols, improving their accuracy and safety and allowing for more objective quality control and patient follow-up.

  17. The migration of femoral components after total hip replacement surgery: accuracy and precision of software-aided measurements

    Energy Technology Data Exchange (ETDEWEB)

    Decking, J. [Dept. of Orthopaedic Surgery, Univ. of Mainz School of Medicine, Mainz (Germany); Schuetz, U.; Decking, R.; Puhl, W. [Orthopaedic Dept., Univ. of Ulm, School of Medicine (Germany)

    2003-09-01

    Objective: To assess the accuracy and precision of a software-aided system to measure migration of femoral components after total hip replacement (THR) on digitised radiographs. Design and patients: Subsidence and varus-valgus tilt of THR stems within the femur were measured on digitised anteroposterior pelvic radiographs. The measuring software (UMA, GEMED, Germany) relies on bony landmarks and comparability parameters of two consecutive radiographs. Its accuracy and precision were calculated by comparing it with the gold standard in migration measurements, radiostereometric analysis (RSA). Radiographs and corresponding RSA measurements were performed in 60 patients (38-69 years) following cementless THR surgery. Results and conclusions: The UMA software measured the subsidence of the stems with an accuracy of {+-}2.5 mm and varus-valgus tilt with an accuracy of {+-}1.8 (95% confidence interval). A good interobserver and intraobserver reliability was calculated with Cronbach's alpha ranging from 0.86 to 0.97. Measuring the subsidence of THR stems within the femur is an important parameter in the diagnosis of implant loosening. Software systems such as UMA improve the accuracy of migration measurements and are easy to use on routinely performed radiographs of operated hip joints. (orig.)

  18. Algorithm for planning a double-jaw orthognathic surgery using a computer-aided surgical simulation (CASS) protocol. Part 1: planning sequence.

    Science.gov (United States)

    Xia, J J; Gateno, J; Teichgraeber, J F; Yuan, P; Chen, K-C; Li, J; Zhang, X; Tang, Z; Alfi, D M

    2015-12-01

    The success of craniomaxillofacial (CMF) surgery depends not only on the surgical techniques, but also on an accurate surgical plan. The adoption of computer-aided surgical simulation (CASS) has created a paradigm shift in surgical planning. However, planning an orthognathic operation using CASS differs fundamentally from planning using traditional methods. With this in mind, the Surgical Planning Laboratory of Houston Methodist Research Institute has developed a CASS protocol designed specifically for orthognathic surgery. The purpose of this article is to present an algorithm using virtual tools for planning a double-jaw orthognathic operation. This paper will serve as an operation manual for surgeons wanting to incorporate CASS into their clinical practice.

  19. Patient-specific simulation of tidal breathing

    Science.gov (United States)

    Walters, M.; Wells, A. K.; Jones, I. P.; Hamill, I. S.; Veeckmans, B.; Vos, W.; Lefevre, C.; Fetitia, C.

    2016-03-01

    Patient-specific simulation of air flows in lungs is now straightforward using segmented airways trees from CT scans as the basis for Computational Fluid Dynamics (CFD) simulations. These models generally use static geometries, which do not account for the motion of the lungs and its influence on important clinical indicators, such as airway resistance. This paper is concerned with the simulation of tidal breathing, including the dynamic motion of the lungs, and the required analysis workflow. Geometries are based on CT scans obtained at the extremes of the breathing cycle, Total Lung Capacity (TLC) and Functional Residual Capacity (FRC). It describes how topologically consistent geometries are obtained at TLC and FRC, using a `skeleton' of the network of airway branches. From this a 3D computational mesh which morphs between TLC and FRC is generated. CFD results for a number of patient-specific cases, healthy and asthmatic, are presented. Finally their potential use in evaluation of the progress of the disease is discussed, focusing on an important clinical indicator, the airway resistance.

  20. Toward patient-specific articular contact mechanics.

    Science.gov (United States)

    Ateshian, Gerard A; Henak, Corinne R; Weiss, Jeffrey A

    2015-03-18

    The mechanics of contacting cartilage layers is fundamentally important to understanding the development, homeostasis and pathology of diarthrodial joints. Because of the highly nonlinear nature of both the materials and the contact problem itself, numerical methods such as the finite element method are typically incorporated to obtain solutions. Over the course of five decades, we have moved from an initial qualitative understanding of articular cartilage material behavior to the ability to perform complex, three-dimensional contact analysis, including multiphasic material representations. This history includes the development of analytical and computational contact analysis methods that now provide the ability to perform highly nonlinear analyses. Numerical implementations of contact analysis based on the finite element method are rapidly advancing and will soon enable patient-specific analysis of joint contact mechanics using models based on medical image data. In addition to contact stress on the articular surfaces, these techniques can predict variations in strain and strain through the cartilage layers, providing the basis to predict damage and failure. This opens up exciting areas for future research and application to patient-specific diagnosis and treatment planning applied to a variety of pathologies that affect joint function and cartilage homeostasis.

  1. Weight Loss Surgery (Bariatric Surgery) (For Parents)

    Science.gov (United States)

    ... Health Growth & Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life First Aid & ... Surgery Types of Surgery Gastric Bypass ... or intestines removed due to ulcers or cancer tended to lose a lot of weight after ...

  2. Pancreas segmentation from 3D abdominal CT images using patient-specific weighted subspatial probabilistic atlases

    Science.gov (United States)

    Karasawa, Kenichi; Oda, Masahiro; Hayashi, Yuichiro; Nimura, Yukitaka; Kitasaka, Takayuki; Misawa, Kazunari; Fujiwara, Michitaka; Rueckert, Daniel; Mori, Kensaku

    2015-03-01

    Abdominal organ segmentations from CT volumes are now widely used in the computer-aided diagnosis and surgery assistance systems. Among abdominal organs, the pancreas is especially difficult to segment because of its large individual differences of the shape and position. In this paper, we propose a new pancreas segmentation method from 3D abdominal CT volumes using patient-specific weighted-subspatial probabilistic atlases. First of all, we perform normalization of organ shapes in training volumes and an input volume. We extract the Volume Of Interest (VOI) of the pancreas from the training volumes and an input volume. We divide each training VOI and input VOI into some cubic regions. We use a nonrigid registration method to register these cubic regions of the training VOI to corresponding regions of the input VOI. Based on the registration results, we calculate similarities between each cubic region of the training VOI and corresponding region of the input VOI. We select cubic regions of training volumes having the top N similarities in each cubic region. We subspatially construct probabilistic atlases weighted by the similarities in each cubic region. After integrating these probabilistic atlases in cubic regions into one, we perform a rough-to-precise segmentation of the pancreas using the atlas. The results of the experiments showed that utilization of the training volumes having the top N similarities in each cubic region led good results of the pancreas segmentation. The Jaccard Index and the average surface distance of the result were 58.9% and 2.04mm on average, respectively.

  3. From Patient-Specific Mathematical Neuro-Oncology to Precision Medicine

    Directory of Open Access Journals (Sweden)

    Anne eBaldock

    2013-04-01

    Full Text Available Gliomas are notoriously aggressive, malignant brain tumors that have variable response to treatment. These patients often have poor prognosis, informed primarily by histopathology. Mathematical neuro-oncology (MNO is a young and burgeoning field that leverages mathematical models to predict and quantify response to therapies. These mathematical models can form the basis of modern precision medicine approaches to tailor therapy in a patient-specific manner. Patient specific models (PSMs can be used to overcome imaging limitations, improve prognostic predictions, stratify patients and assess treatment response in silico. The information gleaned from such models can aid in the construction and efficacy of clinical trials and treatment protocols, accelerating the pace of clinical research in the war on cancer. This review focuses on the growing translation of PSM to clinical neuro-oncology. It will also provide a forward-looking view on a new era of patient-specific mathematical neuro-oncology.

  4. Additive manufacturing of patient-specific tubular continuum manipulators

    Science.gov (United States)

    Amanov, Ernar; Nguyen, Thien-Dang; Burgner-Kahrs, Jessica

    2015-03-01

    Tubular continuum robots, which are composed of multiple concentric, precurved, elastic tubes, provide more dexterity than traditional surgical instruments at the same diameter. The tubes can be precurved such that the resulting manipulator fulfills surgical task requirements. Up to now the only material used for the component tubes of those manipulators is NiTi, a super-elastic shape-memory alloy of nickel and titan. NiTi is a cost-intensive material and fabrication processes are complex, requiring (proprietary) technology, e.g. for shape setting. In this paper, we evaluate component tubes made of 3 different thermoplastic materials (PLA, PCL and nylon) using fused filament fabrication technology (3D printing). This enables quick and cost-effective production of custom, patient-specific continuum manipulators, produced on site on demand. Stress-strain and deformation characteristics are evaluated experimentally for 16 fabricated tubes of each thermoplastic with diameters and shapes equivalent to those of NiTi tubes. Tubes made of PCL and nylon exhibit properties comparable to those made of NiTi. We further demonstrate a tubular continuum manipulator composed of 3 nylon tubes in a transnasal, transsphenoidal skull base surgery scenario in vitro.

  5. Skin Biopsy and Patient-Specific Stem Cell Lines

    Science.gov (United States)

    Li, Yao; Nguyen, Huy V.; Tsang, Stephen H.

    2016-01-01

    The generation of patient-specific induced pluripotent stem (iPS) cells permits the development of next-generation patient-specific systems biology models reflecting personalized genomics profiles to better understand pathophysiology. In this chapter, we describe how to create a patient-specific iPS cell line. There are three major steps: (1) performing a skin biopsy procedure on the patient; (2) extracting human fibroblast cells from the skin biopsy tissue; and (3) reprogramming patient-specific fibroblast cells into the pluripotent stem cell stage. PMID:26141312

  6. Integration of 3D anatomical data obtained by CT imaging and 3D optical scanning for computer aided implant surgery

    OpenAIRE

    Paoli Alessandro; Barone Sandro; Chessa Giacomo; Frisardi Gianni; Razionale Armando; Frisardi Flavio

    2011-01-01

    Abstract Background A precise placement of dental implants is a crucial step to optimize both prosthetic aspects and functional constraints. In this context, the use of virtual guiding systems has been recognized as a fundamental tool to control the ideal implant position. In particular, complex periodontal surgeries can be performed using preoperative planning based on CT data. The critical point of the procedure relies on the lack of accuracy in transferring CT planning information to surgi...

  7. Improved radiographic outcomes with patient-specific total knee arthroplasty.

    Science.gov (United States)

    Ivie, Conrad B; Probst, Patrick J; Bal, Amrit K; Stannard, James T; Crist, Brett D; Sonny Bal, B

    2014-11-01

    Patient-specific guides can improve limb alignment and implant positioning in total knee arthroplasty, although not all studies have supported this benefit. We compared the radiographs of 100 consecutively-performed patient-specific total knees to a similar group that was implanted with conventional instruments instead. The patient-specific group showed more accurate reproduction of the theoretically ideal mechanical axis, with fewer outliers, but implant positioning was comparable between groups. Our odds ratio comparison showed that the patient-specific group was 1.8 times more likely to be within the desired +3° from the neutral mechanical axis when compared to the standard control group. Our data suggest that reliable reproduction of the limb mechanical axis may accrue from patient-specific guides in total knee arthroplasty when compared to standard, intramedullary instrumentation.

  8. A review of rapid prototyped surgical guides for patient-specific total knee replacement.

    Science.gov (United States)

    Krishnan, S P; Dawood, A; Richards, R; Henckel, J; Hart, A J

    2012-11-01

    Improvements in the surgical technique of total knee replacement (TKR) are continually being sought. There has recently been interest in three-dimensional (3D) pre-operative planning using magnetic resonance imaging (MRI) and CT. The 3D images are increasingly used for the production of patient-specific models, surgical guides and custom-made implants for TKR. The users of patient-specific instrumentation (PSI) claim that they allow the optimum balance of technology and conventional surgery by reducing the complexity of conventional alignment and sizing tools. In this way the advantages of accuracy and precision claimed by computer navigation techniques are achieved without the disadvantages of additional intra-operative inventory, new skills or surgical time. This review describes the terminology used in this area and debates the advantages and disadvantages of PSI.

  9. Knee Replacement for Women with Patient-Specific Instructions

    Medline Plus

    Full Text Available Knee Replacement for Women with Patient-Specific Instructions Click Here to view the BroadcastMed, Inc. Privacy Policy and Legal Notice © 2017 BroadcastMed, Inc. All rights reserved.

  10. Integration of 3D anatomical data obtained by CT imaging and 3D optical scanning for computer aided implant surgery

    Directory of Open Access Journals (Sweden)

    Paoli Alessandro

    2011-02-01

    Full Text Available Abstract Background A precise placement of dental implants is a crucial step to optimize both prosthetic aspects and functional constraints. In this context, the use of virtual guiding systems has been recognized as a fundamental tool to control the ideal implant position. In particular, complex periodontal surgeries can be performed using preoperative planning based on CT data. The critical point of the procedure relies on the lack of accuracy in transferring CT planning information to surgical field through custom-made stereo-lithographic surgical guides. Methods In this work, a novel methodology is proposed for monitoring loss of accuracy in transferring CT dental information into periodontal surgical field. The methodology is based on integrating 3D data of anatomical (impression and cast and preoperative (radiographic template models, obtained by both CT and optical scanning processes. Results A clinical case, relative to a fully edentulous jaw patient, has been used as test case to assess the accuracy of the various steps concurring in manufacturing surgical guides. In particular, a surgical guide has been designed to place implants in the bone structure of the patient. The analysis of the results has allowed the clinician to monitor all the errors, which have been occurring step by step manufacturing the physical templates. Conclusions The use of an optical scanner, which has a higher resolution and accuracy than CT scanning, has demonstrated to be a valid support to control the precision of the various physical models adopted and to point out possible error sources. A case study regarding a fully edentulous patient has confirmed the feasibility of the proposed methodology.

  11. Study on hemodynamics in patient-specific thoracic aortic aneurysm

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The objective of this study is to investigate the hemodynamics in patient-specific thoracic aortic aneurysm and discuss the reason for formation of aortic plaque.A 3-Dimensional pulsatile blood flow in thoracic aorta with a fusiform aneurysm and 3 main branched vessels was studied numerically with the average Reynolds number of 1399 and the Womersley number of 19.2.Based on the clinical 2-Dimensional CT slice data,the patient-specific geometry model was constructed using medical image process software.Un...

  12. Patient-specific hip prostheses designed by surgeons

    Directory of Open Access Journals (Sweden)

    Coigny Florian

    2016-09-01

    Full Text Available Patient-specific bone and joint replacement implants lead to better functional and aesthetic results than conventional methods [1], [2], [3]. But extracting 3D shape information from CT Data and designing individual implants is demanding and requires multiple surgeon-to-engineer interactions. For manufacturing purposes, Additive Manufacturing offers various advantages, especially for low volume manufacturing parts, such as patient specific implants. To ease these new approaches and to avoid surgeon-to-engineer interactions a new design software approach is needed which offers highly automated and user friendly planning steps.

  13. [Robotic surgery].

    Science.gov (United States)

    Moreno-Portillo, Mucio; Valenzuela-Salazar, Carlos; Quiroz-Guadarrama, César David; Pachecho-Gahbler, Carlos; Rojano-Rodríguez, Martín

    2014-12-01

    Medicine has experienced greater scientific and technological advances in the last 50 years than in the rest of human history. The article describes relevant events, revises concepts and advantages and clinical applications, summarizes published clinical results, and presents some personal reflections without giving dogmatic conclusions about robotic surgery. The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) defines robotic surgery as a surgical procedure using technology to aid the interaction between surgeon and patient. The objective of the surgical robot is to correct human deficiencies and improve surgical skills. The capacity of repeating tasks with precision and reproducibility has been the base of the robot´s success. Robotic technology offers objective and measurable advantages: - Improving maneuverability and physical capacity during surgery. - Correcting bad postural habits and tremor. - Allowing depth perception (3D images). - Magnifying strength and movement limits. - Offering a platform for sensors, cameras, and instruments. Endoscopic surgery transformed conceptually the way of practicing surgery. Nevertheless in the last decade, robotic assisted surgery has become the next paradigm of our era.

  14. Convolutional Neural Networks for patient-specific ECG classification.

    Science.gov (United States)

    Kiranyaz, Serkan; Ince, Turker; Hamila, Ridha; Gabbouj, Moncef

    2015-01-01

    We propose a fast and accurate patient-specific electrocardiogram (ECG) classification and monitoring system using an adaptive implementation of 1D Convolutional Neural Networks (CNNs) that can fuse feature extraction and classification into a unified learner. In this way, a dedicated CNN will be trained for each patient by using relatively small common and patient-specific training data and thus it can also be used to classify long ECG records such as Holter registers in a fast and accurate manner. Alternatively, such a solution can conveniently be used for real-time ECG monitoring and early alert system on a light-weight wearable device. The experimental results demonstrate that the proposed system achieves a superior classification performance for the detection of ventricular ectopic beats (VEB) and supraventricular ectopic beats (SVEB).

  15. Mutirão de cirurgias de adenotonsilectomias: uma solução viável? Adeno-tonsillectomy surgery in a joint aid effort: a feasible solution ?

    Directory of Open Access Journals (Sweden)

    Marcos Luiz Antunes

    2007-08-01

    for public hospitals, and to compare the incidence of post-operative hemorrhage in joint aid effort surgery with that of regular surgeriy. METHODS: A clinical case-control prospective study of adenotonsillectomies done in joint aid efforts was done from September 2004 to June 2006 at the Diadema State Hospital. An analysis was made of the multiprofessional staff involved in this process, and a comparison was made of the incidence of hemorrhage in joint aid efforts and after regular surgery. RESULTS: 22 joint aid effort events for adenotonsillectomies were done during the period mentioned above (339 surgeries, an average 15.4 surgeries per event. The rate of postoperative hemorrhage requiring surgical revision was 1.48%(5/339, which did not differ statistically from the case-control group (1.37% - 5/364. CONCLUSION: We were able to standardize the results of adenotonsillectomies done in a joint aid effort to the parameters that are considered as safe. This may reduce the waiting line for this procedure. The difference in the incidence of postoperative hemorrhage in the joint aid effort and regular surgery was not statistically significant.

  16. Experimental validation of 3D printed patient-specific implants using digital image correlation and finite element analysis.

    Science.gov (United States)

    Sutradhar, Alok; Park, Jaejong; Carrau, Diana; Miller, Michael J

    2014-09-01

    With the dawn of 3D printing technology, patient-specific implant designs are set to have a paradigm shift. A topology optimization method in designing patient-specific craniofacial implants has been developed to ensure adequate load transfer mechanism and restore the form and function of the mid-face. Patient-specific finite element models are used to design these implants and to validate whether they are viable for physiological loading such as mastication. Validation of these topology optimized finite element models using mechanical testing is a critical step. Instead of inserting the implants into a cadaver or patient, we embed the implants into the computer-aided skull model of a patient and, fuse them together to 3D print the complete skull model with the implant. Masticatory forces are applied in the molar region to simulate chewing and measure the stress-strain trajectory. Until recently, strain gages have been used to measure strains for validation. Digital Image Correlation (DIC) method is a relatively new technique for full-field strain measurement which provides a continuous deformation field data. The main objective of this study is to validate the finite element model of patient-specific craniofacial implants against the strain data from the DIC obtained during the mastication simulation and show that the optimized shapes provide adequate load-transfer mechanism. Patient-specific models are obtained from CT scans. The principal maximum and minimum strains are compared. The computational and experimental approach to designing patient-specific implants proved to be a viable technique for mid-face craniofacial reconstruction.

  17. A population of patient-specific adult acquired flatfoot deformity models before and after surgery.

    Science.gov (United States)

    Spratley, E M; Matheis, E A; Hayes, C W; Adelaar, R S; Wayne, J S

    2014-09-01

    Following IRB approval, a cohort of 3-D rigid-body computational models was created from submillimeter MRIs of clinically diagnosed Adult Acquired Flatfoot Deformity patients and employed to investigate postoperative foot/ankle function and surgical effect during single-leg stance. Models were constrained through physiologic joint contact, passive soft-tissue tension, active muscle force, full body weight, and without idealized joints. Models were validated against patient-matched controls using clinically utilized radiographic angle and distance measures and plantar force distributions in the medial forefoot, lateral forefoot, and hindfoot. Each model further predicted changes in strain for the spring ligament, deltoid ligament, and plantar fascia, as well as joint contact loads for three midfoot joints, the talonavicular, navicular-1st cuneiform, and calcaneocuboid. Radiographic agreement ranged across measures, with average absolute deviations of <5° and <4 mm indicating generally good agreement. Postoperative plantar force loading in patients and models was reduced for the medial forefoot and hindfoot concomitant with increases in the lateral forefoot. Model predicted reductions in medial soft-tissue strain and increases in lateral joint contact load were consistent with in vitro observations and elucidate the biomechanical mechanisms of repair. Thus, validated rigid-body models offer promise for the investigation of foot/ankle kinematics and biomechanical behaviors that are difficult to measure in vivo.

  18. Patient-specific modeling of human cardiovascular system elements

    Science.gov (United States)

    Kossovich, Leonid Yu.; Kirillova, Irina V.; Golyadkina, Anastasiya A.; Polienko, Asel V.; Chelnokova, Natalia O.; Ivanov, Dmitriy V.; Murylev, Vladimir V.

    2016-03-01

    Object of study: The research is aimed at development of personalized medical treatment. Algorithm was developed for patient-specific surgical interventions of the cardiovascular system pathologies. Methods: Geometrical models of the biological objects and initial and boundary conditions were realized by medical diagnostic data of the specific patient. Mechanical and histomorphological parameters were obtained with the help mechanical experiments on universal testing machine. Computer modeling of the studied processes was conducted with the help of the finite element method. Results: Results of the numerical simulation allowed evaluating the physiological processes in the studied object in normal state, in presence of different pathologies and after different types of surgical procedures.

  19. Patient-Specific Pluripotent Stem Cells in Neurological Diseases

    Directory of Open Access Journals (Sweden)

    Serpen Durnaoglu

    2011-01-01

    Full Text Available Many human neurological diseases are not currently curable and result in devastating neurologic sequelae. The increasing availability of induced pluripotent stem cells (iPSCs derived from adult human somatic cells provides new prospects for cellreplacement strategies and disease-related basic research in a broad spectrum of human neurologic diseases. Patient-specific iPSC-based modeling of neurogenetic and neurodegenerative diseases is an emerging efficient tool for in vitro modeling to understand disease and to screen for genes and drugs that modify the disease process. With the exponential increase in iPSC research in recent years, human iPSCs have been successfully derived with different technologies and from various cell types. Although there remain a great deal to learn about patient-specific iPSC safety, the reprogramming mechanisms, better ways to direct a specific reprogramming, ideal cell source for cellular grafts, and the mechanisms by which transplanted stem cells lead to an enhanced functional recovery and structural reorganization, the discovery of the therapeutic potential of iPSCs offers new opportunities for the treatment of incurable neurologic diseases. However, iPSC-based therapeutic strategies need to be thoroughly evaluated in preclinical animal models of neurological diseases before they can be applied in a clinical setting.

  20. Feasibility study of patient-specific surgical templates for the fixation of pedicle screws.

    Science.gov (United States)

    Salako, F; Aubin, C-E; Fortin, C; Labelle, H

    2002-01-01

    Surgery for scoliosis, as well as other posterior spinal surgeries, frequently uses pedicle screws to fix an instrumentation on the spine. Misplacement of a screw can lead to intra- and post-operative complications. The objective of this study is to design patient-specific surgical templates to guide the drilling operation. From the CT-scan of a vertebra, the optimal drilling direction and limit angles are computed from an inverse projection of the pedicle limits. The first template design uses a surface-to-surface registration method and was constructed in a CAD system by subtracting the vertebra from a rectangular prism and a cylinder with the optimal orientation. This template and the vertebra were built using rapid prototyping. The second design uses a point-to-surface registration method and has 6 adjustable screws to adjust the orientation and length of the drilling support device. A mechanism was designed to hold it in place on the spinal process. A virtual prototype was build with CATIA software. During the operation, the surgeon places either template on patient's vertebra until a perfect match is obtained before drilling. The second design seems better than the first one because it can be reused on different vertebra and is less sensible to registration errors. The next step is to build the second design and make experimental and simulations tests to evaluate the benefits of this template during a scoliosis operation.

  1. A patient-specific scatter artifacts correction method

    CERN Document Server

    Zhao, Wei; Niu, Kai; Schafer, Sebastian; Royalty, Kevin; Chen, Guang-Hong

    2015-01-01

    This paper provides a fast and patient-specific scatter artifact correction method for cone-beam computed tomography (CBCT) used in image-guided interventional procedures. Due to increased irradiated volume of interest in CBCT imaging, scatter radiation has increased dramatically compared to 2D imaging, leading to a degradation of image quality. In this study, we propose a scatter artifact correction strategy using an analytical convolution-based model whose free parameters are estimated using a rough estimation of scatter profiles from the acquired cone-beam projections. It was evaluated using Monte Carlo simulations with both monochromatic and polychromatic X-ray sources. The results demonstrated that the proposed method significantly reduced the scatter-induced shading artifacts and recovered CT numbers.

  2. Using an EPID for patient-specific VMAT quality assurance

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    Bakhtiari, M.; Kumaraswamy, L.; Bailey, D. W.; Boer, S. de; Malhotra, H. K.; Podgorsak, M. B. [Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 and Department of Physics, State University of New York at Buffalo, Buffalo, New York 14260 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States)

    2011-03-15

    Purpose: A patient-specific quality assurance (QA) method was developed to verify gantry-specific individual multileaf collimator (MLC) apertures (control points) in volumetric modulated arc therapy (VMAT) plans using an electronic portal imaging device (EPID). Methods: VMAT treatment plans were generated in an Eclipse treatment planning system (TPS). DICOM images from a Varian EPID (aS1000) acquired in continuous acquisition mode were used for pretreatment QA. Each cine image file contains the grayscale image of the MLC aperture related to its specific control point and the corresponding gantry angle information. The TPS MLC file of this RapidArc plan contains the leaf positions for all 177 control points (gantry angles). In-house software was developed that interpolates the measured images based on the gantry angle and overlays them with the MLC pattern for all control points. The 38% isointensity line was used to define the edge of the MLC leaves on the portal images. The software generates graphs and tables that provide analysis for the number of mismatched leaf positions for a chosen distance to agreement at each control point and the frequency in which each particular leaf mismatches for the entire arc. Results: Seven patients plans were analyzed using this method. The leaves with the highest mismatched rate were found to be treatment plan dependent. Conclusions: This in-house software can be used to automatically verify the MLC leaf positions for all control points of VMAT plans using cine images acquired by an EPID.

  3. Efficacy of an Intra-Operative Imaging Software System for Anatomic Anterior Cruciate Ligament Reconstruction Surgery

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    Xudong Zhang

    2012-01-01

    Full Text Available An imaging software system was studied for improving the performance of anatomic anterior cruciate ligament (ACL reconstruction which requires identifying ACL insertion sites for bone tunnel placement. This software predicts and displays the insertion sites based on the literature data and patient-specific bony landmarks. Twenty orthopaedic surgeons performed simulated arthroscopic ACL surgeries on 20 knee specimens, first without and then with the visual guidance by fluoroscopic imaging, and their tunnel entry positions were recorded. The native ACL insertion morphologies of individual specimens were quantified in relation to CT-based bone models and then used to evaluate the software-generated insertion locations. Results suggested that the system was effective in leading surgeons to predetermined locations while the application of averaged insertion morphological information in individual surgeries can be susceptible to inaccuracy and uncertainty. Implications on challenges associated with developing engineering solutions to aid in re-creating or recognizing anatomy in surgical care delivery are discussed.

  4. Respiratory gated radiotherapy-pretreatment patient specific quality assurance

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    Rajesh Thiyagarajan

    2016-01-01

    Full Text Available Organ motions during inter-fraction and intra-fraction radiotherapy introduce errors in dose delivery, irradiating excess of normal tissue, and missing target volume. Lung and heart involuntary motions cause above inaccuracies and gated dose delivery try to overcome above effects. Present work attempts a novel method to verify dynamic dose delivery using a four-dimensional (4D phantom. Three patients with mobile target are coached to maintain regular and reproducible breathing pattern. Appropriate intensity projection image set generated from 4D-computed tomography (4D-CT is used for target delineation. Intensity modulated radiotherapy plans were generated on selected phase using CT simulator (Siemens AG, Germany in conjunction with "Real-time position management" (Varian, USA to acquire 4D-CT images. Verification plans were generated for both ion chamber and Gafchromic (EBT film image sets. Gated verification plans were delivered on the phantom moving with patient respiratory pattern. We developed a MATLAB-based software to generate maximum intensity projection, minimum intensity projections, and average intensity projections, also a program to convert patient breathing pattern to phantom compatible format. Dynamic thorax quality assurance (QA phantom (Computerized Imaging Reference Systems type is used to perform the patient specific QA, which holds an ion chamber and film to measure delivered radiation intensity. Exposed EBT films are analyzed and compared with treatment planning system calculated dose. The ion chamber measured dose shows good agreement with planned dose within ± 0.5% (0.203 ± 0.57%. Gamma value evaluated from EBT film shows passing rates 92–99% (96.63 ± 3.84% for 3% dose and 3 mm distance criteria. Respiratory gated treatment delivery accuracy is found to be within clinically acceptable level.

  5. Generating patient-specific pulmonary vascular models for surgical planning

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    Murff, Daniel; Co-Vu, Jennifer; O'Dell, Walter G.

    2015-03-01

    Each year in the U.S., 7.4 million surgical procedures involving the major vessels are performed. Many of our patients require multiple surgeries, and many of the procedures include "surgical exploration". Procedures of this kind come with a significant amount of risk, carrying up to a 17.4% predicted mortality rate. This is especially concerning for our target population of pediatric patients with congenital abnormalities of the heart and major pulmonary vessels. This paper offers a novel approach to surgical planning which includes studying virtual and physical models of pulmonary vasculature of an individual patient before operation obtained from conventional 3D X-ray computed tomography (CT) scans of the chest. These models would provide clinicians with a non-invasive, intricately detailed representation of patient anatomy, and could reduce the need for invasive planning procedures such as exploratory surgery. Researchers involved in the AirPROM project have already demonstrated the utility of virtual and physical models in treatment planning of the airways of the chest. Clinicians have acknowledged the potential benefit from such a technology. A method for creating patient-derived physical models is demonstrated on pulmonary vasculature extracted from a CT scan with contrast of an adult human. Using a modified version of the NIH ImageJ program, a series of image processing functions are used to extract and mathematically reconstruct the vasculature tree structures of interest. An auto-generated STL file is sent to a 3D printer to create a physical model of the major pulmonary vasculature generated from 3D CT scans of patients.

  6. Linear elastic properties of the facial soft tissues using an aspiration device: towards patient specific characterization.

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    Luboz, V; Promayon, E; Payan, Y

    2014-11-01

    Biomechanical modeling of the facial soft tissue behavior is needed in aesthetic or maxillo-facial surgeries where the simulation of the bone displacements cannot accurately predict the visible outcome on the patient's face. Because these tissues have different nature and elastic properties across the face, depending on their thickness, and their content in fat or muscle, individualizing their mechanical parameters could increase the simulation accuracy. Using a specifically designed aspiration device, the facial soft tissues deformation is measured at four different locations (cheek, cheekbone, forehead, and lower lip) on 16 young subjects. The stiffness is estimated from the deformations generated by a set of negative pressures using an inverse analysis based on a Neo Hookean model. The initial Young's modulus of the cheek, cheekbone, forehead, and lower lip are respectively estimated to be 31.0 kPa±4.6, 34.9 kPa±6.6, 17.3 kPa±4.1, and 33.7 kPa±7.3. Significant intra-subject differences in tissue stiffness are highlighted by these estimations. They also show important inter-subject variability for some locations even when mean stiffness values show no statistical difference. This study stresses the importance of using a measurement device capable of evaluating the patient specific tissue stiffness during an intervention.

  7. Patient-Specific Modeling of Interventricular Hemodynamics in Single Ventricle Physiology

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    Vedula, Vijay; Feinstein, Jeffrey; Marsden, Alison

    2016-11-01

    Single ventricle (SV) congenital heart defects, in which babies are born with only functional ventricle, lead to significant morbidity and mortality with over 30% of patients developing heart failure prior to adulthood. Newborns with SV physiology typically undergo three palliative surgeries, in which the SV becomes the systemic pumping chamber. Depending on which ventricle performs the systemic function, patients are classified as having either a single left ventricle (SLV) or a single right ventricle (SRV), with SRV patients at higher risk of failure. As the native right ventricles are not designed to meet systemic demands, they undergo remodeling leading to abnormal hemodynamics. The hemodynamic characteristics of SLVs compared with SRVs is not well established. We present a validated computational framework for performing patient-specific modeling of ventricular flows, and apply it across 6 SV patients (3SLV + 3SRV), comparing hemodynamic conditions between the two subgroups. Simulations are performed with a stabilized finite element method coupled with an immersed boundary method for modeling heart valves. We discuss identification of hemodynamic biomarkers of ventricular remodeling for early risk assessment of failure. This research is supported in part by the Stanford Child Health Research Institute and the Stanford NIH-NCATS-CTSA through Grant UL1 TR001085 and due to U.S. National Institute of Health through NIH NHLBI R01 Grants 5R01HL129727-02 and 5R01HL121754-03.

  8. Patient-specific system for prognosis of surgical treatment outcomes of human cardiovascular system

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    Golyadkina, Anastasiya A.; Kalinin, Aleksey A.; Kirillova, Irina V.; Kossovich, Elena L.; Kossovich, Leonid Y.; Menishova, Liyana R.; Polienko, Asel V.

    2015-03-01

    Object of study: Improvement of life quality of patients with high stroke risk ia the main goal for development of system for patient-specific modeling of cardiovascular system. This work is dedicated at increase of safety outcomes for surgical treatment of brain blood supply alterations. The objects of study are common carotid artery, internal and external carotid arteries and bulb. Methods: We estimated mechanical properties of carotid arteries tissues and patching materials utilized at angioplasty. We studied angioarchitecture features of arteries. We developed and clinically adapted computer biomechanical models, which are characterized by geometrical, physical and mechanical similarity with carotid artery in norm and with pathology (atherosclerosis, pathological tortuosity, and their combination). Results: Collaboration of practicing cardiovascular surgeons and specialists in the area of Mathematics and Mechanics allowed to successfully conduct finite-element modeling of surgical treatment taking into account various features of operation techniques and patching materials for a specific patient. Numerical experiment allowed to reveal factors leading to brain blood supply decrease and atherosclerosis development. Modeling of carotid artery reconstruction surgery for a specific patient on the basis of the constructed biomechanical model demonstrated the possibility of its application in clinical practice at approximation of numerical experiment to the real conditions.

  9. The Effect of Femoral Cutting Guide Design Improvements for Patient-Specific Instruments

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    Oh-Ryong Kwon

    2015-01-01

    Full Text Available Although the application of patient-specific instruments (PSI for total knee arthroplasty (TKA increases the cost of the surgical procedure, PSI may reduce operative time and improve implant alignment, which could reduce the number of revision surgeries. We report our experience with TKA using PSI techniques in 120 patients from March to December 2014. PSI for TKA were created from data provided by computed tomography (CT scans or magnetic resonance imaging (MRI; which imaging technology is more reliable for the PSI technique remains unclear. In the first 20 patients, the accuracy of bone resection and PSI stability were compared between CT and MRI scans with presurgical results as a reference; MRI produced better results. In the second and third groups, each with 50 patients, the results of bone resection and stability were compared in MRI scans with respect to the quality of scanning due to motion artifacts and experienced know-how in PSI design, respectively. The optimized femoral cutting guide design for PSI showed the closest outcomes in bone resection and PSI stability with presurgical data. It is expected that this design could be a reasonable guideline in PSI.

  10. Patient-Specific Variations in Biomarkers across Gingivitis and Periodontitis.

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    Radhakrishnan Nagarajan

    Full Text Available This study investigates the use of saliva, as an emerging diagnostic fluid in conjunction with classification techniques to discern biological heterogeneity in clinically labelled gingivitis and periodontitis subjects (80 subjects; 40/group A battery of classification techniques were investigated as traditional single classifier systems as well as within a novel selective voting ensemble classification approach (SVA framework. Unlike traditional single classifiers, SVA is shown to reveal patient-specific variations within disease groups, which may be important for identifying proclivity to disease progression or disease stability. Salivary expression profiles of IL-1ß, IL-6, MMP-8, and MIP-1α from 80 patients were analyzed using four classification algorithms (LDA: Linear Discriminant Analysis [LDA], Quadratic Discriminant Analysis [QDA], Naïve Bayes Classifier [NBC] and Support Vector Machines [SVM] as traditional single classifiers and within the SVA framework (SVA-LDA, SVA-QDA, SVA-NB and SVA-SVM. Our findings demonstrate that performance measures (sensitivity, specificity and accuracy of traditional classification as single classifier were comparable to that of the SVA counterparts using clinical labels of the samples as ground truth. However, unlike traditional single classifier approaches, the normalized ensemble vote-counts from SVA revealed varying proclivity of the subjects for each of the disease groups. More importantly, the SVA identified a subset of gingivitis and periodontitis samples that demonstrated a biological proclivity commensurate with the other clinical group. This subset was confirmed across SVA-LDA, SVA-QDA, SVA-NB and SVA-SVM. Heatmap visualization of their ensemble sets revealed lack of consensus between these subsets and the rest of the samples within the respective disease groups indicating the unique nature of the patients in these subsets. While the source of variation is not known, the results presented clearly

  11. Patient-Specific Variations in Biomarkers across Gingivitis and Periodontitis.

    Science.gov (United States)

    Nagarajan, Radhakrishnan; Miller, Craig S; Dawson, Dolph; Al-Sabbagh, Mohanad; Ebersole, Jeffrey L

    2015-01-01

    This study investigates the use of saliva, as an emerging diagnostic fluid in conjunction with classification techniques to discern biological heterogeneity in clinically labelled gingivitis and periodontitis subjects (80 subjects; 40/group) A battery of classification techniques were investigated as traditional single classifier systems as well as within a novel selective voting ensemble classification approach (SVA) framework. Unlike traditional single classifiers, SVA is shown to reveal patient-specific variations within disease groups, which may be important for identifying proclivity to disease progression or disease stability. Salivary expression profiles of IL-1ß, IL-6, MMP-8, and MIP-1α from 80 patients were analyzed using four classification algorithms (LDA: Linear Discriminant Analysis [LDA], Quadratic Discriminant Analysis [QDA], Naïve Bayes Classifier [NBC] and Support Vector Machines [SVM]) as traditional single classifiers and within the SVA framework (SVA-LDA, SVA-QDA, SVA-NB and SVA-SVM). Our findings demonstrate that performance measures (sensitivity, specificity and accuracy) of traditional classification as single classifier were comparable to that of the SVA counterparts using clinical labels of the samples as ground truth. However, unlike traditional single classifier approaches, the normalized ensemble vote-counts from SVA revealed varying proclivity of the subjects for each of the disease groups. More importantly, the SVA identified a subset of gingivitis and periodontitis samples that demonstrated a biological proclivity commensurate with the other clinical group. This subset was confirmed across SVA-LDA, SVA-QDA, SVA-NB and SVA-SVM. Heatmap visualization of their ensemble sets revealed lack of consensus between these subsets and the rest of the samples within the respective disease groups indicating the unique nature of the patients in these subsets. While the source of variation is not known, the results presented clearly elucidate the

  12. Emerging Applications of Bedside 3D Printing in Plastic Surgery

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    Michael P Chae

    2015-06-01

    Full Text Available Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D reconstructions, are limited by their representation on 2D workstations. 3D printing has been embraced by early adopters to produce medical imaging-guided 3D printed biomodels that facilitate various aspects of clinical practice. The cost and size of 3D printers have rapidly decreased over the past decade in parallel with the expiration of key 3D printing patents. With increasing accessibility, investigators are now able to convert standard imaging data into Computer Aided Design (CAD files using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography (SLA, multijet modeling (MJM, selective laser sintering (SLS, binder jet technique (BJT, and fused deposition modeling (FDM. Significant improvements in clinical imaging and user-friendly 3D software have permitted computer-aided 3D modeling of anatomical structures and implants without out-sourcing in many cases. These developments offer immense potential for the application of 3D printing at the bedside for a variety of clinical applications. However, many clinicians have questioned whether the cost-to-benefit ratio justifies its ongoing use. In this review the existing uses of 3D printing in plastic surgery practice, spanning the spectrum from templates for facial transplantation surgery through to the formation of bespoke craniofacial implants to optimize post-operative aesthetics, are described. Furthermore, we discuss the potential of 3D printing to become an essential office-based tool in plastic surgery to assist in preoperative planning, patient and surgical trainee education, and the development of intraoperative guidance tools and patient-specific prosthetics in everyday surgical practice.

  13. Emerging Applications of Bedside 3D Printing in Plastic Surgery.

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    Chae, Michael P; Rozen, Warren M; McMenamin, Paul G; Findlay, Michael W; Spychal, Robert T; Hunter-Smith, David J

    2015-01-01

    Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D) reconstructions, are limited by their representation on 2D workstations. 3D printing, also known as rapid prototyping or additive manufacturing, was once the province of industry to fabricate models from a computer-aided design (CAD) in a layer-by-layer manner. The early adopters in clinical practice have embraced the medical imaging-guided 3D-printed biomodels for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between anatomical structures. With increasing accessibility, investigators are able to convert standard imaging data into a CAD file using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography, multijet modeling, selective laser sintering, binder jet technique, and fused deposition modeling. However, many clinicians have questioned whether the cost-to-benefit ratio justifies its ongoing use. The cost and size of 3D printers have rapidly decreased over the past decade in parallel with the expiration of key 3D printing patents. Significant improvements in clinical imaging and user-friendly 3D software have permitted computer-aided 3D modeling of anatomical structures and implants without outsourcing in many cases. These developments offer immense potential for the application of 3D printing at the bedside for a variety of clinical applications. In this review, existing uses of 3D printing in plastic surgery practice spanning the spectrum from templates for facial transplantation surgery through to the formation of bespoke craniofacial implants to optimize post-operative esthetics are described. Furthermore, we discuss the potential of 3D printing to become an essential office-based tool in plastic surgery to assist in preoperative planning, developing

  14. Circuito Quirúrgico Informatizado: Una herramienta para la mejora de la atención al paciente quirúrgico Improving the Care level on a surgery-needed patient through a Computer-Aided Surgery Cares Program

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    Luis Fuentes Cebada

    2007-11-01

    Full Text Available El Programa de Atención al Paciente Quirúrgico en el Hospital Puerta del Mar (Cádiz surge con el objetivo de personalizar la atención y garantizar la continuidad de cuidados y la seguridad de nuestros pacientes en cada una de las unidades por las que va desarrollándose la actividad quirúrgica. Este programa se soporta en una herramienta informática que es el circuito quirúrgico, la cual ha sido diseñada siguiendo la metodología de mejora continua y la participación desde el inicio de los profesionales enfermeros como actores de su desarrollo e implantación. En sólo ocho meses se ha conseguido que más del 55 % de los pacientes intervenidos quirúrgicamente disponga de un registro informatizado en el que se valoran, diagnostican, planifican y abordan los aspectos relacionados con la propia intervención quirúrgica como una parte añadida a las respuestas humanas que la misma ocasiona tanto a él como a su familia. Todo ello haciendo uso de las taxonomías enfermeras NANDA, NOC y NIC, con un enfoque holístico, centrado en la persona como agente y receptor de cuidados. Acompaña a este registro un sistema de información desde el que se explotan aspectos tales como la prevalencia diagnóstica enfermera, intervenciones realizadas, alergias, profilaxis antibiótica administrada, etc.The Surgery-needed Care Program, currently under test at the Puerta del Mar Hospital in Cadiz, has been conceived with the aim of both tuning the care level to each individual patient and, at the same time, to secure a continuous assistance through all the units involved in the surgery process. It is based on a computer tool so called Surgery Program. This computer application has been designed on the basis of continually-improving approach while counting with the enrolment, from the very first phases, of nurses in the affected units both in development and set-up steps. After just eight months running this Program, we have been able to create a digital

  15. Pentalogy of Cantrell with thoracoabdominal ectopia cordis: Attempted surgical correction and review of recent literature to aid prognostication prior to surgery

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    Vered Lack

    2015-11-01

    Full Text Available Complete ectopia cordis (EC is a rare congenital condition where the heart is extrathoracic, uncovered by pericardium and skin. This condition is often accompanied by intracardiac as well as other congenital anomalies. The thoracoabdominal type is frequently associated with varying degrees of Pentalogy of Cantrell (POC. Unless addressed early post-natally, EC is incompatible with life. Surgery is usually staged, with cover of exposed organs an immediate priority, followed by repair of structural cardiac lesions. Formal repair of the chest wall is performed at a later stage. We present a case of thoracoabdominal EC with complete POC. The patient underwent surgery to cover the exposed heart and the abdominal wall defect, but demised within 48 h due to systemic sepsis. Data gained from a literature survey shows that if the congenital heart defect is haemodynamically stable, and if cover is achieved immediately after birth, there is an associated improved survival. In addition, antenatal diagnosis was found to improve planning of delivery, resulting in improved hemodynamic stability, decreased incidence of sepsis, shorter time to intervention and better overall survival.

  16. Patient-Specific CT-Based Instrumentation versus Conventional Instrumentation in Total Knee Arthroplasty: A Prospective Randomized Controlled Study on Clinical Outcomes and In-Hospital Data

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    Andrzej Kotela

    2015-01-01

    Full Text Available Total knee arthroplasty (TKA is a frequently performed procedure in orthopaedic surgery. Recently, patient-specific instrumentation was introduced to facilitate correct positioning of implants. The aim of this study was to compare the early clinical results of TKA performed with patient-specific CT-based instrumentation and conventional technique. A prospective, randomized controlled trial on 112 patients was performed between January 2011 and December 2011. A group of 112 patients who met the inclusion and exclusion criteria were enrolled in this study and randomly assigned to an experimental or control group. The experimental group comprised 52 patients who received the Signature CT-based implant positioning system, and the control group consisted of 60 patients with conventional instrumentation. Clinical outcomes were evaluated with the KSS scale, WOMAC scale, and VAS scales to assess knee pain severity and patient satisfaction with the surgery. Specified in-hospital data were recorded. Patients were followed up for 12 months. At one year after surgery, there were no statistically significant differences between groups with respect to clinical outcomes and in-hospital data, including operative time, blood loss, hospital length of stay, intraoperative observations, and postoperative complications. Further high-quality investigations of various patient-specific systems and longer follow-up may be helpful in assessing their utility for TKA.

  17. Plastic Surgery

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    ... Surgery? A Week of Healthy Breakfasts Shyness Plastic Surgery KidsHealth > For Teens > Plastic Surgery Print A A ... forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word "plastic" ...

  18. Nose Surgery

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    ... Marketplace Find an ENT Doctor Near You Nose Surgery Nose Surgery Patient Health Information News media interested ... high a priority as appearance. Can Cosmetic Nasal Surgery Create A "Perfect" Nose? Aesthetic nasal surgery (rhinoplasty) ...

  19. Patterns of patient specific dosimetry in total body irradiation

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    Akino, Yuichi [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States); Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); McMullen, Kevin P.; Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)

    2013-04-15

    Purpose: Total body irradiation (TBI) has been used for bone marrow transplant for hematologic and immune deficiency conditions. The goal of TBI is to deliver a homogeneous dose to the entire body, with a generally accepted range of dose uniformity being within {+-}10% of the prescribed dose. The moving table technique for TBI could make dose uniform in whole body by adjusting couch speed. However, it is difficult to accurately estimate the actual dose by calculation and hence in vivo dosimetry (IVD) is routinely performed. Here, the authors present patterns of patient-specific IVD in 161 TBI patients treated at our institution. Methods: Cobalt-60 teletherapy unit (Model C9 Cobalt-60 teletherapy unit, Picker X-ray Corporation) with customized moving bed (SITI Industrial Products, Inc., Fishers, IN) were used for TBI treatment. During treatment, OneDose{sup TM} (Sicel Technology, NC) Metal Oxide-silicon Semiconductor Field Effect Transistor detectors were placed at patient body surface; both entrance and exit side of the beam at patient head, neck, mediastinum, umbilicus, and knee to estimate midplane dose. When large differences (>10%) between the prescribed and measured dose were observed, dose delivery was corrected for subsequent fractions by the adjustment of couch speed and/or bolus placement. Under IRB exempt status, the authors retrospectively analyzed the treatment records of 161 patients who received TBI treatment between 2006 and 2011. Results: Across the entire cohort, the median {+-} SD (range) percent variance between calculated and measured dose for head, neck, mediastinum, umbilicus, and knee was -2.3 {+-} 10.2% (-66.2 to +35.3), 1.1 {+-} 11.5% (-62.2 to +40.3), -1.9 {+-} 9.5% (-66.4 to +46.6), -1.1 {+-} 7.2% (-35.2 to +42.9), and 3.4 {+-} 12.2% (-47.9 to +108.5), respectively. More than half of treatments were within {+-}10% of the prescribed dose for all anatomical regions. For 80% of treatments (10%-90%), dose at the umbilicus was within {+-}10

  20. Methodologies for Development of Patient Specific Bone Models from Human Body CT Scans

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    Chougule, Vikas Narayan; Mulay, Arati Vinayak; Ahuja, Bharatkumar Bhagatraj

    2016-06-01

    This work deals with development of algorithm for physical replication of patient specific human bone and construction of corresponding implants/inserts RP models by using Reverse Engineering approach from non-invasive medical images for surgical purpose. In medical field, the volumetric data i.e. voxel and triangular facet based models are primarily used for bio-modelling and visualization, which requires huge memory space. On the other side, recent advances in Computer Aided Design (CAD) technology provides additional facilities/functions for design, prototyping and manufacturing of any object having freeform surfaces based on boundary representation techniques. This work presents a process to physical replication of 3D rapid prototyping (RP) physical models of human bone from various CAD modeling techniques developed by using 3D point cloud data which is obtained from non-invasive CT/MRI scans in DICOM 3.0 format. This point cloud data is used for construction of 3D CAD model by fitting B-spline curves through these points and then fitting surface between these curve networks by using swept blend techniques. This process also can be achieved by generating the triangular mesh directly from 3D point cloud data without developing any surface model using any commercial CAD software. The generated STL file from 3D point cloud data is used as a basic input for RP process. The Delaunay tetrahedralization approach is used to process the 3D point cloud data to obtain STL file. CT scan data of Metacarpus (human bone) is used as the case study for the generation of the 3D RP model. A 3D physical model of the human bone is generated on rapid prototyping machine and its virtual reality model is presented for visualization. The generated CAD model by different techniques is compared for the accuracy and reliability. The results of this research work are assessed for clinical reliability in replication of human bone in medical field.

  1. Patient-specific parameter estimation in single-ventricle lumped circulation models under uncertainty.

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    Schiavazzi, Daniele E; Baretta, Alessia; Pennati, Giancarlo; Hsia, Tain-Yen; Marsden, Alison L

    2017-03-01

    Computational models of cardiovascular physiology can inform clinical decision-making, providing a physically consistent framework to assess vascular pressures and flow distributions, and aiding in treatment planning. In particular, lumped parameter network (LPN) models that make an analogy to electrical circuits offer a fast and surprisingly realistic method to reproduce the circulatory physiology. The complexity of LPN models can vary significantly to account, for example, for cardiac and valve function, respiration, autoregulation, and time-dependent hemodynamics. More complex models provide insight into detailed physiological mechanisms, but their utility is maximized if one can quickly identify patient specific parameters. The clinical utility of LPN models with many parameters will be greatly enhanced by automated parameter identification, particularly if parameter tuning can match non-invasively obtained clinical data. We present a framework for automated tuning of 0D lumped model parameters to match clinical data. We demonstrate the utility of this framework through application to single ventricle pediatric patients with Norwood physiology. Through a combination of local identifiability, Bayesian estimation and maximum a posteriori simplex optimization, we show the ability to automatically determine physiologically consistent point estimates of the parameters and to quantify uncertainty induced by errors and assumptions in the collected clinical data. We show that multi-level estimation, that is, updating the parameter prior information through sub-model analysis, can lead to a significant reduction in the parameter marginal posterior variance. We first consider virtual patient conditions, with clinical targets generated through model solutions, and second application to a cohort of four single-ventricle patients with Norwood physiology. Copyright © 2016 John Wiley & Sons, Ltd.

  2. The Effect of Patient-Specific Cerebral Oxygenation Monitoring on Postoperative Cognitive Function: A Multicenter Randomized Controlled Trial

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    Ellis, Lucy; Murphy, Gavin J; Culliford, Lucy; Dreyer, Lucy; Clayton, Gemma; Downes, Richard; Nicholson, Eamonn; Stoica, Serban; Reeves, Barnaby C

    2015-01-01

    Background Indices of global tissue oxygen delivery and utilization such as mixed venous oxygen saturation, serum lactate concentration, and arterial hematocrit are commonly used to determine the adequacy of tissue oxygenation during cardiopulmonary bypass (CPB). However, these global measures may not accurately reflect regional tissue oxygenation and ischemic organ injury remains a common and serious complication of CPB. Near-infrared spectroscopy (NIRS) is a noninvasive technology that measures regional tissue oxygenation. NIRS may be used alongside global measures to optimize regional perfusion and reduce organ injury. It may also be used as an indicator of the need for red blood cell transfusion in the presence of anemia and tissue hypoxia. However, the clinical benefits of using NIRS remain unclear and there is a lack of high-quality evidence demonstrating its efficacy and cost effectiveness. Objective The aim of the patient-specific cerebral oxygenation monitoring as part of an algorithm to reduce transfusion during heart valve surgery (PASPORT) trial is to determine whether the addition of NIRS to CPB management algorithms can prevent cognitive decline, postoperative organ injury, unnecessary transfusion, and reduce health care costs. Methods Adults aged 16 years or older undergoing valve or combined coronary artery bypass graft and valve surgery at one of three UK cardiac centers (Bristol, Hull, or Leicester) are randomly allocated in a 1:1 ratio to either a standard algorithm for optimizing tissue oxygenation during CPB that includes a fixed transfusion threshold, or a patient-specific algorithm that incorporates cerebral NIRS monitoring and a restrictive red blood cell transfusion threshold. Allocation concealment, Internet-based randomization stratified by operation type and recruiting center, and blinding of patients, ICU and ward care staff, and outcome assessors reduce the risk of bias. The primary outcomes are cognitive function 3 months after

  3. 微信辅助教学法在外科手术学基础课程中的应用%Application of Wechat-aided teaching in foundation courses of surgery science

    Institute of Scientific and Technical Information of China (English)

    单成祥; 裘年存; 仇明; 徐志飞; 沈宏亮

    2014-01-01

    Wechat, popular instant messaging software in smartphones, has a lot of functions and features, making it have the potential of being widely used in practice-oriented medical course teaching. Our hospital has carried out the practice of Wechat-aided teaching in foundation courses of surgery.It breaks the shackles of the traditional classroom in space and time, mobilizes students'enthusiasm for learning, improves their ability to practice operations, and enhances their communication skills and sense of teamwork, thus achieving better teaching results.%微信是智能手机中一款非常普及的即时通讯软件,它本身具备的很多功能和特性在实践类医学课程教学中有较大的潜在应用价值。第二军医大学附属长征医院在外科手术基础教学中应用微信辅助教学,突破了传统课堂教学空间和时间的束缚,调动了学生自主学习的积极性,提高了学生实践操作的能力,增强了学生沟通能力及团队协作意识,取得了较好的教学效果。

  4. Cataract Surgery

    Science.gov (United States)

    ... and Videos: What Do Cataracts Look Like? Cataract Surgery Written by: Kierstan Boyd Reviewed by: Elena M ... how they work. What to expect with cataract surgery Before surgery: Your ophthalmologist will measure your eye ...

  5. Hearing Aids

    Science.gov (United States)

    ... more in both quiet and noisy situations. Hearing aids help people who have hearing loss from damage ... your doctor. There are different kinds of hearing aids. They differ by size, their placement on or ...

  6. AIDS (image)

    Science.gov (United States)

    AIDS (acquired immune deficiency syndrome) is caused by HIV (human immunodeficiency virus), and is a syndrome that ... life-threatening illnesses. There is no cure for AIDS, but treatment with antiviral medicine can suppress symptoms. ...

  7. Combining population and patient-specific characteristics for prostate segmentation on 3D CT images

    Science.gov (United States)

    Ma, Ling; Guo, Rongrong; Tian, Zhiqiang; Venkataraman, Rajesh; Sarkar, Saradwata; Liu, Xiabi; Tade, Funmilayo; Schuster, David M.; Fei, Baowei

    2016-03-01

    Prostate segmentation on CT images is a challenging task. In this paper, we explore the population and patient-specific characteristics for the segmentation of the prostate on CT images. Because population learning does not consider the inter-patient variations and because patient-specific learning may not perform well for different patients, we are combining the population and patient-specific information to improve segmentation performance. Specifically, we train a population model based on the population data and train a patient-specific model based on the manual segmentation on three slice of the new patient. We compute the similarity between the two models to explore the influence of applicable population knowledge on the specific patient. By combining the patient-specific knowledge with the influence, we can capture the population and patient-specific characteristics to calculate the probability of a pixel belonging to the prostate. Finally, we smooth the prostate surface according to the prostate-density value of the pixels in the distance transform image. We conducted the leave-one-out validation experiments on a set of CT volumes from 15 patients. Manual segmentation results from a radiologist serve as the gold standard for the evaluation. Experimental results show that our method achieved an average DSC of 85.1% as compared to the manual segmentation gold standard. This method outperformed the population learning method and the patient-specific learning approach alone. The CT segmentation method can have various applications in prostate cancer diagnosis and therapy.

  8. Weight Loss Surgery (Bariatric Surgery) (For Parents)

    Science.gov (United States)

    ... Your 1- to 2-Year-Old Weight Loss Surgery (Bariatric Surgery) KidsHealth > For Parents > Weight Loss Surgery (Bariatric Surgery) ... bariatric surgery might be an option. About Bariatric Surgery Bariatric surgery had its beginnings in the 1960s, ...

  9. Aid Effectiveness

    DEFF Research Database (Denmark)

    Arndt, Channing; Jones, Edward Samuel; Tarp, Finn

    Controversy over the aggregate impact of foreign aid has focused on reduced form estimates of the aid-growth link. The causal chain, through which aid affects developmental outcomes including growth, has received much less attention. We address this gap by: (i) specifying a structural model of th...

  10. Computer simulation in the daily practice of orthognathic surgery.

    Science.gov (United States)

    Schendel, S A

    2015-12-01

    The availability of computers and advances in imaging, especially over the last 10 years, have allowed the adoption of three-dimensional (3D) imaging in the office setting. The affordability and ease of use of this modality has led to its widespread implementation in diagnosis and treatment planning, teaching, and follow-up care. 3D imaging is particularly useful when the deformities are complex and involve both function and aesthetics, such as those in the dentofacial area, and for orthognathic surgery. Computer imaging involves combining images obtained from different modalities to create a virtual record of an individual. In this article, the system is described and its use in the office demonstrated. Computer imaging with simulation, and more specifically patient-specific anatomic records (PSAR), permit a more accurate analysis of the deformity as an aid to diagnosis and treatment planning. 3D imaging and computer simulation can be used effectively for the planning of office-based procedures. The technique can be used to perform virtual surgery and establish a definitive and objective treatment plan for correction of the facial deformity. In addition, patient education and follow-up can be facilitated. The end result is improved patient care and decreased expense.

  11. Lung surgery

    Science.gov (United States)

    ... are thoracotomy and video-assisted thoracoscopic surgery (VATS). Robotic surgery may also be used. Lung surgery using a ... clot from the pulmonary artery ( pulmonary embolism ) Treat complications of tuberculosis Video-assisted thoracoscopic surgery can be used to treat many of these ...

  12. Patient specific root-analogue dental implants – additive manufacturing and finite element analysis

    OpenAIRE

    Gattinger Johannes; Bullemer Christian N.; Harrysson Ola L. A.

    2016-01-01

    Aim of this study was to prove the possibility of manufacturing patient specific root analogue two-part (implant and abutment) implants by direct metal laser sintering. The two-part implant design enables covered healing of the implant. Therefore, CT-scans of three patients are used for reverse engineering of the implants, abutments and crowns. Patient specific implants are manufactured and measured concerning dimensional accuracy and surface roughness. Impacts of occlusal forces are simulate...

  13. Long-Term Morphological and Microarchitectural Stability of Tissue-Engineered, Patient-Specific Auricles In Vivo.

    Science.gov (United States)

    Cohen, Benjamin Peter; Hooper, Rachel C; Puetzer, Jennifer L; Nordberg, Rachel; Asanbe, Ope; Hernandez, Karina A; Spector, Jason A; Bonassar, Lawrence J

    2016-03-01

    Current techniques for autologous auricular reconstruction produce substandard ear morphologies with high levels of donor-site morbidity, whereas alloplastic implants demonstrate poor biocompatibility. Tissue engineering, in combination with noninvasive digital photogrammetry and computer-assisted design/computer-aided manufacturing technology, offers an alternative method of auricular reconstruction. Using this method, patient-specific ears composed of collagen scaffolds and auricular chondrocytes have generated auricular cartilage with great fidelity following 3 months of subcutaneous implantation, however, this short time frame may not portend long-term tissue stability. We hypothesized that constructs developed using this technique would undergo continued auricular cartilage maturation without degradation during long-term (6 month) implantation. Full-sized, juvenile human ear constructs were injection molded from high-density collagen hydrogels encapsulating juvenile bovine auricular chondrocytes and implanted subcutaneously on the backs of nude rats for 6 months. Upon explantation, constructs retained overall patient morphology and displayed no evidence of tissue necrosis. Limited contraction occurred in vivo, however, no significant change in size was observed beyond 1 month. Constructs at 6 months showed distinct auricular cartilage microstructure, featuring a self-assembled perichondrial layer, a proteoglycan-rich bulk, and rounded cellular lacunae. Verhoeff's staining also revealed a developing elastin network comparable to native tissue. Biochemical measurements for DNA, glycosaminoglycan, and hydroxyproline content and mechanical properties of aggregate modulus and hydraulic permeability showed engineered tissue to be similar to native cartilage at 6 months. Patient-specific auricular constructs demonstrated long-term stability and increased cartilage tissue development during extended implantation, and offer a potential tissue-engineered solution for

  14. SU-E-T-04: 3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Cumming, I; Lasso, A; Rankin, A; Fichtinger, G [Laboratory for Percutaneous Surgery, School of Computing, Queen' s University, Kingston, Ontario (Canada); Joshi, C P; Falkson, C; Schreiner, L John [CCSEO, Kingston General Hospital and Department of Oncology, Queen' s University, Kingston, Ontario (Canada)

    2014-06-01

    Purpose: Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions. Methods: We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer ( http://www.slicer.org ) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement. A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material. Results: The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm. Conclusion: Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required

  15. Stereolithography for craniofacial surgery.

    Science.gov (United States)

    Sinn, Douglas P; Cillo, Joseph E; Miles, Brett A

    2006-09-01

    Advances in computer technology have aided in the diagnostic and clinical management of complex congenital craniofacial deformities. The use of stereolithographic models has begun to replace traditional milled models in the treatment of craniofacial deformities. Research has shown that stereolithography models are highly accurate and provide added information in treatment planning for the correction of craniofacial deformities. These include the added visualization of the complex craniofacial anatomy and preoperative surgical planning with a highly accurate three-dimensional model. While the stereolithographic process has had a beneficial impact on the field of craniofacial surgery, the added cost of the procedure continues to be a hindrance to its widespread acceptance in clinical practice. With improved technology and accessibility the utilization of stereolithography in craniofacial surgery is expected to increase. This review will highlight the development and current usage of stereolithography in craniofacial surgery and provide illustration of it use.

  16. Development of an integrated CAD-FEA system for patient-specific design of spinal cages.

    Science.gov (United States)

    Zhang, Mingzheng; Pu, Fang; Xu, Liqiang; Zhang, Linlin; Liang, Hang; Li, Deyu; Wang, Yu; Fan, Yubo

    2017-03-01

    Spinal cages are used to create a suitable mechanical environment for interbody fusion in cases of degenerative spinal instability. Due to individual variations in bone structures and pathological conditions, patient-specific cages can provide optimal biomechanical conditions for fusion, strengthening patient recovery. Finite element analysis (FEA) is a valuable tool in the biomechanical evaluation of patient-specific cage designs, but the time- and labor-intensive process of modeling limits its clinical application. In an effort to facilitate the design and analysis of patient-specific spinal cages, an integrated CAD-FEA system (CASCaDeS, comprehensive analytical spinal cage design system) was developed. This system produces a biomechanical-based patient-specific design of spinal cages and is capable of rapid implementation of finite element modeling. By comparison with commercial software, this system was validated and proven to be both accurate and efficient. CASCaDeS can be used to design patient-specific cages with a superior biomechanical performance to commercial spinal cages.

  17. Effects of Vessel Tortuosity on Coronary Hemodynamics: An Idealized and Patient-Specific Computational Study.

    Science.gov (United States)

    Vorobtsova, Natalya; Chiastra, Claudio; Stremler, Mark A; Sane, David C; Migliavacca, Francesco; Vlachos, Pavlos

    2016-07-01

    Although coronary tortuosity can influence the hemodynamics of coronary arteries, the relationship between tortuosity and flow has not been thoroughly investigated partly due to the absence of a widely accepted definition of tortuosity and the lack of patient-specific studies that analyze complete coronary trees. Using a computational approach we investigated the effects of tortuosity on coronary flow parameters including pressure drop, wall shear stress, and helical flow strength as measured by helicity intensity. Our analysis considered idealized and patient-specific geometries. Overall results indicate that perfusion pressure decreases with increased tortuosity, but the patient-specific results show that more tortuous vessels have higher physiological wall shear stress values. Differences between the idealized and patient-specific results reveal that an accurate representation of coronary tortuosity must account for all relevant geometric aspects, including curvature imposed by the heart shape. The patient-specific results exhibit a strong correlation between tortuosity and helicity intensity, and the corresponding helical flow contributes directly to the observed increase in wall shear stress. Therefore, helicity intensity may prove helpful in developing a universal parameter to describe tortuosity and assess its impact on patient health. Our data suggest that increased tortuosity could have a deleterious impact via a reduction in coronary perfusion pressure, but the attendant increase in wall shear stress could afford protection against atherosclerosis.

  18. After Surgery

    Science.gov (United States)

    ... side effects. There is usually some pain with surgery. There may also be swelling and soreness around ... the first few days, weeks, or months after surgery. Some other questions to ask are How long ...

  19. Turbinate surgery

    Science.gov (United States)

    Turbinectomy; Turbinoplasty; Turbinate reduction; Nasal airway surgery ... There are several types of turbinate surgery: Turbinectomy: All or part of the lower turbinate is taken out. This can be done in several different ways, but sometimes a ...

  20. Brand Aid

    DEFF Research Database (Denmark)

    Richey, Lisa Ann; Ponte, Stefano

    A critical account of the rise of celebrity-driven “compassionate consumption” Cofounded by the rock star Bono in 2006, Product RED exemplifies a new trend in celebrity-driven international aid and development, one explicitly linked to commerce, not philanthropy. Brand Aid offers a deeply informed...

  1. Foreign aid

    DEFF Research Database (Denmark)

    Tarp, Finn

    2008-01-01

    Foreign aid has evolved significantly since the Second World War in response to a dramatically changing global political and economic context. This article (a) reviews this process and associated trends in the volume and distribution of foreign aid; (b) reviews the goals, principles...

  2. Application of visoelastic materials aided nucleus extraction in small-incision cataract surgery%首创小切口白内障手术中黏弹剂辅助脱核方法

    Institute of Scientific and Technical Information of China (English)

    洪杉

    2011-01-01

    目的 介绍首创黏弹剂辅助脱核方法的操作过程. 方法 回顾分析年龄相关性白内障患者260例(298眼)在连续环形撕囊下应用黏弹剂辅助脱核方法脱核,施行手法无缝线小切口白内障手术,对其术后视力及其他临床资料进行分析. 结果 术后患者视力均有不同程度的提高.术后3 d最佳视力≥0.05者296眼,复明率99.33%;视力≥0.3者277眼,脱残率占92.95%.术后30 d最佳矫正视力≥0.05者296眼,复明率99.33%,≥0.3者282眼,脱残率占94.63%.术后90 d最佳矫正视力≥0.05者295眼,复明率98.99%,≥0.3者280眼,脱残率占93.96%.术中和术后出现不同程度的并发症,角膜内皮线性混浊伴角膜雾状混浊和前房水混浊21眼,虹膜炎2眼,后囊膜混浊1眼,经对症处理后均得到好转和治愈,未见大泡性角膜炎、眼内炎等严重并发症发生. 结论 黏弹剂辅助脱核方法在手法无缝线小切口白内障手术中是一种简单、实用、快捷、经济、术后效果好的新方法.%Objective To introduce the application of viscoelastic materials aid during nucleus extraction in manual sutureless small-incision cataract surgery. Methods About 260 age-related cataract patients(298 eyes) were retrospectively analyzed, and they were taken continuous circular capsulorhexis,manual sutureless small-incision cataract surgery with viscoelastic needle to assist nucleus extraction. Postoperative visual acuity and clinical data were analyzed. Results All cases had vision improvement postoperatively. At postoperative 3 days,best corrected visual acuity be and more than 0.5 was in 296 eyes, and the rate of requiring sight was 99. 33% ; Visual acuity be and more than 0.3 was in 277 eyes,and the rate of getting ride of disability was 92. 95% . At postoperative 30 days,best corrected visual acuity be and more than 0. 05 was in 296 eyes,and the rate of requiring sight was 99. 33% ; Visual acuity be and more than 0. 3 was in 282 eyes, the

  3. Development of a patient specific artificial tracheal prosthesis: design, mechanical behavior analysis and manufacturing.

    Science.gov (United States)

    Chua C H, Matthew; Chui, Chee Kong; Rai, Bina; Lau D P, David

    2013-01-01

    There is a need to create patient specific organ replacements as there are differences in the anatomical dimensions among individuals. High failure rates in tracheal prosthesis are attributed to the lack of mechanical strength and flexibility, slow rate of growth of ciliated epithelium and leakage of interstitial fluid into the lumen. This paper proposes a methodology of design, simulations and fabrication of a patient specific artificial tracheal prosthesis for implantation to closely mimic the biomechanical properties of the natural trachea, and describes the prototype device and its materials. Results show that the patient-specific trachea prosthesis has mechanical properties approximate that of normal tracheal rings. The user centric tracheal prosthesis is demonstrated to be a promising candidate for tracheal replacement.

  4. Toward patient-specific simulations of cardiac valves: state-of-the-art and future directions.

    Science.gov (United States)

    Votta, Emiliano; Le, Trung Bao; Stevanella, Marco; Fusini, Laura; Caiani, Enrico G; Redaelli, Alberto; Sotiropoulos, Fotis

    2013-01-18

    Recent computational methods enabling patient-specific simulations of native and prosthetic heart valves are reviewed. Emphasis is placed on two critical components of such methods: (1) anatomically realistic finite element models for simulating the structural dynamics of heart valves; and (2) fluid structure interaction methods for simulating the performance of heart valves in a patient-specific beating left ventricle. It is shown that the significant progress achieved in both fronts paves the way toward clinically relevant computational models that can simulate the performance of a range of heart valves, native and prosthetic, in a patient-specific left heart environment. The significant algorithmic and model validation challenges that need to be tackled in the future to realize this goal are also discussed.

  5. Heart Surgery Terms

    Science.gov (United States)

    ... Patients Choosing Wisely® Adult Cardiac Surgery What is Pediatric Heart Disease? What is Risk Adjustment? Valve Repair/Replacement Surgery Esophageal Surgery Lung/Thoracic Surgery Aneurysm Surgery Arrhythmia Surgery Other Types of Surgery Clinical ...

  6. Computational biomechanics for medicine fundamental science and patient-specific applications

    CERN Document Server

    Miller, Karol; Wittek, Adam; Nielsen, Poul

    2014-01-01

    One of the greatest challenges facing the computational engineering community is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, the biomedical sciences, and medicine. The Computational Biomechanics for Medicine titles provide an opportunity for specialists in computational biomechanics to present their latest methodologies and advancements. This latest installment comprises nine of the latest developments in both fundamental science and patient-specific applications, from researchers in Australia, New Zealand, USA, UK, France, Ireland, and China. Some of the interesting topics discussed are: cellular mechanics; tumor growth and modeling; medical image analysis; and both patient-specific fluid dynamics and solid mechanics simulations.

  7. Mesh structure-independent modeling of patient-specific atrial fiber orientation

    Directory of Open Access Journals (Sweden)

    Wachter Andreas

    2015-09-01

    Full Text Available The fiber orientation in the atria has a significant contribution to the electrophysiologic behavior of the heart and to the genesis of arrhythmia. Atrial fiber orientation has a direct effect on excitation propagation, activation patterns and the P-wave. We present a rule-based algorithm that works robustly on different volumetric meshes composed of either isotropic hexahedra or arbitrary tetrahedra as well as on 3-dimensional triangular surface meshes in patient-specific geometric models. This method fosters the understanding of general proarrhythmic mechanisms and enhances patient-specific modeling approaches.

  8. Patient specific root-analogue dental implants – additive manufacturing and finite element analysis

    Directory of Open Access Journals (Sweden)

    Gattinger Johannes

    2016-09-01

    Full Text Available Aim of this study was to prove the possibility of manufacturing patient specific root analogue two-part (implant and abutment implants by direct metal laser sintering. The two-part implant design enables covered healing of the implant. Therefore, CT-scans of three patients are used for reverse engineering of the implants, abutments and crowns. Patient specific implants are manufactured and measured concerning dimensional accuracy and surface roughness. Impacts of occlusal forces are simulated via FEA and compared to those of standard implants.

  9. Evaluation of Constant Thickness Cartilage Models vs. Patient Specific Cartilage Models for an Optimized Computer-Assisted Planning of Periacetabular Osteotomy.

    Directory of Open Access Journals (Sweden)

    Li Liu

    Full Text Available Modern computerized planning tools for periacetabular osteotomy (PAO use either morphology-based or biomechanics-based methods. The latter relies on estimation of peak contact pressures and contact areas using either patient specific or constant thickness cartilage models. We performed a finite element analysis investigating the optimal reorientation of the acetabulum in PAO surgery based on simulated joint contact pressures and contact areas using patient specific cartilage model. Furthermore we investigated the influences of using patient specific cartilage model or constant thickness cartilage model on the biomechanical simulation results. Ten specimens with hip dysplasia were used in this study. Image data were available from CT arthrography studies. Bone models were reconstructed. Mesh models for the patient specific cartilage were defined and subsequently loaded under previously reported boundary and loading conditions. Peak contact pressures and contact areas were estimated in the original position. Afterwards we used a validated preoperative planning software to change the acetabular inclination by an increment of 5° and measured the lateral center edge angle (LCE at each reorientation position. The position with the largest contact area and the lowest peak contact pressure was defined as the optimal position. In order to investigate the influence of using patient specific cartilage model or constant thickness cartilage model on the biomechanical simulation results, the same procedure was repeated with the same bone models but with a cartilage mesh of constant thickness. Comparison of the peak contact pressures and the contact areas between these two different cartilage models showed that good correlation between these two cartilage models for peak contact pressures (r = 0.634 ∈ [0.6, 0.8], p 0.8, p < 0.001. For both cartilage models, the largest contact areas and the lowest peak pressures were found at the same position. Our study is

  10. 急诊外科创伤患者病死的危险因素及急救措施%Risk factors of mortality in patients with trauma in emergency surgery and first aid measures

    Institute of Scientific and Technical Information of China (English)

    张永亮

    2016-01-01

    目的:探讨分析引起急诊外科创伤患者病死因素及相关急救措施。方法对本院急诊外科2012年11月至2015年10月收治的156例创伤死亡患者进行回顾分析,统计患者资料,利用Logistic分析对可能引起创伤患者死亡的因素进行研究分析。结果20岁以上的创伤死亡患者占75.64%,为急诊创伤死亡主要人群。91例患者有多处创伤,多发率为58.33%,创伤集中部位主要为腹部、胸部及头部,101例患者院前抢救无效,院前死亡率占64.74%。从致伤原因分析,以交通事故、高空坠落创伤致死为主,分占60.26%、25.00%,Logistic多因素分析显示,创伤患者年龄、现场急救、机械通气及GCS评分、ISS评分是引起创伤患者病死的主要危险因素。结论医疗机构应该建立专业的急救团队及系统、迅速的应急机制,强化院前急救与院内急诊的急救水平,保证创伤患者可以第一时间得到救治,以提高急救成功率。%Objective To investigate and analyze the factors that cause the death of trauma patients in emergency surgery and related emergency measures. Methods Retrospective analysis of 156 cases of trauma deaths in our hospital from October 2015 to November 2012 in our hospital, statistical data of patients, using Logistic analysis to analyze the fac-tors that may cause the death of trauma patients. Results Trauma deaths accounted for 20 of patients over the age of 75.64%, and the major population of emergency trauma deaths. 91 cases of patients with multiple trauma, multiple rate was 58.33%, the trauma focused on the main parts of the abdomen, chest and head, 101 cases of patients with pre hospital res-cue is invalid, the pre hospital mortality rate was 64.74%. Analysis of the causes of injury, traffic accidents, injuries to the upper air crash deaths, accounting for 60.26%, 25%, Logistic multi factor analysis showed that the age of trauma patients, on-site first aid

  11. Hearing Aid

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A man realized that he needed to purchase ahearing aid, but he was unwilling to spend muchmoney. "How much do they run?"he asked theclerk. "That depends," said. the salesman. "Theyrun from 2 to 2000."

  12. Hearing Aids

    Science.gov (United States)

    ... slightly different from the ITC and is nearly hidden in the ear canal. Both canal hearing aids ... Privacy Policy & Terms of Use Visit the Nemours Web site. Note: All information on TeensHealth® is for ...

  13. An effective algorithm for the generation of patient-specific Purkinje networks in computational electrocardiology

    Science.gov (United States)

    Palamara, Simone; Vergara, Christian; Faggiano, Elena; Nobile, Fabio

    2015-02-01

    The Purkinje network is responsible for the fast and coordinated distribution of the electrical impulse in the ventricle that triggers its contraction. Therefore, it is necessary to model its presence to obtain an accurate patient-specific model of the ventricular electrical activation. In this paper, we present an efficient algorithm for the generation of a patient-specific Purkinje network, driven by measures of the electrical activation acquired on the endocardium. The proposed method provides a correction of an initial network, generated by means of a fractal law, and it is based on the solution of Eikonal problems both in the muscle and in the Purkinje network. We present several numerical results both in an ideal geometry with synthetic data and in a real geometry with patient-specific clinical measures. These results highlight an improvement of the accuracy provided by the patient-specific Purkinje network with respect to the initial one. In particular, a cross-validation test shows an accuracy increase of 19% when only the 3% of the total points are used to generate the network, whereas an increment of 44% is observed when a random noise equal to 20% of the maximum value of the clinical data is added to the measures.

  14. Development of a Patient-Specific Finite Element Model for Predicting Implant Failure in Pelvic Ring Fracture Fixation

    Science.gov (United States)

    Höch, Andreas; Peldschus, Steffen

    2017-01-01

    Introduction. The main purpose of this study is to develop an efficient technique for generating FE models of pelvic ring fractures that is capable of predicting possible failure regions of osteosynthesis with acceptable accuracy. Methods. Patient-specific FE models of two patients with osteoporotic pelvic fractures were generated. A validated FE model of an uninjured pelvis from our previous study was used as a master model. Then, fracture morphologies and implant positions defined by a trauma surgeon in the preoperative CT were manually introduced as 3D splines to the master model. Four loading cases were used as boundary conditions. Regions of high stresses in the models were compared with actual locations of implant breakages and loosening identified from follow-up X-rays. Results. Model predictions and the actual clinical outcomes matched well. For Patient A, zones of increased tension and maximum stress coincided well with the actual locations of implant loosening. For Patient B, the model predicted accurately the loosening of the implant in the anterior region. Conclusion. Since a significant reduction in time and labour was achieved in our mesh generation technique, it can be considered as a viable option to be implemented as a part of the clinical routine to aid presurgical planning and postsurgical management of pelvic ring fracture patients. PMID:28255332

  15. Dimensional evaluation of patient-specific 3D printing using calcium phosphate cement for craniofacial bone reconstruction.

    Science.gov (United States)

    Bertol, Liciane Sabadin; Schabbach, Rodrigo; Dos Santos, Luís Alberto Loureiro

    2016-12-01

    The 3D printing process is highlighted nowadays as a possibility to generate individual parts with complex geometries. Moreover, the development of 3D printing hardware, software and parameters permits the manufacture of parts that can be not only used as prototypes, but are also made from materials that are suitable for implantation. In this way, this study investigates the process involved in the production of patient-specific craniofacial implants using calcium phosphate cement, and its dimensional accuracy. The implants were previously generated in a computer-aided design environment based on the patient's tomographic data. The fabrication of the implants was carried out in a commercial 3D powder printing system using alfa-tricalcium phosphate powder and an aqueous solution of Na2HPO4 as a binder. The fit of the 3D printed implants was measured by three-dimensional laser scanning and by checking the right adjustment to the patient's anatomical biomodel. The printed parts presented a good degree of fitting and accuracy.

  16. Patient-specific instrumentation does not improve radiographic alignment or clinical outcomes after total knee arthroplasty.

    Science.gov (United States)

    Huijbregts, Henricus J T A M; Khan, Riaz J K; Sorensen, Emma; Fick, Daniel P; Haebich, Samantha

    2016-08-01

    Background and purpose - Patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) has been introduced to improve alignment and reduce outliers, increase efficiency, and reduce operation time. In order to improve our understanding of the outcomes of patient-specific instrumentation, we conducted a meta-analysis. Patients and methods - We identified randomized and quasi-randomized controlled trials (RCTs) comparing patient-specific and conventional instrumentation in TKA. Weighted mean differences and risk ratios were determined for radiographic accuracy, operation time, hospital stay, blood loss, number of surgical trays required, and patient-reported outcome measures. Results - 21 RCTs involving 1,587 TKAs were included. Patient-specific instrumentation resulted in slightly more accurate hip-knee-ankle axis (0.3°), coronal femoral alignment (0.3°, femoral flexion (0.9°), tibial slope (0.7°), and femoral component rotation (0.5°). The risk ratio of a coronal plane outlier (> 3° deviation of chosen target) for the tibial component was statistically significantly increased in the PSI group (RR =1.64). No significance was found for other radiographic measures. Operation time, blood loss, and transfusion rate were similar. Hospital stay was significantly shortened, by approximately 8 h, and the number of surgical trays used decreased by 4 in the PSI group. Knee Society scores and Oxford knee scores were similar. Interpretation - Patient-specific instrumentation does not result in clinically meaningful improvement in alignment, fewer outliers, or better early patient-reported outcome measures. Efficiency is improved by reducing the number of trays used, but PSI does not reduce operation time.

  17. Types of Hearing Aids

    Science.gov (United States)

    ... Devices Consumer Products Hearing Aids Types of Hearing Aids Share Tweet Linkedin Pin it More sharing options ... some features for hearing aids? What are hearing aids? Hearing aids are sound-amplifying devices designed to ...

  18. Thyroid Surgery

    Science.gov (United States)

    ... etc.). Surgery is also an option for the treatment of hyperthyroidism (Grave’s disease or a “toxic nodule” (see Hyperthyroidism brochure ), for large and multinodular goiters and for any goiter that may be causing ... MEANS OF TREATMENT? Surgery is definitely indicated to remove nodules suspicious ...

  19. Evaluation of a patient specific femoral alignment guide for hip resurfacing.

    Science.gov (United States)

    Olsen, Michael; Naudie, Douglas D; Edwards, Max R; Sellan, Michael E; McCalden, Richard W; Schemitsch, Emil H

    2014-03-01

    A novel alternative to conventional instrumentation for femoral component insertion in hip resurfacing is a patient specific, computed tomography based femoral alignment guide. A benchside study using cadaveric femora was performed comparing a custom alignment guide to conventional instrumentation and computer navigation. A clinical series of twenty-five hip resurfacings utilizing a custom alignment guide was conducted by three surgeons experienced in hip resurfacing. Using cadaveric femora, the custom guide was comparable to conventional instrumentation with computer navigation proving superior to both. Clinical femoral component alignment accuracy was 3.7° and measured within ± 5° of plan in 20 of 24 cases. Patient specific femoral alignment guides provide a satisfactory level of accuracy and may be a better alternative to conventional instrumentation for initial femoral guidewire placement in hip resurfacing.

  20. Anisotropic Finite Element Modeling Based on a Harmonic Field for Patient-Specific Sclera

    Directory of Open Access Journals (Sweden)

    Xu Jia

    2017-01-01

    Full Text Available Purpose. This study examined the influence of anisotropic material for human sclera. Method. First, the individual geometry of patient-specific sclera was reproduced from a laser scan. Then, high quality finite element modeling of individual sclera was performed using a convenient automatic hexahedral mesh generator based on harmonic field and integrated with anisotropic material assignment function. Finally, comparison experiments were designed to investigate the effects of anisotropy on finite element modeling of sclera biomechanics. Results. The experimental results show that the presented approach can generate high quality anisotropic hexahedral mesh for patient-specific sclera. Conclusion. The anisotropy shows significant differences for stresses and strain distribution and careful consideration should be given to its use in biomechanical FE studies.

  1. Anisotropic Finite Element Modeling Based on a Harmonic Field for Patient-Specific Sclera.

    Science.gov (United States)

    Jia, Xu; Liao, Shenghui; Duan, Xuanchu; Zheng, Wanqiu; Zou, Beiji

    2017-01-01

    Purpose. This study examined the influence of anisotropic material for human sclera. Method. First, the individual geometry of patient-specific sclera was reproduced from a laser scan. Then, high quality finite element modeling of individual sclera was performed using a convenient automatic hexahedral mesh generator based on harmonic field and integrated with anisotropic material assignment function. Finally, comparison experiments were designed to investigate the effects of anisotropy on finite element modeling of sclera biomechanics. Results. The experimental results show that the presented approach can generate high quality anisotropic hexahedral mesh for patient-specific sclera. Conclusion. The anisotropy shows significant differences for stresses and strain distribution and careful consideration should be given to its use in biomechanical FE studies.

  2. MRI is more accurate than CT for patient-specific total knee arthroplasty.

    Science.gov (United States)

    Frye, Benjamin M; Najim, Amjad A; Adams, Joanne B; Berend, Keith R; Lombardi, Adolph V

    2015-12-01

    Previous reports have stated that MRI is less accurate than CT for patient specific guide creation in total knee arthroplasty (TKA). Twenty-three TKAs were performed with CT-based guides and 27 with MRI-based guides. A mechanical axis through the central third of the knee was achieved in 88.9% of MRI-guided TKA versus 69.6% of CT-guided TKA (p=0.07). There were nine component outliers in the CT group (39.1%) and two in the MRI group (7.4%, p=0.00768). The relative risk of having an outlier using a CT-based guide was 5.28 times that of an MRI-based guide. Superior overall alignment and fewer outliers were achieved with the use of MRI compared with CT. MRI is the best imaging modality for surgeons wishing to utilize patient specific guides for TKA.

  3. Patient Specification Quality Assurance for Glioblastoma Multiforme Brain Tumors Treated with Intensity Modulated Radiation Therapy

    OpenAIRE

    Al-Mohammed, H. I.

    2011-01-01

    The aim of this study was to evaluate the significance of performing patient specification quality assurance for patients diagnosed with glioblastoma multiforme treated with intensity modulated radiation therapy. The study evaluated ten intensity modulated radiation therapy treatment plans using 10 MV beams, a total dose of 60 Gy (2 Gy/fraction, five fractions a week for a total of six weeks treatment). For the quality assurance protocol we used a two-dimensional ionization-chamber array (2D-...

  4. Choosing surgery

    DEFF Research Database (Denmark)

    Thorstensson, Carina; Lohmander, L; Frobell, Richard

    2009-01-01

    ABSTRACT: BACKGROUND: The objective was to understand patients' views of treatment after acute anterior cruciate ligament (ACL) injury, and their reasons for deciding to request surgery despite consenting to participate in a randomised controlled trial (to 'cross-over'). METHODS: Thirty-four in......-depth qualitative interviews were conducted with young (aged 18-35), physically active individuals with ACL rupture who were participating in a RCT comparing training and surgical reconstruction with training only. 22/34 were randomised to training only but crossed over to surgery. Of these, 11 were interviewed...... before surgery, and 11 were interviewed at least 6 months after surgery. To provide additional information, 12 patients were interviewed before randomisation. Interviews were audio-recorded, transcribed and analysed using the Framework approach. RESULTS: Strong preference for surgery was commonplace...

  5. Patient-specific simulations of stenting procedures in coronary bifurcations: two clinical cases.

    Science.gov (United States)

    Morlacchi, Stefano; Colleoni, Sebastian George; Cárdenes, Rubén; Chiastra, Claudio; Diez, Jose Luis; Larrabide, Ignacio; Migliavacca, Francesco

    2013-09-01

    Computational simulations of stenting procedures in idealized geometries can only provide general guidelines and their use in the patient-specific planning of percutaneous treatments is inadequate. Conversely, image-based patient-specific tools that are able to realistically simulate different interventional options might facilitate clinical decision-making and provide useful insights on the treatment for each individual patient. The aim of this work is the implementation of a patient-specific model that uses image-based reconstructions of coronary bifurcations and is able to replicate real stenting procedures following clinical indications. Two clinical cases are investigated focusing the attention on the open problems of coronary bifurcations and their main treatment, the provisional side branch approach. Image-based reconstructions are created combining the information from conventional coronary angiography and computed tomography angiography while structural finite element models are implemented to replicate the real procedure performed in the patients. First, numerical results show the biomechanical influence of stents deployment in the coronary bifurcations during and after the procedures. In particular, the straightening of the arterial wall and the influence of two overlapping stents on stress fields are investigated here. Results show that a sensible decrease of the vessel tortuosity occurs after stent implantation and that overlapping devices result in an increased stress state of both the artery and the stents. Lastly, the comparison between numerical and image-based post-stenting configurations proved the reliability of such models while replicating stent deployment in coronary arteries.

  6. Activity and High-Order Effective Connectivity Alterations in Sanfilippo C Patient-Specific Neuronal Networks

    Directory of Open Access Journals (Sweden)

    Isaac Canals

    2015-10-01

    Full Text Available Induced pluripotent stem cell (iPSC technology has been successfully used to recapitulate phenotypic traits of several human diseases in vitro. Patient-specific iPSC-based disease models are also expected to reveal early functional phenotypes, although this remains to be proved. Here, we generated iPSC lines from two patients with Sanfilippo type C syndrome, a lysosomal storage disorder with inheritable progressive neurodegeneration. Mature neurons obtained from patient-specific iPSC lines recapitulated the main known phenotypes of the disease, not present in genetically corrected patient-specific iPSC-derived cultures. Moreover, neuronal networks organized in vitro from mature patient-derived neurons showed early defects in neuronal activity, network-wide degradation, and altered effective connectivity. Our findings establish the importance of iPSC-based technology to identify early functional phenotypes, which can in turn shed light on the pathological mechanisms occurring in Sanfilippo syndrome. This technology also has the potential to provide valuable readouts to screen compounds, which can prevent the onset of neurodegeneration.

  7. A Patient-Specific Airway Branching Model for Mechanically Ventilated Patients

    Directory of Open Access Journals (Sweden)

    Nor Salwa Damanhuri

    2014-01-01

    Full Text Available Background. Respiratory mechanics models have the potential to guide mechanical ventilation. Airway branching models (ABMs were developed from classical fluid mechanics models but do not provide accurate models of in vivo behaviour. Hence, the ABM was improved to include patient-specific parameters and better model observed behaviour (ABMps. Methods. The airway pressure drop of the ABMps was compared with the well-accepted dynostatic algorithm (DSA in patients diagnosed with acute respiratory distress syndrome (ARDS. A scaling factor (α was used to equate the area under the pressure curve (AUC from the ABMps to the AUC of the DSA and was linked to patient state. Results. The ABMps recorded a median α value of 0.58 (IQR: 0.54–0.63; range: 0.45–0.66 for these ARDS patients. Significantly lower α values were found for individuals with chronic obstructive pulmonary disease (P<0.001. Conclusion. The ABMps model allows the estimation of airway pressure drop at each bronchial generation with patient-specific physiological measurements and can be generated from data measured at the bedside. The distribution of patient-specific α values indicates that the overall ABM can be readily improved to better match observed data and capture patient condition.

  8. [Establishment of hemophilia A patient-specific inducible pluripotent stem cells with urine cells].

    Science.gov (United States)

    Hu, Zhiqing; Hu, Xuyun; Pang, Jialun; Wang, Xiaolin; Lin Peng, Siyuan; Li, Zhuo; Wu, Yong; Wu, Lingqian; Liang, Desheng

    2015-10-01

    OBJECTIVE To generate hemophilia A (HA) patient-specific inducible pluripotent stem cells (iPSCs) and induce endothelial differentiation. METHODS Tubular epithelial cells were isolated and cultured from the urine of HA patients. The iPSCs were generated by forced expression of Yamanaka factors (Oct4, Sox2, c-Myc and Klf4) using retroviruses and characterized by cell morphology, pluripotent marker staining and in vivo differentiation through teratoma formation. Induced endothelial differentiation of the iPSCs was achieved with the OP9 cell co-culture method. RESULTS Patient-specific iPSCs were generated from urine cells of the HA patients, which could be identified by cell morphology, pluripotent stem cell surface marker staining and in vivo differentiation of three germ layers. The teratoma experiment has confirmed that such cells could differentiate into endothelial cells expressing the endothelial-specific markers CD144, CD31 and vWF. CONCLUSION HA patient-specific iPSCs could be generated from urine cells and can differentiate into endothelial cells. This has provided a new HA disease modeling approach and may serve as an applicable autologous cell source for gene correction and cell therapy studies for HA.

  9. Activity and High-Order Effective Connectivity Alterations in Sanfilippo C Patient-Specific Neuronal Networks

    Science.gov (United States)

    Canals, Isaac; Soriano, Jordi; Orlandi, Javier G.; Torrent, Roger; Richaud-Patin, Yvonne; Jiménez-Delgado, Senda; Merlin, Simone; Follenzi, Antonia; Consiglio, Antonella; Vilageliu, Lluïsa; Grinberg, Daniel; Raya, Angel

    2015-01-01

    Summary Induced pluripotent stem cell (iPSC) technology has been successfully used to recapitulate phenotypic traits of several human diseases in vitro. Patient-specific iPSC-based disease models are also expected to reveal early functional phenotypes, although this remains to be proved. Here, we generated iPSC lines from two patients with Sanfilippo type C syndrome, a lysosomal storage disorder with inheritable progressive neurodegeneration. Mature neurons obtained from patient-specific iPSC lines recapitulated the main known phenotypes of the disease, not present in genetically corrected patient-specific iPSC-derived cultures. Moreover, neuronal networks organized in vitro from mature patient-derived neurons showed early defects in neuronal activity, network-wide degradation, and altered effective connectivity. Our findings establish the importance of iPSC-based technology to identify early functional phenotypes, which can in turn shed light on the pathological mechanisms occurring in Sanfilippo syndrome. This technology also has the potential to provide valuable readouts to screen compounds, which can prevent the onset of neurodegeneration. PMID:26411903

  10. Activity and High-Order Effective Connectivity Alterations in Sanfilippo C Patient-Specific Neuronal Networks.

    Science.gov (United States)

    Canals, Isaac; Soriano, Jordi; Orlandi, Javier G; Torrent, Roger; Richaud-Patin, Yvonne; Jiménez-Delgado, Senda; Merlin, Simone; Follenzi, Antonia; Consiglio, Antonella; Vilageliu, Lluïsa; Grinberg, Daniel; Raya, Angel

    2015-10-13

    Induced pluripotent stem cell (iPSC) technology has been successfully used to recapitulate phenotypic traits of several human diseases in vitro. Patient-specific iPSC-based disease models are also expected to reveal early functional phenotypes, although this remains to be proved. Here, we generated iPSC lines from two patients with Sanfilippo type C syndrome, a lysosomal storage disorder with inheritable progressive neurodegeneration. Mature neurons obtained from patient-specific iPSC lines recapitulated the main known phenotypes of the disease, not present in genetically corrected patient-specific iPSC-derived cultures. Moreover, neuronal networks organized in vitro from mature patient-derived neurons showed early defects in neuronal activity, network-wide degradation, and altered effective connectivity. Our findings establish the importance of iPSC-based technology to identify early functional phenotypes, which can in turn shed light on the pathological mechanisms occurring in Sanfilippo syndrome. This technology also has the potential to provide valuable readouts to screen compounds, which can prevent the onset of neurodegeneration.

  11. Brand Aid

    DEFF Research Database (Denmark)

    Richey, Lisa Ann; Ponte, Stefano

    2011-01-01

    activists, scholars and venture capitalists, discusses the pros and cons of changing the world by ‘voting with your dollars’. Lisa Ann Richey and Stefano Ponte (Professor at Roskilde University and Senior Researcher at DIIS respectively), authors of Brand Aid: Shopping Well to Save the World, highlight how...

  12. Improved Surgery Planning Using 3-D Printing: a Case Study.

    Science.gov (United States)

    Singhal, A J; Shetty, V; Bhagavan, K R; Ragothaman, Ananthan; Shetty, V; Koneru, Ganesh; Agarwala, M

    2016-04-01

    The role of 3-D printing is presented for improved patient-specific surgery planning. Key benefits are time saved and surgery outcome. Two hard-tissue surgery models were 3-D printed, for orthopedic, pelvic surgery, and craniofacial surgery. We discuss software data conversion in computed tomography (CT)/magnetic resonance (MR) medical image for 3-D printing. 3-D printed models save time in surgery planning and help visualize complex pre-operative anatomy. Time saved in surgery planning can be as much as two thirds. In addition to improved surgery accuracy, 3-D printing presents opportunity in materials research. Other hard-tissue and soft-tissue cases in maxillofacial, abdominal, thoracic, cardiac, orthodontics, and neurosurgery are considered. We recommend using 3-D printing as standard protocol for surgery planning and for teaching surgery practices. A quick turnaround time of a 3-D printed surgery model, in improved accuracy in surgery planning, is helpful for the surgery team. It is recommended that these costs be within 20 % of the total surgery budget.

  13. Fluid-structure interaction of a patient-specific abdominal aortic aneurysm treated with an endovascular stent-graft.

    LENUS (Irish Health Repository)

    Molony, David S

    2009-01-01

    BACKGROUND: Abdominal aortic aneurysms (AAA) are local dilatations of the infrarenal aorta. If left untreated they may rupture and lead to death. One form of treatment is the minimally invasive insertion of a stent-graft into the aneurysm. Despite this effective treatment aneurysms may occasionally continue to expand and this may eventually result in post-operative rupture of the aneurysm. Fluid-structure interaction (FSI) is a particularly useful tool for investigating aneurysm biomechanics as both the wall stresses and fluid forces can be examined. METHODS: Pre-op, Post-op and Follow-up models were reconstructed from CT scans of a single patient and FSI simulations were performed on each model. The FSI approach involved coupling Abaqus and Fluent via a third-party software - MpCCI. Aneurysm wall stress and compliance were investigated as well as the drag force acting on the stent-graft. RESULTS: Aneurysm wall stress was reduced from 0.38 MPa before surgery to a value of 0.03 MPa after insertion of the stent-graft. Higher stresses were seen in the aneurysm neck and iliac legs post-operatively. The compliance of the aneurysm was also reduced post-operatively. The peak Post-op axial drag force was found to be 4.85 N. This increased to 6.37 N in the Follow-up model. CONCLUSION: In a patient-specific case peak aneurysm wall stress was reduced by 92%. Such a reduction in aneurysm wall stress may lead to shrinkage of the aneurysm over time. Hence, post-operative stress patterns may help in determining the likelihood of aneurysm shrinkage post EVAR. Post-operative remodelling of the aneurysm may lead to increased drag forces.

  14. Fluid-structure interaction of a patient-specific abdominal aortic aneurysm treated with an endovascular stent-graft

    Directory of Open Access Journals (Sweden)

    McGloughlin Tim M

    2009-10-01

    Full Text Available Abstract Background Abdominal aortic aneurysms (AAA are local dilatations of the infrarenal aorta. If left untreated they may rupture and lead to death. One form of treatment is the minimally invasive insertion of a stent-graft into the aneurysm. Despite this effective treatment aneurysms may occasionally continue to expand and this may eventually result in post-operative rupture of the aneurysm. Fluid-structure interaction (FSI is a particularly useful tool for investigating aneurysm biomechanics as both the wall stresses and fluid forces can be examined. Methods Pre-op, Post-op and Follow-up models were reconstructed from CT scans of a single patient and FSI simulations were performed on each model. The FSI approach involved coupling Abaqus and Fluent via a third-party software - MpCCI. Aneurysm wall stress and compliance were investigated as well as the drag force acting on the stent-graft. Results Aneurysm wall stress was reduced from 0.38 MPa before surgery to a value of 0.03 MPa after insertion of the stent-graft. Higher stresses were seen in the aneurysm neck and iliac legs post-operatively. The compliance of the aneurysm was also reduced post-operatively. The peak Post-op axial drag force was found to be 4.85 N. This increased to 6.37 N in the Follow-up model. Conclusion In a patient-specific case peak aneurysm wall stress was reduced by 92%. Such a reduction in aneurysm wall stress may lead to shrinkage of the aneurysm over time. Hence, post-operative stress patterns may help in determining the likelihood of aneurysm shrinkage post EVAR. Post-operative remodelling of the aneurysm may lead to increased drag forces.

  15. The patient's perspective of the feasibility of a patient-specific instrument in physiotherapy goal setting: a qualitative study

    NARCIS (Netherlands)

    Stevens, A.; Moser, A.; Koke, A.; Weijden, T.T. van der; Beurskens, A.

    2016-01-01

    BACKGROUND: Patient participation in goal setting is important to deliver client-centered care. In daily practice, however, patient involvement in goal setting is not optimal. Patient-specific instruments, such as the Patient Specific Complaints (PSC) instrument, can support the goal-setting process

  16. The patient's perspective of the feasibility of a patient-specific instrument in physiotherapy goal setting : a qualitative study

    NARCIS (Netherlands)

    Stevens, Anita; Moser, Albine; Köke, Albère; Weijden, Trudy van der; Beurskens, Anna

    2016-01-01

    Background: Patient participation in goal setting is important to deliver client-centered care. In daily practice, however, patient involvement in goal setting is not optimal. Patient-specific instruments, such as the Patient Specific Complaints (PSC) instrument, can support the goal-setting process

  17. Outpatient Surgery

    Science.gov (United States)

    ... thirds of all operations are performed in outpatient facilities, according to the Centers for Disease Control and Prevention. Outpatient surgery provides patients with the convenience of recovering at home, and can cost less. ...

  18. Brain surgery

    Science.gov (United States)

    Craniotomy; Surgery - brain; Neurosurgery; Craniectomy; Stereotactic craniotomy; Stereotactic brain biopsy; Endoscopic craniotomy ... cut depends on where the problem in the brain is located. The surgeon creates a hole in ...

  19. Laparoscopic Surgery

    Science.gov (United States)

    ... surgeon’s perspective, laparoscopic surgery may allow for easier dissection of abdominal scar tissue (adhesions), less surgical trauma, ... on Facebook About ACG ACG Store ACG Patient Education & Resource Center Home GI Health and Disease Recursos ...

  20. Tactile Aids

    Directory of Open Access Journals (Sweden)

    Mohtaramossadat Homayuni

    1996-04-01

    Full Text Available Tactile aids, which translate sound waves into vibrations that can be felt by the skin, have been used for decades by people with severe/profound hearing loss to enhance speech/language development and improve speechreading.The development of tactile aids dates from the efforts of Goults and his co-workers in the 1920s; Although The power supply was too voluminous and it was difficult to carry specially by children, it was too huge and heavy to be carried outside the laboratories and its application was restricted to the experimental usage. Nowadays great advances have been performed in producing this instrument and its numerous models is available in markets around the world.

  1. Negotiating Aid

    DEFF Research Database (Denmark)

    Whitfield, Lindsay; Fraser, Alastair

    2011-01-01

    This article presents a new analytical approach to the study of aid negotiations. Building on existing approaches but trying to overcome their limitations, it argues that factors outside of individual negotiations (or the `game' in game-theoretic approaches) significantly affect the preferences...... of actors, the negotiating strategies they fashion, and the success of those strategies. This approach was employed to examine and compare the experiences of eight countries: Botswana, Ethiopia, Ghana, Mali, Mozambique, Rwanda, Tanzania and Zambia. The article presents findings from these country studies...... which investigated the strategies these states have adopted in talks with aid donors, the sources of leverage they have been able to bring to bear in negotiations, and the differing degrees of control that they have been able to exercise over the policies agreed in negotiations and those implemented...

  2. [Aesthetic surgery].

    Science.gov (United States)

    Bruck, Johannes C

    2006-01-01

    The WHO describes health as physical, mental and social well being. Ever since the establishment of plastic surgery aesthetic surgery has been an integral part of this medical specialty. It aims at reconstructing subjective well-being by employing plastic surgical procedures as described in the educational code and regulations for specialists of plastic surgery. This code confirms that plastic surgery comprises cosmetic procedures for the entire body that have to be applied in respect of psychological exploration and selection criteria. A wide variety of opinions resulting from very different motivations shows how difficult it is to differentiate aesthetic surgery as a therapeutic procedure from beauty surgery as a primarily economic service. Jurisdiction, guidelines for professional conduct and ethical codes have tried to solve this question. Regardless of the intention and ability of the health insurances, it has currently been established that the moral and legal evaluation of advertisements for medical procedures depends on their purpose: advertising with the intent of luring patients into cosmetic procedures that do not aim to reconstruct a subjective physical disorder does not comply with a medical indication. If, however, the initiative originates with the patient requesting the amelioration of a subjective disorder of his body, a medical indication can be assumed.

  3. Patient-specific in vitro models for hemodynamic analysis of congenital heart disease - Additive manufacturing approach.

    Science.gov (United States)

    Medero, Rafael; García-Rodríguez, Sylvana; François, Christopher J; Roldán-Alzate, Alejandro

    2017-03-21

    Non-invasive hemodynamic assessment of total cavopulmonary connection (TCPC) is challenging due to the complex anatomy. Additive manufacturing (AM) is a suitable alternative for creating patient-specific in vitro models for flow measurements using four-dimensional (4D) Flow MRI. These in vitro systems have the potential to serve as validation for computational fluid dynamics (CFD), simulating different physiological conditions. This study investigated three different AM technologies, stereolithography (SLA), selective laser sintering (SLS) and fused deposition modeling (FDM), to determine differences in hemodynamics when measuring flow using 4D Flow MRI. The models were created using patient-specific MRI data from an extracardiac TCPC. These models were connected to a perfusion pump circulating water at three different flow rates. Data was processed for visualization and quantification of velocity, flow distribution, vorticity and kinetic energy. These results were compared between each model. In addition, the flow distribution obtained in vitro was compared to in vivo. The results showed significant difference in velocities measured at the outlets of the models that required internal support material when printing. Furthermore, an ultrasound flow sensor was used to validate flow measurements at the inlets and outlets of the in vitro models. These results were highly correlated to those measured with 4D Flow MRI. This study showed that commercially available AM technologies can be used to create patient-specific vascular models for in vitro hemodynamic studies at reasonable costs. However, technologies that do not require internal supports during manufacturing allow smoother internal surfaces, which makes them better suited for flow analyses.

  4. Validation of a Cochlear Implant Patient Specific Model of the Voltage Distribution in a Clinical Setting

    Directory of Open Access Journals (Sweden)

    Waldo Nogueira

    2016-11-01

    Full Text Available Cochlear Implants (CIs are medical implantable devices that can restore the sense of hearing in people with profound hearing loss. Clinical trials assessing speech intelligibility in CI users have found large inter-subject variability. One possibility to explain the variability is the individual differences in the interface created between electrodes of the CI and the auditory nerve. In order to understand the variability, models of the voltage distribution of the electrically stimulated cochlea may be useful. With this purpose in mind, we developed a parametric model that can be adapted to each CI user based on landmarks from individual cone beam computed tomography (CBCT scans of the cochlea before and after implantation. The conductivity values of each cochlea compartment as well as the weighting factors of different grounding modes have been also parameterized. Simulations were performed modeling the cochlea and electrode positions of 12 CI users. Three models were compared with different levels of detail: A homogeneous model (HM, a non-patient specific model (NPSM and a patient specific model (PSM. The model simulations were compared with voltage distribution measurements obtained from the backward telemetry of the 12 CI users. Results show that the PSM produces the lowest error when predicting individual voltage distributions. Given a patient specific geometry and electrode positions we show an example on how to optimize the parameters of the model and how to couple it to an auditory nerve model. The model here presented may help to understand speech performance variability and support the development of new sound coding strategies for CIs.

  5. Creating Patient-Specific Neural Cells for the In Vitro Study of Brain Disorders.

    Science.gov (United States)

    Brennand, Kristen J; Marchetto, M Carol; Benvenisty, Nissim; Brüstle, Oliver; Ebert, Allison; Izpisua Belmonte, Juan Carlos; Kaykas, Ajamete; Lancaster, Madeline A; Livesey, Frederick J; McConnell, Michael J; McKay, Ronald D; Morrow, Eric M; Muotri, Alysson R; Panchision, David M; Rubin, Lee L; Sawa, Akira; Soldner, Frank; Song, Hongjun; Studer, Lorenz; Temple, Sally; Vaccarino, Flora M; Wu, Jun; Vanderhaeghen, Pierre; Gage, Fred H; Jaenisch, Rudolf

    2015-12-01

    As a group, we met to discuss the current challenges for creating meaningful patient-specific in vitro models to study brain disorders. Although the convergence of findings between laboratories and patient cohorts provided us confidence and optimism that hiPSC-based platforms will inform future drug discovery efforts, a number of critical technical challenges remain. This opinion piece outlines our collective views on the current state of hiPSC-based disease modeling and discusses what we see to be the critical objectives that must be addressed collectively as a field.

  6. Creating Patient-Specific Neural Cells for the In Vitro Study of Brain Disorders

    Directory of Open Access Journals (Sweden)

    Kristen J. Brennand

    2015-12-01

    Full Text Available As a group, we met to discuss the current challenges for creating meaningful patient-specific in vitro models to study brain disorders. Although the convergence of findings between laboratories and patient cohorts provided us confidence and optimism that hiPSC-based platforms will inform future drug discovery efforts, a number of critical technical challenges remain. This opinion piece outlines our collective views on the current state of hiPSC-based disease modeling and discusses what we see to be the critical objectives that must be addressed collectively as a field.

  7. Generation of Transplantable Beta Cells for Patient-Specific Cell Therapy

    Directory of Open Access Journals (Sweden)

    Xiaojie Wang

    2012-01-01

    Full Text Available Islet cell transplantation offers a potential cure for type 1 diabetes, but it is challenged by insufficient donor tissue and side effects of current immunosuppressive drugs. Therefore, alternative sources of insulin-producing cells and isletfriendly immunosuppression are required to increase the efficiency and safety of this procedure. Beta cells can be transdifferentiated from precursors or another heterologous (non-beta-cell source. Recent advances in beta cell regeneration from somatic cells such as fibroblasts could circumvent the usage of immunosuppressive drugs. Therefore, generation of patient-specific beta cells provides the potential of an evolutionary treatment for patients with diabetes.

  8. Tennis elbow surgery

    Science.gov (United States)

    Lateral epicondylitis - surgery; Lateral tendinosis - surgery; Lateral tennis elbow - surgery ... Surgery to repair tennis elbow is usually an outpatient surgery. This means you will not stay in the hospital overnight. You will be given ...

  9. Manufacture of patient-specific vascular replicas for endovascular simulation using fast, low-cost method

    Science.gov (United States)

    Kaneko, Naoki; Mashiko, Toshihiro; Ohnishi, Taihei; Ohta, Makoto; Namba, Katsunari; Watanabe, Eiju; Kawai, Kensuke

    2016-12-01

    Patient-specific vascular replicas are essential to the simulation of endovascular treatment or for vascular research. The inside of silicone replica is required to be smooth for manipulating interventional devices without resistance. In this report, we demonstrate the fabrication of patient-specific silicone vessels with a low-cost desktop 3D printer. We show that the surface of an acrylonitrile butadiene styrene (ABS) model printed by the 3D printer can be smoothed by a single dipping in ABS solvent in a time-dependent manner, where a short dip has less effect on the shape of the model. The vascular mold is coated with transparent silicone and then the ABS mold is dissolved after the silicone is cured. Interventional devices can pass through the inside of the smoothed silicone vessel with lower pushing force compared to the vessel without smoothing. The material cost and time required to fabricate the silicone vessel is about USD $2 and 24 h, which is much lower than the current fabrication methods. This fast and low-cost method offers the possibility of testing strategies before attempting particularly difficult cases, while improving the training of endovascular therapy, enabling the trialing of new devices, and broadening the scope of vascular research.

  10. Effect of voxel size when calculating patient specific radionuclide dosimetry estimates using direct Monte Carlo simulation.

    Science.gov (United States)

    Hickson, Kevin J; O'Keefe, Graeme J

    2014-09-01

    The scalable XCAT voxelised phantom was used with the GATE Monte Carlo toolkit to investigate the effect of voxel size on dosimetry estimates of internally distributed radionuclide calculated using direct Monte Carlo simulation. A uniformly distributed Fluorine-18 source was simulated in the Kidneys of the XCAT phantom with the organ self dose (kidney ← kidney) and organ cross dose (liver ← kidney) being calculated for a number of organ and voxel sizes. Patient specific dose factors (DF) from a clinically acquired FDG PET/CT study have also been calculated for kidney self dose and liver ← kidney cross dose. Using the XCAT phantom it was found that significantly small voxel sizes are required to achieve accurate calculation of organ self dose. It has also been used to show that a voxel size of 2 mm or less is suitable for accurate calculations of organ cross dose. To compensate for insufficient voxel sampling a correction factor is proposed. This correction factor is applied to the patient specific dose factors calculated with the native voxel size of the PET/CT study.

  11. Patient-specific biomechanical model as whole-body CT image registration tool.

    Science.gov (United States)

    Li, Mao; Miller, Karol; Joldes, Grand Roman; Doyle, Barry; Garlapati, Revanth Reddy; Kikinis, Ron; Wittek, Adam

    2015-05-01

    Whole-body computed tomography (CT) image registration is important for cancer diagnosis, therapy planning and treatment. Such registration requires accounting for large differences between source and target images caused by deformations of soft organs/tissues and articulated motion of skeletal structures. The registration algorithms relying solely on image processing methods exhibit deficiencies in accounting for such deformations and motion. We propose to predict the deformations and movements of body organs/tissues and skeletal structures for whole-body CT image registration using patient-specific non-linear biomechanical modelling. Unlike the conventional biomechanical modelling, our approach for building the biomechanical models does not require time-consuming segmentation of CT scans to divide the whole body into non-overlapping constituents with different material properties. Instead, a Fuzzy C-Means (FCM) algorithm is used for tissue classification to assign the constitutive properties automatically at integration points of the computation grid. We use only very simple segmentation of the spine when determining vertebrae displacements to define loading for biomechanical models. We demonstrate the feasibility and accuracy of our approach on CT images of seven patients suffering from cancer and aortic disease. The results confirm that accurate whole-body CT image registration can be achieved using a patient-specific non-linear biomechanical model constructed without time-consuming segmentation of the whole-body images.

  12. Simulations of blood flow in patient-specific aortic dissections with a deformable wall model

    Science.gov (United States)

    Baeumler, Kathrin; Vedula, Vijay; Sailer Karmann, Anna; Marsden, Alison; Fleischmann, Dominik

    2016-11-01

    Aortic dissection is a life-threatening condition in which blood penetrates into the vessel wall, creating a second flow channel, often requiring emergency surgical repair. Up to 50% of patients who survive the acute event face late complications like aortic dilatation and eventual rupture. Prediction of late complications, however, remains challenging. We therefore aim to perform accurate and reliable patient-specific simulations of blood flow in aortic dissections, validated by 4D-Flow MRI. Among other factors, this is a computational challenge due to the compliance of the vessel walls and the large degree of membrane deformation between the two flow channels. We construct an anatomic patient-specific model from CT data including both flow channels and the membrane between them. We then run fluid structure interaction simulations using an arbitrary Lagrangian-Eulerian (ALE) formulation within a multiscale variational framework, employing stabilized finite element methods. We compare hemodynamics between a rigid and a deformable wall model and examine membrane dynamics and pressure differences between the two flow channels. The study focuses on the computational and modeling challenges emphasizing the importance of employing a deformable wall model for aortic dissections.

  13. Designing patient-specific 3D printed craniofacial implants using a novel topology optimization method.

    Science.gov (United States)

    Sutradhar, Alok; Park, Jaejong; Carrau, Diana; Nguyen, Tam H; Miller, Michael J; Paulino, Glaucio H

    2016-07-01

    Large craniofacial defects require efficient bone replacements which should not only provide good aesthetics but also possess stable structural function. The proposed work uses a novel multiresolution topology optimization method to achieve the task. Using a compliance minimization objective, patient-specific bone replacement shapes can be designed for different clinical cases that ensure revival of efficient load transfer mechanisms in the mid-face. In this work, four clinical cases are introduced and their respective patient-specific designs are obtained using the proposed method. The optimized designs are then virtually inserted into the defect to visually inspect the viability of the design . Further, once the design is verified by the reconstructive surgeon, prototypes are fabricated using a 3D printer for validation. The robustness of the designs are mechanically tested by subjecting them to a physiological loading condition which mimics the masticatory activity. The full-field strain result through 3D image correlation and the finite element analysis implies that the solution can survive the maximum mastication of 120 lb. Also, the designs have the potential to restore the buttress system and provide the structural integrity. Using the topology optimization framework in designing the bone replacement shapes would deliver surgeons new alternatives for rather complicated mid-face reconstruction.

  14. Computational Simulations of Inferior Vena Cava (IVC) Filter Placement and Hemodynamics in Patient-Specific Geometries

    Science.gov (United States)

    Aycock, Kenneth; Sastry, Shankar; Kim, Jibum; Shontz, Suzanne; Campbell, Robert; Manning, Keefe; Lynch, Frank; Craven, Brent

    2013-11-01

    A computational methodology for simulating inferior vena cava (IVC) filter placement and IVC hemodynamics was developed and tested on two patient-specific IVC geometries: a left-sided IVC, and an IVC with a retroaortic left renal vein. Virtual IVC filter placement was performed with finite element analysis (FEA) using non-linear material models and contact modeling, yielding maximum vein displacements of approximately 10% of the IVC diameters. Blood flow was then simulated using computational fluid dynamics (CFD) with four cases for each patient IVC: 1) an IVC only, 2) an IVC with a placed filter, 3) an IVC with a placed filter and a model embolus, all at resting flow conditions, and 4) an IVC with a placed filter and a model embolus at exercise flow conditions. Significant hemodynamic differences were observed between the two patient IVCs, with the development of a right-sided jet (all cases) and a larger stagnation region (cases 3-4) in the left-sided IVC. These results support further investigation of the effects of IVC filter placement on a patient-specific basis.

  15. Patient-specific models of microglia-mediated engulfment of synapses and neural progenitors

    Science.gov (United States)

    Sellgren, C M; Sheridan, S D; Gracias, J; Xuan, D; Fu, T; Perlis, R H

    2017-01-01

    Engulfment of synapses and neural progenitor cells (NPCs) by microglia is critical for the development and maintenance of proper brain circuitry, and has been implicated in neurodevelopmental as well as neurodegenerative disease etiology. We have developed and validated models of these mechanisms by reprogramming microglia-like cells from peripheral blood mononuclear cells, and combining them with NPCs and neurons derived from induced pluripotent stem cells to create patient-specific cellular models of complement-dependent synaptic pruning and elimination of NPCs. The resulting microglia-like cells express appropriate markers and function as primary human microglia, while patient-matched macrophages differ markedly. As a demonstration of disease-relevant application, we studied the role of C4, recently implicated in schizophrenia, in engulfment of synaptic structures by human microglia. The ability to create complete patient-specific cellular models of critical microglial functions utilizing samples taken during a single clinical visit will extend the ability to model central nervous system disease while facilitating high-throughput screening. PMID:27956744

  16. Patient-specific computer modelling of coronary bifurcation stenting: the John Doe programme.

    Science.gov (United States)

    Mortier, Peter; Wentzel, Jolanda J; De Santis, Gianluca; Chiastra, Claudio; Migliavacca, Francesco; De Beule, Matthieu; Louvard, Yves; Dubini, Gabriele

    2015-01-01

    John Doe, an 81-year-old patient with a significant distal left main (LM) stenosis, was treated using a provisional stenting approach. As part of an European Bifurcation Club (EBC) project, the complete stenting procedure was repeated using computational modelling. First, a tailored three-dimensional (3D) reconstruction of the bifurcation anatomy was created by fusion of multislice computed tomography (CT) imaging and intravascular ultrasound. Second, finite element analysis was employed to deploy and post-dilate the stent virtually within the generated patient-specific anatomical bifurcation model. Finally, blood flow was modelled using computational fluid dynamics. This proof-of-concept study demonstrated the feasibility of such patient-specific simulations for bifurcation stenting and has provided unique insights into the bifurcation anatomy, the technical aspects of LM bifurcation stenting, and the positive impact of adequate post-dilatation on blood flow patterns. Potential clinical applications such as virtual trials and preoperative planning seem feasible but require a thorough clinical validation of the predictive power of these computer simulations.

  17. Teaching AIDS.

    Science.gov (United States)

    Short, R V

    1989-06-01

    This article reviews a peer group Acquired Immunodeficiency Syndrome (AIDS) educational program at a university in Australia. Studies in the US have shown that most adolescents, although sexually active, do not believe they are likely to become infected with the Human Immunodeficiency Virus, and therefore do not attempt to modify their sexual behavior. A 1st step in educating students is to introduce them to condoms and impress upon them the fact that condoms should be used at the beginning of all sexual relationships, whether homosexual or heterosexual. In this program 3rd year medical students were targeted, as they are effective communicators and disseminators of information to the rest of the student body. After class members blow up condoms, giving them a chance to handle various brands and observe the varying degrees of strength, statistical evidence about the contraceptive failure rate of condoms (0.6-14.7 per 100 women-years) is discussed. Spermicides, such as nonoxynol-9 used in conjunction with condoms, are also discussed, as are condoms for women, packaging and marketing of condoms, including those made from latex and from the caecum of sheep, the latter condoms being of questionable effectiveness in preventing transmission of the virus. The care of terminal AIDS cases and current global and national statistics on AIDS are presented. The program also includes cash prizes for the best student essays on condom use, the distribution of condoms, condom key rings and T-shirts, and a student-run safe sex stand during orientation week. All of these activities are intended to involve students and attract the interest of the undergraduate community. Questionnaires administered to students at the end of the course revealed that the lectures were received favorably. Questionnaires administered to new medical and English students attending orientation week revealed that 72% of students thought the stand was a good idea and 81% and 83%, respectively found it

  18. Brand Aid

    DEFF Research Database (Denmark)

    Richey, Lisa Ann; Ponte, Stefano

    2011-01-01

    activists, scholars and venture capitalists, discusses the pros and cons of changing the world by ‘voting with your dollars’. Lisa Ann Richey and Stefano Ponte (Professor at Roskilde University and Senior Researcher at DIIS respectively), authors of Brand Aid: Shopping Well to Save the World, highlight how......Can Citizen Consumers Make a Difference? DIIS researcher contributes to a Boston Review - New Democracy Forum In the current issue of Boston Review (November/December 2011), contributors to a ‘New Democracy Forum’ debate whether Citizen Consumers can make a difference in stimulating responsible...

  19. Corneal Topographical Changes Flollowing Strabismus Surgery

    Institute of Scientific and Technical Information of China (English)

    MaiGH; WangZ

    1999-01-01

    Purpose:To study corneal topographical changes after strabismus surgery.Methods:Computer-aided corneal topography was used in 43 strabismus patients(45 eyes)one or two days prior to and six or seven ays after strabismus surgery.The spherical and cylindrical equivalents were calculated based on the simulated keratometry.Results:After the surgery,only the changes at 3mm in the inferior quadrant were statistically significant.The changes at 3mm in the rest quadrants and the changes at 7mm were no significant.Significant changes in spherical equivalent were found post-operatively.neither the horizontal nor the verical meridional equivalent showed significant changes after surgery.Conclusions:The results of corneal topographical changes following strabismus surgery in our preliminary study indicated the little effect of strabismus surgery on corneal curvature and corneal astigmatism.

  20. Surgical management of maxillomandibular advancement in sleep apnea patients: specific technical considerations.

    Science.gov (United States)

    Gilon, Y; Raskin, S; Heymans, O; Poirrier, R

    2001-01-01

    Maxillomandibular advancement is an integral part of the surgical treatment of patients suffering from obstructive sleep apnea. A number of publications report its efficacy and have attempted to define predictive success criteria. However, few authors have shown an interest in the surgical specificity of this intervention and in the difficulties that can be encountered, which differ from those seen in conventional orthognathic surgery. In this article, a series of patients treated with maxillomandibular osteotomy to correct obstructive sleep apnea syndrome (n = 17) are compared with patients who underwent surgery for the correction of dentofacial disharmonies (n = 33). Observations emphasized the importance of respecting a strict surgical and postsurgical protocol to avoid any technical traps linked to maxillomandibular advancement, both in preoperative simulations and during and after surgery. Results concerning sleep parameters will be the subject of a future publication.

  1. Orthognathic Surgery

    DEFF Research Database (Denmark)

    Kjærgaard Larsen, Marie; Thygesen, Torben Henrik

    2016-01-01

    The literature shows that the indications for orthognathic surgery (OS) are often functional problems and unsatisfactory facial esthetics. This study investigated the esthetic outcomes and overall satisfaction following OS. Somatosensory change is a relatively common complication and its influence...... on the level of satisfaction was studied. The social-networking web site Facebook was used to identify the study population. An online questionnaire was performed using the website SurveyMonkey. In all, 105 (9%) respondents from the Danish Facebook group about OS, called Kaebeoperation (jaw surgery), were...... in beauty than women (P = 0.030). Sixty-four percent replied that their attractiveness had been increased after OS. Eighty-six percent were happy with the results and 89% would recommend the surgery to others in need. No significant differences in esthetic results and satisfaction were seen with regard...

  2. Anesthesia and perioperative management of colorectal surgical patients - specific issues (part 2

    Directory of Open Access Journals (Sweden)

    Santosh Patel

    2012-01-01

    Full Text Available Colorectal surgery carries significant morbidity and mortality, which is associated with an enormous use of healthcare resources. Patients with pre-existing morbidities, and those undergoing emergency colorectal surgery due to complications such as perforation, obstruction, or ischemia / infarction are at an increased risk for adverse outcomes. Fluid therapy in emergency colorectal surgical patients can be challenging as hypovolemic and septic shock may coexist. Abdominal sepsis is a serious complication and may be diagnosed during pre-, intra-, or postoperative periods. Early suspicion and recognition of medical and / or surgical complications are essential. The critical care management of complicated colorectal surgical patients require collaborative and multidisciplinary efforts.

  3. [Geriatric surgery].

    Science.gov (United States)

    Paulino-Netto, Augusto

    2005-10-01

    Modern medicine, which is evidence-based and overly scientific, has forgotten its artistic component, which is very important for surgery in general and for geriatric surgery in particular. The surgeon treating an old patient must be a politician more than a technician, more an artist than a scientist. Like Leonardo da Vinci, he or she must use scientific knowledge with intelligence and sensitivity, transforming the elderly patient's last days of life into a beautiful and harmonious painting and not into something like an atomic power station which, while no doubt useful, is deprived of beauty and sometimes very dangerous.

  4. Patient-Specific Predictive Modeling Using Random Forests: An Observational Study for the Critically Ill

    Science.gov (United States)

    2017-01-01

    Background With a large-scale electronic health record repository, it is feasible to build a customized patient outcome prediction model specifically for a given patient. This approach involves identifying past patients who are similar to the present patient and using their data to train a personalized predictive model. Our previous work investigated a cosine-similarity patient similarity metric (PSM) for such patient-specific predictive modeling. Objective The objective of the study is to investigate the random forest (RF) proximity measure as a PSM in the context of personalized mortality prediction for intensive care unit (ICU) patients. Methods A total of 17,152 ICU admissions were extracted from the Multiparameter Intelligent Monitoring in Intensive Care II database. A number of predictor variables were extracted from the first 24 hours in the ICU. Outcome to be predicted was 30-day mortality. A patient-specific predictive model was trained for each ICU admission using an RF PSM inspired by the RF proximity measure. Death counting, logistic regression, decision tree, and RF models were studied with a hard threshold applied to RF PSM values to only include the M most similar patients in model training, where M was varied. In addition, case-specific random forests (CSRFs), which uses RF proximity for weighted bootstrapping, were trained. Results Compared to our previous study that investigated a cosine similarity PSM, the RF PSM resulted in superior or comparable predictive performance. RF and CSRF exhibited the best performances (in terms of mean area under the receiver operating characteristic curve [95% confidence interval], RF: 0.839 [0.835-0.844]; CSRF: 0.832 [0.821-0.843]). RF and CSRF did not benefit from personalization via the use of the RF PSM, while the other models did. Conclusions The RF PSM led to good mortality prediction performance for several predictive models, although it failed to induce improved performance in RF and CSRF. The distinction

  5. Computer assisted radiology and surgery. CARS 2010

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-06-15

    The conference proceedings include contributions to the following topics: (1) CARS Clinical Day: minimally invasive spiral surgery, interventional radiology; (2) CARS - computer assisted radiology and surgery: ophthalmology, stimulation methods, new approaches to diagnosis and therapy; (3) Computer assisted radiology 24th International congress and exhibition: computer tomography and magnetic resonance, digital angiographic imaging, digital radiography, ultrasound, computer assisted radiation therapy, medical workstations, image processing and display; (4) 14th Annual conference of the International Society for computer aided surgery; ENT-CMF head and neck surgery computer-assisted neurosurgery, cardiovascular surgery, image guided liver surgery, abdominal and laparoscopic surgery, computer-assisted orthopedic surgery, image processing and visualization, surgical robotics and instrumentation, surgical modeling, simulation and education; (5) 28th International EuroPACS meeting: image distribution and integration strategies, planning and evaluation, telemedicine and standards, workflow and data flow in radiology; (6) 11th CARS/SPIE/EuroPACS joint workshop on surgical PACS and the digital operating, management and assessment of OR systems and integration; (7) 12th International workshop on computer-aided diagnosis: special session on breast CAD, special session on thoracic CAD, special session on abdominal brain, lumbar spine CAD; (8) 16th computed Maxillofacial imaging congress: computed maxillofacial imaging in dental implantology, orthodontics and dentofacial orthopedics; approaches to 3D maxillofacial imaging; surgical navigation; (9) 2nd EuroNOTES/CARS workshop on NOTES: an interdisciplinary challenge; (10) 2nd EPMA/CARS workshop on personalized medicine and ICT.; (11)poster sessions.

  6. Carotid artery surgery

    Science.gov (United States)

    Carotid endarterectomy; CAS surgery; Carotid artery stenosis - surgery; Endarterectomy - carotid artery ... through the catheter around the blocked area during surgery. Your carotid artery is opened. The surgeon removes ...

  7. Modeling the consequences of tongue surgery on tongue mobility

    CERN Document Server

    Buchaillard, Stéphanie; Perrier, Pascal; Payan, Yohan

    2007-01-01

    This paper presents the current achievements of a long term project aiming at predicting and assessing the impact of tongue and mouth floor surgery on tongue mobility. The ultimate objective of this project is the design of a software with which surgeons should be able (1) to design a 3D biomechanical model of the tongue and of the mouth floor that matches the anatomical characteristics of each patient specific oral cavity, (2) to simulate the anatomical changes induced by the surgery and the possible reconstruction, and (3) to quantitatively predict and assess the consequences of these anatomical changes on tongue mobility and speech production after surgery.

  8. Clinical Potentials of Cardiomyocytes Derived from Patient-Specific Induced Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Kwong-Man Ng

    2014-10-01

    Full Text Available The lack of appropriate human cardiomyocyte-based experimental platform has largely hindered the study of cardiac diseases and the development of therapeutic strategies. To date, somatic cells isolated from human subjects can be reprogramed into induced pluripotent stem cells (iPSCs and subsequently differentiated into functional cardiomyocytes. This powerful reprogramming technology provides a novel in vitro human cell-based platform for the study of human hereditary cardiac disorders. The clinical potential of using iPSCs derived from patients with inherited cardiac disorders for therapeutic studies have been increasingly highlighted. In this review, the standard procedures for generating patient-specific iPSCs and the latest commonly used cardiac differentiation protocols will be outlined. Furthermore, the progress and limitations of current applications of iPSCs and iPSCs-derived cardiomyocytes in cell replacement therapy, disease modeling, drug-testing and toxicology studies will be discussed in detail.

  9. Ansys Fluent versus Sim Vascular for 4-D patient-specific computational hemodynamics in renal arteries

    Science.gov (United States)

    Mumbaraddi, Avinash; Yu, Huidan (Whitney); Sawchuk, Alan; Dalsing, Michael

    2015-11-01

    The objective of this clinical-need driven research is to investigate the effect of renal artery stenosis (RAS) on the blood flow and wall shear stress in renal arteries through 4-D patient-specific computational hemodynamics (PSCH) and search for possible critical RASs that significantly alter the pressure gradient across the stenosis by manually varying the size of RAS from 50% to 95%. The identification of the critical RAS is important to understand the contribution of RAS to the overall renal resistance thus appropriate clinical therapy can be determined in order to reduce the hypertension. Clinical CT angiographic data together with Doppler Ultra sound images of an anonymous patient are used serving as the required inputs of the PSCH. To validate the PSCH, we use both Ansys Fluent and Sim Vascular and compare velocity, pressure, and wall-shear stress under identical conditions. Renal Imaging Technology Development Program (RITDP) Grant.

  10. Wall Shear Stress Prediction Using Computational Simulation on Patient Specific Artery with Aneurysm

    Directory of Open Access Journals (Sweden)

    Yunus Muhamad

    2014-07-01

    Full Text Available An aneurysm is formed when a blood vessel becomes dilated or distorted. It will cause the vessel to expand to a size greater than its original diameter. In this study, Wall Shear Stress (WSS of cerebral artery with aneurysm was predicted using Computational Fluid Dynamics (CFD. WSS in the artery is one of the indicators for brain artery disease progression. Based on the results, the maximum value of blood velocity and WSS on patient specific artery with aneurysm are 3.23 m/s and 60.1 Pa, respectively. The location of high WSS is before and after the aneurysm bulge. The WSS is above the normal physiological value where the artery wall is exposed to high stress. Hence, the vessel at this location is anticipated to become weaker and could be further dilated.

  11. Patient-specific modelling of pulmonary airflow using GPU cluster for the application in medical practice.

    Science.gov (United States)

    Miki, T; Wang, X; Aoki, T; Imai, Y; Ishikawa, T; Takase, K; Yamaguchi, T

    2012-01-01

    In this paper, we propose a novel patient-specific method of modelling pulmonary airflow using graphics processing unit (GPU) computation that can be applied in medical practice. To overcome the barriers imposed by computation speed, installation price and footprint to the application of computational fluid dynamics, we focused on GPU computation and the lattice Boltzmann method (LBM). The GPU computation and LBM are compatible due to the characteristics of the GPU. As the optimisation of data access is essential for the performance of the GPU computation, we developed an adaptive meshing method, in which an airway model is covered by isotropic subdomains consisting of a uniform Cartesian mesh. We found that 4(3) size subdomains gave the best performance. The code was also tested on a small GPU cluster to confirm its performance and applicability, as the price and footprint are reasonable for medical applications.

  12. Ionization chamber array for patient specific VMAT, Tomotherapy and IMRT QA

    Energy Technology Data Exchange (ETDEWEB)

    Stathakis, Sotiri, E-mail: Stathakis@uthscsa.ed [Department of Radiation Oncology, Cancer Therapy and Research Center at the University of Texas Health Science Center, San Antonio TX 78229 (United States)

    2010-11-01

    The evaluation between measured and calculated dose is essential in the patient specific quality assurance procedures for intensity modulated radiation therapy. The high complexity of volumetric arc radiotherapy, Tomotherpay and intensity modulated radiation therapy deliveries attributed to the dynamic and synchronization requirements of such techniques require new methods and potentially new tools for the quality assurance of such techniques. Studies evaluating the dosimetric performance of EDR2 film and a 2D ionization chamber array quality assurance device have been performed in our institution. Our results showed that differences between the detector systems are small. The respective gamma index histograms showed that when 3% dose difference and 3mm distance to agreement are used, more than 90% of the evaluated points were within the tolerance criteria

  13. Colorectal cancer driver genes identified by patient specific comparison of cytogenetic microarray

    Directory of Open Access Journals (Sweden)

    Mohammad Azhar Aziz

    2014-12-01

    Full Text Available Colorectal cancer (CRC, which has high prevalence in Saudi Arabia and worldwide, needs better understanding by exploiting the latest available cytogenetic microarrays. We used biopsy tissue from consenting colorectal cancer patients to extract DNA and carry out microarray analysis using a CytoScan HD platform from Affymetrix. Patient specific comparisons of tumor–normal pairs were carried out. To find out the high probability key players, we performed Genomic Identification of Significant Targets in Cancer analysis and found 144 genes to form the list of driver genes. Of these, 24 genes attained high GISTIC scores and suggest being significantly associated with CRC. Loss of heterozygosity and uniparental disomy were found to affect 9 genes and suggest different mechanisms associated with CRC in every patient. Here we present the details of the methods used in carrying out the above analyses. Also, we provide some additional data on biomarker analysis that would complement the findings.

  14. Characterization of the transport topology in patient-specific abdominal aortic aneurysm models

    Science.gov (United States)

    Arzani, Amirhossein; Shadden, Shawn C.

    2012-08-01

    Abdominal aortic aneurysm (AAA) is characterized by disturbed blood flow patterns that are hypothesized to contribute to disease progression. The transport topology in six patient-specific abdominal aortic aneurysms was studied. Velocity data were obtained by image-based computational fluid dynamics modeling, with magnetic resonance imaging providing the necessary simulation parameters. Finite-time Lyapunov exponent (FTLE) fields were computed from the velocity data, and used to identify Lagrangian coherent structures (LCS). The combination of FTLE fields and LCS was used to characterize topological flow features such as separation zones, vortex transport, mixing regions, and flow impingement. These measures offer a novel perspective into AAA flow. It was observed that all aneurysms exhibited coherent vortex formation at the proximal segment of the aneurysm. The evolution of the systolic vortex strongly influences the flow topology in the aneurysm. It was difficult to predict the vortex dynamics from the aneurysm morphology, motivating the application of image-based flow modeling.

  15. EFFECTS OF PARENT ARTERY SEGMENTATION AND ANEURISMALWALL ELASTICITY ON PATIENT-SPECIFIC HEMODYNAMIC SIMULATIONS

    Institute of Scientific and Technical Information of China (English)

    CHEN Jia-liang; DING Guang-hong; YANG Xin-jian; LI Hai-yun

    2011-01-01

    It is well known that hemodynamics and wall tension play an important role in the formation,growth and rupture of aneurysms.In the present study,the authors investigated the influence of parent artery segmentation and aneurismal-wall elasticity on patient-specific hemodynamic simulations with two patient-specific eases of cerebral aneurysms.Realistic models of the aneurysms were constructed from 3-D angiography images and blood flow dynamics was studied under physiologically representative waveform of inflow.For each aneurysm three computational models were constructed:Model 1 with more extensive upstream parent artery with the rigid arterial and aneurismal wall,Model 2 with the partial upstream parent artery with the elastic arterial and aneurismal wall,Model 3 with more extensive upstream parent artery with the rigid wall for arterial wall far from the aneurysm and the elastic wall for arterial wall near the aneurysm.The results show that Model 1 could predict complex intra-aneurismal flow patterns and wall shear stress distribution in the aneurysm,but is unable to give aneurismal wall deformation and tension,Model 2 demonstrates aneurismal wall deformation and tension,but fails to properly model inflow pattern contributed by the upstream parent artery,resulting in local misunderstanding Wall Shear Stress (WSS) distribution,Model 3 can overcome limitations of the former two models,and give an overall and accurate analysis on intra-aneurismal flow patterns,wall shear stress distribution,aneurismal-wall deformation and tension.Therefore we suggest that the proper length of extensive upstream parent artery and aneuri-smal-wall elasticity should be considered carefully in establishing computational model to predict the intra-aneurismal hemodynamic and wall tension.

  16. Development of a patient-specific dosimetry estimation system in nuclear medicine examination

    Energy Technology Data Exchange (ETDEWEB)

    Lin, H. H.; Dong, S. L.; Yang, H. J. [Dept. of Biomedical Engineering and Environmental Sciences, National Tsing-Hua Univ., Taiwan (China); Chen, S. [Dept. of Medical Imaging and Radiological Sciences, Kaohsiung Medical Univ., Taiwan (China); Shih, C. T. [Dept. of Biomedical Engineering and Environmental Sciences, National Tsing-Hua Univ., Taiwan (China); Chuang, K. S. [Inst. of Nuclear Engineering and Sciences, National Tsing-Hua Univ., Taiwan (China); Lin, C. H. [Dept. of Biomedical Engineering and Environmental Sciences, National Tsing-Hua Univ., Taiwan (China); Yao, W. J. [PET Center, National Cheng Kung Univ. Hospital, Taiwan (China); Jan, M. L. [Physics Div., Inst. of Nuclear Energy Research, Atomic Energy Council, Taiwan (China)

    2011-07-01

    The purpose of this study is to develop a patient-specific dosimetry estimation system in nuclear medicine examination using a SimSET-based Monte Carlo code. We added a dose deposition routine to store the deposited energy of the photons during their flights in SimSET and developed a user-friendly interface for reading PET and CT images. Dose calculated on ORNL phantom was used to validate the accuracy of this system. The S values for {sup 99m}Tc, {sup 18}F and {sup 131}I obtained by the system were compared to those from the MCNP4C code and OLINDA. The ratios of S values computed by this system to those obtained with OLINDA for various organs were ranged from 0.93 to 1.18, which are comparable to that obtained from MCNP4C code (0.94 to 1.20). The average ratios of S value were 0.99{+-}0.04, 1.03{+-}0.05, and 1.00{+-}0.07 for isotopes {sup 131}I, {sup 18}F, and {sup 99m}Tc, respectively. The simulation time of SimSET was two times faster than MCNP4C's for various isotopes. A 3D dose calculation was also performed on a patient data set with PET/CT examination using this system. Results from the patient data showed that the estimated S values using this system differed slightly from those of OLINDA for ORNL phantom. In conclusion, this system can generate patient-specific dose distribution and display the isodose curves on top of the anatomic structure through a friendly graphic user interface. It may also provide a useful tool to establish an appropriate dose-reduction strategy to patients in nuclear medicine environments. (authors)

  17. The influence of boundary conditions on wall shear stress distribution in patients specific coronary trees.

    Science.gov (United States)

    van der Giessen, Alina G; Groen, Harald C; Doriot, Pierre-André; de Feyter, Pim J; van der Steen, Antonius F W; van de Vosse, Frans N; Wentzel, Jolanda J; Gijsen, Frank J H

    2011-04-01

    Patient specific geometrical data on human coronary arteries can be reliably obtained multislice computer tomography (MSCT) imaging. MSCT cannot provide hemodynamic variables, and the outflow through the side branches must be estimated. The impact of two different models to determine flow through the side branches on the wall shear stress (WSS) distribution in patient specific geometries is evaluated. Murray's law predicts that the flow ratio through the side branches scales with the ratio of the diameter of the side branches to the third power. The empirical model is based on flow measurements performed by Doriot et al. (2000) in angiographically normal coronary arteries. The fit based on these measurements showed that the flow ratio through the side branches can best be described with a power of 2.27. The experimental data imply that Murray's law underestimates the flow through the side branches. We applied the two models to study the WSS distribution in 6 coronary artery trees. Under steady flow conditions, the average WSS between the side branches differed significantly for the two models: the average WSS was 8% higher for Murray's law and the relative difference ranged from -5% to +27%. These differences scale with the difference in flow rate. Near the bifurcations, the differences in WSS were more pronounced: the size of the low WSS regions was significantly larger when applying the empirical model (13%), ranging from -12% to +68%. Predicting outflow based on Murray's law underestimates the flow through the side branches. Especially near side branches, the regions where atherosclerotic plaques preferentially develop, the differences are significant and application of Murray's law underestimates the size of the low WSS region.

  18. An automatic CFD-based flow diverter optimization principle for patient-specific intracranial aneurysms.

    Science.gov (United States)

    Janiga, Gábor; Daróczy, László; Berg, Philipp; Thévenin, Dominique; Skalej, Martin; Beuing, Oliver

    2015-11-01

    The optimal treatment of intracranial aneurysms using flow diverting devices is a fundamental issue for neuroradiologists as well as neurosurgeons. Due to highly irregular manifold aneurysm shapes and locations, the choice of the stent and the patient-specific deployment strategy can be a very difficult decision. To support the therapy planning, a new method is introduced that combines a three-dimensional CFD-based optimization with a realistic deployment of a virtual flow diverting stent for a given aneurysm. To demonstrate the feasibility of this method, it was applied to a patient-specific intracranial giant aneurysm that was successfully treated using a commercial flow diverter. Eight treatment scenarios with different local compressions were considered in a fully automated simulation loop. The impact on the corresponding blood flow behavior was evaluated qualitatively as well as quantitatively, and the optimal configuration for this specific case was identified. The virtual deployment of an uncompressed flow diverter reduced the inflow into the aneurysm by 24.4% compared to the untreated case. Depending on the positioning of the local stent compression below the ostium, blood flow reduction could vary between 27.3% and 33.4%. Therefore, a broad range of potential treatment outcomes was identified, illustrating the variability of a given flow diverter deployment in general. This method represents a proof of concept to automatically identify the optimal treatment for a patient in a virtual study under certain assumptions. Hence, it contributes to the improvement of virtual stenting for intracranial aneurysms and can support physicians during therapy planning in the future.

  19. SU-E-T-603: PBS Prostate Plan Robustness: A Tool for Patient Specific Setup Tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Tang, S; Song, L; Chen, C; Chang, C; Chon, B; Tsai, H; Soffen, E; Cahlon, O; Mah, D [Procure Proton Therapy Center, Somerset, NJ (United States)

    2015-06-15

    Purpose: Fiducial markers are commonly used for setup of prostate patients using orthogonal radiographs. After aligned with the markers, the displacement of the bony anatomy relative to the planned DRR can be up to 10 mm. Such offset can potentially have significant dosimetric effects because it changes the radiological path length of protons in differing amounts of bone. It is imperative to develop a method to evaluate its impact on target coverage and hence establish patient specific setup tolerance for prostate proton PBS treatment. Methods: Prostate patients were planned in RayStation according to the PCG protocol with bi-lateral beams. The primary planning objectives are: (1) 100% of CTV receives full prescription dose; (2) 98% of the prescription dose covers at least 98% of the PTV; (3) OARs meet criteria per protocol. For each patient 108 dose perturbations were automatically generated using an in-house script, which considered the isocenter shifting in S-I and A-P directions (up to ±15 mm with an interval of 6mm) as well as the range uncertainty (±3.5%). The target coverage was evaluated on the contour shifted along with prostate to mimic the daily treatment. Results: The minimum CTV coverage as a function of offsets in S-I and A-P directions is presented in a 2D contour map. The offsets along A-P direction generally have greater impact than along S-I direction. Both the CTV D98%>98% or CTV V98%>98% are achievable for most patients if the offset is <10 mm in either direction despite of range uncertainties. Conclusion: We developed a method to evaluate the plan robustness for proton PBS prostate treatment. It can provide patient specific setup tolerance of bony structure offset. For our current planning approach, a 1 cm displacement is acceptable. This approach can be generalized to other target structures that move relative to bony anatomy.

  20. Towards Effective and Efficient Patient-Specific Quality Assurance for Spot Scanning Proton Therapy

    Directory of Open Access Journals (Sweden)

    X. Ronald. Zhu

    2015-04-01

    Full Text Available An intensity-modulated proton therapy (IMPT patient-specific quality assurance (PSQA program based on measurement alone can be very time consuming due to the highly modulated dose distributions of IMPT fields. Incorporating independent dose calculation and treatment log file analysis could reduce the time required for measurements. In this article, we summarize our effort to develop an efficient and effective PSQA program that consists of three components: measurements, independent dose calculation, and analysis of patient-specific treatment delivery log files. Measurements included two-dimensional (2D measurements using an ionization chamber array detector for each field delivered at the planned gantry angles with the electronic medical record (EMR system in the QA mode and the accelerator control system (ACS in the treatment mode, and additional measurements at depths for each field with the ACS in physics mode and without the EMR system. Dose distributions for each field in a water phantom were calculated independently using a recently developed in-house pencil beam algorithm and compared with those obtained using the treatment planning system (TPS. The treatment log file for each field was analyzed in terms of deviations in delivered spot positions from their planned positions using various statistical methods. Using this improved PSQA program, we were able to verify the integrity of the data transfer from the TPS to the EMR to the ACS, the dose calculation of the TPS, and the treatment delivery, including the dose delivered and spot positions. On the basis of this experience, we estimate that the in-room measurement time required for each complex IMPT case (e.g., a patient receiving bilateral IMPT for head and neck cancer is less than 1 h using the improved PSQA program. Our experience demonstrates that it is possible to develop an efficient and effective PSQA program for IMPT with the equipment and resources available in the clinic.

  1. Dose reconstruction for real-time patient-specific dose estimation in CT

    Energy Technology Data Exchange (ETDEWEB)

    De Man, Bruno, E-mail: deman@ge.com; Yin, Zhye [Image Reconstruction Laboratory, GE Global Research, Niskayuna, New York 12309 (United States); Wu, Mingye [X-ray and CT Laboratory, GE Global Research, Shanghai 201203 (China); FitzGerald, Paul [Radiation Systems Laboratory, GE Global Research, Niskayuna, New York 12309 (United States); Kalra, Mannudeep [Divisions of Thoracic and Cardiac Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)

    2015-05-15

    Purpose: Many recent computed tomography (CT) dose reduction approaches belong to one of three categories: statistical reconstruction algorithms, efficient x-ray detectors, and optimized CT acquisition schemes with precise control over the x-ray distribution. The latter category could greatly benefit from fast and accurate methods for dose estimation, which would enable real-time patient-specific protocol optimization. Methods: The authors present a new method for volumetrically reconstructing absorbed dose on a per-voxel basis, directly from the actual CT images. The authors’ specific implementation combines a distance-driven pencil-beam approach to model the first-order x-ray interactions with a set of Gaussian convolution kernels to model the higher-order x-ray interactions. The authors performed a number of 3D simulation experiments comparing the proposed method to a Monte Carlo based ground truth. Results: The authors’ results indicate that the proposed approach offers a good trade-off between accuracy and computational efficiency. The images show a good qualitative correspondence to Monte Carlo estimates. Preliminary quantitative results show errors below 10%, except in bone regions, where the authors see a bigger model mismatch. The computational complexity is similar to that of a low-resolution filtered-backprojection algorithm. Conclusions: The authors present a method for analytic dose reconstruction in CT, similar to the techniques used in radiation therapy planning with megavoltage energies. Future work will include refinements of the proposed method to improve the accuracy as well as a more extensive validation study. The proposed method is not intended to replace methods that track individual x-ray photons, but the authors expect that it may prove useful in applications where real-time patient-specific dose estimation is required.

  2. The numerical analysis of non-Newtonian blood flow in human patient-specific left ventricle.

    Science.gov (United States)

    Doost, Siamak N; Zhong, Liang; Su, Boyang; Morsi, Yosry S

    2016-04-01

    Recently, various non-invasive tools such as the magnetic resonance image (MRI), ultrasound imaging (USI), computed tomography (CT), and the computational fluid dynamics (CFD) have been widely utilized to enhance our current understanding of the physiological parameters that affect the initiation and the progression of the cardiovascular diseases (CVDs) associated with heart failure (HF). In particular, the hemodynamics of left ventricle (LV) has attracted the attention of the researchers due to its significant role in the heart functionality. In this study, CFD owing its capability of predicting detailed flow field was adopted to model the blood flow in images-based patient-specific LV over cardiac cycle. In most published studies, the blood is modeled as Newtonian that is not entirely accurate as the blood viscosity varies with the shear rate in non-linear manner. In this paper, we studied the effect of Newtonian assumption on the degree of accuracy of intraventricular hemodynamics. In doing so, various non-Newtonian models and Newtonian model are used in the analysis of the intraventricular flow and the viscosity of the blood. Initially, we used the cardiac MRI images to reconstruct the time-resolved geometry of the patient-specific LV. After the unstructured mesh generation, the simulations were conducted in the CFD commercial solver FLUENT to analyze the intraventricular hemodynamic parameters. The findings indicate that the Newtonian assumption cannot adequately simulate the flow dynamic within the LV over the cardiac cycle, which can be attributed to the pulsatile and recirculation nature of the flow and the low blood shear rate.

  3. Are patient-specific joint and inertial parameters necessary for accurate inverse dynamics analyses of gait?

    Science.gov (United States)

    Reinbolt, Jeffrey A; Haftka, Raphael T; Chmielewski, Terese L; Fregly, Benjamin J

    2007-05-01

    Variations in joint parameter (JP) values (axis positions and orientations in body segments) and inertial parameter (IP) values (segment masses, mass centers, and moments of inertia) as well as kinematic noise alter the results of inverse dynamics analyses of gait. Three-dimensional linkage models with joint constraints have been proposed as one way to minimize the effects of noisy kinematic data. Such models can also be used to perform gait optimizations to predict post-treatment function given pre-treatment gait data. This study evaluates whether accurate patient-specific JP and IP values are needed in three-dimensional linkage models to produce accurate inverse dynamics results for gait. The study was performed in two stages. First, we used optimization analyses to evaluate whether patient-specific JP and IP values can be calibrated accurately from noisy kinematic data, and second, we used Monte Carlo analyses to evaluate how errors in JP and IP values affect inverse dynamics calculations. Both stages were performed using a dynamic, 27 degrees-of-freedom, full-body linkage model and synthetic (i.e., computer generated) gait data corresponding to a nominal experimental gait motion. In general, JP but not IP values could be found accurately from noisy kinematic data. Root-mean-square (RMS) errors were 3 degrees and 4 mm for JP values and 1 kg, 22 mm, and 74 500 kg * mm2 for IP values. Furthermore, errors in JP but not IP values had a significant effect on calculated lower-extremity inverse dynamics joint torques. The worst RMS torque error averaged 4% bodyweight * height (BW * H) due to JP variations but less than 0.25% (BW * H) due to IP variations. These results suggest that inverse dynamics analyses of gait utilizing linkage models with joint constraints should calibrate the model's JP values to obtain accurate joint torques.

  4. Patient-specific independent 3D GammaPlan quality assurance for Gamma Knife Perfexion radiosurgery.

    Science.gov (United States)

    Mamalui-Hunter, Maria; Yaddanapudi, Sridhar; Zhao, Tianyu; Mutic, Sasa; Low, Daniel A; Drzymala, Robert E

    2013-01-07

    One of the most important aspects of quality assurance (QA) in radiation therapy is redundancy of patient treatment dose calculation. This work is focused on the patient-specific time and 3D dose treatment plan verification for stereotactic radiosurgery using Leksell Gamma Knife Perfexion (LGK PFX). The virtual model of LGK PFX was developed in MATLAB, based on the physical dimensions provided by the manufacturer. The ring-specific linear attenuation coefficients (LAC) and output factors (OFs) reported by the manufacturer were replaced by the measurement-based collimator size-specific OFs and a single LAC = 0.0065 mm-1. Calculation depths for each LGK PFX shot were obtained by ray-tracing technique, and the dose calculation formalism was similar to the one used by GammaPlan treatment planning software versions 8 and 9. The architecture of the QA process was based on the in-house online database search of the LGK PFX database search for plan-specific information. A series of QA phantom plans was examined to verify geometric and dosimetric accuracy of the software. The accuracy of the QA process was further evaluated through evaluation of a series of patient plans. The shot time/focus point dose verification for each shot took less than 1 sec/shot with full 3D isodose verification taking about 30 sec/shot on a desktop PC. GammaPlan database access time took less than 0.05 sec. The geometric accuracy (location of the point of maximum dose) of the phantom and patient plan was dependent on the resolution of the original dose matrix and was of the order of 1 dose element. Dosimetric accuracy of the independently calculated phantom and patient point (focus) doses was within 3.5% from the GammaPlan, with the mean = 2.3% and SD= 1.1%. The process for independent pretreatment patient-specific Gamma Knife Perfexion time and dose verification was created and validated.

  5. AIDS.gov

    Science.gov (United States)

    ... concerns. Search Services Share This Help National HIV/AIDS Strategy Check out NHAS's latest progress in the ... from AIDS.gov Read more AIDS.gov tweets AIDS.gov HIV/AIDS Basics • Federal Resources • Using New ...

  6. Aids for Handicapped Readers.

    Science.gov (United States)

    Library of Congress, Washington, DC. Div. for the Blind and Physically Handicapped.

    The reference circular provides information on approximately 50 reading and writing aids intended for physically or visually handicapped individuals. Described are low vision aids, aids for holding a book or turning pages, aids for reading in bed, handwriting aids, typewriters and accessories, braille writing equipment, sound reproducers, and aids…

  7. Lung Carcinoid Tumor: Surgery

    Science.gov (United States)

    ... Disease Lung Carcinoid Tumor Treating Lung Carcinoid Tumors Surgery to Treat Lung Carcinoid Tumors Surgery is the ... be cured by surgery alone. Types of lung surgery Different operations can be used to treat (and ...

  8. Preparing for Surgery

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Preparing for Surgery Home For Patients Search FAQs Preparing for Surgery ... Surgery FAQ080, August 2011 PDF Format Preparing for Surgery Gynecologic Problems What is the difference between outpatient ...

  9. Pediatric heart surgery

    Science.gov (United States)

    Heart surgery - pediatric; Heart surgery for children; Acquired heart disease; Heart valve surgery - children ... outside the heart. Some heart defects may need surgery right after the baby is born. For others, ...

  10. Scoliosis surgery - child

    Science.gov (United States)

    Spinal curvature surgery - child; Kyphoscoliosis surgery - child; Video-assisted thoracoscopic surgery - child; VATS - child ... Before surgery, your child will receive general anesthesia. This will make your child unconscious and unable to feel pain ...

  11. What Is Refractive Surgery?

    Science.gov (United States)

    ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ...

  12. LASIK - Laser Eye Surgery

    Science.gov (United States)

    ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ...

  13. Corrective Jaw Surgery

    Science.gov (United States)

    ... out more. Cleft Lip/Palate and Craniofacial Surgery Cleft Lip/Palate and Craniofacial Surgery A cleft lip may ... out more. Cleft Lip/Palate and Craniofacial Surgery Cleft Lip/Palate and Craniofacial Surgery A cleft lip may ...

  14. Dental Implant Surgery

    Science.gov (United States)

    ... out more. Cleft Lip/Palate and Craniofacial Surgery Cleft Lip/Palate and Craniofacial Surgery A cleft lip may ... out more. Cleft Lip/Palate and Craniofacial Surgery Cleft Lip/Palate and Craniofacial Surgery A cleft lip may ...

  15. Facial Cosmetic Surgery

    Science.gov (United States)

    ... out more. Cleft Lip/Palate and Craniofacial Surgery Cleft Lip/Palate and Craniofacial Surgery A cleft lip may ... out more. Cleft Lip/Palate and Craniofacial Surgery Cleft Lip/Palate and Craniofacial Surgery A cleft lip may ...

  16. Macroeconomic Issues in Foreign Aid

    DEFF Research Database (Denmark)

    Hjertholm, Peter; Laursen, Jytte; White, Howard

    foreign aid, macroeconomics of aid, gap models, aid fungibility, fiscal response models, foreign debt,......foreign aid, macroeconomics of aid, gap models, aid fungibility, fiscal response models, foreign debt,...

  17. Impact of Radioimmunoguided Surgery.

    Science.gov (United States)

    La Valle, G J; Chevinsky, A; Martin, E W

    1991-01-01

    Radioimmunoguided surgery (RIGS) is a technique employed to locate tumor deposits with the aid of intravenously injected, tumor-specific, radiolabeled monoclonal antibodies and a small gamma detecting device. The gamma detecting probe (GDP) is a small, portable unit which has the capacity to be used intraoperatively to survey the entire peritoneal surface for increased radioactivity indicative of targeted tumor tissue during abdominal exploration for colorectal cancer. Trials in humans have demonstrated the ability of this system to locate clinically nonpalpable tumor deposits in patients undergoing carcinoembryonic antigen second-look laparotomies. This feature may be of value in improving the definition of tumor location and extent as well as allowing a more thorough resection of tumor-bearing tissue to be performed and hopefully improving overall patient survival.

  18. Emergency surgery

    DEFF Research Database (Denmark)

    Stoneham, M; Murray, D; Foss, N

    2014-01-01

    National reports recommended that peri-operative care should be improved for elderly patients undergoing emergency surgery. Postoperative mortality and morbidity rates remain high, and indicate that emergency ruptured aneurysm repair, laparotomy and hip fracture fixation are high-risk procedures...... undertaken on elderly patients with limited physiological reserve. National audits have reported variations in care quality, data that are increasingly being used to drive quality improvement through professional guidance. Given that the number of elderly patients presenting for emergency surgery is likely...... to rise as the population ages, this review summarises the evidence on which such guidance is based, and provides information about how anaesthetists might participate in audit and research aimed at improving local and national outcomes for these most vulnerable of patients....

  19. Linear Elastic Properties of the Facial Soft Tissues Using an Aspiration Device: Towards Patient Specific Characterization.

    OpenAIRE

    Luboz, Vincent; Promayon, Emmanuel; Payan, Yohan

    2014-01-01

    International audience; Biomechanical modeling of the facial soft tissue behavior is needed in aesthetic or maxillo-facial surgeries where the simulation of the bone displacements cannot accurately predict the visible outcome on the patient's face. Because these tissues have different nature and elastic properties across the face, depending on their thickness, and their content in fat or muscle, individualizing their mechanical parameters could increase the simulation accuracy. Using a specif...

  20. Crawling Aid

    Science.gov (United States)

    1982-01-01

    The Institute for the Achievement of Human Potential developed a device known as the Vehicle for Initial Crawling (VIC); the acronym is a tribute to the crawler's inventor, Hubert "Vic" Vykukal; is an effective crawling aid. The VIC is used by brain injured children who are unable to crawl due to the problems of weight-bearing and friction, caused by gravity. It is a rounded plywood frame large enough to support the child's torso, leaving arms and legs free to move. On its underside are three aluminum discs through which air is pumped to create an air-bearing surface that has less friction than a film of oil. Upper side contains the connection to the air supply and a pair of straps which restrain the child and cause the device to move with him. VIC is used with the intent to recreate the normal neurological connection between brain and muscles. Over repetitive use of the device the child develops his arm and leg muscles as well as coordination. Children are given alternating therapy, with and without the VIC until eventually the device is no longer needed.

  1. Patient-specific Monte Carlo dose calculations for 103Pd breast brachytherapy

    Science.gov (United States)

    Miksys, N.; Cygler, J. E.; Caudrelier, J. M.; Thomson, R. M.

    2016-04-01

    This work retrospectively investigates patient-specific Monte Carlo (MC) dose calculations for 103Pd permanent implant breast brachytherapy, exploring various necessary assumptions for deriving virtual patient models: post-implant CT image metallic artifact reduction (MAR), tissue assignment schemes (TAS), and elemental tissue compositions. Three MAR methods (thresholding, 3D median filter, virtual sinogram) are applied to CT images; resulting images are compared to each other and to uncorrected images. Virtual patient models are then derived by application of different TAS ranging from TG-186 basic recommendations (mixed adipose and gland tissue at uniform literature-derived density) to detailed schemes (segmented adipose and gland with CT-derived densities). For detailed schemes, alternate mass density segmentation thresholds between adipose and gland are considered. Several literature-derived elemental compositions for adipose, gland and skin are compared. MC models derived from uncorrected CT images can yield large errors in dose calculations especially when used with detailed TAS. Differences in MAR method result in large differences in local doses when variations in CT number cause differences in tissue assignment. Between different MAR models (same TAS), PTV {{D}90} and skin {{D}1~\\text{c{{\\text{m}}3}}} each vary by up to 6%. Basic TAS (mixed adipose/gland tissue) generally yield higher dose metrics than detailed segmented schemes: PTV {{D}90} and skin {{D}1~\\text{c{{\\text{m}}3}}} are higher by up to 13% and 9% respectively. Employing alternate adipose, gland and skin elemental compositions can cause variations in PTV {{D}90} of up to 11% and skin {{D}1~\\text{c{{\\text{m}}3}}} of up to 30%. Overall, AAPM TG-43 overestimates dose to the PTV ({{D}90} on average 10% and up to 27%) and underestimates dose to the skin ({{D}1~\\text{c{{\\text{m}}3}}} on average 29% and up to 48%) compared to the various MC models derived using the post-MAR CT images studied

  2. HIV and AIDS

    Science.gov (United States)

    ... Emergency Room? What Happens in the Operating Room? HIV and AIDS KidsHealth > For Kids > HIV and AIDS ... actually the virus that causes the disease AIDS. HIV Hurts the Immune System People who are HIV ...

  3. Heart attack first aid

    Science.gov (United States)

    First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... A heart attack occurs when the blood flow that carries oxygen to the heart is blocked. The heart muscle ...

  4. Breathing difficulties - first aid

    Science.gov (United States)

    Difficulty breathing - first aid; Dyspnea - first aid; Shortness of breath - first aid ... Breathing difficulty is almost always a medical emergency. An exception is feeling slightly winded from normal activity, ...

  5. Patient Specification Quality Assurance for Glioblastoma Multiforme Brain Tumors Treated with Intensity Modulated Radiation Therapy

    Directory of Open Access Journals (Sweden)

    H. I. Al-Mohammed

    2011-01-01

    Full Text Available The aim of this study was to evaluate the significance of performing patient specification quality assurance for patients diagnosed with glioblastoma multiforme treated with intensity modulated radiation therapy. The study evaluated ten intensity modulated radiation therapy treatment plans using 10 MV beams, a total dose of 60 Gy (2 Gy/fraction, five fractions a week for a total of six weeks treatment. For the quality assurance protocol we used a two-dimensional ionization-chamber array (2D-ARRAY. The results showed a very good agreement between the measured dose and the pretreatment planned dose. All the plans passed >95% gamma criterion with pixels within 5% dose difference and 3 mm distance to agreement. We concluded that using the 2D-ARRAY ion chamber for intensity modulated radiation therapy is an important step for intensity modulated radiation therapy treatment plans, and this study has shown that our treatment planning for intensity modulated radiation therapy is accurately done.

  6. Induced radioactivity in a patient-specific collimator used in proton therapy

    CERN Document Server

    Silari, M; Mauro, Egidio; Silari, Marco

    2010-01-01

    This paper discusses the activation of a patient-specific collimator, calculating dose rates, total activities and activities per unit mass of the mixture of radionuclides generated by proton irradiation in the energy range 100-250 MeV. Monte Carlo simulations were first performed for a generic case, using an approximate geometry and on the basis of assumptions on beam intensity and irradiation profile. A collimator used for a prostate cancer treatment was obtained from the MD Anderson Cancer Center (MDACC), Houston, USA, from which a number of samples were cut and analyzed by gamma spectrometry. The results of the gamma spectrometry are compared with the results of Monte Carlo simulations performed using geometrical and irradiation data specific to the unit. The assumptions made for the simulations and their impact on the results are discussed. Dose rate measurements performed in a low-background area at CERN and routine radiation protection measurements at the MDACC are also reported. It is shown that it sh...

  7. Cell reprogramming for the creation of patient-specific pluripotent stem cells by defined factors

    Institute of Scientific and Technical Information of China (English)

    Huiqun YIN; Heng WANG; Hongguo CAO; Yunhai ZHANG; Yong TAO; Xiaorong ZHANG

    2009-01-01

    Pluripotent stem cells (PSCs), characterized by being able to differentiate into various types of cells, are generally regarded as the most promising sources for cell replacement therapies. However, as typical PSCs, embryonic stem cells (ESCs) are still far away from human clinics so far due to ethical issues and immune rejection response. One way to avoid such problems is to use stem cells derived from autologous somatic cells. Up to date, PSCs could be obtained by reprogramming somatic cells to pluripotent state with approaches including somatic cell nuclear transfer (SCNT), fusion with stem cells, coculture with cells' extracts, and induction with defined factors. Among these, through reprogramming somatic cells directly by retroviral transduction of transcription factors, induced pluripotent stem (iPS) cells have been successfully generated in both mouse and human recently. These iPS cells shared similar morphology and growth properties to ESCs, could express ESCs marker genes, and could produce adult or germline-competent chimaeras and differentiate into a variety of cell types, including germ cells. Moreover, with iPS technique, patient specific PSCs could be derived more easily from handful somatic cells in human without immune rejection responses innately connected to ESCs. Consequently, generation of iPS cells would be of great help to further understand disease mechanisms, drug screening, and cell transplantation therapies as well.In summary,the recent progress in the study of cell reprogramming for the creation of patientspecific pluripotent stem cells, some existing problems, and research perspectives were suggested.

  8. Patient-specific modeling of individual sickle cell behavior under transient hypoxia

    Science.gov (United States)

    Li, Xuejin; Du, E.; Dao, Ming; Suresh, Subra; Karniadakis, George Em

    2017-01-01

    Sickle cell disease (SCD) is a highly complex genetic blood disorder in which red blood cells (RBC) exhibit heterogeneous morphology changes and decreased deformability. We employ a kinetic model for cell morphological sickling that invokes parameters derived from patient-specific data. This model is used to investigate the dynamics of individual sickle cells in a capillary-like microenvironment in order to address various mechanisms associated with SCD. We show that all RBCs, both hypoxia-unaffected and hypoxia-affected ones, regularly pass through microgates under oxygenated state. However, the hypoxia-affected cells undergo sickling which significantly alters cell dynamics. In particular, the dense and rigid sickle RBCs are obstructed thereby clogging blood flow while the less dense and deformable ones are capable of circumnavigating dead (trapped) cells ahead of them by choosing a serpentine path. Informed by recent experiments involving microfluidics that provide in vitro quantitative information on cell dynamics under transient hypoxia conditions, we have performed detailed computational simulations of alterations to cell behavior in response to morphological changes and membrane stiffening. Our model reveals that SCD exhibits substantial heterogeneity even within a particular density-fractionated subpopulation. These findings provide unique insights into how individual sickle cells move through capillaries under transient hypoxic conditions, and offer novel possibilities for designing effective therapeutic interventions for SCD. PMID:28288152

  9. Patient-specific dosimetry in peptide receptor radionuclide therapy: a clinical review.

    Science.gov (United States)

    Chalkia, M T; Stefanoyiannis, A P; Chatziioannou, S N; Round, W H; Efstathopoulos, E P; Nikiforidis, G C

    2015-03-01

    Neuroendocrine tumours (NETs) belong to a relatively rare class of neoplasms. Nonetheless, their prevalence has increased significantly during the last decades. Peptide receptor radionuclide therapy (PRRT) is a relatively new treatment approach for inoperable or metastasised NETs. The therapeutic effect is based on the binding of radiolabelled somatostatin analogue peptides with NETs' somatostatin receptors, resulting in internal irradiation of tumours. Pre-therapeutic patient-specific dosimetry is essential to ensure that a treatment course has high levels of safety and efficacy. This paper reviews the methods applied for PRRT dosimetry, as well as the dosimetric results presented in the literature. Focus is given on data concerning the therapeutic somatostatin analogue radiopeptides (111)In-[DTPA(0),D-Phe(1)]-octreotide ((111)In-DTPA-octreotide), (90)Y-[DOTA(0),Tyr(3)]-octreotide ((90)Y-DOTATOC) and (177)Lu-[DOTA(0),Tyr(3),Thr(8)]-octreotide ((177)Lu-DOTATATE). Following the Medical Internal Radiation Dose (MIRD) Committee formalism, dosimetric analysis demonstrates large interpatient variability in tumour and organ uptake, with kidneys and bone marrow being the critical organs. The results are dependent on the image acquisition and processing protocol, as well as the dosimetric imaging radiopharmaceutical.

  10. Modeling retinal degeneration using patient-specific induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Zi-Bing Jin

    Full Text Available Retinitis pigmentosa (RP is the most common inherited human eye disease resulting in night blindness and visual defects. It is well known that the disease is caused by rod photoreceptor degeneration; however, it remains incurable, due to the unavailability of disease-specific human photoreceptor cells for use in mechanistic studies and drug screening. We obtained fibroblast cells from five RP patients with distinct mutations in the RP1, RP9, PRPH2 or RHO gene, and generated patient-specific induced pluripotent stem (iPS cells by ectopic expression of four key reprogramming factors. We differentiated the iPS cells into rod photoreceptor cells, which had been lost in the patients, and found that they exhibited suitable immunocytochemical features and electrophysiological properties. Interestingly, the number of the patient-derived rod cells with distinct mutations decreased in vitro; cells derived from patients with a specific mutation expressed markers for oxidation or endoplasmic reticulum stress, and exhibited different responses to vitamin E than had been observed in clinical trials. Overall, patient-derived rod cells recapitulated the disease phenotype and expressed markers of cellular stresses. Our results demonstrate that the use of patient-derived iPS cells will help to elucidate the pathogenic mechanisms caused by genetic mutations in RP.

  11. Patient-specific analysis of blood stasis in the left atrium

    Science.gov (United States)

    Flores, Oscar; Gonzalo, Alejandro; Garcia-Villalba, Manuel; Rossini, Lorenzo; Hsiao, Albert; McVeigh, Elliot; Kahn, Andrew M.; Del Alamo, Juan C.

    2016-11-01

    Atrial fibrillation (AF) is a common arrhythmia in which the left atrium (LA) beats rapidly and irregularly. Patients with AF are at increased risk of thromboembolic events (TE), particularly stroke. Anticoagulant therapy can reduce the risk of TE in AF, but it can also increase the risks of adverse events such as internal bleeding. The current lack of tools to predict each patient's risk of LA thrombogenesis makes it difficult to decide whether to anticoagulate patients with AF. The aim of this work is to evaluate blood stasis in patient-specific models of the LA, because stasis is a known thrombogenesis risk factor. To achieve our aim, we performed direct numerical simulations of left atrial flow using an immersed boundary solver developed at the UC3M, coupled to a 0D model for the pulmonary circulation. The LA geometry is obtained from time-resolved CT scans and the parameters of the 0D model are found by fitting pulmonary vein flow data obtained by 4D phase contrast MRI. Blood stasis is evaluated from the flow data by computing blood residence time together with other kinematic indices of the velocity field (e.g. strain and kinetic energy). We focus on the flow in the left atrial appendage, including a sensitivity analysis of the effect of the parameters of the 0D model. Funded by the Spanish MECD, the Clinical and Translational Research Institute at UCSD and the American Heart Association.

  12. An automated workflow for patient-specific quality control of contour propagation.

    Science.gov (United States)

    Beasley, William J; McWilliam, Alan; Slevin, Nicholas J; Mackay, Ranald I; van Herk, Marcel

    2016-12-21

    Contour propagation is an essential component of adaptive radiotherapy, but current contour propagation algorithms are not yet sufficiently accurate to be used without manual supervision. Manual review of propagated contours is time-consuming, making routine implementation of real-time adaptive radiotherapy unrealistic. Automated methods of monitoring the performance of contour propagation algorithms are therefore required. We have developed an automated workflow for patient-specific quality control of contour propagation and validated it on a cohort of head and neck patients, on which parotids were outlined by two observers. Two types of error were simulated-mislabelling of contours and introducing noise in the scans before propagation. The ability of the workflow to correctly predict the occurrence of errors was tested, taking both sets of observer contours as ground truth, using receiver operator characteristic analysis. The area under the curve was 0.90 and 0.85 for the observers, indicating good ability to predict the occurrence of errors. This tool could potentially be used to identify propagated contours that are likely to be incorrect, acting as a flag for manual review of these contours. This would make contour propagation more efficient, facilitating the routine implementation of adaptive radiotherapy.

  13. Concise Review: Patient-Specific Stem Cells to Interrogate Inherited Eye Disease.

    Science.gov (United States)

    Giacalone, Joseph C; Wiley, Luke A; Burnight, Erin R; Songstad, Allison E; Mullins, Robert F; Stone, Edwin M; Tucker, Budd A

    2016-02-01

    Whether we are driving to work or spending time with loved ones, we depend on our sense of vision to interact with the world around us. Therefore, it is understandable why blindness for many is feared above death itself. Heritable diseases of the retina, such as glaucoma, age-related macular degeneration, and retinitis pigmentosa, are major causes of blindness worldwide. The recent success of gene augmentation trials for the treatment of RPE65-associated Leber congenital amaurosis has underscored the need for model systems that accurately recapitulate disease. With the advent of patient-specific induced pluripotent stem cells (iPSCs), researchers are now able to obtain disease-specific cell types that would otherwise be unavailable for molecular analysis. In the present review, we discuss how the iPSC technology is being used to confirm the pathogenesis of novel genetic variants, interrogate the pathophysiology of disease, and accelerate the development of patient-centered treatments. Significance: Stem cell technology has created the opportunity to advance treatments for multiple forms of blindness. Researchers are now able to use a person's cells to generate tissues found in the eye. This technology can be used to elucidate the genetic causes of disease and develop treatment strategies. In the present review, how stem cell technology is being used to interrogate the pathophysiology of eye disease and accelerate the development of patient-centered treatments is discussed.

  14. Surface mesh to voxel data registration for patient-specific anatomical modeling

    Science.gov (United States)

    de Oliveira, Júlia E. E.; Giessler, Paul; Keszei, András.; Herrler, Andreas; Deserno, Thomas M.

    2016-03-01

    Virtual Physiological Human (VPH) models are frequently used for training, planning, and performing medical procedures. The Regional Anaesthesia Simulator and Assistant (RASimAs) project has the goal of increasing the application and effectiveness of regional anesthesia (RA) by combining a simulator of ultrasound-guided and electrical nerve-stimulated RA procedures and a subject-specific assistance system through an integration of image processing, physiological models, subject-specific data, and virtual reality. Individualized models enrich the virtual training tools for learning and improving regional anaesthesia (RA) skills. Therefore, we suggest patient-specific VPH models that are composed by registering the general mesh-based models with patient voxel data-based recordings. Specifically, the pelvis region has been focused for the support of the femoral nerve block. The processing pipeline is composed of different freely available toolboxes such as MatLab, the open Simulation framework (SOFA), and MeshLab. The approach of Gilles is applied for mesh-to-voxel registration. Personalized VPH models include anatomical as well as mechanical properties of the tissues. Two commercial VPH models (Zygote and Anatomium) were used together with 34 MRI data sets. Results are presented for the skin surface and pelvic bones. Future work will extend the registration procedure to cope with all model tissue (i.e., skin, muscle, bone, vessel, nerve, fascia) in a one-step procedure and extrapolating the personalized models to body regions actually being out of the captured field of view.

  15. Patient specific quality control for Stereotactic Ablative Body Radiotherapy (SABR): it takes more than one phantom

    Science.gov (United States)

    Kron, T.; Ungureanu, E.; Antony, R.; Hardcastle, N.; Clements, N.; Ukath, J.; Fox, C.; Lonski, P.; Wanigaratne, D.; Haworth, A.

    2017-01-01

    Stereotactic Ablative Body Radiotherapy (SABR) is an extension of the concepts of Stereotactic Radiosurgery from intracranial procedures to extracranial targets. This brings with it new technological challenges for set-up of a SABR program and continuing quality assurance. Compared with intracranial procedures SABR requires consideration of motion and inhomogeneities and has to deal with a much larger variety of targets ranging from lung to liver, kidney and bone. To meet many of the challenges virtually all advances in modern radiotherapy, such as Intensity Modulated and Image Guided Radiation Therapy (IMRT and IGRT) are used. Considering the few fractions and high doses per fraction delivered to complex targets it is not surprising that patient specific quality control is considered essential for safe delivery. Given the variety of targets and clinical scenarios we employ different strategies for different patients to ensure that the most important aspects of the treatment are appropriately tested, be it steep dose gradients, inhomogeneities or the delivery of dose in the presence of motion. The current paper reviews the different approaches and phantoms utilised at Peter MacCallum Cancer Centre for SABR QA.

  16. Complexity metric as a complement to measurement based IMRT/VMAT patient-specific QA

    Science.gov (United States)

    Götstedt, J.; Karlsson Hauer, A.; Bäck, A.

    2015-01-01

    IMRT/VMAT treatment plans contain treatment fields with MLC openings of various size and shape. Clinical dose calculation algorithms show limitations in calculating the correct dose in small and irregular parts of a MLC opening which leads to differences between the planned and delivered dose distributions. The patient-specific IMRT QA is often designed to compare planned and measured dose distributions and is therefore heavily dependent on the measurement equipment and the evaluation method. The purpose of this study is to develop a complexity metric based on shape and size of MLC openings that correlates to the dose differences between planned and delivered 3D dose distributions. Different MLC openings are measured and evaluated and used to determine a penalty function to steer the complexity metric and make the complexity scores correlate to dose difference pass rates. Results of this initial study show that a correlation was found between complexity scores and dose difference pass rates for static fields with varied complexity. Preliminary results also show that the complexity metric can distinguish clinical IMRT fields with higher complexity.

  17. Commissioning and validation of COMPASS system for VMAT patient specific quality assurance

    Science.gov (United States)

    Pimthong, J.; Kakanaporn, C.; Tuntipumiamorn, L.; Laojunun, P.; Iampongpaiboon, P.

    2016-03-01

    Pre-treatment patient specific quality assurance (QA) of advanced treatment techniques such as volumetric modulated arc therapy (VMAT) is one of important QA in radiotherapy. The fast and reliable dosimetric device is required. The objective of this study is to commission and validate the performance of COMPASS system for dose verification of VMAT technique. The COMPASS system is composed of an array of ionization detectors (MatriXX) mounted to the gantry using a custom holder and software for the analysis and visualization of QA results. We validated the COMPASS software for basic and advanced clinical application. For the basic clinical study, the simple open field in various field sizes were validated in homogeneous phantom. And the advanced clinical application, the fifteen prostate and fifteen nasopharyngeal cancers VMAT plans were chosen to study. The treatment plans were measured by the MatriXX. The doses and dose-volume histograms (DVHs) reconstructed from the fluence measurements were compared to the TPS calculated plans. And also, the doses and DVHs computed using collapsed cone convolution (CCC) Algorithm were compared with Eclipse TPS calculated plans using Analytical Anisotropic Algorithm (AAA) that according to dose specified in ICRU 83 for PTV.

  18. Fluid-Structure Simulations of a Ruptured Intracranial Aneurysm: Constant versus Patient-Specific Wall Thickness.

    Science.gov (United States)

    Voß, S; Glaßer, S; Hoffmann, T; Beuing, O; Weigand, S; Jachau, K; Preim, B; Thévenin, D; Janiga, G; Berg, P

    2016-01-01

    Computational Fluid Dynamics is intensively used to deepen the understanding of aneurysm growth and rupture in order to support physicians during therapy planning. However, numerous studies considering only the hemodynamics within the vessel lumen found no satisfactory criteria for rupture risk assessment. To improve available simulation models, the rigid vessel wall assumption has been discarded in this work and patient-specific wall thickness is considered within the simulation. For this purpose, a ruptured intracranial aneurysm was prepared ex vivo, followed by the acquisition of local wall thickness using μCT. The segmented inner and outer vessel surfaces served as solid domain for the fluid-structure interaction (FSI) simulation. To compare wall stress distributions within the aneurysm wall and at the rupture site, FSI computations are repeated in a virtual model using a constant wall thickness approach. Although the wall stresses obtained by the two approaches-when averaged over the complete aneurysm sac-are in very good agreement, strong differences occur in their distribution. Accounting for the real wall thickness distribution, the rupture site exhibits much higher stress values compared to the configuration with constant wall thickness. The study reveals the importance of geometry reconstruction and accurate description of wall thickness in FSI simulations.

  19. PATIENT-SPECIFIC BLOOD DYNAMIC SIMULATIONS IN ASSESSING ENDOVASCULAR OCCLUSION OF INTRACRANIAL ANEURYSMS

    Institute of Scientific and Technical Information of China (English)

    CHEN Jia-liang; WANG Sheng-zhang; DING Guang-hong; YANG Xin-jian; LI Hai-yun

    2009-01-01

    According to recent studies, there are various potential predictors for surgical outcome for cerebral aneurysms. An accurate surgical outcome assessment would help make better-informed decisions and avoid the risk of rebleeding. It is well known that hemodynamic factors play an important role in the pathogenesis and treatment of intracranial aneurysms. In this article, a computational fluid dynamic analysis is applied to one patient-specific model of the cerebral aneurysm located at the tip of basilar artery, by which the differences of hemodynamic parameters before and after endovascular treatment may be evaluated. Based on the model, we show that the flow behavior near the neck of the aneurysm sees great differences after endovascular treatment as compared with that before treatment, which also affects the wall shear stress and the displacement distribution. In addition, our whole simulation process is based on a series of CFD commercial software packages, which are easily available for doctors to implement such a method in their daily practice. These results would be used to assess the outcome of endovascular treatment for the aneurysm occlusion.

  20. Patient-specific structural effects on hemodynamics in the ischemic lower limb artery

    Science.gov (United States)

    Xu, Pengcheng; Liu, Xin; Song, Qi; Chen, Guishan; Wang, Defeng; Zhang, Heye; Yan, Li; Liu, Dan; Huang, Wenhua

    2016-12-01

    Lower limb peripheral artery disease is a prevalent chronic non-communicable disease without obvious symptoms. However, the effect of ischemic lower limb peripheral arteries on hemodynamics remains unclear. In this study, we investigated the variation of the hemodynamics caused by patient-specific structural artery characteristics. Computational fluid dynamic simulations were performed on seven lower limb (including superficial femoral, deep femoral and popliteal) artery models that were reconstructed from magnetic resonance imaging. We found that increased wall shear stress (WSS) was mainly caused by the increasing severity of stenosis, bending, and branching. Our results showed that the increase in the WSS value at a stenosis at the bifurcation was 2.7 Pa. In contrast, the isolated stenosis and branch caused a WSS increase of 0.7 Pa and 0.5 Pa, respectively. The WSS in the narrow popliteal artery was more sensitive to a reduction in radius. Our results also demonstrate that the distribution of the velocity and pressure gradient are highly structurally related. At last, Ultrasound Doppler velocimeter measured result was presented as a validation. In conclusion, the distribution of hemodynamics may serve as a supplement for clinical decision-making to prevent the occurrence of a morbid or mortal ischemic event.

  1. An automated workflow for patient-specific quality control of contour propagation

    Science.gov (United States)

    Beasley, William J.; McWilliam, Alan; Slevin, Nicholas J.; Mackay, Ranald I.; van Herk, Marcel

    2016-12-01

    Contour propagation is an essential component of adaptive radiotherapy, but current contour propagation algorithms are not yet sufficiently accurate to be used without manual supervision. Manual review of propagated contours is time-consuming, making routine implementation of real-time adaptive radiotherapy unrealistic. Automated methods of monitoring the performance of contour propagation algorithms are therefore required. We have developed an automated workflow for patient-specific quality control of contour propagation and validated it on a cohort of head and neck patients, on which parotids were outlined by two observers. Two types of error were simulated—mislabelling of contours and introducing noise in the scans before propagation. The ability of the workflow to correctly predict the occurrence of errors was tested, taking both sets of observer contours as ground truth, using receiver operator characteristic analysis. The area under the curve was 0.90 and 0.85 for the observers, indicating good ability to predict the occurrence of errors. This tool could potentially be used to identify propagated contours that are likely to be incorrect, acting as a flag for manual review of these contours. This would make contour propagation more efficient, facilitating the routine implementation of adaptive radiotherapy.

  2. Reconstruction with a patient-specific titanium implant after a wide anterior chest wall resection

    Science.gov (United States)

    Turna, Akif; Kavakli, Kuthan; Sapmaz, Ersin; Arslan, Hakan; Caylak, Hasan; Gokce, Hasan Suat; Demirkaya, Ahmet

    2014-01-01

    The reconstruction of full-thickness chest wall defects is a challenging problem for thoracic surgeons, particularly after a wide resection of the chest wall that includes the sternum. The location and the size of the defect play a major role when selecting the method of reconstruction, while acceptable cosmetic and functional results remain the primary goal. Improvements in preoperative imaging techniques and reconstruction materials have an important role when planning and performing a wide chest wall resection with a low morbidity rate. In this report, we describe the reconstruction of a wide anterior chest wall defect with a patient-specific custom-made titanium implant. An infected mammary tumour recurrence in a 62-year old female, located at the anterior chest wall including the sternum, was resected, followed by a large custom-made titanium implant. Latissimus dorsi flap and split-thickness graft were also used for covering the implant successfully. A titanium custom-made chest wall implant could be a viable alternative for patients who had large chest wall tumours. PMID:24227881

  3. Validation of a population of patient-specific adult acquired flatfoot deformity models.

    Science.gov (United States)

    Spratley, E Meade; Matheis, Erika A; Hayes, Curtis W; Adelaar, Robert S; Wayne, Jennifer S

    2013-12-01

    Adult acquired flatfoot deformity (AAFD) is a degenerative disease resulting in malalignment of the mid- and hindfoot secondary to posterior tibial tendon dysfunction and increasing implication of ligament pathologies. Despite the complex 3D nature of AAFD, 2D radiographs are still employed to diagnose and stage the disease. Computer modeling techniques allow for accurate 3D recreations of musculoskeletal systems for the investigation of biomechanical factors contributing to disease. Following Institutional Review Board approval, the lower limbs of six diagnosed AAFD sufferers were imaged with MRI, photographs, and X-ray. Next, a radiologist graded the MRI attenuation of eight soft-tissues implicated in AAFD. Six patient-specific rigid-body models were then created and loaded according to patient weight, graded soft-tissues, and extrinsic muscles. Model function was validated using clinically relevant kinematic measures in three planes. Agreement varied depending on the measure, with average absolute deviations of < 7° for angles and <4 mm for distances. Additionally, the clinically favored AP talonavicular coverage angle, ML talo-1st metatarsal angle, and ML 1st cuneiform height showed strong correlations of R(2) = 0.63, 0.75, and 0.85, respectively. Thus, computer modeling offers a promising methodology for the non-invasive investigation of in vivo kinematic behavior in pathologic feet and, once validated, may further be used to investigate biomechanical parameters that are difficult to measure clinically.

  4. Effects of Degree of Surgical Correction for Flatfoot Deformity in Patient-Specific Computational Models.

    Science.gov (United States)

    Spratley, E M; Matheis, E A; Hayes, C W; Adelaar, R S; Wayne, J S

    2015-08-01

    A cohort of adult acquired flatfoot deformity rigid-body models was developed to investigate the effects of isolated tendon transfer with successive levels of medializing calcaneal osteotomy (MCO). Following IRB approval, six diagnosed flatfoot sufferers were subjected to magnetic resonance imaging (MRI) and their scans used to derive patient-specific models. Single-leg stance was modeled, constrained solely through physiologic joint contact, passive soft-tissue tension, extrinsic muscle force, body weight, and without assumptions of idealized mechanical joints. Surgical effect was quantified using simulated mediolateral (ML) and anteroposterior (AP) X-rays, pedobarography, soft-tissue strains, and joint contact force. Radiographic changes varied across states with the largest average improvements for the tendon transfer (TT) + 10 mm MCO state evidenced through ML and AP talo-1st metatarsal angles. Interestingly, 12 of 14 measures showed increased deformity following TT-only, though all increases disappeared with inclusion of MCO. Plantar force distributions showed medial forefoot offloading concomitant with increases laterally such that the most corrected state had 9.0% greater lateral load. Predicted alterations in spring, deltoid, and plantar fascia soft-tissue strain agreed with prior cadaveric and computational works suggesting decreased strain medially with successive surgical repair. Finally, joint contact force demonstrated consistent medial offloading concomitant with variable increases laterally. Rigid-body modeling thus offers novel advantages for the investigation of foot/ankle biomechanics not easily measured in vivo.

  5. Fast Monte Carlo Simulation for Patient-specific CT/CBCT Imaging Dose Calculation

    CERN Document Server

    Jia, Xun; Gu, Xuejun; Jiang, Steve B

    2011-01-01

    Recently, X-ray imaging dose from computed tomography (CT) or cone beam CT (CBCT) scans has become a serious concern. Patient-specific imaging dose calculation has been proposed for the purpose of dose management. While Monte Carlo (MC) dose calculation can be quite accurate for this purpose, it suffers from low computational efficiency. In response to this problem, we have successfully developed a MC dose calculation package, gCTD, on GPU architecture under the NVIDIA CUDA platform for fast and accurate estimation of the x-ray imaging dose received by a patient during a CT or CBCT scan. Techniques have been developed particularly for the GPU architecture to achieve high computational efficiency. Dose calculations using CBCT scanning geometry in a homogeneous water phantom and a heterogeneous Zubal head phantom have shown good agreement between gCTD and EGSnrc, indicating the accuracy of our code. In terms of improved efficiency, it is found that gCTD attains a speed-up of ~400 times in the homogeneous water ...

  6. Experimental unsteady flow study in a patient-specific abdominal aortic aneurysm model

    Science.gov (United States)

    Stamatopoulos, Ch.; Mathioulakis, D. S.; Papaharilaou, Y.; Katsamouris, A.

    2011-06-01

    The velocity field in a patient-specific abdominal aneurysm model including the aorto-iliac bifurcation was measured by 2D PIV. Phase-averaged velocities obtained in 14 planes reveal details of the flow evolution during a cycle. The aneurysm expanding asymmetrically toward the anterior side of the aorta causes the generation of a vortex at its entrance, covering the entire aneurysm bulge progressively before flow peak. The fluid entering the aneurysm impinges on the left side of its distal end, following the axis of the upstream aorta segment, causing an increased flow rate in the left (compared to the right) common iliac artery. High shear stresses appear at the aneurysm inlet and outlet as well as along the posterior wall, varying proportionally to the flow rate. At the same regions, elevated flow disturbances are observed, being intensified at flow peak and during the deceleration phase. Low shear stresses are present in the recirculation region, being two orders of magnitude smaller than the previous ones. At flow peak and during the deceleration phase, a clockwise swirling motion (viewed from the inlet) is present in the aneurysm due to the out of plane curvature of the aorta.

  7. Flow topology in patient-specific abdominal aortic aneurysms during rest and exercise

    Science.gov (United States)

    Arzani, Amirhossein; Shadden, Shawn

    2012-11-01

    Abdominal aortic aneurysm (AAA) is a permanent, localized widening of the abdominal aorta. Flow in AAA is dominated by recirculation, transitional turbulence and low wall shear stress. Image-based CFD has recently enabled high resolution flow data in patient-specific AAA. This study aims to characterize transport in different AAAs, and understand flow topology changes from rest to exercise, which has been a hypothesized therapy due to potential acute changes in flow. Velocity data in 6 patients with different AAA morphology were obtained using image-based CFD under rest and exercise conditions. Finite-time Lyapunov exponent (FTLE) fields were computed from integration of the velocity data to identify dominant Lagrangian coherent structures. The flow topology was compared between rest and exercise conditions. For all patients, the systolic inflow jet resulted in coherent vortex formation. The evolution of this vortex varied greatly between patients and was a major determinant of transport inside the AAA during diastole. During exercise, previously observed stagnant regions were either replaced with undisturbed flow, regions of uniform high mixing, or persisted relatively unchanged. A mix norm measure provided a quantitative assessment of mixing. This work was supported by the National Institutes of Health, grant number 5R21HL108272.

  8. Effect of exercise on patient specific abdominal aortic aneurysm flow topology and mixing.

    Science.gov (United States)

    Arzani, Amirhossein; Les, Andrea S; Dalman, Ronald L; Shadden, Shawn C

    2014-02-01

    Computational fluid dynamics modeling was used to investigate changes in blood transport topology between rest and exercise conditions in five patient-specific abdominal aortic aneurysm models. MRI was used to provide the vascular anatomy and necessary boundary conditions for simulating blood velocity and pressure fields inside each model. Finite-time Lyapunov exponent fields and associated Lagrangian coherent structures were computed from blood velocity data and were used to compare features of the transport topology between rest and exercise both mechanistically and qualitatively. A mix-norm and mix-variance measure based on fresh blood distribution throughout the aneurysm over time were implemented to quantitatively compare mixing between rest and exercise. Exercise conditions resulted in higher and more uniform mixing and reduced the overall residence time in all aneurysms. Separated regions of recirculating flow were commonly observed in rest, and these regions were either reduced or removed by attached and unidirectional flow during exercise, or replaced with regional chaotic and transiently turbulent mixing, or persisted and even extended during exercise. The main factor that dictated the change in flow topology from rest to exercise was the behavior of the jet of blood penetrating into the aneurysm during systole.

  9. [Impact of digital technology on clinical practices: perspectives from surgery].

    Science.gov (United States)

    Zhang, Y; Liu, X J

    2016-04-09

    Digital medical technologies or computer aided medical procedures, refer to imaging, 3D reconstruction, virtual design, 3D printing, navigation guided surgery and robotic assisted surgery techniques. These techniques are integrated into conventional surgical procedures to create new clinical protocols that are known as "digital surgical techniques". Conventional health care is characterized by subjective experiences, while digital medical technologies bring quantifiable information, transferable data, repeatable methods and predictable outcomes into clinical practices. Being integrated into clinical practice, digital techniques facilitate surgical care by improving outcomes and reducing risks. Digital techniques are becoming increasingly popular in trauma surgery, orthopedics, neurosurgery, plastic and reconstructive surgery, imaging and anatomic sciences. Robotic assisted surgery is also evolving and being applied in general surgery, cardiovascular surgery and orthopedic surgery. Rapid development of digital medical technologies is changing healthcare and clinical practices. It is therefore important for all clinicians to purposefully adapt to these technologies and improve their clinical outcomes.

  10. Trends in biomedical engineering: focus on Patient Specific Modeling and Life Support Systems.

    Science.gov (United States)

    Dubini, Gabriele; Ambrosi, Davide; Bagnoli, Paola; Boschetti, Federica; Caiani, Enrico G; Chiastra, Claudio; Conti, Carlo A; Corsini, Chiara; Costantino, Maria Laura; D'Angelo, Carlo; Formaggia, Luca; Fumero, Roberto; Gastaldi, Dario; Migliavacca, Francesco; Morlacchi, Stefano; Nobile, Fabio; Pennati, Giancarlo; Petrini, Lorenza; Quarteroni, Alfio; Redaelli, Alberto; Stevanella, Marco; Veneziani, Alessandro; Vergara, Christian; Votta, Emiliano; Wu, Wei; Zunino, Paolo

    2011-01-01

    Over the last twenty years major advancements have taken place in the design of medical devices and personalized therapies. They have paralleled the impressive evolution of three-dimensional, non invasive, medical imaging techniques and have been continuously fuelled by increasing computing power and the emergence of novel and sophisticated software tools. This paper aims to showcase a number of major contributions to the advancements of modeling of surgical and interventional procedures and to the design of life support systems. The selected examples will span from pediatric cardiac surgery procedures to valve and ventricle repair techniques, from stent design and endovascular procedures to life support systems and innovative ventilation techniques.

  11. Patient-specific simulation of stent-graft deployment within an abdominal aortic aneurysm

    CERN Document Server

    Perrin, David; Avril, Stéphane; Albertini, Jean-Noël; Orgéas, Laurent; Geindreau, Christian; Dumenil, Aurélien; Goksu, Cemil

    2014-01-01

    In this study, finite element analysis is used to simulate the surgical deployment procedure of a bifurcated stent-graft on a real patient's arterial geometry. The stent-graft is modeled using realistic constitutive properties for both the stent and most importantly for the graft. The arterial geometry is obtained from pre-operative imaging exam. The obtained results are in good agreement with the post-operative imaging data. As the whole computational time was reduced to less than 2 hours, this study constitutes an essential step towards predictive planning simulations of aneurysmal endovascular surgery

  12. SU-E-T-149: Brachytherapy Patient Specific Quality Assurance for a HDR Vaginal Cylinder Case

    Energy Technology Data Exchange (ETDEWEB)

    Barbiere, J; Napoli, J; Ndlovu, A [Hackensack Univ Medical Center, Hackensack, NJ (United States)

    2015-06-15

    Purpose: Commonly Ir-192 HDR treatment planning system commissioning is only based on a single absolute measurement of source activity supplemented by tabulated parameters for multiple factors without independent verification that the planned distribution corresponds to the actual delivered dose. The purpose on this work is to present a methodology using Gafchromic film with a statistically valid calibration curve that can be used to validate clinical HDR vaginal cylinder cases by comparing the calculated plan dose distribution in a plane with the corresponding measured planar dose. Methods: A vaginal cylinder plan was created with Oncentra treatment planning system. The 3D dose matrix was exported to a Varian Eclipse work station for convenient extraction of a 2D coronal dose plane corresponding to the film position. The plan was delivered with a sheet of Gafchromic EBT3 film positioned 1mm from the catheter using an Ir-192 Nucletron HDR source. The film was then digitized with an Epson 10000 XL color scanner. Film analysis is performed with MatLab imaging toolbox. A density to dose calibration curve was created using TG43 formalism for a single dwell position exposure at over 100 points for statistical accuracy. The plan and measured film dose planes were registered using a known dwell position relative to four film marks. The plan delivered 500 cGy to points 2 cm from the sources. Results: The distance to agreement of the 500 cGy isodose between the plan and film measurement laterally was 0.5 mm but can be as much as 1.5 mm superior and inferior. The difference between the computed plan dose and film measurement was calculated per pixel. The greatest errors up to 50 cGy are near the apex. Conclusion: The methodology presented will be useful to implement more comprehensive quality assurance to verify patient-specific dose distributions.

  13. A retrospective analysis for patient-specific quality assurance of volumetric-modulated arc therapy plans

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guangjun [Radiation Physics Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China); Wu, Kui [Department of Radiotherapy, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province (China); Peng, Guang; Zhang, Yingjie [Radiation Physics Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China); Bai, Sen, E-mail: baisen@scu.edu.cn [Radiation Physics Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China)

    2014-01-01

    Volumetric-modulated arc therapy (VMAT) is now widely used clinically, as it is capable of delivering a highly conformal dose distribution in a short time interval. We retrospectively analyzed patient-specific quality assurance (QA) of VMAT and examined the relationships between the planning parameters and the QA results. A total of 118 clinical VMAT cases underwent pretreatment QA. All plans had 3-dimensional diode array measurements, and 69 also had ion chamber measurements. Dose distribution and isocenter point dose were evaluated by comparing the measurements and the treatment planning system (TPS) calculations. In addition, the relationship between QA results and several planning parameters, such as dose level, control points (CPs), monitor units (MUs), average field width, and average leaf travel, were also analyzed. For delivered dose distribution, a gamma analysis passing rate greater than 90% was obtained for all plans and greater than 95% for 100 of 118 plans with the 3%/3-mm criteria. The difference (mean ± standard deviation) between the point doses measured by the ion chamber and those calculated by TPS was 0.9% ± 2.0% for all plans. For all cancer sites, nasopharyngeal carcinoma and gastric cancer have the lowest and highest average passing rates, respectively. From multivariate linear regression analysis, the dose level (p = 0.001) and the average leaf travel (p < 0.001) showed negative correlations with the passing rate, and the average field width (p = 0.003) showed a positive correlation with the passing rate, all indicating a correlation between the passing rate and the plan complexity. No statistically significant correlation was found between MU or CP and the passing rate. Analysis of the results of dosimetric pretreatment measurements as a function of VMAT plan parameters can provide important information to guide the plan parameter setting and optimization in TPS.

  14. Nanomedicine-Based Neuroprotective Strategies in Patient Specific-iPSC and Personalized Medicine

    Directory of Open Access Journals (Sweden)

    Shih-Fan Jang

    2014-03-01

    -based neuroprotective manipulations in patient specific-iPSCs and personalized medicine.

  15. Patient-specific FDG dosimetry for adult males, adult females, and very low birth weight infants

    Science.gov (United States)

    Niven, Erin

    Fluorodeoxyglucose is the most commonly used radiopharmaceutical in Positron Emission Tomography, with applications in neurology, cardiology, and oncology. Despite its routine use worldwide, the radiation absorbed dose estimates from FDG have been based primarily on data obtained from two dogs studied in 1977 and 11 adults (most likely males) studied in 1982. In addition, the dose estimates calculated for FDG have been centered on the adult male, with little or no mention of variations in the dose estimates due to sex, age, height, weight, nationality, diet, or pathological condition. Through an extensive investigation into the Medical Internal Radiation Dose schema for calculating absorbed doses, I have developed a simple patient-specific equation; this equation incorporates the parameters necessary for alterations to the mathematical values of the human model to produce an estimate more representative of the individual under consideration. I have used this method to determine the range of absorbed doses to FDG from the collection of a large quantity of biological data obtained in adult males, adult females, and very low birth weight infants. Therefore, a more accurate quantification of the dose to humans from FDG has been completed. My results show that per unit administered activity, the absorbed dose from FDG is higher for infants compared to adults, and the dose for adult women is higher than for adult men. Given an injected activity of approximately 3.7 MBq kg-1, the doses for adult men, adult women, and full-term newborns would be on the order of 5.5, 7.1, and 2.8 mSv, respectively. These absorbed doses are comparable to the doses received from other nuclear medicine procedures.

  16. Nanomedicine-based neuroprotective strategies in patient specific-iPSC and personalized medicine.

    Science.gov (United States)

    Jang, Shih-Fan; Liu, Wei-Hsiu; Song, Wen-Shin; Chiang, Kuan-Lin; Ma, Hsin-I; Kao, Chung-Lan; Chen, Ming-Teh

    2014-03-04

    manipulations in patient specific-iPSCs and personalized medicine.

  17. On the use of biomathematical models in patient-specific IMRT dose QA

    Energy Technology Data Exchange (ETDEWEB)

    Zhen Heming [UT Southwestern Medical Center, Dallas, Texas 75390 (United States); Nelms, Benjamin E. [Canis Lupus LLC, Merrimac, Wisconsin 53561 (United States); Tome, Wolfgang A. [Department of Radiation Oncology, Division of Medical Physics, Montefiore Medical Center and Institute of Onco-Physics, Albert Einstein College of Medicine, Bronx, New York 10461 (United States)

    2013-07-15

    Purpose: To investigate the use of biomathematical models such as tumor control probability (TCP) and normal tissue complication probability (NTCP) as new quality assurance (QA) metrics.Methods: Five different types of error (MLC transmission, MLC penumbra, MLC tongue and groove, machine output, and MLC position) were intentionally induced to 40 clinical intensity modulated radiation therapy (IMRT) patient plans (20 H and N cases and 20 prostate cases) to simulate both treatment planning system errors and machine delivery errors in the IMRT QA process. The changes in TCP and NTCP for eight different anatomic structures (H and N: CTV, GTV, both parotids, spinal cord, larynx; prostate: CTV, rectal wall) were calculated as the new QA metrics to quantify the clinical impact on patients. The correlation between the change in TCP/NTCP and the change in selected DVH values was also evaluated. The relation between TCP/NTCP change and the characteristics of the TCP/NTCP curves is discussed.Results:{Delta}TCP and {Delta}NTCP were summarized for each type of induced error and each structure. The changes/degradations in TCP and NTCP caused by the errors vary widely depending on dose patterns unique to each plan, and are good indicators of each plan's 'robustness' to that type of error.Conclusions: In this in silico QA study the authors have demonstrated the possibility of using biomathematical models not only as patient-specific QA metrics but also as objective indicators that quantify, pretreatment, a plan's robustness with respect to possible error types.

  18. Efficient generation of lens progenitor cells from cataract patient-specific induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Xiaodi Qiu

    Full Text Available The development of a technique to induce the transformation of somatic cells to a pluripotent state via the ectopic expression of defined transcription factors was a transformational event in the field of regenerative medicine. The development of this technique also impacted ophthalmology, as patient-specific induced pluripotent stemcells (iPSCs may be useful resources for some ophthalmological diseases. The lens is a key refractive element in the eye that focuses images of the visual world onto the retina. To establish a new model for drug screening to treat lens diseases and investigating lens aging and development, we examined whether human lens epithelial cells (HLECs could be induced into iPSCs and if lens-specific differentiation of these cells could be achieved under defined chemical conditions. We first efficiently reprogrammed HLECs from age-related cataract patients to iPSCs with OCT-4, SOX-2, and KLF-4. The resulting HLEC-derived iPS (HLE-iPS colonies were indistinguishable from human ES cells with respect to morphology, gene expression, pluripotent marker expression and their ability to generate all embryonic germ-cell layers. Next, we performed a 3-step induction procedure: HLE-iPS cells were differentiated into large numbers of lens progenitor-like cells with defined factors (Noggin, BMP and FGF2, and we determined that these cells expressed lens-specific markers (PAX6, SOX2, SIX3, CRYAB, CRYAA, BFSP1, and MIP. In addition, HLE-iPS-derived lens cells exhibited reduced expression of epithelial mesenchymal transition (EMT markers compared with human embryonic stem cells (hESCs and fibroblast-derived iPSCs. Our study describes a highly efficient procedure for generating lens progenitor cells from cataract patient HLEC-derived iPSCs. These patient-derived pluripotent cells provide a valuable model for studying the developmental and molecular biological mechanisms that underlie cell determination in lens development and cataract

  19. Statistical process control analysis for patient-specific IMRT and VMAT QA.

    Science.gov (United States)

    Sanghangthum, Taweap; Suriyapee, Sivalee; Srisatit, Somyot; Pawlicki, Todd

    2013-05-01

    This work applied statistical process control to establish the control limits of the % gamma pass of patient-specific intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) quality assurance (QA), and to evaluate the efficiency of the QA process by using the process capability index (Cpml). A total of 278 IMRT QA plans in nasopharyngeal carcinoma were measured with MapCHECK, while 159 VMAT QA plans were undertaken with ArcCHECK. Six megavolts with nine fields were used for the IMRT plan and 2.5 arcs were used to generate the VMAT plans. The gamma (3%/3 mm) criteria were used to evaluate the QA plans. The % gamma passes were plotted on a control chart. The first 50 data points were employed to calculate the control limits. The Cpml was calculated to evaluate the capability of the IMRT/VMAT QA process. The results showed higher systematic errors in IMRT QA than VMAT QA due to the more complicated setup used in IMRT QA. The variation of random errors was also larger in IMRT QA than VMAT QA because the VMAT plan has more continuity of dose distribution. The average % gamma pass was 93.7% ± 3.7% for IMRT and 96.7% ± 2.2% for VMAT. The Cpml value of IMRT QA was 1.60 and VMAT QA was 1.99, which implied that the VMAT QA process was more accurate than the IMRT QA process. Our lower control limit for % gamma pass of IMRT is 85.0%, while the limit for VMAT is 90%. Both the IMRT and VMAT QA processes are good quality because Cpml values are higher than 1.0.

  20. Home Health Aides

    Science.gov (United States)

    ... specifications Help to keep clients engaged in their social networks and communities Home health aides, unlike personal care aides , typically work ... self-care and everyday tasks. They also provide social supports and assistance that enable clients to participate in their ... more information about home health aides, including voluntary credentials for aides, visit ...

  1. Aid and Development

    DEFF Research Database (Denmark)

    Tarp, Finn

    Foreign aid looms large in the public discourse; and international development assistance remains squarely on most policy agendas concerned with growth, poverty and inequality in Africa and elsewhere in the developing world. The present review takes a retrospective look at how foreign aid has...... evolved since World War II in response to a dramatically changing global political and economic context. I review the aid process and associated trends in the volume and distribution of aid and categorize some of the key goals, principles and institutions of the aid system. The evidence on whether aid has...... for aid in the future...

  2. Types of Foreign Aid

    DEFF Research Database (Denmark)

    Bjørnskov, Christian

    Foreign aid is given for many purposes and different intentions, yet most studies treat aid flows as a unitary concept. This paper uses factor analysis to separate aid flows into different types. The main types can be interpreted as aid for economic purposes, social purposes, and reconstruction......; a residual category captures remaining purposes. Estimating the growth effects of separable types of aid suggests that most aid has no effects while reconstruction aid has direct positive effects. Although this type only applies in special circumstances, it has become more prevalent in more recent years....

  3. Predicting changes in blood flow in patient-specific operative plans for treating aortoiliac occlusive disease.

    Science.gov (United States)

    Wilson, Nathan M; Arko, Frank R; Taylor, Charles A

    2005-07-01

    Traditionally, a surgeon will select a procedure for a particular patient on the basis of past experience with patients with a similar state of disease. The experience gained from this patient will be selectively used when treating the next patient with similar symptoms. This article describes a surgical planning system that was developed to enable a vascular surgeon to create and test alternative operative plans prior to surgery for a given patient. One-dimensional and three-dimensional hemodynamic (i.e., blood flow) simulations were performed for rest and exercise for operative plans for two aorto-femoral bypass patients and compared with actual postoperative data. The information obtained from one-dimensional (volume flow distribution and pressure losses) and three-dimensional (flow, pressure, and wall shear stress) hemodynamic simulations may be clinically relevant to vascular surgeons planning interventions.

  4. Methods for intraoperative, sterile pose-setting of patient-specific microstereotactic frames

    Science.gov (United States)

    Vollmann, Benjamin; Müller, Samuel; Kundrat, Dennis; Ortmaier, Tobias; Kahrs, Lüder A.

    2015-03-01

    This work proposes new methods for a microstereotactic frame based on bone cement fixation. Microstereotactic frames are under investigation for minimal invasive temporal bone surgery, e.g. cochlear implantation, or for deep brain stimulation, where products are already on the market. The correct pose of the microstereotactic frame is either adjusted outside or inside the operating room and the frame is used for e.g. drill or electrode guidance. We present a patientspecific, disposable frame that allows intraoperative, sterile pose-setting. Key idea of our approach is bone cement between two plates that cures while the plates are positioned with a mechatronics system in the desired pose. This paper includes new designs of microstereotactic frames, a system for alignment and first measurements to analyze accuracy and applicable load.

  5. Patient-Specific Prosthetic Fingers by Remote Collaboration - A Case Study

    CERN Document Server

    Cabibihan, John-John

    2011-01-01

    The concealment of amputation through prosthesis usage can shield an amputee from social stigma and help improve the emotional healing process especially at the early stages of hand or finger loss. However, the traditional techniques in prosthesis fabrication defy this as the patients need numerous visits to the clinics for measurements, fitting and follow-ups. This paper presents a method for constructing a prosthetic finger through online collaboration with the designer. The main input from the amputee comes from the Computer Tomography (CT) data in the region of the affected and the non-affected fingers. These data are sent over the internet and the prosthesis is constructed using visualization, computer-aided design and manufacturing tools. The finished product is then shipped to the patient. A case study with a single patient having an amputated ring finger at the proximal interphalangeal joint shows that the proposed method has a potential to address the patient's psychosocial concerns and minimize the ...

  6. [Orthognathic surgery: corrective bone operations].

    Science.gov (United States)

    Reuther, J

    2000-05-01

    The article reviews the history of orthognathic surgery from the middle of the last century up to the present. Initially, mandibular osteotomies were only performed in cases of severe malformations. But during the last century a precise and standardized procedure for correction of the mandible was established. Multiple modifications allowed control of small fragments, functionally stable osteosynthesis, and finally a precise positioning of the condyle. In 1955 Obwegeser and Trauner introduced the sagittal split osteotomy by an intraoral approach. It was the final breakthrough for orthognathic surgery as a standard treatment for corrections of the mandible. Surgery of the maxilla dates back to the nineteenth century. B. von Langenbeck from Berlin is said to have performed the first Le Fort I osteotomy in 1859. After minor changes, Wassmund corrected a posttraumatic malocclusion by a Le Fort I osteotomy in 1927. But it was Axhausen who risked the total mobilization of the maxilla in 1934. By additional modifications and further refinements, Obwegeser paved the way for this approach to become a standard procedure in maxillofacial surgery. Tessier mobilized the whole midface by a Le Fort III osteotomy and showed new perspectives in the correction of severe malformations of the facial bones, creating the basis of modern craniofacial surgery. While the last 150 years were distinguished by the creation and standardization of surgical methods, the present focus lies on precise treatment planning and the consideration of functional aspects of the whole stomatognathic system. To date, 3D visualization by CT scans, stereolithographic models, and computer-aided treatment planning and simulation allow surgery of complex cases and accurate predictions of soft tissue changes.

  7. Computer-Assisted Planning and Patient-Specific Instruments for Bone Tumor Resection within the Pelvis: A Series of 11 Patients

    Directory of Open Access Journals (Sweden)

    François Gouin

    2014-01-01

    Full Text Available Pelvic bone tumor resection is challenging due to complex geometry, limited visibility, and restricted workspace. Accurate resection including a safe margin is required to decrease the risk of local recurrence. This clinical study reports 11 cases of pelvic bone tumor resected by using patient-specific instruments. Magnetic resonance imaging was used to delineate the tumor and computerized tomography to localize it in 3D. Resection planning consisted in desired cutting planes around the tumor including a safe margin. The instruments were designed to fit into unique position on the bony structure and to indicate the desired resection planes. Intraoperatively, instruments were positioned freehand by the surgeon and bone cutting was performed with an oscillating saw. Histopathological analysis of resected specimens showed tumor-free bone resection margins for all cases. Available postoperative computed tomography was registered to preoperative computed tomography to measure location accuracy (minimal distance between an achieved and desired cut planes and errors on safe margin (minimal distance between the achieved cut planes and the tumor boundary. The location accuracy averaged 2.5 mm. Errors in safe margin averaged −0.8 mm. Instruments described in this study may improve bone tumor surgery within the pelvis by providing good cutting accuracy and clinically acceptable margins.

  8. Using patient-specific phantoms to evaluate deformable image registration algorithms for adaptive radiation therapy.

    Science.gov (United States)

    Stanley, Nick; Glide-Hurst, Carri; Kim, Jinkoo; Adams, Jeffrey; Li, Shunshan; Wen, Ning; Chetty, Indrin J; Zhong, Hualiang

    2013-11-04

    The quality of adaptive treatment planning depends on the accuracy of its underlying deformable image registration (DIR). The purpose of this study is to evaluate the performance of two DIR algorithms, B-spline-based deformable multipass (DMP) and deformable demons (Demons), implemented in a commercial software package. Evaluations were conducted using both computational and physical deformable phantoms. Based on a finite element method (FEM), a total of 11 computational models were developed from a set of CT images acquired from four lung and one prostate cancer patients. FEM generated displacement vector fields (DVF) were used to construct the lung and prostate image phantoms. Based on a fast-Fourier transform technique, image noise power spectrum was incorporated into the prostate image phantoms to create simulated CBCT images. The FEM-DVF served as a gold standard for verification of the two registration algorithms performed on these phantoms. The registration algorithms were also evaluated at the homologous points quantified in the CT images of a physical lung phantom. The results indicated that the mean errors of the DMP algorithm were in the range of 1.0 ~ 3.1 mm for the computational phantoms and 1.9 mm for the physical lung phantom. For the computational prostate phantoms, the corresponding mean error was 1.0-1.9 mm in the prostate, 1.9-2.4mm in the rectum, and 1.8-2.1 mm over the entire patient body. Sinusoidal errors induced by B-spline interpolations were observed in all the displacement profiles of the DMP registrations. Regions of large displacements were observed to have more registration errors. Patient-specific FEM models have been developed to evaluate the DIR algorithms implemented in the commercial software package. It has been found that the accuracy of these algorithms is patient dependent and related to various factors including tissue deformation magnitudes and image intensity gradients across the regions of interest. This may suggest that

  9. On the evaluation of patient specific IMRT QA using EPID, dynalog files and patient anatomy

    Directory of Open Access Journals (Sweden)

    Dewayne Lee Defoor

    2014-03-01

    Full Text Available Purpose: This research, investigates the viability of using the Electronic portal imaging device (EPID coupled with the treatment planning system (TPS, to calculate the doses delivered and verify agreement with the treatment plan. The results of QA analysis using the EPID, Delta4 and fluence calculations using the multi-leaf collimator (MLC dynalog files on 10 IMRT patients are presented in this study.Methods: EPID Fluence Images in integrated mode and Dynalog files for each field were acquired for 10 IMRT (6MV patients and processed through an in house MatLab program to create an opening density matrix (ODM which was used as the input fluence for dose calculation with the TPS (Pinnacle3, Philips. The EPID used in this study was the aSi1000 Varian on a Novalis TX linac equipped with high definition MLC. The resulting dose distributions were then exported to VeriSoft (PTW where a 3D gamma was calculated using 3 mm-3% criteria. The Scandidos Delta4 phantom was also used to measure a 2D dose distribution for all 10 patients and a 2D gamma was calculated for each patient using the Delta4 software.Results: The average 3D gamma for all 10 patients using the EPID images was 98.2% ± 2.6%. The average 3D gamma using the dynalog files was 94.6% ± 4.9%. The average 2D gamma from the Delta4 was 98.1% ± 2.5%. The minimum 3D gamma for the EPID and dynalog reconstructed dose distributions was found on the same patient which had a very large PTV, requiring the jaws to open to the maximum field size. Conclusion: Use of the EPID, combined with a TPS is a viable method for QA of IMRT plans. A larger ODM size can be implemented to accommodate larger field sizes. An adaptation of this process to Volumetric Arc Therapy (VMAT is currently under way.-----------------------------Cite this article as: Defoor D, Mavroidis P, Quino L, Gutierrez A, Papanikolaou N, Stathakis S. On the evaluation of patient specific IMRT QA using EPID, dynalog files and patient anatomy

  10. SU-E-T-159: Evaluation of a Patient Specific QA Tool Based On TG119

    Energy Technology Data Exchange (ETDEWEB)

    Ashmeg, S; Zhang, Y; O' Daniel, J; Yin, F; Ren, L [Duke University Medical Center, Durham, NC (United States)

    2014-06-01

    Purpose: To evaluate the accuracy of a 3D patient specific QA tool by analysis of the results produced from associated software in homogenous phantom and heterogonous patient CT. Methods: IMRT and VMAT plans of five test suites introduced by TG119 were created in ECLIPSE on a solid water phantom. The ten plans -of increasing complexity- were delivered to Delta4 to give a 3D measurement. The Delta4's “Anatomy” software uses the measured dose to back-calculate the energy fluence of the delivered beams, which is used for dose calculation in a patient CT using a pencilbeam algorithm. The effect of the modulated beams' complexity on the accuracy of the “Anatomy” calculation was evaluated. Both measured and Anatomy doses were compared to ECLIPSE calculation using 3% - 3mm gamma criteria.We also tested the effect of heterogeneity by analyzing the results of “Anatomy” calculation on a Brain VMAT and a 3D conformal lung cases. Results: In homogenous phantom, the gamma passing rates were found to be as low as 74.75% for a complex plan with high modulation. The mean passing rates were 91.47% ± 6.35% for “Anatomy” calculation and 99.46% ± 0.62% for Delta4 measurements.As for the heterogeneous cases, the rates were 96.54%±3.67% and 83.87%±9.42% for Brain VMAT and 3D lung respectively. This increased error in the lung case could be due to the use of the pencil beam algorithm as opposed to the AAA used by ECLIPSE.Also, gamma analysis showed high discrepancy along the beam edge in the “Anatomy” calculated results. This suggests a poor beam modeling in the penumbra region. Conclusion: The results show various sources of errors in “Anatomy” calculations. These include beam modeling in the penumbra region, complexity of a modulated beam (shown in homogenous phantom and brain cases) and dose calculation algorithms (3D conformal lung case)

  11. Graph-cuts based reconstructing patient specific right ventricle: first human study.

    Science.gov (United States)

    Zhong, Liang; Wan, Min; Su, Yi; Teo, Soo Kng; Lim, Chi Wan; Zhao, Xiaodan; Zhang, Jun-Mei; Su, Bo Yang; Tan, Ju Le; Tan, Ru San

    2014-01-01

    Right ventricular (RV) function is increasingly recognized to play an important role in the clinical status and long-term outcome in patients with congenital heart disease as well as ischemic cardiomyopathy with left ventricular dysfunction. However, quantification of RV characteristics and function are still challenging due to its complex morphology and its thin wall with coarse trabeculations. To assess RV functions quantitatively, establishing the patient-specific model from medical images is a prerequisite task. This study aims to develop a novel method for RV model reconstruction. Magnetic resonance images were acquired and preprocessed. Contours of right ventricle, right atrium and pulmonary artery were manually delineated at all slices and all time frames. The contour coordinates as well as the medical image specifications such as image pixel resolution and slick thickness were exported. The contours were transformed to the correct positions. Reorientation and matching were executed in between neighboring contours; extrapolation and interpolation were conducted upon all contours. After preprocessing, the more dense point set was reconstructed through a variational tool. A Delaunay-based tetrahedral mesh was generated on the region of interest. The weighted minimal surface model was used to describe RV surface. The graphcuts technique, i.e., max-flow/min-cut algorithm, was applied to minimize the energy defined by the model. The reconstructed surface was extracted from the mesh according to the mincut. Smoothing and remeshing were performed. The CPU time to reconstruct the model for one frame was approximately 2 minutes. In 10 consecutive subjects referred for cardiac MRI (80% female), right ventricular volumes were measured using our method against the commercial available CMRtools package. The results demonstrated that there was a significant correlation in end-diastolic and end-systolic volumes between our method and commercial software (r= 0.89 for end

  12. Patient-Specific Dosimetry and Radiobiological Modeling of Targeted Radionuclide Therapy Grant - final report

    Energy Technology Data Exchange (ETDEWEB)

    George Sgouros, Ph.D.

    2007-03-20

    radionuclide therapy to obtain normal organ and tumor dose vs. response correlations. Completion of the aims outlined above will make it possible to perform patient-specific dosimetry that incorporates considerations likely to provide robust dose-response relationships. Such an advance will improve targeted radionuclide therapy by making it possible to adopt treatment planning methodologies.

  13. Patient specific optimization-based treatment planning for catheter-based ultrasound hyperthermia and thermal ablation

    Science.gov (United States)

    Prakash, Punit; Chen, Xin; Wootton, Jeffery; Pouliot, Jean; Hsu, I.-Chow; Diederich, Chris J.

    2009-02-01

    A 3D optimization-based thermal treatment planning platform has been developed for the application of catheter-based ultrasound hyperthermia in conjunction with high dose rate (HDR) brachytherapy for treating advanced pelvic tumors. Optimal selection of applied power levels to each independently controlled transducer segment can be used to conform and maximize therapeutic heating and thermal dose coverage to the target region, providing significant advantages over current hyperthermia technology and improving treatment response. Critical anatomic structures, clinical target outlines, and implant/applicator geometries were acquired from sequential multi-slice 2D images obtained from HDR treatment planning and used to reconstruct patient specific 3D biothermal models. A constrained optimization algorithm was devised and integrated within a finite element thermal solver to determine a priori the optimal applied power levels and the resulting 3D temperature distributions such that therapeutic heating is maximized within the target, while placing constraints on maximum tissue temperature and thermal exposure of surrounding non-targeted tissue. This optimizationbased treatment planning and modeling system was applied on representative cases of clinical implants for HDR treatment of cervix and prostate to evaluate the utility of this planning approach. The planning provided significant improvement in achievable temperature distributions for all cases, with substantial increase in T90 and thermal dose (CEM43T90) coverage to the hyperthermia target volume while decreasing maximum treatment temperature and reducing thermal dose exposure to surrounding non-targeted tissues and thermally sensitive rectum and bladder. This optimization based treatment planning platform with catheter-based ultrasound applicators is a useful tool that has potential to significantly improve the delivery of hyperthermia in conjunction with HDR brachytherapy. The planning platform has been extended

  14. Transcriptome profiling of patient-specific human iPSC-cardiomyocytes predicts individual drug safety and efficacy responses in vitro

    Science.gov (United States)

    Matsa, Elena; Burridge, Paul W.; Yu, Kun-Hsing; Ahrens, John H.; Termglinchan, Vittavat; Wu, Haodi; Liu, Chun; Shukla, Praveen; Sayed, Nazish; Churko, Jared M.; Shao, Ningyi; Woo, Nicole A.; Chao, Alexander S.; Gold, Joseph D.; Karakikes, Ioannis; Snyder, Michael P.; Wu, Joseph C.

    2016-01-01

    SUMMARY Understanding individual susceptibility to drug-induced cardiotoxicity is key to improving patient safety and preventing drug attrition. Human induced pluripotent stem cells (hiPSCs) enable the study of pharmacological and toxicological responses in patient-specific cardiomyocytes (CMs), and may serve as preclinical platforms for precision medicine. Transcriptome profiling in hiPSC-CMs from seven individuals lacking known cardiovascular disease-associated mutations, and in three isogenic human heart tissue and hiPSC-CM pairs, showed greater inter-patient variation than intra-patient variation, verifying that reprogramming and differentiation preserve patient-specific gene expression, particularly in metabolic and stress-response genes. Transcriptome-based toxicology analysis predicted and risk-stratified patient-specific susceptibility to cardiotoxicity, and functional assays in hiPSC-CMs using tacrolimus and rosiglitazone, drugs targeting pathways predicted to produce cardiotoxicity, validated inter-patient differential responses. CRISPR/Cas9-mediated pathway correction prevented drug-induced cardiotoxicity. Our data suggest that hiPSC-CMs can be used in vitro to predict and validate patient-specific drug safety and efficacy, potentially enabling future clinical approaches to precision medicine. PMID:27545504

  15. Geometrical aspects of patient-specific modelling of the intervertebral disc: collagen fibre orientation and residual stress distribution.

    Science.gov (United States)

    Marini, Giacomo; Studer, Harald; Huber, Gerd; Püschel, Klaus; Ferguson, Stephen J

    2016-06-01

    Patient-specific modelling of the spine is a powerful tool to explore the prevention and the treatment of injuries and pathologies. Albeit several methods have been proposed for the discretization of the bony structures, the efficient representation of the intervertebral disc anisotropy remains a challenge, especially with complex geometries. Furthermore, the swelling of the disc's nucleus pulposus is normally added to the model after geometry definition, at the cost of changes of the material properties and an unrealistic description of the prestressed state. The aim of this study was to develop techniques, which preserve the patient-specific geometry of the disc and allow the representation of the system anisotropy and residual stresses, independent of the system discretization. Depending on the modelling features, the developed approaches resulted in a response of patient-specific models that was in good agreement with the physiological response observed in corresponding experiments. The proposed methods represent a first step towards the development of patient-specific models of the disc which respect both the geometry and the mechanical properties of the specific disc.

  16. Automatic construction of patient-specific finite-element mesh of the spine from IVDs and vertebra segmentations

    Science.gov (United States)

    Castro-Mateos, Isaac; Pozo, Jose M.; Lazary, Aron; Frangi, Alejandro F.

    2016-03-01

    Computational medicine aims at developing patient-specific models to help physicians in the diagnosis and treatment selection for patients. The spine, and other skeletal structures, is an articulated object, composed of rigid bones (vertebrae) and non-rigid parts (intervertebral discs (IVD), ligaments and muscles). These components are usually extracted from different image modalities, involving patient repositioning. In the case of the spine, these models require the segmentation of IVDs from MR and vertebrae from CT. In the literature, there exists a vast selection of segmentations methods, but there is a lack of approaches to align the vertebrae and IVDs. This paper presents a method to create patient-specific finite element meshes for biomechanical simulations, integrating rigid and non-rigid parts of articulated objects. First, the different parts are aligned in a complete surface model. Vertebrae extracted from CT are rigidly repositioned in between the IVDs, initially using the IVDs location and then refining the alignment using the MR image with a rigid active shape model algorithm. Finally, a mesh morphing algorithm, based on B-splines, is employed to map a template finite-element (volumetric) mesh to the patient-specific surface mesh. This morphing reduces possible misalignments and guarantees the convexity of the model elements. Results show that the accuracy of the method to align vertebrae into MR, together with IVDs, is similar to that of the human observers. Thus, this method is a step forward towards the automation of patient-specific finite element models for biomechanical simulations.

  17. Structural correlation method for model reduction and practical estimation of patient specific parameters illustrated on heart rate regulation

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.; Mehlsen, Jesper; Olufsen, Mette

    2014-01-01

    We consider the inverse and patient specific problem of short term (seconds to minutes) heart rate regulation specified by a system of nonlinear ODEs and corresponding data. We show how a recent method termed the structural correlation method (SCM) can be used for model reduction and for obtaining...

  18. Future perspectives in robotic surgery.

    Science.gov (United States)

    Wedmid, Alexei; Llukani, Elton; Lee, David I

    2011-09-01

    • Robotics of the current day have advanced significantly from early computer-aided design/manufacturing systems to modern master-slave robotic systems that replicate the surgeon's exact movements onto robotic instruments in the patient. • Globally >300,000 robotic procedures were completed in 2010, including ≈98,000 robot-assisted radical prostatectomies. • Broadening applications of robotics for urological procedures are being investigated in both adult and paediatric urology. • The use of the current robotic system continues to be further refined. Increasing experience has optimized port placement reducing arm collisions to allow for more expedient surgery. Improved three-dimensional camera magnification provides improved intraoperative identification of structures. • Robotics has probably improved the learning curve of laparoscopic surgery while still maintaining its patient recovery advantages and outcomes. • The future of robotic surgery will take this current platform forward by improving haptic (touch) feedback, improving vision beyond even the magnified eye, improving robot accessibility with a reduction of entry ports and miniaturizing the slave robot. • Here, we focus on the possible advancements that may change the future landscape of robotic surgery.

  19. [Minimally invasive surgery and robotic surgery: surgery 4.0?].

    Science.gov (United States)

    Feußner, H; Wilhelm, D

    2016-03-01

    Surgery can only maintain its role in a highly competitive environment if results are continuously improved, accompanied by further reduction of the interventional trauma for patients and with justifiable costs. Significant impulse to achieve this goal was expected from minimally invasive surgery and, in particular, robotic surgery; however, a real breakthrough has not yet been achieved. Accordingly, the new strategic approach of cognitive surgery is required to optimize the provision of surgical treatment. A full scale integration of all modules utilized in the operating room (OR) into a comprehensive network and the development of systems with technical cognition are needed to upgrade the current technical environment passively controlled by the surgeon into an active collaborative support system (surgery 4.0). Only then can the true potential of minimally invasive surgery and robotic surgery be exploited.

  20. Computational Patient Avatars for Surgery Planning.

    Science.gov (United States)

    González, David; Cueto, Elías; Chinesta, Francisco

    2016-01-01

    In this paper a new method is described for the generation of computational patient avatars for surgery planning. By "patient avatar" a computational, patient-specific, model of the patient is meant, that should be able to provide the surgeon with an adequate response under real-time restrictions, possibly including haptic response. The method is based on the use of computational vademecums (F. Chinesta et al., PGD-based computational vademecum for efficient design, optimization and control. Arch. Comput. Methods Eng. 20(1):31-59, 2013), that are properly interpolated so as to generate a patient-specific model. It is highlighted how the interpolation of shapes needs for a specialized technique, since a direct interpolation of biological shapes would produce, in general, non-physiological shapes. To this end a manifold learning technique is employed, that allows for a proper interpolation that provides very accurate results in describing patient-specific organ geometries. These interpolated vademecums thus give rise to very accurate patient avatars able to run at kHz feedback rates, enabling not only visual, but also haptic response to the surgeon.

  1. Who Needs Heart Surgery?

    Science.gov (United States)

    ... this page from the NHLBI on Twitter. Who Needs Heart Surgery? Heart surgery is used to treat ... will work with you to decide whether you need heart surgery. A cardiologist specializes in diagnosing and ...

  2. Laser surgery - skin

    Science.gov (United States)

    Surgery using a laser ... used is directly related to the type of surgery being performed and the color of the tissue ... Laser surgery can be used to: Close small blood vessels to reduce blood loss Remove warts , moles , sunspots, and ...

  3. Gastric Sleeve Surgery

    Science.gov (United States)

    ... A Week of Healthy Breakfasts Shyness Gastric Sleeve Surgery KidsHealth > For Teens > Gastric Sleeve Surgery Print A ... buying healthy food ) continue Preparing for Gastric Sleeve Surgery Preparing for this major operation takes months of ...

  4. Surgery for Breast Cancer

    Science.gov (United States)

    ... Cancer During Pregnancy Breast Cancer Breast Cancer Treatment Surgery for Breast Cancer Surgery is a common treatment ... removed (breast reconstruction) Relieve symptoms of advanced cancer Surgery to remove breast cancer There are two main ...

  5. Surgery for Pancreatic Cancer

    Science.gov (United States)

    ... of the Tumor Pancreatic Cancer Treating Pancreatic Cancer Surgery for Pancreatic Cancer Two general types of surgery ... how far the cancer has spread. Potentially curative surgery Studies have shown that removing only part of ...

  6. Cavus Foot Surgery

    Science.gov (United States)

    ... All Site Content AOFAS / FootCareMD / Treatments Cavus Foot Surgery Page Content What is a cavus foot? A ... problems. What are the goals of cavus foot surgery? The main goal of surgery is to reduce ...

  7. Smoking and surgery

    Science.gov (United States)

    Surgery - quitting smoking; Surgery - quitting tobacco; Wound healing - smoking ... Smokers who have surgery have a higher chance than nonsmokers of blood clots forming in their legs. These clots may travel to and ...

  8. Coronary Artery Bypass Surgery

    Science.gov (United States)

    ... t help, you may need coronary artery bypass surgery. The surgery creates a new path for blood to flow ... more than one bypass. The results of the surgery usually are excellent. Many people remain symptom-free ...

  9. Tennis elbow surgery - discharge

    Science.gov (United States)

    ... epicondylitis surgery - discharge; Lateral tendinosis surgery - discharge; Lateral tennis elbow surgery - discharge ... long as you are told. This helps ensure tennis elbow will not return. You may be prescribed a ...

  10. Open heart surgery

    Science.gov (United States)

    Heart surgery - open ... lung machine is used in most cases during open heart surgery. While the surgeon works on the ... with these procedures, the surgeon may have to open the chest to do the surgery.

  11. Plastic Surgery Statistics

    Science.gov (United States)

    ... PSN PSEN GRAFT Contact Us News Plastic Surgery Statistics Plastic surgery procedural statistics from the American Society of Plastic Surgeons. Statistics by Year Print 2016 Plastic Surgery Statistics 2015 ...

  12. Corrective Jaw Surgery

    Medline Plus

    Full Text Available ... Soft Tissue Surgery Dental Implant Surgery Facial Cosmetic Surgery Head, Neck and Oral Pathology Obstructive Sleep Apnea TMJ and Facial Pain Treatment of Facial Injury Wisdom Teeth Management Procedures Administration of Anesthesia Administration of Anesthesia Oral ...

  13. Ear Plastic Surgery

    Science.gov (United States)

    ... receive light-weight earrings. Does Insurance Pay for Cosmetic Ear Surgery? Insurance usually does not cover surgery solely for ... republication strictly prohibited without prior written permission. Ears Cosmetic Surgery, Facelift, Rhinoplasty, Blepharoplasty ... Get Involved Professional Development Practice ...

  14. Carotid artery surgery - discharge

    Science.gov (United States)

    ... Surgery, Society for Vascular Medicine, and Society for Vascular Surgery. J Am Coll Cardiol . 2011 Feb 22;57( ... 21288680 . Kinlay S, Bhatt DL. Treatment of noncoronary obstructive ... Textbook of Surgery . 19th ed. Elsevier Saunders; 2012:chap 63.

  15. CARS 2008: Computer Assisted Radiology and Surgery. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-06-15

    The proceedings contain contributions to the following topics: digital imaging, computed tomography, magnetic resonance, cardiac and vascular imaging, computer assisted radiation therapy, image processing and display, minimal invasive spinal surgery, computer assisted treatment of the prostate, the interventional radiology suite of the future, interventional oncology, computer assisted neurosurgery, computer assisted head and neck and ENT surgery, cardiovascular surgery, computer assisted orthopedic surgery, image processing and visualization, surgical robotics, instrumentation and navigation, surgical modelling, simulation and education, endoscopy and related techniques, workflow and new concepts in surgery, research training group 1126: intelligent surgery, digital operating room, image distribution and integration strategies, regional PACS and telemedicine, PACS - beyond radiology and E-learning, workflow and standardization, breast CAD, thoracic CAD, abdominal CAD, brain CAD, orthodontics, dentofacial orthopedics and airways, imaging and treating temporomandibular joint conditions, maxillofacial cone beam CT, craniomaxillofacial image fusion and CBCT incidental findings, image guided craniomaxillofacial procedures, imaging as a biomarker for therapy response, computer aided diagnosis. The Poster sessions cover the topics computer aided surgery, Euro PACS meeting, computer assisted radiology, computer aided diagnosis and computer assisted radiology and surgery.

  16. Single incision laparoscopic surgery

    Institute of Scientific and Technical Information of China (English)

    Arun; Prasad

    2010-01-01

    As a complement to standard laparoscopic surgery and a safe alternative to natural orifice transluminal endoscopic surgery,single incision laparoscopic surgery is gaining popularity.There are expensive ports,disposable hand instruments and flexible endoscopes that have been suggested to do this surgery and would increase the cost of operation.For a simple surgery like laparoscopic cholecystectomy,these extras are not needed and the surgery can be performed using standard ports,instruments and telescopes.Tri...

  17. Aid and growth regressions

    DEFF Research Database (Denmark)

    Hansen, Henrik; Tarp, Finn

    2001-01-01

    This paper examines the relationship between foreign aid and growth in real GDP per capita as it emerges from simple augmentations of popular cross country growth specifications. It is shown that aid in all likelihood increases the growth rate, and this result is not conditional on ‘good’ policy....... There are, however, decreasing returns to aid, and the estimated effectiveness of aid is highly sensitive to the choice of estimator and the set of control variables. When investment and human capital are controlled for, no positive effect of aid is found. Yet, aid continues to impact on growth via...

  18. Aid and Development

    DEFF Research Database (Denmark)

    Tarp, Finn

    evolved since World War II in response to a dramatically changing global political and economic context. I review the aid process and associated trends in the volume and distribution of aid and categorize some of the key goals, principles and institutions of the aid system. The evidence on whether aid has......Foreign aid looms large in the public discourse; and international development assistance remains squarely on most policy agendas concerned with growth, poverty and inequality in Africa and elsewhere in the developing world. The present review takes a retrospective look at how foreign aid has...

  19. Aid and development

    DEFF Research Database (Denmark)

    Tarp, Finn

    2006-01-01

    evolved since World War II in response to a dramatically changing global political and economic context. I review the aid process and associated trends in the volume and distribution of aid and categorize some of the key goals, principles and institutions of the aid system. The evidence on whether aid has......Foreign aid looms large in the public discourse; and international development assistance remains squarely on most policy agendas concerned with growth, poverty and inequality in Africa and elsewhere in the developing world. The present review takes a retrospective look at how foreign aid has...

  20. Toward Patient Specific Long Lasting Metallic Implants for Mandibular Segmental Defects

    Science.gov (United States)

    Shayesteh Moghaddam, Narges

    Mandibular defects may result from tumor resection, trauma, or inflammation. The goals of mandibular reconstruction surgeries are to restore mandible function and aesthetics. To this end, surgeons use a combination of bone grafts and metallic implants. These implants have drastically different mechanical properties than the surrounding bone. As a result, the stress distribution in the mandible changes after surgery. The long-term abnormal stress/strain distribution may lead to either graft failure due to bone resorption as a result of stress shielding, or hardware failure due to stress concentrations. During the healing period of six to nine months it is important that complete immobilization, bringing mandibular micro-motion down to the level of 200-500 mum during chewing, is achieved. After this period it is desired that bone undergo normal stress for long-term success of the treatment. Although current high stiffness fixation hardware accomplishes this immobilization during the healing period, the hardware continues to alter the normal stress-strain trajectory seen during chewing once the engrafted bone heals. Over the long-term, the immobilized and stress-shielded engrafted bone tends to resorb. On the other hand, hardware fracturing or/and screw loosening is observed as the stress is concentrated at certain locations on the hardware. Equally as important is the permanent loss of chewing power due to the altered stress-strain relationships. The first stage of this research is to study the problems encountered following a mandibular segmental defect reconstructive surgery. To this end, we constructed a finite element model of a healthy mandible, which includes cortical and cancellous bone, teeth (enamel and dentin components), and the periodontal ligament. Using this model, we studied a healthy adult mandible under maximum molar bite force for stress, strain, displacement, and reaction force distribution. For mandibular segmental defect reconstruction the

  1. Radioiodine Therapy of Hyperthyroidism. Simplified patient-specific absorbed dose planning

    Energy Technology Data Exchange (ETDEWEB)

    Joensson, Helene

    2003-10-01

    Radioiodine therapy of hyperthyroidism is the most frequently performed radiopharmaceutical therapy. To calculate the activity of {sup 131}I to be administered for giving a certain absorbed dose to the thyroid, the mass of the thyroid and the individual biokinetic data, normally in the form of uptake and biologic half-time, have to be determined. The biologic half-time is estimated from several uptake measurements and the first one is usually made 24 hours after the intake of the test activity. However, many hospitals consider it time-consuming since at least three visits of the patient to the hospital are required (administration of test activity, first uptake measurement, second uptake measurement plus treatment). Instead, many hospitals use a fixed effective half-time or even a fixed administered activity, only requiring two visits. However, none of these methods considers the absorbed dose to the thyroid of the individual patient. In this work a simplified patient-specific method for treating hyperthyroidism is proposed, based on one single uptake measurement, thus requiring only two visits to the hospital. The calculation is as accurate as using the individual biokinetic data. The simplified method is as patient-convenient and time effective as using a fixed effective half-time or a fixed administered activity. The simplified method is based upon a linear relation between the late uptake measurement 4-7 days after intake of the test activity and the product of the extrapolated initial uptake and the effective half-time. Treatments not considering individual biokinetics in the thyroid result in a distribution of administered absorbed dose to the thyroid, with a range of -50 % to +160 % compared to a protocol calculating the absorbed dose to the thyroid of the individual patient. Treatments with a fixed administered activity of 370 MBq will in general administer 250 % higher activity to the patient, with a range of -30 % to +770 %. The absorbed dose to other

  2. A eletromiografia como auxílio na conduta terapêutica após cirurgia de craniotomia fronto-temporal: relato de caso Electromyography as an aid in therapeutic behavior after fronto-temporal craniotomy surgery: case report

    Directory of Open Access Journals (Sweden)

    Maristella Cecco Oncins

    2009-01-01

    insertion. After the surgery, the patient had dysfunction in temporal muscle and in temporo-mandibular joint, with reduction of the opening of mouth, pain while speaking and eating. Electromyography was used to quantitatively record the electrical activity of the temporal and masseter muscles in the initial evaluation and during the therapeutic process. Records were made at rest position, maximum occlusion and chew. They did miofuncional therapy throughout the process. RESULTS: examination data showed a significant increase in the electrical activity of the right anterior temporal muscle and a reduction in the activity of the left anterior temporal muscle. The initial Record showed a lower electrical activity on the right side compared to the left. With the miofunctional exercises there was a more effective participation of the right anterior temporal muscle, greater openness of mouth, without pain, making easier chewing and speech tasks, harmonizing the stomatognathic system. CONCLUSION: comparative records concerning electromyography in different stages of the therapeutic process helped and directed the best therapy, achieving a balance concerning the functions of breathing, sucking, chewing, swallowing and speech related to the stomatognathic system, considering the limitations of the case.

  3. Patient-specific prosthetic fingers by remote collaboration--a case study.

    Directory of Open Access Journals (Sweden)

    John-John Cabibihan

    Full Text Available The concealment of amputation through prosthesis usage can shield an amputee from social stigma and help improve the emotional healing process especially at the early stages of hand or finger loss. However, the traditional techniques in prosthesis fabrication defy this as the patients need numerous visits to the clinics for measurements, fitting and follow-ups. This paper presents a method for constructing a prosthetic finger through online collaboration with the designer. The main input from the amputee comes from the Computer Tomography (CT data in the region of the affected and the non-affected fingers. These data are sent over the internet and the prosthesis is constructed using visualization, computer-aided design and manufacturing tools. The finished product is then shipped to the patient. A case study with a single patient having an amputated ring finger at the proximal interphalangeal joint shows that the proposed method has a potential to address the patient's psychosocial concerns and minimize the exposure of the finger loss to the public.

  4. The Plastic Surgery Compass: Navigating the Reconstructive Ladder in the Personalized Health Care Era.

    Science.gov (United States)

    Sandberg, Lars Johan M

    2016-09-01

    The reconstructive ladder and the reconstructive elevator have withstood the test of time as didactic tools for resident education. Over time, many alternative models have been suggested to incorporate the technological advances in plastic surgery, but none of them have focused on the patient. Changes in practice and the trend toward personalized health care demand a 360-degree evaluation and solution of surgical problems incorporating patient-specific characteristics. We, therefore, suggest the concept of the plastic surgery compass to navigate the ladder.

  5. A patient-specific aperture system with an energy absorber for spot scanning proton beams: Verification for clinical application

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Keisuke, E-mail: k.yasui.20@west-med.jp [Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1, Hirate-cho, Kita-ku, Nagoya-shi, Aichi-ken 462-8508, Japan and Department of Radiological Sciences, Nagoya University Graduate School of Medicine, 1-1-20, Daikouminami, Higashi-ku, Nagoya-shi, Aichi-ken 461-8673 (Japan); Toshito, Toshiyuki; Omachi, Chihiro; Kibe, Yoshiaki; Hayashi, Kensuke; Shibata, Hiroki; Tanaka, Kenichiro; Nikawa, Eiki; Asai, Kumiko; Shimomura, Akira; Kinou, Hideto; Isoyama, Shigeru; Mizoe, Jun-etsu [Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1, Hirate-cho, Kita-ku, Nagoya-shi, Aichi-ken 462-8508 (Japan); Fujii, Yusuke; Takayanagi, Taisuke; Hirayama, Shusuke [Hitachi, Ltd., Hitachi Research Laboratory, 7-1-1, Omika-chou, Hitachi-shi, Ibaraki-ken 319-1292 (Japan); Nagamine, Yoshihiko [Hitachi, Ltd., Hitachi Works, 3-1-1, Saiwai-chou, Hitachi-shi, Ibaraki-ken 317-8511 (Japan); Shibamoto, Yuta [Graduate School of Medical Sciences, Nagoya City University, 1, Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya-shi, Aichi-ken 467-8601 (Japan); Komori, Masataka [Department of Radiological Sciences, Nagoya University Graduate School of Medicine, 1-1-20, Daikouminami, Higashi-ku, Nagoya-shi, Aichi-ken 461-8673 (Japan)

    2015-12-15

    Purpose: In the authors’ proton therapy system, the patient-specific aperture can be attached to the nozzle of spot scanning beams to shape an irradiation field and reduce lateral fall-off. The authors herein verified this system for clinical application. Methods: The authors prepared four types of patient-specific aperture systems equipped with an energy absorber to irradiate shallow regions less than 4 g/cm{sup 2}. The aperture was made of 3-cm-thick brass and the maximum water equivalent penetration to be used with this system was estimated to be 15 g/cm{sup 2}. The authors measured in-air lateral profiles at the isocenter plane and integral depth doses with the energy absorber. All input data were obtained by the Monte Carlo calculation, and its parameters were tuned to reproduce measurements. The fluence of single spots in water was modeled as a triple Gaussian function and the dose distribution was calculated using a fluence dose model. The authors compared in-air and in-water lateral profiles and depth doses between calculations and measurements for various apertures of square, half, and U-shaped fields. The absolute doses and dose distributions with the aperture were then validated by patient-specific quality assurance. Measured data were obtained by various chambers and a 2D ion chamber detector array. Results: The patient-specific aperture reduced the penumbra from 30% to 70%, for example, from 34.0 to 23.6 mm and 18.8 to 5.6 mm. The calculated field width for square-shaped apertures agreed with measurements within 1 mm. Regarding patient-specific aperture plans, calculated and measured doses agreed within −0.06% ± 0.63% (mean ± SD) and 97.1% points passed the 2%-dose/2 mm-distance criteria of the γ-index on average. Conclusions: The patient-specific aperture system improved dose distributions, particularly in shallow-region plans.

  6. HIV/AIDS Coinfection

    Science.gov (United States)

    ... Laotian Mongolian Spanish Turkish Vietnamese Hindi Subscribe HIV/AIDS Coinfection Approximately 10% of the HIV-infected population ... Control and Prevention website to learn about HIV/AIDS and Viral Hepatitis guidelines and resources. Home About ...

  7. HIV/AIDS Basics

    Science.gov (United States)

    ... Partner Spotlight Awareness Days Get Tested Find an HIV testing site near you. Enter ZIP code or ... AIDS Get Email Updates on AAA Anonymous Feedback HIV/AIDS Media Infographics Syndicated Content Podcasts Slide Sets ...

  8. Neurological Complications of AIDS

    Science.gov (United States)

    ... in recent years has improved significantly because of new drugs and treatments. AIDS clinicians often fail to recognize ... in recent years has improved significantly because of new drugs and treatments. AIDS clinicians often fail to recognize ...

  9. Combined Soft and Hard Tissue Peri-Implant Plastic Surgery Techniques to Enhance Implant Rehabilitation: A Case Report

    Science.gov (United States)

    Baltacıoğlu, Esra; Korkmaz, Fatih Mehmet; Bağış, Nilsun; Aydın, Güven; Yuva, Pınar; Korkmaz, Yavuz Tolga; Bağış, Bora

    2014-01-01

    This case report presents an implant-aided prosthetic treatment in which peri-implant plastic surgery techniques were applied in combination to satisfactorily attain functional aesthetic expectations. Peri-implant plastic surgery enables the successful reconstruction and restoration of the balance between soft and hard tissues and allows the option of implant-aided fixed prosthetic rehabilitation. PMID:25489351

  10. Visual design and verification tool for collision-free dexterous patient specific neurosurgical instruments

    Science.gov (United States)

    Hess, Maggie; Eastwood, Kyle; Linder, Bence; Bodani, Vivek; Lasso, Andras; Looi, Thomas; Fichtinger, Gabor; Drake, James

    2016-03-01

    PURPOSE: In many minimally invasive neurosurgical procedures, the surgical workspace is a small tortuous cavity that is accessed using straight, rigid instruments with limited dexterity. Specifically considering neuroendoscopy, it is often challenging for surgeons, using standard instruments, to reach multiple surgical targets from a single incision. To address this problem, continuum tools are under development to create highly dexterous minimally invasive instruments. However, this design process is not trivial, and therefore, a user-friendly design platform capable of easily incorporating surgeon input is needed. METHODS: We propose a method that uses simulation and visual verification to design continuum tools that are patient and procedure specific. Our software module utilizes pre-operative scans and virtual threedimensional (3D) patient models to intuitively aid instrument design. The user specifies basic tool parameters and the parameterized tools and trocar are modeled within the virtual patient. By selecting and dragging the instrument models, the tools are instantly reshaped and repositioned. The tool geometry and surgical entry points are then returned as outputs to undergo optimization. We have completed an initial validation of the software by comparing a simulation of a physical instrument's reachability to the corresponding virtual design. RESULTS AND CONCLUSION: The software was assessed qualitatively by two neurosurgeons, who design tools for an intraventricular endoscopic procedure. Further, validation experiments comparing the design of a virtual instrument to a physical tool demonstrate that the software module functions correctly. Thus, our platform permits user-friendly, application specific design of continuum instruments. These instruments will give surgeons much more flexibility in developing future minimally invasive procedures.

  11. Aid and growth regressions

    DEFF Research Database (Denmark)

    Hansen, Henrik; Tarp, Finn

    2001-01-01

    . There are, however, decreasing returns to aid, and the estimated effectiveness of aid is highly sensitive to the choice of estimator and the set of control variables. When investment and human capital are controlled for, no positive effect of aid is found. Yet, aid continues to impact on growth via...... investment. We conclude by stressing the need for more theoretical work before this kind of cross-country regressions are used for policy purposes....

  12. Development of an improved approach to radiation treatment therapy using high-definition patient-specific voxel phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Ward, R.C.; Ryman, J.C.; Worley, B.A.; Stallings, D.C. [Oak Ridge National Lab., TN (United States)

    1998-09-01

    Through an internally funded project at Oak Ridge National Laboratory, a high-resolution phantom was developed based on the National Library of Medicine`s Visible Human Data. Special software was written using the interactive data language (IDL) visualization language to automatically segment and classify some of the organs and the skeleton of the Visible Male. A high definition phantom consisting of nine hundred 512 x 512 slices was constructed of the entire torso. Computed tomography (CT) images of a patient`s tumor near the spine were scaled and morphed into the phantom model to create a patient-specific phantom. Calculations of dose to the tumor and surrounding tissue were then performed using the patient-specific phantom.

  13. Generation of Patient-Specific induced Pluripotent Stem Cell from Peripheral Blood Mononuclear Cells by Sendai Reprogramming Vectors.

    Science.gov (United States)

    Quintana-Bustamante, Oscar; Segovia, Jose C

    2016-01-01

    Induced pluripotent stem cells (iPSC) technology has changed preclinical research since their generation was described by Shinya Yamanaka in 2006. iPSCs are derived from somatic cells after being reprogrammed back to an embryonic state by specific combination of reprogramming factors. These reprogrammed cells resemble all the characteristic of embryonic stem cells (ESC). The reprogramming technology is even more valuable to research diseases biology and treatment by opening gene and cell therapies in own patient's iPSC. Patient-specific iPSC can be generated from a large variety of patient cells by any of the myriad of reprogramming platforms described. Here, we describe the generation of patient-specific iPSC from patient peripheral blood mononuclear cells by Sendai Reprogramming vectors.

  14. Designing State Aid Formulas

    Science.gov (United States)

    Zhao, Bo; Bradbury, Katharine

    2009-01-01

    This paper designs a new equalization-aid formula based on fiscal gaps of local communities. When states are in transition to a new local aid formula, the issue of whether and how to hold existing aid harmless poses a challenge. The authors show that some previous studies and the formulas derived from them give differential weights to existing and…

  15. Determinants of State Aid

    NARCIS (Netherlands)

    Buiren, K.; Brouwer, E.

    2010-01-01

    From economic theory we derive a set of hypotheses on the determination of state aid. Econometric analysis on EU state aid panel data is carried out to test whether the determinants we expect on the basis of theory, correspond to the occurrence of state aid in practice in the EU. We find that politi

  16. Fever: First Aid

    Science.gov (United States)

    First aid Fever: First aid Fever: First aid By Mayo Clinic Staff A fever is a rise in body temperature. It's usually a sign of infection. The ... 2 C) or higher Should I treat a fever? When you or your child is sick, the ...

  17. Stroke: First Aid

    Science.gov (United States)

    First aid Stroke: First aid Stroke: First aid By Mayo Clinic Staff A stroke occurs when there's bleeding into your brain or when normal blood flow to ... next several hours. Seek immediate medical assistance. A stroke is a true emergency. The sooner treatment is ...

  18. Aid and Development

    DEFF Research Database (Denmark)

    Tarp, Finn; Arndt, Channing; Jones, Edward Samuel

    inputs. We take as our point of departure a growth accounting analysis and review both intended and unintended effects of aid. Mozambique has benefited from sustained aid inflows in conflict, post-conflict and reconstruction periods. In each of these phases aid has made an unambiguous, positive...

  19. Gastric bypass surgery

    Science.gov (United States)

    ... Roux-en-Y; Weight-loss surgery - gastric bypass; Obesity surgery - gastric bypass ... bypass surgery is not a quick fix for obesity. It will greatly change your lifestyle. After this surgery, you must eat healthy foods, control portion sizes of ...

  20. Corrective Jaw Surgery

    Medline Plus

    Full Text Available ... out more. Cleft Lip/Palate and Craniofacial Surgery Cleft Lip/Palate and Craniofacial Surgery A cleft lip may ... out more. Cleft Lip/Palate and Craniofacial Surgery Cleft Lip/Palate and Craniofacial Surgery A cleft lip may ...

  1. Implantation of 3D-Printed Patient-Specific Aneurysm Models into Cadaveric Specimens: A New Training Paradigm to Allow for Improvements in Cerebrovascular Surgery and Research

    Directory of Open Access Journals (Sweden)

    Arnau Benet

    2015-01-01

    Full Text Available Aim. To evaluate the feasibility of implanting 3D-printed brain aneurysm model in human cadavers and to assess their utility in neurosurgical research, complex case management/planning, and operative training. Methods. Two 3D-printed aneurysm models, basilar apex and middle cerebral artery, were generated and implanted in four cadaveric specimens. The aneurysms were implanted at the same anatomical region as the modeled patient. Pterional and orbitozygomatic approaches were done on each specimen. The aneurysm implant, manipulation capabilities, and surgical clipping were evaluated. Results. The 3D aneurysm models were successfully implanted to the cadaveric specimens’ arterial circulation in all cases. The features of the neck in terms of flexibility and its relationship with other arterial branches allowed for the practice of surgical maneuvering characteristic to aneurysm clipping. Furthermore, the relationship of the aneurysm dome with the surrounding structures allowed for better understanding of the aneurysmal local mass effect. Noticeably, all of these observations were done in a realistic environment provided by our customized embalming model for neurosurgical simulation. Conclusion. 3D aneurysms models implanted in cadaveric specimens may represent an untapped training method for replicating clip technique; for practicing certain approaches to aneurysms specific to a particular patient; and for improving neurosurgical research.

  2. IMRT patient-specific QA using the Delta4 dosimetry system and evaluation based on ICRU 83 recommendations

    Science.gov (United States)

    Nilsson, J.; Karlsson Hauer, A.; Bäck, A.

    2013-06-01

    Patient-specific IMRT QA is dependent on the dosimetry system and the evaluation procedure. The ICRU report 83 provides recommendations of tolerated deviations between measured and calculated absorbed dose distributions for QA of IMRT treatment plans. The result of doing IMRT patient-specific QA with the Delta4 dosimetry system and using the ICRU recommendations for evaluation is studied. To be able to investigate the QA procedure the original IMRT treatment plans were modified in the treatment planning system to create calculated dose distributions with dosimetric deviations from the original treatment plans. The modified dose distributions were compared to the dose distributions from the Delta4 measurements of the original treatment plans and the differences were evaluated with criteria and tolerance levels according to the recommendations from ICRU. The evaluation for all 28 modified dose distributions have gamma passing rates higher than the tolerance level recommended from ICRU and will therefore pass the patient-specific QA. More than half of the evaluations have a gamma passing rate of 100 %. Evaluation of the differences between the modified and the original calculated dose distributions revealed in several cases large unacceptable dose differences in the PTV volumes and the organs at risk, for example an increase in the near-maximum dose D2% to the spinal cord of 5.5 Gy. This study indicates that patient-specific QA with the Delta4 dosimetry system and the ICRU recommendations for evaluation can not be used to distinguish differences between planned and measured dose of dosimetrical relevance.

  3. A patient-specific EMG-driven neuromuscular model for the potential use of human-inspired gait rehabilitation robots.

    Science.gov (United States)

    Ma, Ye; Xie, Shengquan; Zhang, Yanxin

    2016-03-01

    A patient-specific electromyography (EMG)-driven neuromuscular model (PENm) is developed for the potential use of human-inspired gait rehabilitation robots. The PENm is modified based on the current EMG-driven models by decreasing the calculation time and ensuring good prediction accuracy. To ensure the calculation efficiency, the PENm is simplified into two EMG channels around one joint with minimal physiological parameters. In addition, a dynamic computation model is developed to achieve real-time calculation. To ensure the calculation accuracy, patient-specific muscle kinematics information, such as the musculotendon lengths and the muscle moment arms during the entire gait cycle, are employed based on the patient-specific musculoskeletal model. Moreover, an improved force-length-velocity relationship is implemented to generate accurate muscle forces. Gait analysis data including kinematics, ground reaction forces, and raw EMG signals from six adolescents at three different speeds were used to evaluate the PENm. The simulation results show that the PENm has the potential to predict accurate joint moment in real-time. The design of advanced human-robot interaction control strategies and human-inspired gait rehabilitation robots can benefit from the application of the human internal state provided by the PENm.

  4. Towards the Personalized Treatment of Glioblastoma: Integrating Patient-Specific Clinical Data in a Continuous Mechanical Model.

    Directory of Open Access Journals (Sweden)

    Maria Cristina Colombo

    Full Text Available Glioblastoma multiforme (GBM is the most aggressive and malignant among brain tumors. In addition to uncontrolled proliferation and genetic instability, GBM is characterized by a diffuse infiltration, developing long protrusions that penetrate deeply along the fibers of the white matter. These features, combined with the underestimation of the invading GBM area by available imaging techniques, make a definitive treatment of GBM particularly difficult. A multidisciplinary approach combining mathematical, clinical and radiological data has the potential to foster our understanding of GBM evolution in every single patient throughout his/her oncological history, in order to target therapeutic weapons in a patient-specific manner. In this work, we propose a continuous mechanical model and we perform numerical simulations of GBM invasion combining the main mechano-biological characteristics of GBM with the micro-structural information extracted from radiological images, i.e. by elaborating patient-specific Diffusion Tensor Imaging (DTI data. The numerical simulations highlight the influence of the different biological parameters on tumor progression and they demonstrate the fundamental importance of including anisotropic and heterogeneous patient-specific DTI data in order to obtain a more accurate prediction of GBM evolution. The results of the proposed mathematical model have the potential to provide a relevant benefit for clinicians involved in the treatment of this particularly aggressive disease and, more importantly, they might drive progress towards improving tumor control and patient's prognosis.

  5. Hemodynamic Assessment of Compliance of Pre-Stressed Pulmonary Valve-Vasculature in Patient Specific Geometry Using an Inverse Algorithm

    Science.gov (United States)

    Hebbar, Ullhas; Paul, Anup; Banerjee, Rupak

    2016-11-01

    Image based modeling is finding increasing relevance in assisting diagnosis of Pulmonary Valve-Vasculature Dysfunction (PVD) in congenital heart disease patients. This research presents compliant artery - blood interaction in a patient specific Pulmonary Artery (PA) model. This is an improvement over our previous numerical studies which assumed rigid walled arteries. The impedance of the arteries and the energy transfer from the Right Ventricle (RV) to PA is governed by compliance, which in turn is influenced by the level of pre-stress in the arteries. In order to evaluate the pre-stress, an inverse algorithm was developed using an in-house script written in MATLAB and Python, and implemented using the Finite Element Method (FEM). This analysis used a patient specific material model developed by our group, in conjunction with measured pressure (invasive) and velocity (non-invasive) values. The analysis was performed on an FEM solver, and preliminary results indicated that the Main PA (MPA) exhibited higher compliance as well as increased hysteresis over the cardiac cycle when compared with the Left PA (LPA). The computed compliance values for the MPA and LPA were 14% and 34% lesser than the corresponding measured values. Further, the computed pressure drop and flow waveforms were in close agreement with the measured values. In conclusion, compliant artery - blood interaction models of patient specific geometries can play an important role in hemodynamics based diagnosis of PVD.

  6. Robotic surgery is ready for prime time in India: Against the motion

    Directory of Open Access Journals (Sweden)

    Tehemton E Udwadia

    2015-01-01

    Full Text Available The use of Robotic Surgery as a purported adjunct and aid to Minimal Access Surgery (MAS is growing in several areas. The acknowledged advantages as also the obvious and hidden disadvantages of Robotic Surgery are highlighted. Survey of literature shows that while Robotic Surgery is "feasible" and the results are "comparable" there is no convincing evidence that it is any better than MAS or even open surgery in most areas. To move "Robotic Surgery is ready for prime time in India" with no less than two dozen robots, many sub-optimally utilized for a population of 1.2 billion seems untenable.

  7. Robotic surgery is ready for prime time in India: Against the motion.

    Science.gov (United States)

    Udwadia, Tehemton E

    2015-01-01

    The use of Robotic Surgery as a purported adjunct and aid to Minimal Access Surgery (MAS) is growing in several areas. The acknowledged advantages as also the obvious and hidden disadvantages of Robotic Surgery are highlighted. Survey of literature shows that while Robotic Surgery is "feasible" and the results are "comparable" there is no convincing evidence that it is any better than MAS or even open surgery in most areas. To move "Robotic Surgery is ready for prime time in India" with no less than two dozen robots, many sub-optimally utilized for a population of 1.2 billion seems untenable.

  8. Conditional Aid Effectiveness

    DEFF Research Database (Denmark)

    Doucouliagos, Hristos; Paldam, Martin

    The AEL (aid effectiveness literature) studies the effect of development aid using econometrics on macro data. It contains about 100 papers of which a third analyzes conditional models where aid effectiveness depends upon z, so that aid only works for a certain range of the variable. The key term...... in this family of AEL models is thus an interaction term of z times aid. The leading candidates for z are a good policy index and aid itself. In this paper, meta-analysis techniques are used (i) to determine whether the AEL has established the said interaction terms, and (ii) to identify some of the determinants...... of the differences in results between studies. Taking all available studies in consideration, we find no support for conditionality with respect to policy, while conditionality regarding aid itself is dubious. However, the results differ depending on the authors’ institutional affiliation....

  9. Aid and Development

    DEFF Research Database (Denmark)

    Tarp, Finn; Arndt, Channing; Jones, Edward Samuel

    This paper considers the relationship between external aid and development in Mozambique from 1980 to 2004. The main objective is to identify the specific mechanisms through which aid has influenced the developmental trajectory of the country and whether one can plausibly link outcomes to aid...... inputs. We take as our point of departure a growth accounting analysis and review both intended and unintended effects of aid. Mozambique has benefited from sustained aid inflows in conflict, post-conflict and reconstruction periods. In each of these phases aid has made an unambiguous, positive...... contribution both enabling and supporting rapid growth since 1992. At the same time, the proliferation of donors and aid-supported interventions has burdened local administration and there is a distinct need to develop government accountability to its own citizens rather than donor agencies. In ensuring...

  10. China vs. AIDS

    Institute of Scientific and Technical Information of China (English)

    LURUCAI

    2004-01-01

    CHINA's first HIV positive diagnosis was in 1985, the victim an ArgentineAmerican. At that time most Chinese,medical workers included, thought of AIDS as a phenomenon occurring outside of China. Twenty years later, the number of HIV/AIDS patients has risen alarmingly. In 2003, the Chinese Ministry of Health launched an AIDS Epidemiological Investigation across China with the support of the WHO and UN AIDS Program. Its results show that there are currently 840,000 HIV carriers, including 80,000 people with full-blown AIDS, in 31 Chinese provinces, municipalities and autonomous regions. This means China has the second highest number of HIV/AIDS cases in Asia and 14th highest in the world. Statistics from the Chinese Venereal Disease and AIDS Prevention Association indicate that the majority of Chinese HIV carriers are young to middle aged, more than half of them between the ages of 20 and 29.

  11. Aid Effectiveness on Growth

    DEFF Research Database (Denmark)

    Doucouliagos, Hristos; Paldam, Martin

    The AEL (aid effectiveness literature) is econo¬metric studies of the macroeconomic effects of development aid. It contains about 100 papers of which 68 are reduced form estimates of theeffect of aid on growth in the recipient country. The raw data show that growth is unconnected to aid......, but the AEL has put so much structure on the data that all results possible have emerged. The present meta study considers both the best-set of the 68 papers and the all-set of 543 regressions published. Both sets have a positive average aid-growth elasticity, but it is small and insignificant: The AEL has...... betweenstudies is real. In particular, the aid-growth association is stronger for Asian countries, and the aid-growth association is shown to have been weaker in the 1970s....

  12. The evaluation for outcome of surgery in children with intermittent exotropia based on computer-aided method for strabismus measurement%计算机辅助儿童斜视客观定量诊断技术对儿童间歇性外斜视手术疗效评估

    Institute of Scientific and Technical Information of China (English)

    况丹; 项道满; 郑德慧; 龙静姬

    2016-01-01

    目的 回顾性分析一组儿童间歇性外斜视病人的手术疗效,分析计算机辅助儿童斜视客观定量诊断技术在间歇性外斜视诊治中的应用价值,研究儿童间歇性外斜视病人不同年龄段手术的效果.方法 回顾性系列病例研究.对2011年9月至2014年12月在广州妇女儿童医疗中心就诊的50例1~7岁的间歇性外斜视患儿,运用“计算机辅助儿童斜视客观定量诊断技术”进行斜视角度测量.在此基础上进行手术治疗.通过比对临床资料与随访信息,分析术后不同时期各年龄组间的正位率,及术后半年及1年双眼视功能的获得比率有无差异.结果 不同年龄组间之间、术后不同时期正位率无显著差异.将4~7岁患儿按年龄分为4组,各组间术后1年融合功能的获得比率有差异,4岁组的获得比率最高差异有统计学意义(P<0.05),且随年龄增长存在显著下降趋势(P<0.01).结论 “计算机辅助儿童斜视客观定量诊断技术”,对婴幼儿间歇性外斜视病人,也可以获得斜视度数.儿童间歇性外斜视在获得准确的斜视角的基础上,婴幼儿期的间歇性斜视手术可以获得与大龄儿童一样的正位率.儿童间歇性外斜视病人,越早手术获得双眼同时视功能和融合功能的机会越大.%Objective To retrospectively analyze the outcome of surgery in a group of children with intermittent exotropia,analysis the application value of "computer-aided method for strabismus measurement" for intermittent strabismus diagnosis,and study the outcome of surgery in children with intermittent exotropia from different ages.Methods For 50 cases of 1-7 years children with intermittent exotropia,"computer-aided method for strabismus measurement" was used for the strabismus angle measurement,and carry out surgical treatment on this basis.Positive rate analysis on basis of the clinical data and follow-up information after different periods between different

  13. The use of patient-specific measurement instruments in the process of goal-setting: a systematic review of available instruments and their feasibility

    NARCIS (Netherlands)

    Stevens, A.; Beurskens, A.; Koke, A.; Weijden, T.T. van der

    2013-01-01

    OBJECTIVE: The aim of this study was to identify the currently available patient-specific measurement instruments used in the process of goal-setting and to assess their feasibility. METHODS: After a systematic search in PubMed, EMBASE, CINAHL, PsychINFO and REHABDATA, patient-specific instruments w

  14. Infections in outpatient surgery.

    Science.gov (United States)

    Nazarian Mobin, Sheila S; Keyes, Geoffrey R; Singer, Robert; Yates, James; Thompson, Dennis

    2013-07-01

    In the plastic surgery patient population, outpatient surgery is cost effective and will continue to grow as the preferred arena for performing surgery in healthy patients. Although there is a widespread myth that outpatient surgery centers may suffer from increased infection rates due to lax infection control, the data presented from American Association for Accreditation of Ambulatory Surgery Facilities-accredited facilities prove the contrary. There is a lack of data investigating infection prevention in the perioperative period in plastic surgery patients. As data collection becomes more refined, tracking the postoperative care environment should offer additional opportunities to lower the incidence of postoperative infections.

  15. Dental outcomes in computer-assisted orthognathic surgery.

    Science.gov (United States)

    Hamilton, Travis; Markiewicz, Michael R; Jarman, Joseph; Bell, R Bryan

    2012-05-01

    The purpose of this study was to assess the effectiveness of computer-aided orthognathic surgery in reducing incisal overjet and establishing class I occlusion in subjects with dentofacial deformities. To address the research purpose, the investigators initiated a retrospective cohort study and enrolled a sample of subjects who underwent computer-assisted orthognathic surgery for dentofacial deformities. Two examiners assessed preoperative and postoperative lateral cephalometric radiographs for change in overjet after computer-assisted orthognathic surgery. Preoperative and postoperative occlusal photographs were then reviewed to assess for establishment of class I occlusion after computer-assisted orthognathic surgery. Cohen κ coefficient was used to assess for interrater agreement. A matched-pairs t-test was used to assess reduction in incisal overjet after computer-assisted orthognathic surgery. The sample was composed of 9 subjects who underwent computer-assisted surgery for dentofacial deformities. There was good interrater consistency for preoperative measurement of overjet (κ = 0.7, P ≤ 0.001). There was fair interrater consistency for postoperative measurement of overjet (κ = 0.4, P = 0 .02). Both examiners agreed on preoperative and postoperative assessments of occlusal photographs. There was a 3.4-mm reduction in incisal overjet after computer-assisted orthognathic surgery (P ≤ 0.001). Mean postoperative absolute overjet was 1.3 mm. In subjects with dentofacial deformities, computer-aided orthognathic surgery was effective in reducing incisal overjet and establishing class I occlusion.

  16. Feasibility study of patient-specific quality assurance system for high-dose-rate brachytherapy in patients with cervical cancer

    Science.gov (United States)

    Lee, Boram; Ahn, Sung Hwan; Kim, Hyeyoung; Han, Youngyih; Huh, Seung Jae; Kim, Jin Sung; Kim, Dong Wook; Sim, Jina; Yoon, Myonggeun

    2016-04-01

    This study was conducted for the purpose of establishing a quality-assurance (QA) system for brachytherapy that can ensure patient-specific QA by enhancing dosimetric accuracy for the patient's therapy plan. To measure the point-absorbed dose and the 2D dose distribution for the patient's therapy plan, we fabricated a solid phantom that allowed for the insertion of an applicator for patient-specific QA and used an ion chamber and a film as measuring devices. The patient treatment plan was exported to the QA dose-calculation software, which calculated the time weight of dwell position stored in the plan DICOM (Digital Imaging and Communications in Medicine) file to obtain an overall beam quality correction factor, and that correction was applied to the dose calculations. Experiments were conducted after importing the patient's treatment planning source data for the fabricated phantom and inserting the applicator, ion chamber, and film into the phantom. On completion of dose delivery, the doses to the ion chamber and film were checked against the corresponding treatment plan to evaluate the dosimetric accuracy. For experimental purposes, five treatment plans were randomly selected. The beam quality correction factors for ovoid and tandem brachytherapy applicators were found to be 1.15 and 1.10 - 1.12, respectively. The beam quality correction factor in tandem fluctuated by approximately 2%, depending on the changes in the dwell position. The doses measured by using the ion chamber showed differences ranging from -2.4% to 0.6%, compared to the planned doses. As for the film, the passing rate was 90% or higher when assessed using a gamma value of the local dose difference of 3% and a distance to agreement of 3 mm. The results show that the self-fabricated phantom was suitable for QA in clinical settings. The proposed patient-specific QA for the treatment planning is expected to contribute to reduce dosimetric errors in brachytherapy and, thus, to enhancing treatment

  17. The feasibility of producing patient-specific acrylic cranioplasty implants with a low-cost 3D printer.

    Science.gov (United States)

    Tan, Eddie T W; Ling, Ji Min; Dinesh, Shree Kumar

    2016-05-01

    OBJECT Commercially available, preformed patient-specific cranioplasty implants are anatomically accurate but costly. Acrylic bone cement is a commonly used alternative. However, the manual shaping of the bone cement is difficult and may not lead to a satisfactory implant in some cases. The object of this study was to determine the feasibility of fabricating molds using a commercial low-cost 3D printer for the purpose of producing patient-specific acrylic cranioplasty implants. METHODS Using data from a high-resolution brain CT scan of a patient with a calvarial defect posthemicraniectomy, a skull phantom and a mold were generated with computer software and fabricated with the 3D printer using the fused deposition modeling method. The mold was used as a template to shape the acrylic implant, which was formed via a polymerization reaction. The resulting implant was fitted to the skull phantom and the cranial index of symmetry was determined. RESULTS The skull phantom and mold were successfully fabricated with the 3D printer. The application of acrylic bone cement to the mold was simple and straightforward. The resulting implant did not require further adjustment or drilling prior to being fitted to the skull phantom. The cranial index of symmetry was 96.2% (the cranial index of symmetry is 100% for a perfectly symmetrical skull). CONCLUSIONS This study showed that it is feasible to produce patient-specific acrylic cranioplasty implants with a low-cost 3D printer. Further studies are required to determine applicability in the clinical setting. This promising technique has the potential to bring personalized medicine to more patients around the world.

  18. High-fidelity tissue engineering of patient-specific auricles for reconstruction of pediatric microtia and other auricular deformities.

    Directory of Open Access Journals (Sweden)

    Alyssa J Reiffel

    Full Text Available INTRODUCTION: Autologous techniques for the reconstruction of pediatric microtia often result in suboptimal aesthetic outcomes and morbidity at the costal cartilage donor site. We therefore sought to combine digital photogrammetry with CAD/CAM techniques to develop collagen type I hydrogel scaffolds and their respective molds that would precisely mimic the normal anatomy of the patient-specific external ear as well as recapitulate the complex biomechanical properties of native auricular elastic cartilage while avoiding the morbidity of traditional autologous reconstructions. METHODS: Three-dimensional structures of normal pediatric ears were digitized and converted to virtual solids for mold design. Image-based synthetic reconstructions of these ears were fabricated from collagen type I hydrogels. Half were seeded with bovine auricular chondrocytes. Cellular and acellular constructs were implanted subcutaneously in the dorsa of nude rats and harvested after 1 and 3 months. RESULTS: Gross inspection revealed that acellular implants had significantly decreased in size by 1 month. Cellular constructs retained their contour/projection from the animals' dorsa, even after 3 months. Post-harvest weight of cellular constructs was significantly greater than that of acellular constructs after 1 and 3 months. Safranin O-staining revealed that cellular constructs demonstrated evidence of a self-assembled perichondrial layer and copious neocartilage deposition. Verhoeff staining of 1 month cellular constructs revealed de novo elastic cartilage deposition, which was even more extensive and robust after 3 months. The equilibrium modulus and hydraulic permeability of cellular constructs were not significantly different from native bovine auricular cartilage after 3 months. CONCLUSIONS: We have developed high-fidelity, biocompatible, patient-specific tissue-engineered constructs for auricular reconstruction which largely mimic the native auricle both

  19. Models for Planning and Simulation in Computer Assisted Orthognatic Surgery

    CERN Document Server

    Chabanas, M; Payan, Y; Boutault, F; Chabanas, Matthieu; Marecaux, Christophe; Payan, Yohan; Boutault, Franck

    2002-01-01

    Two aspects required to establish a planning in orthognatic surgery are addressed in this paper. First, a 3D cephalometric analysis, which is clini-cally essential for the therapeutic decision. Then, an original method to build a biomechanical model of patient face soft tissue, which provides evaluation of the aesthetic outcomes of an intervention. Both points are developed within a clinical application context for computer aided maxillofacial surgery.

  20. Aid and Growth

    DEFF Research Database (Denmark)

    Arndt, Channing; Jones, Edward Samuel; Tarp, Finn

    The micro-macro paradox has been revived. Despite broadly positive evaluations at the micro and meso-levels, recent literature has turned decidedly pessimistic with respect to the ability of foreign aid to foster economic growth. Policy implications, such as the complete cessation of aid to Africa......, are being drawn on the basis of fragile evidence. This paper first assesses the aid-growth literature with a focus on recent contributions. The aid-growth literature is then framed, for the first time, in terms of the Rubin Causal Model, applied at the macroeconomic level. Our results show that aid has...... a positive and statistically significant causal effect on growth over the long run with point estimates at levels suggested by growth theory. We conclude that aid remains an important tool for enhancing the development prospects of poor nations....

  1. Aid and Growth

    DEFF Research Database (Denmark)

    Arndt, Channing; Jones, Edward Samuel; Tarp, Finn

    2009-01-01

    The micro-macro paradox has been revived. Despite broadly positive evaluations at the micro and meso-levels, recent literature has turned decidedly pessimistic with respect to the ability of foreign aid to foster economic growth. Policy implications, such as the complete cessation of aid to Africa......, are being drawn on the basis of fragile evidence. This paper first assesses the aid-growth literature with a focus on recent contributions. The aid-growth literature is then framed, for the first time, in terms of the Rubin Causal Model, applied at the macroeconomic level. Our results show that aid has...... a positive and statistically significant causal effect on growth over the long run with point estimates at levels suggested by growth theory. We conclude that aid remains an important tool for enhancing the development prospects of poor nations....

  2. Generation of patient-specific pluripotent stem cells and directed differentiation of embryonic stem cells for regenerative medicine

    Institute of Scientific and Technical Information of China (English)

    Minyue Ma; Jiahao Sha; Zuomin Zhou; Qi Zhou; Qingzhang Li

    2008-01-01

    Embryonic stem(ES) cells are pluripotent cells that can give rise to derivatives of all three embryonic germ layers. Due to its characteristics, the patient-specific ES cells are of great potential for transplantation therapies. Several strategies can reprogramme somatic cells back to pluripotent stem cells: nuclear transfer, fusion with ES cells, treatment with cell extract and induction by specific factors. Considering the future clinical use, the differentiation from ES to neurons, cardiomyocytes and many other types of cell scurrently provide basic cognition and experience to regenerative medicine. This article will review two courses, the reprogramming of differentiated cells and the differentiation of ES cells to specific cell types.

  3. Correlation of phantom-based and log file patient-specific QA with complexity scores for VMAT.

    Science.gov (United States)

    Agnew, Christina E; Irvine, Denise M; McGarry, Conor K

    2014-11-08

    The motivation for this study was to reduce physics workload relating to patient- specific quality assurance (QA). VMAT plan delivery accuracy was determined from analysis of pre- and on-treatment trajectory log files and phantom-based ionization chamber array measurements. The correlation in this combination of measurements for patient-specific QA was investigated. The relationship between delivery errors and plan complexity was investigated as a potential method to further reduce patient-specific QA workload. Thirty VMAT plans from three treatment sites - prostate only, prostate and pelvic node (PPN), and head and neck (H&N) - were retrospectively analyzed in this work. The 2D fluence delivery reconstructed from pretreatment and on-treatment trajectory log files was compared with the planned fluence using gamma analysis. Pretreatment dose delivery verification was also car- ried out using gamma analysis of ionization chamber array measurements compared with calculated doses. Pearson correlations were used to explore any relationship between trajectory log file (pretreatment and on-treatment) and ionization chamber array gamma results (pretreatment). Plan complexity was assessed using the MU/ arc and the modulation complexity score (MCS), with Pearson correlations used to examine any relationships between complexity metrics and plan delivery accu- racy. Trajectory log files were also used to further explore the accuracy of MLC and gantry positions. Pretreatment 1%/1 mm gamma passing rates for trajectory log file analysis were 99.1% (98.7%-99.2%), 99.3% (99.1%-99.5%), and 98.4% (97.3%-98.8%) (median (IQR)) for prostate, PPN, and H&N, respectively, and were significantly correlated to on-treatment trajectory log file gamma results (R = 0.989, p log file gamma results (R = 0.623, p 0.57, p log file fluence delivery and ionization chamber array measurements were strongly correlated with on-treatment trajectory log file fluence delivery. The strong corre- lation

  4. AIDS in South Africa.

    Science.gov (United States)

    Ijsselmuiden, C; Evian, C; Matjilla, J; Steinberg, M; Schneider, H

    1993-01-01

    The National AIDS Convention in South Africa (NACOSA) in October 1992 was the first real attempt to address HIV/AIDS. In Soweto, government, the African National Congress, nongovernmental organizations, and organized industry and labor representatives worked for 2 days to develop a national plan of action, but it did not result in a united effort to fight AIDS. The highest HIV infection rates in South Africa are among the KwaZulu in Natal, yet the Inkatha Freedom Party did not attend NACOSA. This episode exemplifies the key obstacles for South Africa to prevent and control AIDS. Inequality of access to health care may explain why health workers did not diagnose the first AIDS case in blacks until 1985. Migrant labor, Bantu education, and uprooted communities affect the epidemiology of HIV infection. Further, political and social polarization between blacks and whites contributes to a mindset that AIDS is limited to the other race which only diminishes the personal and collective sense of susceptibility and the volition and aptitude to act. The Department of National Health and Population Development's voluntary register of anonymously reported cases of AIDS specifies 1517 cumulative AIDS cases (October 1992), but this number is low. Seroprevalence studies show between 400,000-450,000 HIV positive cases. Public hospitals cannot give AIDS patients AZT and DDI. Few communities provided community-based care. Not all hospitals honor confidentiality and patients' need for autonomy. Even though HIV testing is not mandatory, it is required sometimes, e.g., HIV testing of immigrants. AIDS Training, Information and Counselling Centers are in urban areas, but not in poor areas where the need is most acute. The government just recently developed in AIDS education package for schools, but too many people consider it improper, so it is not being used. The poor quality education provided blacks would make it useless anyhow. Lifting of the academic boycott will allow South African

  5. JPRS Report, Epidemiology, Aids

    Science.gov (United States)

    2007-11-02

    at home. For this they can thank the National Federation of Gays and Lesbians (LBL). -To develop an adequate core of specialists in AIDS prevention... Homosexuality [Vusie Ginindza; Mbabane THE TIMES OF SWAZILAND, 15 May 91] ...................................... 4 JPRS-TEP-91-012 5 June 1991 2 AIDS TANZANIA...sensitivity and not to sensa- tionalize the issue. Health Workers ’Alarmed’ at rise in AIDS, Homosexuality SWAZILAND MB1505085891 Mbabane THE TIMES

  6. Radiographic imaging of aids

    CERN Document Server

    Mahmoud, M B

    2002-01-01

    The acquired immunodeficiency syndrome (AIDS) has impacted the civilized world like no other disease. This research aimed to discuss some of the main aids-related complications and their detection by radiology tests, specifically central nervous system and musculoskeletal system disorders. The objectives are: to show specific characteristics of various diseases of HIV patient, to analyze the effect of pathology in patients by radiology, to enhance the knowledge of technologists in aids imaging and to improve communication skills between patient and radiology technologists.

  7. Orthodontic-orthognathic interventions in orthognathic surgical cases: "Paper surgery" and "model surgery" concepts in surgical orthodontics.

    Science.gov (United States)

    Gandedkar, Narayan H; Chng, Chai Kiat; Yeow, Vincent Kok Leng

    2016-01-01

    Thorough planning and execution is the key for successful treatment of dentofacial deformity involving surgical orthodontics. Presurgical planning (paper surgery and model surgery) are the most essential prerequisites of orthognathic surgery, and orthodontist is the one who carries out this procedure by evaluating diagnostic aids such as crucial clinical findings and radiographic assessments. However, literature pertaining to step-by-step orthognathic surgical guidelines is limited. Hence, this article makes an attempt to provide an insight and nuances involved in the planning and execution. The diagnostic information revealed from clinical findings and radiographic assessments is integrated in the "paper surgery" to establish "surgical-plan." Furthermore, the "paper surgery" is emulated in "model surgery" such that surgical bite-wafers are created, which aid surgeon to preview the final outcome and make surgical movements that are deemed essential for the desired skeletal and dental outcomes. Skeletal complexities are corrected by performing "paper surgery" and an occlusion is set up during "model surgery" for the fabrication of surgical bite-wafers. Further, orthodontics is carried out for the proper settling and finishing of occlusion. Article describes the nuances involved in the treatment of Class III skeletal deformity individuals treated with orthognathic surgical approach and illustrates orthodontic-orthognathic step-by-step procedures from "treatment planning" to "execution" for successful management of aforementioned dentofacial deformity.

  8. Orthodontic-orthognathic interventions in orthognathic surgical cases: "Paper surgery" and "model surgery" concepts in surgical orthodontics

    Directory of Open Access Journals (Sweden)

    Narayan H Gandedkar

    2016-01-01

    Full Text Available Thorough planning and execution is the key for successful treatment of dentofacial deformity involving surgical orthodontics. Presurgical planning (paper surgery and model surgery are the most essential prerequisites of orthognathic surgery, and orthodontist is the one who carries out this procedure by evaluating diagnostic aids such as crucial clinical findings and radiographic assessments. However, literature pertaining to step-by-step orthognathic surgical guidelines is limited. Hence, this article makes an attempt to provide an insight and nuances involved in the planning and execution. The diagnostic information revealed from clinical findings and radiographic assessments is integrated in the "paper surgery" to establish "surgical-plan." Furthermore, the "paper surgery" is emulated in "model surgery" such that surgical bite-wafers are created, which aid surgeon to preview the final outcome and make surgical movements that are deemed essential for the desired skeletal and dental outcomes. Skeletal complexities are corrected by performing "paper surgery" and an occlusion is set up during "model surgery" for the fabrication of surgical bite-wafers. Further, orthodontics is carried out for the proper settling and finishing of occlusion. Article describes the nuances involved in the treatment of Class III skeletal deformity individuals treated with orthognathic surgical approach and illustrates orthodontic-orthognathic step-by-step procedures from "treatment planning" to "execution" for successful management of aforementioned dentofacial deformity.

  9. Washington DC Area Computer Aided Surgery Society Monthly Meetings

    Science.gov (United States)

    2009-03-01

    experience shows that IR endoscopy can be used to define intracardiac and vascular anatomy and guide interventional procedures. 3.1.3 The Mathematics...scanning of non- sedated infants and image analysis methods that can cope with very low contrast-to-noise ratio, small brain size, variability of brain

  10. Music and hearing aids.

    Science.gov (United States)

    Madsen, Sara M K; Moore, Brian C J

    2014-10-31

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems.

  11. Heart bypass surgery - discharge

    Science.gov (United States)

    ... Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery . 19th ed. Philadelphia, PA: Elsevier ... Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery . 20th ed. Philadelphia, PA: Elsevier; ...

  12. LASIK Eye Surgery

    Science.gov (United States)

    ... are nearsighted. You may need another refractive surgery (enhancement surgery) within a year to remove more tissue. ... may happen due to certain conditions, such as abnormal wound healing, hormonal imbalances or pregnancy. Visual loss ...

  13. Heart valve surgery

    Science.gov (United States)

    ... techniques are used: Percutaneous surgery (through the skin) Robot-assisted surgery If your surgeon can repair your ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  14. Otoplasty (Cosmetic Ear Surgery)

    Science.gov (United States)

    ... By Mayo Clinic Staff Otoplasty — also known as cosmetic ear surgery — is a procedure to change the shape, position ... age 5 — through adulthood. In some cases, the surgery is done as early as age 3. If ...

  15. Cosmetic breast surgery - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000273.htm Cosmetic breast surgery - discharge To use the sharing features on this page, please enable JavaScript. You had cosmetic breast surgery to change the size or shape ...

  16. Cosmetic ear surgery

    Science.gov (United States)

    Otoplasty; Ear pinning; Ear surgery - cosmetic; Ear reshaping; Pinnaplasty ... Cosmetic ear surgery may be done in the surgeon's office, an outpatient clinic, or a hospital. It can be performed under ...

  17. Weight Loss Surgery

    Science.gov (United States)

    Weight loss surgery helps people with extreme obesity to lose weight. It may be an option if you cannot lose weight ... obesity. There are different types of weight loss surgery. They often limit the amount of food you ...

  18. Hip fracture surgery

    Science.gov (United States)

    ... neck fracture repair; Trochanteric fracture repair; Hip pinning surgery; Osteoarthritis-hip ... You may receive general anesthesia before this surgery. This means ... spinal anesthesia. With this kind of anesthesia, medicine is ...

  19. Laparoscopic Spine Surgery

    Science.gov (United States)

    ... Exhibit Opportunities Sponsorship Opportunities Log In Laparoscopic Spine Surgery Patient Information from SAGES Download PDF Find a SAGES Surgeon Laparoscopic Spine Surgery Your spine surgeon has determined that you need ...

  20. Types of Heart Surgery

    Science.gov (United States)

    ... from the NHLBI on Twitter. Types of Heart Surgery Coronary Artery Bypass Grafting Coronary artery bypass grafting ( ... TAHs) might be used to treat these patients. Surgery To Place Ventricular Assist Devices or Total Artificial ...

  1. Breast Reduction Surgery

    Science.gov (United States)

    ... breastfeeding: A systematic review. Journal of Plastic, Reconstructive & Aesthetic Surgery. 2010;63:1688. Kerrigan CL, et al. Evidence-based medicine: Reduction mammoplasty. Plastic and Reconstructive Surgery. 2013;132: ...

  2. General Dermatologic Surgery Information

    Science.gov (United States)

    ... all dermatologic surgeons perform both medically necessary and cosmetic surgery procedures to maintain the health, function and appearance ... and refinement of many of today’s therapeutic and cosmetic surgery procedures. Great strides in minimally invasive techniques and ...

  3. Bariatric Surgery Procedures

    Science.gov (United States)

    ... Center Access to Care Toolkit EHB Access Toolkit Bariatric Surgery Procedures Bariatric surgical procedures cause weight loss by ... Bariatric procedures also often cause hormonal changes. Most weight loss surgeries today are performed using minimally invasive techniques (laparoscopic ...

  4. Bariatric Surgery Misconceptions

    Science.gov (United States)

    ... from depression or anxiety and to have lower self-esteem and overall quality of life than someone who ... is a Candidate for Bariatric Surgery? Childhood and Adolescent Obesity Find a Provider Benefits of Bariatric Surgery ...

  5. Surgery for Testicular Cancer

    Science.gov (United States)

    ... Stage Testicular Cancer Treating Testicular Cancer Surgery for Testicular Cancer Surgery is typically the first treatment for all ... Testicular Cancer, by Type and Stage More In Testicular Cancer About Testicular Cancer Causes, Risk Factors, and Prevention ...

  6. The application of problem-based learning with computer aided technology in teaching of breast surgery clinical practice%以问题为基础的学习结合计算机辅助技术在乳腺外科临床见习教学中的应用

    Institute of Scientific and Technical Information of China (English)

    牛兆河; 董蒨; 王海波

    2014-01-01

    Objective To probe the teaching method of application of problem-based learning (PBL)with computer aided technology in teaching of breast surgery clinical practice.Methods 48 students were randomly divided into two groups:control group(n=24) were taught by lecture-based learning(LBL),experimental group (n=24) were taught by method of application of problem-based learning(PBL)with computer aided technology.Questionnaire was provided to the students of experimental group to investigate the degree of recognition to the teaching method of problem-based learning (PBL)with computer aided technology.5 patients from experimental group and 5 patients from control group participating in teaching were given questionnaires to investigate if their right of privacy were violated.The theory examination score(out of 50) and comprehensive skills assessment score (out of 50) were compared between the two groups; the mean differences between the two groups were compared by t test.Result The teaching method of application of problem-based learning(PBL) with computer aided technology was recognition by 91.7 %(22 persons) of students.20 percent(one person) of the experimental group patients felt their right of privacy violated; 60 percent(three persons) of the control group patients felt their right of privacy violated.The theory test scores of the experimental group and control group were (46.23 ± 2.45) and (45.52 ± 3.29).There was no statistical significance (t=1.230,P=0.225).The skill test scores of the experimental group and control group were(47.23± 2.45) and (36.52 t 3.29).There was statistical significance(t=12.791,P=0.000).Conclusion The teaching method of application of problem-based learning(PBL) with computer aided technology can help encourage the study interest of students,and cultivate their clinical thinking method and capacity,and protect the right of privacy of the patients,avoiding patient-hospital disputes.%目的 探讨

  7. Limb salvage surgery

    Directory of Open Access Journals (Sweden)

    Dinesh Kadam

    2013-01-01

    Full Text Available The threat of lower limb loss is seen commonly in severe crush injury, cancer ablation, diabetes, peripheral vascular disease and neuropathy. The primary goal of limb salvage is to restore and maintain stability and ambulation. Reconstructive strategies differ in each condition such as: Meticulous debridement and early coverage in trauma, replacing lost functional units in cancer ablation, improving vascularity in ischaemic leg and providing stable walking surface for trophic ulcer. The decision to salvage the critically injured limb is multifactorial and should be individualised along with laid down definitive indications. Early cover remains the standard of care, delayed wound coverage not necessarily affect the final outcome. Limb salvage is more cost-effective than amputations in a long run. Limb salvage is the choice of procedure over amputation in 95% of limb sarcoma without affecting the survival. Compound flaps with different tissue components, skeletal reconstruction; tendon transfer/reconstruction helps to restore function. Adjuvant radiation alters tissue characters and calls for modification in reconstructive plan. Neuropathic ulcers are wide and deep often complicated by osteomyelitis. Free flap reconstruction aids in faster healing and provides superior surface for offloading. Diabetic wounds are primarily due to neuropathy and leads to six-fold increase in ulcerations. Control of infections, aggressive debridement and vascular cover are the mainstay of management. Endovascular procedures are gaining importance and have reduced extent of surgery and increased amputation free survival period. Though the standard approach remains utilising best option in the reconstruction ladder, the recent trend shows running down the ladder of reconstruction with newer reliable local flaps and negative wound pressure therapy.

  8. Limb salvage surgery.

    Science.gov (United States)

    Kadam, Dinesh

    2013-05-01

    The threat of lower limb loss is seen commonly in severe crush injury, cancer ablation, diabetes, peripheral vascular disease and neuropathy. The primary goal of limb salvage is to restore and maintain stability and ambulation. Reconstructive strategies differ in each condition such as: Meticulous debridement and early coverage in trauma, replacing lost functional units in cancer ablation, improving vascularity in ischaemic leg and providing stable walking surface for trophic ulcer. The decision to salvage the critically injured limb is multifactorial and should be individualised along with laid down definitive indications. Early cover remains the standard of care, delayed wound coverage not necessarily affect the final outcome. Limb salvage is more cost-effective than amputations in a long run. Limb salvage is the choice of procedure over amputation in 95% of limb sarcoma without affecting the survival. Compound flaps with different tissue components, skeletal reconstruction; tendon transfer/reconstruction helps to restore function. Adjuvant radiation alters tissue characters and calls for modification in reconstructive plan. Neuropathic ulcers are wide and deep often complicated by osteomyelitis. Free flap reconstruction aids in faster healing and provides superior surface for offloading. Diabetic wounds are primarily due to neuropathy and leads to six-fold increase in ulcerations. Control of infections, aggressive debridement and vascular cover are the mainstay of management. Endovascular procedures are gaining importance and have reduced extent of surgery and increased amputation free survival period. Though the standard approach remains utilising best option in the reconstruction ladder, the recent trend shows running down the ladder of reconstruction with newer reliable local flaps and negative wound pressure therapy.

  9. High-quality conforming hexahedral meshes of patient-specific abdominal aortic aneurysms including their intraluminal thrombi.

    Science.gov (United States)

    Tarjuelo-Gutierrez, J; Rodriguez-Vila, B; Pierce, D M; Fastl, T E; Verbrugghe, P; Fourneau, I; Maleux, G; Herijgers, P; Holzapfel, G A; Gomez, E J

    2014-02-01

    In order to perform finite element (FE) analyses of patient-specific abdominal aortic aneurysms, geometries derived from medical images must be meshed with suitable elements. We propose a semi-automatic method for generating conforming hexahedral meshes directly from contours segmented from medical images. Magnetic resonance images are generated using a protocol developed to give the abdominal aorta high contrast against the surrounding soft tissue. These data allow us to distinguish between the different structures of interest. We build novel quadrilateral meshes for each surface of the sectioned geometry and generate conforming hexahedral meshes by combining the quadrilateral meshes. The three-layered morphology of both the arterial wall and thrombus is incorporated using parameters determined from experiments. We demonstrate the quality of our patient-specific meshes using the element Scaled Jacobian. The method efficiently generates high-quality elements suitable for FE analysis, even in the bifurcation region of the aorta into the iliac arteries. For example, hexahedral meshes of up to 125,000 elements are generated in less than 130 s, with 94.8 % of elements well suited for FE analysis. We provide novel input for simulations by independently meshing both the arterial wall and intraluminal thrombus of the aneurysm, and their respective layered morphologies.

  10. Patient-specific stopping power calibration for proton therapy planning based on single-detector proton radiography.

    Science.gov (United States)

    Doolan, P J; Testa, M; Sharp, G; Bentefour, E H; Royle, G; Lu, H-M

    2015-03-07

    A simple robust optimizer has been developed that can produce patient-specific calibration curves to convert x-ray computed tomography (CT) numbers to relative stopping powers (HU-RSPs) for proton therapy treatment planning. The difference between a digitally reconstructed radiograph water-equivalent path length (DRRWEPL) map through the x-ray CT dataset and a proton radiograph (set as the ground truth) is minimized by optimizing the HU-RSP calibration curve. The function of the optimizer is validated with synthetic datasets that contain no noise and its robustness is shown against CT noise. Application of the procedure is then demonstrated on a plastic and a real tissue phantom, with proton radiographs produced using a single detector. The mean errors using generic/optimized calibration curves between the DRRWEPL map and the proton radiograph were 1.8/0.4% for a plastic phantom and -2.1/ - 0.2% for a real tissue phantom. It was then demonstrated that these optimized calibration curves offer a better prediction of the water equivalent path length at a therapeutic depth. We believe that these promising results are suggestive that a single proton radiograph could be used to generate a patient-specific calibration curve as part of the current proton treatment planning workflow.

  11. cGMP production of patient-specific iPSCs and photoreceptor precursor cells to treat retinal degenerative blindness.

    Science.gov (United States)

    Wiley, Luke A; Burnight, Erin R; DeLuca, Adam P; Anfinson, Kristin R; Cranston, Cathryn M; Kaalberg, Emily E; Penticoff, Jessica A; Affatigato, Louisa M; Mullins, Robert F; Stone, Edwin M; Tucker, Budd A

    2016-07-29

    Immunologically-matched, induced pluripotent stem cell (iPSC)-derived photoreceptor precursor cells have the potential to restore vision to patients with retinal degenerative diseases like retinitis pigmentosa. The purpose of this study was to develop clinically-compatible methods for manufacturing photoreceptor precursor cells from adult skin in a non-profit cGMP environment. Biopsies were obtained from 35 adult patients with inherited retinal degeneration and fibroblast lines were established under ISO class 5 cGMP conditions. Patient-specific iPSCs were then generated, clonally expanded and validated. Post-mitotic photoreceptor precursor cells were generated using a stepwise cGMP-compliant 3D differentiation protocol. The recapitulation of the enhanced S-cone phenotype in retinal organoids generated from a patient with NR2E3 mutations demonstrated the fidelity of these protocols. Transplantation into immune compromised animals revealed no evidence of abnormal proliferation or tumor formation. These studies will enable clinical trials to test the safety and efficiency of patient-specific photoreceptor cell replacement in humans.

  12. Influence of Geometry and Mechanical Properties on the Accuracy of Patient-Specific Simulation of Women Pelvic Floor.

    Science.gov (United States)

    Mayeur, Olivier; Witz, Jean-François; Lecomte, Pauline; Brieu, Mathias; Cosson, Michel; Miller, Karol

    2016-01-01

    The woman pelvic system involves multiple organs, muscles, ligaments, and fasciae where different pathologies may occur. Here we are most interested in abnormal mobility, often caused by complex and not fully understood mechanisms. Computer simulation and modeling using the finite element (FE) method are the tools helping to better understand the pathological mobility, but of course patient-specific models are required to make contribution to patient care. These models require a good representation of the pelvic system geometry, information on the material properties, boundary conditions and loading. In this contribution we focus on the relative influence of the inaccuracies in geometry description and of uncertainty of patient-specific material properties of soft connective tissues. We conducted a comparative study using several constitutive behavior laws and variations in geometry description resulting from the imprecision of clinical imaging and image analysis. We find that geometry seems to have the dominant effect on the pelvic organ mobility simulation results. Provided that proper finite deformation non-linear FE solution procedures are used, the influence of the functional form of the constitutive law might be for practical purposes negligible. These last findings confirm similar results from the fields of modeling neurosurgery and abdominal aortic aneurysms.

  13. Future of liver transplantation: non-human primates for patient-specific organs from induced pluripotent stem cells.

    Science.gov (United States)

    Sanal, Madhusudana Girija

    2011-08-28

    Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the complex relations between different cell types, generation of adequate vasculature, and immunological complications are road blocks in generation of bioengineered organs, while immunological complications limit the use of humanized organs produced in animals. Recent developments in induced pluripotent stem cell (iPSC) biology offer a possibility of generating human, patient-specific organs in non-human primates (NHP) using patient-derived iPSC and NHP-derived iPSC lacking the critical developmental genes for the organ of interest complementing a NHP tetraploid embryo. The organ derived in this way will have the same human leukocyte antigen (HLA) profile as the patient. This approach can be curative in genetic disorders as this offers the possibility of gene manipulation and correction of the patient's genome at the iPSC stage before tetraploid complementation. The process of generation of patient-specific organs such as the liver in this way has the great advantage of making use of the natural signaling cascades in the natural milieu probably resulting in organs of great quality for transplantation. However, the inexorable scientific developments in this direction involve several social issues and hence we need to educate and prepare society in advance to accept the revolutionary consequences, good, bad and ugly.

  14. Future of liver transplantation: Non-human primates for patient-specific organs from induced pluripotent stem cells

    Institute of Scientific and Technical Information of China (English)

    Madhusudana Girija Sanal

    2011-01-01

    Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and im-plantable bioengineered constructs. Reproducing the complex relations between different cell types, gen-eration of adequate vasculature, and immunological complications are road blocks in generation of bioengi-neered organs, while immunological complications limit the use of humanized organs produced in animals. Recent developments in induced pluripotent stem cell (iPSC) biology offer a possibility of generating human, patient-specific organs in non-human primates (NHP) using patient-derived iPSC and NHP-derived iPSC lack-ing the critical developmental genes for the organ of interest complementing a NHP tetraploid embryo. The organ derived in this way will have the same human leukocyte antigen (HLA) profile as the patient. This ap-proach can be curative in genetic disorders as this of-fers the possibility of gene manipulation and correction of the patient's genome at the iPSC stage before tet-raploid complementation. The process of generation of patient-specific organs such as the liver in this way has the great advantage of making use of the natural sig-naling cascades in the natural milieu probably resulting in organs of great quality for transplantation. However, the inexorable scientific developments in this direction involve several social issues and hence we need to educate and prepare society in advance to accept the revolutionary consequences, good, bad and ugly.

  15. Analysis of measurement deviations for the patient-specific quality assurance using intensity-modulated spot-scanning particle beams

    Science.gov (United States)

    Li, Yongqiang; Hsi, Wen C.

    2017-04-01

    To analyze measurement deviations of patient-specific quality assurance (QA) using intensity-modulated spot-scanning particle beams, a commercial radiation dosimeter using 24 pinpoint ionization chambers was utilized. Before the clinical trial, validations of the radiation dosimeter and treatment planning system were conducted. During the clinical trial 165 measurements were performed on 36 enrolled patients. Two or three fields of particle beam were used for each patient. Measurements were typically performed with the dosimeter placed at special regions of dose distribution along depth and lateral profiles. In order to investigate the dosimeter accuracy, repeated measurements with uniform dose irradiations were also carried out. A two-step approach was proposed to analyze 24 sampling points over a 3D treatment volume. The mean value and the standard deviation of each measurement did not exceed 5% for all measurements performed on patients with various diseases. According to the defined intervention thresholds of mean deviation and the distance-to-agreement concept with a Gamma index analysis using criteria of 3.0% and 2 mm, a decision could be made regarding whether the dose distribution was acceptable for the patient. Based measurement results, deviation analysis was carried out. In this study, the dosimeter was used for dose verification and provided a safety guard to assure precise dose delivery of highly modulated particle therapy. Patient-specific QA will be investigated in future clinical operations.

  16. Patient-specific cardiovascular progenitor cells derived from integration-free induced pluripotent stem cells for vascular tissue regeneration.

    Science.gov (United States)

    Hu, Jiang; Wang, Yongyu; Jiao, Jiao; Liu, Zhongning; Zhao, Chao; Zhou, Zhou; Zhang, Zhanpeng; Forde, Kaitlynn; Wang, Lunchang; Wang, Jiangang; Baylink, David J; Zhang, Xiao-Bing; Gao, Shaorong; Yang, Bo; Chen, Y Eugene; Ma, Peter X

    2015-12-01

    Tissue-engineered blood vessels (TEBVs) are promising in regenerating a live vascular replacement. However, the vascular cell source is limited, and it is crucial to develop a scaffold that accommodates new type of vascular progenitor cells and facilitates in vivo lineage specification of the cells into functional vascular smooth muscle cells (VSMCs) to regenerate vascular tissue. In the present study, integration-free human induced pluripotent stem cells (hiPSCs) were established from patient peripheral blood mononuclear cells through episomal vector nucleofection of reprogramming factors. The established hiPSCs were then induced into mesoderm-originated cardiovascular progenitor cells (CVPCs) with a highly efficient directed lineage specification method. The derived CVPCs were demonstrated to be able to differentiate into functional VSMCs. Subcutaneous implantation of CVPCs seeded on macroporous nanofibrous poly(l-lactide) scaffolds led to in vivo VSMC lineage specification and matrix deposition inside the scaffolds. In summary, we established integration-free patient-specific hiPSCs from peripheral blood mononuclear cells, derived CVPCs through directed lineage specification, and developed an advanced scaffold for these progenitor cells to further differentiate in vivo into VSMCs and regenerate vascular tissue in a subcutaneous implantation model. This study has established an efficient patient-specific approach towards in vivo regeneration of vascular tissue.

  17. Percutaneous Transcatheter Mitral Valve Replacement: Patient-specific Three-dimensional Computer-based Heart Model and Prototyping.

    Science.gov (United States)

    Vaquerizo, Beatriz; Theriault-Lauzier, Pascal; Piazza, Nicolo

    2015-12-01

    Mitral regurgitation is the most prevalent valvular heart disease worldwide. Despite the widespread availability of curative surgical intervention, a considerable proportion of patients with severe mitral regurgitation are not referred for treatment, largely due to the presence of left ventricular dysfunction, advanced age, and comorbid illnesses. Transcatheter mitral valve replacement is a promising therapeutic alternative to traditional surgical valve replacement. The complex anatomical and pathophysiological nature of the mitral valvular complex, however, presents significant challenges to the successful design and implementation of novel transcatheter mitral replacement devices. Patient-specific 3-dimensional computer-based models enable accurate assessment of the mitral valve anatomy and preprocedural simulations for transcatheter therapies. Such information may help refine the design features of novel transcatheter mitral devices and enhance procedural planning. Herein, we describe a novel medical image-based processing tool that facilitates accurate, noninvasive assessment of the mitral valvular complex, by creating precise three-dimensional heart models. The 3-dimensional computer reconstructions are then converted to a physical model using 3-dimensional printing technology, thereby enabling patient-specific assessment of the interaction between device and patient. It may provide new opportunities for a better understanding of the mitral anatomy-pathophysiology-device interaction, which is of critical importance for the advancement of transcatheter mitral valve replacement.

  18. Patient-specific finite element analysis of chronic contact stress exposure after intraarticular fracture of the tibial plafond.

    Science.gov (United States)

    Li, Wendy; Anderson, Donald D; Goldsworthy, Jane K; Marsh, J Lawrence; Brown, Thomas D

    2008-08-01

    The role of altered contact mechanics in the pathogenesis of posttraumatic osteoarthritis (PTOA) following intraarticular fracture remains poorly understood. One proposed etiology is that residual incongruities lead to altered joint contact stresses that, over time, predispose to PTOA. Prevailing joint contact stresses following surgical fracture reduction were quantified in this study using patient-specific contact finite element (FE) analysis. FE models were created for 11 ankle pairs from tibial plafond fracture patients. Both (reduced) fractured ankles and their intact contralaterals were modeled. A sequence of 13 loading instances was used to simulate the stance phase of gait. Contact stresses were summed across loadings in the simulation, weighted by resident time in the gait cycle. This chronic exposure measure, a metric of degeneration propensity, was then compared between intact and fractured ankle pairs. Intact ankles had lower peak contact stress exposures that were more uniform and centrally located. The series-average peak contact stress elevation for fractured ankles was 38% (p = 0.0015; peak elevation was 82%). Fractured ankles had less area with low contact stress exposure than intact ankles and a greater area with high exposure. Chronic contact stress overexposures (stresses exceeding a damage threshold) ranged from near zero to a high of 18 times the matched intact value. The patient-specific FE models represent substantial progress toward elucidating the relationship between altered contact stresses and the outcome of patients treated for intraarticular fractures.

  19. Use of 3D printers to create a patient-specific 3D bolus for external beam therapy.

    Science.gov (United States)

    Burleson, Sarah; Baker, Jamie; Hsia, An Ting; Xu, Zhigang

    2015-05-08

    The purpose of this paper is to demonstrate that an inexpensive 3D printer can be used to manufacture patient-specific bolus for external beam therapy, and to show we can accurately model this printed bolus in our treatment planning system for accurate treatment delivery. Percent depth-dose measurements and tissue maximum ratios were used to determine the characteristics of the printing materials, acrylonitrile butadiene styrene and polylactic acid, as bolus material with physical density of 1.04 and 1.2 g/cm3, and electron density of 3.38 × 10²³ electrons/cm3 and 3.80 × 10²³ electrons/ cm3, respectively. Dose plane comparisons using Gafchromic EBT2 film and the RANDO phantom were used to verify accurate treatment planning. We accurately modeled a printing material in Eclipse treatment planning system, assigning it a Hounsfield unit of 260. We were also able to verify accurate treatment planning using gamma analysis for dose plane comparisons. With gamma criteria of 5% dose difference and 2 mm DTA, we were able to have 86.5% points passing, and with gamma criteria of 5% dose difference and 3 mm DTA, we were able to have 95% points passing. We were able to create a patient-specific bolus using an inexpensive 3D printer and model it in our treatment planning system for accurate treatment delivery.

  20. MO-H-19A-03: Patient Specific Bolus with 3D Printing Technology for Electron Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Zou, W; Swann, B; Siderits, R; McKenna, M; Khan, A; Yue, N; Zhang, M [Rutgers University, New Brunswick, NJ (United States); Fisher, T [Memorial Medical Center, Modesto, CA (United States)

    2014-06-15

    Purpose: Bolus is widely used in electron radiotherapy to achieve desired dose distribution. 3D printing technologies provide clinicians with easy access to fabricate patient specific bolus accommodating patient body surface irregularities and tissue inhomogeneity. This study presents the design and the clinical workflow of 3D printed bolus for patient electron therapy in our clinic. Methods: Patient simulation CT images free of bolus were exported from treatment planning system (TPS) to an in-house developed software package. Bolus with known material properties was designed in the software package and then exported back to the TPS as a structure. Dose calculation was carried out to examine the coverage of the target. After satisfying dose distribution was achieved, the bolus structure was transferred in Standard Tessellation Language (STL) file format for the 3D printer to generate the machine codes for printing. Upon receiving printed bolus, a quick quality assurance was performed with patient resimulated with bolus in place to verify the bolus dosimetric property before treatment started. Results: A patient specific bolus for electron radiotherapy was designed and fabricated in Form 1 3D printer with methacrylate photopolymer resin. Satisfying dose distribution was achieved in patient with bolus setup. Treatment was successfully finished for one patient with the 3D printed bolus. Conclusion: The electron bolus fabrication with 3D printing technology was successfully implemented in clinic practice.

  1. Surgery Videos: MedlinePlus

    Science.gov (United States)

    ... Winston-Salem, NC, 1/15/2009) Weight Loss Surgery Laparoscopic Gastric Bypass Surgery (University of Miami Hospital ... Boston, Boston, MA, 6/08/2010) Weight Loss Surgery Laparoscopic Gastric Bypass Surgery (University of Miami Hospital ...

  2. Predicting Surgery Targets in Temporal Lobe Epilepsy through Structural Connectome Based Simulations.

    Directory of Open Access Journals (Sweden)

    Frances Hutchings

    2015-12-01

    Full Text Available Temporal lobe epilepsy (TLE is a prevalent neurological disorder resulting in disruptive seizures. In the case of drug resistant epilepsy resective surgery is often considered. This is a procedure hampered by unpredictable success rates, with many patients continuing to have seizures even after surgery. In this study we apply a computational model of epilepsy to patient specific structural connectivity derived from diffusion tensor imaging (DTI of 22 individuals with left TLE and 39 healthy controls. We validate the model by examining patient-control differences in simulated seizure onset time and network location. We then investigate the potential of the model for surgery prediction by performing in silico surgical resections, removing nodes from patient networks and comparing seizure likelihood post-surgery to pre-surgery simulations. We find that, first, patients tend to transit from non-epileptic to epileptic states more often than controls in the model. Second, regions in the left hemisphere (particularly within temporal and subcortical regions that are known to be involved in TLE are the most frequent starting points for seizures in patients in the model. In addition, our analysis also implicates regions in the contralateral and frontal locations which may play a role in seizure spreading or surgery resistance. Finally, the model predicts that patient-specific surgery (resection areas chosen on an individual, model-prompted, basis and not following a predefined procedure may lead to better outcomes than the currently used routine clinical procedure. Taken together this work provides a first step towards patient specific computational modelling of epilepsy surgery in order to inform treatment strategies in individuals.

  3. Magnetic Implants Aid Hearing

    Institute of Scientific and Technical Information of China (English)

    陈宏

    1995-01-01

    The next generation of hearing aids may use tiny magnets that fit inside the ear. Researchersat a California company and an engineer at the University of Virginia are both developing systems that rely on magnets to convey sounds. Conventional hearing aids have three components:a microphone, an amplifier, and a speaker. The microphone picks up sounds and sends them to the am-

  4. Genetic Immunity to AIDS

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In an article on genetic immunity to AIDS published in Science magazine, American and Chinese scientists claim to have discovered why certain HIV carriers do not develop full-blown AIDS. They say that the key to this conundrum lies in a particular protein in the endocrine system that inhibits development of HIV.

  5. Aid and sectoral growth

    DEFF Research Database (Denmark)

    Selaya, Pablo; Thiele, Rainer

    2010-01-01

    This article examines empirically the proposition that aid to poor countries is detrimental for external competitiveness, giving rise to Dutch disease type effects. At the aggregate level, aid is found to have a positive effect on growth. A sectoral decomposition shows that the effect is (i...

  6. International Aid to Education

    Science.gov (United States)

    Benavot, Aaron

    2010-01-01

    Recent evidence highlights several worrisome trends regarding aid pledges and disbursements, which have been exacerbated by the global financial crisis. First, while overall development assistance rose in 2008, after 2 years of decline, the share of all sector aid going to the education sector has remained virtually unchanged at about 12 percent…

  7. AIDS Epidemiological models

    Science.gov (United States)

    Rahmani, Fouad Lazhar

    2010-11-01

    The aim of this paper is to present mathematical modelling of the spread of infection in the context of the transmission of the human immunodeficiency virus (HIV) and the acquired immune deficiency syndrome (AIDS). These models are based in part on the models suggested in the field of th AIDS mathematical modelling as reported by ISHAM [6].

  8. Aid and Income

    DEFF Research Database (Denmark)

    Lof, Matthijs; Mekasha, Tseday Jemaneh; Tarp, Finn

    2015-01-01

    to nonrandom omission of a large proportion of observations. Furthermore, we show that NDHKM’s use of co-integrated regressions is not a suitable empirical strategy for estimating the causal effect of aid on income. Evidence from a Panel VAR model estimated on the dataset of NDHKM, suggests a positive...... and statistically significant long-run effect of aid on income....

  9. First Aid: Burns

    Science.gov (United States)

    ... Your 1- to 2-Year-Old First Aid: Burns KidsHealth > For Parents > First Aid: Burns A A A Scald burns from hot water and other liquids are the most common burns in early childhood. Because burns range from mild ...

  10. The Aid Effectiveness Literature

    DEFF Research Database (Denmark)

    Doucouliagos, Hristos; Paldam, Martin

    The AEL consists of empirical macro studies of the effects of development aid. At the end of 2004 it had reached 97 studies of three families, which we have summarized in one study each using meta-analysis. Studies of the effect on investments show that they rise by 1/3 of the aid – the rest is c...

  11. First Aid: Diaper Rash

    Science.gov (United States)

    ... Your 1- to 2-Year-Old First Aid: Diaper Rash KidsHealth > For Parents > First Aid: Diaper Rash A A A Diaper rash is a common skin condition in babies. ... rash is due to irritation caused by the diaper, but it can have other causes not related ...

  12. First Aid: Burns

    Science.gov (United States)

    ... Old Feeding Your 8- to 12-Month-Old Feeding Your 1- to 2-Year-Old First Aid: Burns KidsHealth > For Parents > First Aid: Burns Print A A A Scald burns from hot water and other liquids are the most common burns in early childhood. Because burns range from mild to life threatening, ...

  13. Aid, Development, and Education

    Science.gov (United States)

    Klees, Steven J.

    2010-01-01

    The world faces pervasive poverty and inequality. Hundreds of billions of dollars in international aid have been given or loaned to developing countries though bilateral and multilateral mechanisms, at least, ostensibly, in order to do something about these problems. Has such aid helped? Debates around this question have been ongoing for decades,…

  14. HIV and AIDS

    Science.gov (United States)

    ... one HIV test by the time they are teens. If you are having sex, have had sex in the past, or shared ... reviewed: October 2015 previous 1 • 2 • ... STDs How Do People Get AIDS? Can You Get HIV From Having Sex With Someone Who Has AIDS? Can Someone Get ...

  15. First Aid: Falls

    Science.gov (United States)

    ... Your 1- to 2-Year-Old First Aid: Falls KidsHealth > For Parents > First Aid: Falls Print A A A en español Folleto de instructiones: Caídas (Falls) With all the running, climbing, and exploring kids ...

  16. AIDS as Metaphor.

    Science.gov (United States)

    McMillen, Liz

    1994-01-01

    Scholarly interest in Acquired Immune Deficiency Syndrome (AIDS) has spread throughout the humanities, attracting the attention of historians of medicine, political scientists, sociologists, public health scholars, and anthropologists. Most theorists hope their research will aid in policymaking or change understanding of the epidemic. (MSE)

  17. Pneumatic tourniquets in extremity surgery.

    LENUS (Irish Health Repository)

    Wakai, A

    2012-02-03

    Pneumatic tourniquets maintain a relatively bloodless field during extremity surgery, minimize blood loss, aid identification of vital structures, and expedite the procedure. However, they may induce an ischemia-reperfusion injury with potentially harmful local and systemic consequences. Modern pneumatic tourniquets are designed with mechanisms to regulate and maintain pressure. Routine maintenance helps ensure that these systems are working properly. The complications of tourniquet use include postoperative swelling, delay of recovery of muscle power, compression neurapraxia, wound hematoma with the potential for infection, vascular injury, tissue necrosis, and compartment syndrome. Systemic complications can also occur. The incidence of complications can be minimized by use of wider tourniquets, careful preoperative patient evaluation, and adherence to accepted principles of tourniquet use.

  18. WE-D-BRA-05: Pseudo In Vivo Patient Dosimetry Using a 3D-Printed Patient-Specific Phantom

    Energy Technology Data Exchange (ETDEWEB)

    Ger, R; Craft, DF [The University of Texas Graduate School of Biomedical Sciences (United States); Burgett, EA [Idaho State University, Pocatello, idaho (United States); Price, RR [RANDJ Consulting, Frederick, MD (United States); Kry, SF; Howell, RM [The University of Texas Graduate School of Biomedical Sciences (United States); The University of Texas MD Anderson Cancer Ctr., Houston, TX (United States)

    2015-06-15

    Purpose: To test the feasibility of using 3D-printed patient-specific phantoms for intensity-modulated radiation therapy (IMRT) quality assurance (QA). Methods: We created a patient-specific whole-head phantom using a 3D printer. The printer data file was created from high-resolution DICOM computed tomography (CT) images of 3-year old child treated at our institution for medulloblastoma. A custom-modified extruder system was used to create tissue-equivalent materials. For the printing process, the Hounsfield Units from the CT images were converted to proportional volumetric densities. A 5-field IMRT plan was created from the patient CT and delivered to the 3D- phantom. Dose was measured by an ion chamber placed through the eye. The ion chamber was placed at the posterior edge of the planning target volume in a high dose gradient region. CT scans of the patient and 3D-phantom were fused by using commercial treatment planning software (TPS). The patient’s plan was calculated on the phantom CT images. The ion chamber’s active volume was delineated in the TPS; dose per field and total dose were obtained. Measured and calculated doses were compared. Results: The 3D-phantom dimensions and tissue densities were in good agreement with the patient. However, because of a printing error, there was a large discrepancy in the density in the frontal cortex. The calculated and measured treatment plan doses were 1.74 Gy and 1.72 Gy, respectively. For individual fields, the absolute dose difference between measured and calculated values was on average 3.50%. Conclusion: This study demonstrated the feasibility of using 3D-printed patient-specific phantoms for IMRT QA. Such phantoms would be particularly advantageous for complex IMRT treatment plans featuring high dose gradients and/or for anatomical sites with high variation in tissue densities. Our preliminary findings are promising. We anticipate that, once the printing process is further refined, the agreement between

  19. Computational assessment of effective dose and patient specific doses for kilovoltage stereotactic radiosurgery of wet age-related macular degeneration

    Science.gov (United States)

    Hanlon, Justin Mitchell

    Age-related macular degeneration (AMD) is a leading cause of vision loss and a major health problem for people over the age of 50 in industrialized nations. The current standard of care, ranibizumab, is used to help slow and in some cases stabilize the process of AMD, but requires frequent invasive injections into the eye. Interest continues for stereotactic radiosurgery (SRS), an option that provides a non-invasive treatment for the wet form of AMD, through the development of the IRay(TM) (Oraya Therapeutics, Inc., Newark, CA). The goal of this modality is to destroy choroidal neovascularization beneath the pigment epithelium via delivery of three 100 kVp photon beams entering through the sclera and overlapping on the macula delivering up to 24 Gy of therapeutic dose over a span of approximately 5 minutes. The divergent x-ray beams targeting the fovea are robotically positioned and the eye is gently immobilized by a suction-enabled contact lens. Device development requires assessment of patient effective dose, reference patient mean absorbed doses to radiosensitive tissues, and patient specific doses to the lens and optic nerve. A series of head phantoms, including both reference and patient specific, was derived from CT data and employed in conjunction with the MCNPX 2.5.0 radiation transport code to simulate treatment and evaluate absorbed doses to potential tissues-at-risk. The reference phantoms were used to evaluate effective dose and mean absorbed doses to several radiosensitive tissues. The optic nerve was modeled with changeable positions based on individual patient variability seen in a review of head CT scans gathered. Patient specific phantoms were used to determine the effect of varying anatomy and gaze. The results showed that absorbed doses to the non-targeted tissues were below the threshold levels for serious complications; specifically the development of radiogenic cataracts and radiation induced optic neuropathy (RON). The effective dose

  20. [First aid to persons with explosion trauma].

    Science.gov (United States)

    Shapovalov, V M; Samokhvalov, I M

    2012-10-01

    Modern organization providing medical aid to victims of explosion trauma in peace time, the success of which largely depends on the timely and professional interaction among the structures involeved into emergency relief operation is represented in the article. Content and sequence of events providing emergency medical and first medical aid to victims of the explosions, and the appropriateness of allocation affected groups, based on the predicted effectiveness of medical care is analyzed. The algorithm, currently used by ambulance crews, of assistance to victims with explosion and order evacuations is analyzed. The content of therapeutic measures in receipt of the wounded on the steps of skilled and specialized surgical care in accordance with the idea of a separation surgery on three stages (damage control). The content of the main levels of damage control orthopedics is introduced.

  1. HIV/AIDS and Alcohol

    Science.gov (United States)

    ... Psychiatric Disorders Other Substance Abuse HIV/AIDS HIV/AIDS Human immunodeficiency virus (HIV) targets the body’s immune ... and often leads to acquired immune deficiency syndrome (AIDS). Each year in the United States, between 55, ...

  2. HIV, AIDS, and the Future

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues HIV / AIDS HIV, AIDS, and the Future Past Issues / Summer 2009 ... turn Javascript on. Photo: The NAMES Project Foundation HIV and AIDS are a global catastrophe. While advances ...

  3. Mathematical modeling of coupled drug and drug-encapsulated nanoparticle transport in patient-specific coronary artery walls

    KAUST Repository

    Hossain, Shaolie S.

    2011-08-20

    The majority of heart attacks occur when there is a sudden rupture of atherosclerotic plaque, exposing prothrombotic emboli to coronary blood flow, forming clots that can cause blockages of the arterial lumen. Diseased arteries can be treated with drugs delivered locally to vulnerable plaques. The objective of this work was to develop a computational tool-set to support the design and analysis of a catheter-based nanoparticulate drug delivery system to treat vulnerable plaques and diffuse atherosclerosis. A threedimensional mathematical model of coupled mass transport of drug and drug-encapsulated nanoparticles was developed and solved numerically utilizing isogeometric finite element analysis. Simulations were run on a patient-specific multilayered coronary artery wall segment with a vulnerable plaque and the effect of artery and plaque inhomogeneity was analyzed. The method captured trends observed in local drug delivery and demonstrated potential for optimizing drug design parameters, including delivery location, nanoparticle surface properties, and drug release rate. © Springer-Verlag 2011.

  4. Personalised computational cardiology: Patient-specific modelling in cardiac mechanics and biomaterial injection therapies for myocardial infarction

    Science.gov (United States)

    Sack, Kevin L.; Davies, Neil H.; Guccione, Julius M.

    2016-01-01

    Predictive computational modelling in biomedical research offers the potential to integrate diverse data, uncover biological mechanisms that are not easily accessible through experimental methods and expose gaps in knowledge requiring further research. Recent developments in computing and diagnostic technologies have initiated the advancement of computational models in terms of complexity and specificity. Consequently, computational modelling can increasingly be utilised as enabling and complementing modality in the clinic—with medical decisions and interventions being personalised. Myocardial infarction and heart failure are amongst the leading causes of death globally despite optimal modern treatment. The development of novel MI therapies is challenging and may be greatly facilitated through predictive modelling. Here, we review the advances in patient-specific modelling of cardiac mechanics, distinguishing specificity in cardiac geometry, myofibre architecture and mechanical tissue properties. Thereafter, the focus narrows to the mechanics of the infarcted heart and treatment of myocardial infarction with particular attention on intramyocardial biomaterial delivery. PMID:26833320

  5. Mathematical modeling of coupled drug and drug-encapsulated nanoparticle transport in patient-specific coronary artery walls

    Science.gov (United States)

    Hossain, Shaolie S.; Hossainy, Syed F. A.; Bazilevs, Yuri; Calo, Victor M.; Hughes, Thomas J. R.

    2012-02-01

    The majority of heart attacks occur when there is a sudden rupture of atherosclerotic plaque, exposing prothrombotic emboli to coronary blood flow, forming clots that can cause blockages of the arterial lumen. Diseased arteries can be treated with drugs delivered locally to vulnerable plaques. The objective of this work was to develop a computational tool-set to support the design and analysis of a catheter-based nanoparticulate drug delivery system to treat vulnerable plaques and diffuse atherosclerosis. A three-dimensional mathematical model of coupled mass transport of drug and drug-encapsulated nanoparticles was developed and solved numerically utilizing isogeometric finite element analysis. Simulations were run on a patient-specific multilayered coronary artery wall segment with a vulnerable plaque and the effect of artery and plaque inhomogeneity was analyzed. The method captured trends observed in local drug delivery and demonstrated potential for optimizing drug design parameters, including delivery location, nanoparticle surface properties, and drug release rate.

  6. Stapes surgery: a National Survey of British Otologists.

    Science.gov (United States)

    Lancer, Hannah; Manickavasagam, Jaiganesh; Zaman, Azreena; Lancer, Jack

    2016-02-01

    To investigate individual stapes surgery practice in the UK, a retrospective study was conducted by postal questionnaire to all 'assumed' stapes-performing otologists. 225 questionnaires were sent out to practicing otologists in the UK. 184 replies (81.8 %) indicated that 134 (72.9 %) otologists perform stapes surgery [stapedectomy (8.2 %), stapedotomy (91.0 %) or other (0.8 %)]. The '6-10 stapes operation per year' category is the most common, with most using general anaesthetic (GA) (78.3 %). Unilateral surgery is advised in 89.6 %, and 96.3 % perform second-side surgery, with all advising the option of a hearing aid prior to surgery. The majority (88.1 %) would fit the prosthesis after removing the stapes, with the top three prostheses being Causse, Smart and Teflon (as described by respondents). 42.5 % always use a vein graft or fat to cover the fenestration, 9.3 % use a laser and 48.5 % carry out the surgery as a day case. For an overhanging facial nerve (less than 50 % of the footplate obscured), the majority stated that it would depend whether they would abandon surgery. 25.4 % have encountered a 'gusher' and 83.6 % would recommend revision surgery. 82.8 % have a registrar present when carrying out stapes operations, but 69.4 % only offer training to trainees with an otological interest. In the UK, stapedotomy is the preferred technique. Most prefer the Causse prosthesis, general anaesthesia and an inpatient stay. Hearing aids are advised prior to surgery. Day-case and inpatient practice is about equal. 'Gushers' are encountered rarely. Revision surgery is advised if a conductive loss returns. Flying is recommended from 6 weeks. Most otologists are willing to teach trainees with an otological interest.

  7. Political dimensions of AIDS.

    Science.gov (United States)

    Blewett, N

    1988-01-01

    World political aspects and the example of Australia as a national political response to AIDS are presented. Global policy on AIDS is influenced by the fact that the AIDS epidemic is the 1st to be largely predictable, that long lag times occur between intervention and measurable events, and by the prompt, professional leadership of WHO, lead by Dr. J. Mann. WHO began a Global Programme on AIDS in 1987, modelled on the responses of Canada and Australia. A world summit of Ministers of Health was convened in January 1988. These moves generated a response qualified by openness, cooperation, hope and common sense. The AIDS epidemic calls for unprecedented involvement of politicians: they must coordinate medical knowledge with community action, deal with public fear, exert strong, rational leadership and avoid quick, appealing counterproductive responses. 3 clear directions must be taken to deal with the epidemic: 1) strong research and education campaigns; 2) close contact with political colleagues, interest groups and the community; 3) a national strategy which enjoins diverse interest groups, with courage, rationality and compassion. In Australia, the AIDS response began with the unwitting infection of 3 infants by blood transfusion. A public information campaign emphasizing a penetrating TV ad campaign was instituted in 1987. Policy discussions were held in all parliamentary bodies. The AIDS epidemic demands rapid, creative responses, a break from traditions in health bureaucracy, continual scrutiny of funding procedures and administrative arrangements. In practical terms in Australia, this meant establishing a special AIDS branch within the Health Advancement Division of the Community Health Department. AIDS issues must remain depoliticized to defuse adversary politics and keep leaders in a united front.

  8. Patient-specific metrics of invasiveness reveal significant prognostic benefit of resection in a predictable subset of gliomas.

    Directory of Open Access Journals (Sweden)

    Anne L Baldock

    Full Text Available Malignant gliomas are incurable, primary brain neoplasms noted for their potential to extensively invade brain parenchyma. Current methods of clinical imaging do not elucidate the full extent of brain invasion, making it difficult to predict which, if any, patients are likely to benefit from gross total resection. Our goal was to apply a mathematical modeling approach to estimate the overall tumor invasiveness on a patient-by-patient basis and determine whether gross total resection would improve survival in patients with relatively less invasive gliomas.In 243 patients presenting with contrast-enhancing gliomas, estimates of the relative invasiveness of each patient's tumor, in terms of the ratio of net proliferation rate of the glioma cells to their net dispersal rate, were derived by applying a patient-specific mathematical model to routine pretreatment MR imaging. The effect of varying degrees of extent of resection on overall survival was assessed for cohorts of patients grouped by tumor invasiveness.We demonstrate that patients with more diffuse tumors showed no survival benefit (P = 0.532 from gross total resection over subtotal/biopsy, while those with nodular (less diffuse tumors showed a significant benefit (P = 0.00142 with a striking median survival benefit of over eight months compared to sub-totally resected tumors in the same cohort (an 80% improvement in survival time for GTR only seen for nodular tumors.These results suggest that our patient-specific, model-based estimates of tumor invasiveness have clinical utility in surgical decision making. Quantification of relative invasiveness assessed from routinely obtained pre-operative imaging provides a practical predictor of the benefit of gross total resection.

  9. Wall-Less Flow Phantoms With Tortuous Vascular Geometries: Design Principles and a Patient-Specific Model Fabrication Example.

    Science.gov (United States)

    Ho, Chung Kit; Chee, Adrian J Y; Yiu, Billy Y S; Tsang, Anderson C O; Chow, Kwok Wing; Yu, Alfred C H

    2017-01-01

    Flow phantoms with anatomically realistic geometry and high acoustic compatibility are valuable investigative tools in vascular ultrasound studies. Here, we present a new framework to fabricate ultrasound-compatible flow phantoms to replicate human vasculature that is tortuous, nonplanar, and branching in nature. This framework is based upon the integration of rapid prototyping and investment casting principles. A pedagogical walkthrough of our engineering protocol is presented in this paper using a patient-specific cerebral aneurysm model as an exemplar demonstration. The procedure for constructing the flow circuit component of the phantoms is also presented, including the design of a programmable flow pump system, the fabrication of blood mimicking fluid, and flow rate calibration. Using polyvinyl alcohol cryogel as the tissue mimicking material, phantoms developed with the presented protocol exhibited physiologically relevant acoustic properties [attenuation coefficient: 0.229±0.032 dB/( [Formula: see text]) and acoustic speed: 1535±2.4 m/s], and their pulsatile flow dynamics closely resembled the flow profile input. As a first application of our developed phantoms, the flow pattern of the patient-specific aneurysm model was visualized by performing high-frame-rate color-encoded speckle imaging over multiple time-synchronized scan planes. Persistent recirculation was observed, and the vortex center was found to shift in position over a cardiac cycle, indicating the 3-D nature of flow recirculation inside an aneurysm. These findings suggest that phantoms produced from our reported protocol can serve well as acoustically compatible test beds for vascular ultrasound studies, including 3-D flow imaging.

  10. A human pluripotent stem cell model of catecholaminergic polymorphic ventricular tachycardia recapitulates patient-specific drug responses

    Directory of Open Access Journals (Sweden)

    Marcela K. Preininger

    2016-09-01

    Full Text Available Although β-blockers can be used to eliminate stress-induced ventricular arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT, this treatment is unsuccessful in ∼25% of cases. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs generated from these patients have potential for use in investigating the phenomenon, but it remains unknown whether they can recapitulate patient-specific drug responses to β-blockers. This study assessed whether the inadequacy of β-blocker therapy in an individual can be observed in vitro using patient-derived CPVT iPSC-CMs. An individual with CPVT harboring a novel mutation in the type 2 cardiac ryanodine receptor (RyR2 was identified whose persistent ventricular arrhythmias during β-blockade with nadolol were abolished during flecainide treatment. iPSC-CMs generated from this patient and two control individuals expressed comparable levels of excitation-contraction genes, but assessment of the sarcoplasmic reticulum Ca2+ leak and load relationship revealed intracellular Ca2+ homeostasis was altered in the CPVT iPSC-CMs. β-adrenergic stimulation potentiated spontaneous Ca2+ waves and unduly frequent, large and prolonged Ca2+ sparks in CPVT compared with control iPSC-CMs, validating the disease phenotype. Pursuant to the patient's in vivo responses, nadolol treatment during β-adrenergic stimulation achieved negligible reduction of Ca2+ wave frequency and failed to rescue Ca2+ spark defects in CPVT iPSC-CMs. In contrast, flecainide reduced both frequency and amplitude of Ca2+ waves and restored the frequency, width and duration of Ca2+ sparks to baseline levels. By recapitulating the improved response of an individual with CPVT to flecainide compared with β-blocker therapy in vitro, these data provide new evidence that iPSC-CMs can capture basic components of patient-specific drug responses.

  11. NOTE: Development and preliminary evaluation of a prototype audiovisual biofeedback device incorporating a patient-specific guiding waveform

    Science.gov (United States)

    Venkat, Raghu B.; Sawant, Amit; Suh, Yelin; George, Rohini; Keall, Paul J.

    2008-06-01

    The aim of this research was to investigate the effectiveness of a novel audio-visual biofeedback respiratory training tool to reduce respiratory irregularity. The audiovisual biofeedback system acquires sample respiratory waveforms of a particular patient and computes a patient-specific waveform to guide the patient's subsequent breathing. Two visual feedback models with different displays and cognitive loads were investigated: a bar model and a wave model. The audio instructions were ascending/descending musical tones played at inhale and exhale respectively to assist in maintaining the breathing period. Free-breathing, bar model and wave model training was performed on ten volunteers for 5 min for three repeat sessions. A total of 90 respiratory waveforms were acquired. It was found that the bar model was superior to free breathing with overall rms displacement variations of 0.10 and 0.16 cm, respectively, and rms period variations of 0.77 and 0.33 s, respectively. The wave model was superior to the bar model and free breathing for all volunteers, with an overall rms displacement of 0.08 cm and rms periods of 0.2 s. The reduction in the displacement and period variations for the bar model compared with free breathing was statistically significant (p = 0.005 and 0.002, respectively); the wave model was significantly better than the bar model (p = 0.006 and 0.005, respectively). Audiovisual biofeedback with a patient-specific guiding waveform significantly reduces variations in breathing. The wave model approach reduces cycle-to-cycle variations in displacement by greater than 50% and variations in period by over 70% compared with free breathing. The planned application of this device is anatomic and functional imaging procedures and radiation therapy delivery.

  12. SU-E-T-120: Analytic Dose Verification for Patient-Specific Proton Pencil Beam Scanning Plans

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C; Mah, D [ProCure Proton Therapy Centers, Somerset, NJ (United States)

    2015-06-15

    Purpose: To independently verify the QA dose of proton pencil beam scanning (PBS) plans using an analytic dose calculation model. Methods: An independent proton dose calculation engine is created using the same commissioning measurements as those employed to build our commercially available treatment planning system (TPS). Each proton PBS plan is exported from the TPS in DICOM format and calculated by this independent dose engine in a standard 40 x 40 x 40 cm water tank. This three-dimensional dose grid is then compared with the QA dose calculated by the commercial TPS, using standard Gamma criterion. A total of 18 measured pristine Bragg peaks, ranging from 100 to 226 MeV, are used in the model. Intermediate proton energies are interpolated. Similarly, optical properties of the spots are measured in air over 15 cm upstream and downstream, and fitted to a second-order polynomial. Multiple Coulomb scattering in water is approximated analytically using Preston and Kohler formula for faster calculation. The effect of range shifters on spot size is modeled with generalized Highland formula. Note that the above formulation approximates multiple Coulomb scattering in water and we therefore chose not use the full Moliere/Hanson form. Results: Initial examination of 3 patient-specific prostate PBS plans shows that agreement exists between 3D dose distributions calculated by the TPS and the independent proton PBS dose calculation engine. Both calculated dose distributions are compared with actual measurements at three different depths per beam and good agreements are again observed. Conclusion: Results here showed that 3D dose distributions calculated by this independent proton PBS dose engine are in good agreement with both TPS calculations and actual measurements. This tool can potentially be used to reduce the amount of different measurement depths required for patient-specific proton PBS QA.

  13. Maturation-Based Model of Arrhythmogenic Right Ventricular Dysplasia Using Patient-Specific Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Wen, Jian-Yan; Wei, Chuan-Yu; Shah, Khooshbu; Wong, Johnson; Wang, Cheng; Chen, Huei-Sheng Vincent

    2015-01-01

    Cellular reprogramming of somatic cells to patient-specific induced pluripotent stem cells (iPSCs) enables in-vitro modeling of human cardiac disorders for pathogenic and therapeutic investigations. However, using iPSC-derived cardiomyocytes (iPSC-CMs) to model an adult-onset heart disease remains challenging because of the uncertainty regarding the ability of relatively immature iPSC-CMs to fully recapitulate adult disease phenotypes. Arrhythmogenic right ventricular dysplasia (ARVD) is an inherited cardiomyopathy characterized by pathological fibrofatty infiltration and cardiomyocyte (CM) loss predominantly in the right ventricle (RV), leading to heart failure and lethal arrhythmias. Over 50% of affected individuals have desmosome gene mutations, most commonly inPKP2encoding plakophilin-2. Using Yamanaka's pluripotent factors, we generated iPSC lines from ARVD patients withPKP2mutations. We first developed a method to induce metabolic maturation of iPSC-CMs and showed that induction of adult-like metabolic energetics from an embryonic/glycolytic state is essential to model an adult-onset cardiac disease using patient-specific iPSCs. Furthermore, we showed that coactivation of normal peroxisome proliferator-activated receptor (PPAR)-α and abnormal PPARγ pathways in ARVD iPSC-CMs resulted in exaggerated CM lipogenesis, CM apoptosis, Na(+)channel downregulation and defective intracellular calcium handling, recapitulating the pathological signatures of ARVD. Using this model, we revealed novel pathogenic insights that metabolic derangement in an adult-like metabolic milieu underlies ARVD pathologies, enabling us to propose novel disease-modifying therapeutic strategies.

  14. A comparative study on patient specific absolute dosimetry using slab phantom, acrylic body phantom and goat head phantom

    Directory of Open Access Journals (Sweden)

    Om Prakash Gurjar

    2015-01-01

    Full Text Available Purpose: To compare the results of patient specific absolute dosimetry using slab phantom, acrylic body phantom and goat head phantom. Methods: Fifteen intensity modulated radiotherapy (IMRT plans already planned on treatment planning system (TPS for head-and-neck cancer patients were exported on all three kinds of phantoms viz. slab phantom, acrylic body phantom and goat head phantom, and dose was calculated using anisotropic analytic algorithm (AAA. All the gantry angles were set to zero in case of slab phantom while set to as it is in actual plan in case of other two phantoms. All the plans were delivered by linear accelerator (LA and dose for each plan was measured by 0.13 cc ion chamber. The percentage (% variations between planned and measured doses were calculated and analyzed. Results: The mean % variations between planned and measured doses of all IMRT quality assurance (QA plans were as 0.65 (Standard deviation (SD: 0.38 with confidence limit (CL 1.39, 1.16 (SD: 0.61 with CL 2.36 and 2.40 (SD: 0.86 with CL 4.09 for slab phantom, acrylic head phantom and goat head phantom respectively. Conclusion: Higher dose variations found in case of real tissue phantom compare to results in case of slab and acrylic body phantoms. The algorithm AAA does not calculate doses in heterogeneous medium as accurate as it calculates in homogeneous medium. Therefore the patient specific absolute dosimetry should be done using heterogeneous phantom mimicking density wise as well as design wise to the actual human body.  

  15. SU-E-T-475: An Accurate Linear Model of Tomotherapy MLC-Detector System for Patient Specific Delivery QA

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y; Mo, X; Chen, M; Olivera, G; Parnell, D; Key, S; Lu, W [21st Century Oncology, Madison, WI (United States); Reeher, M [21st Century Oncology, Naples, FL (United States); Galmarini, D [21st Century Oncology, Fort Myers, FL (United States)

    2014-06-01

    Purpose: An accurate leaf fluence model can be used in applications such as patient specific delivery QA and in-vivo dosimetry for TomoTherapy systems. It is known that the total fluence is not a linear combination of individual leaf fluence due to leakage-transmission, tongue-and-groove, and source occlusion effect. Here we propose a method to model the nonlinear effects as linear terms thus making the MLC-detector system a linear system. Methods: A leaf pattern basis (LPB) consisting of no-leaf-open, single-leaf-open, double-leaf-open and triple-leaf-open patterns are chosen to represent linear and major nonlinear effects of leaf fluence as a linear system. An arbitrary leaf pattern can be expressed as (or decomposed to) a linear combination of the LPB either pulse by pulse or weighted by dwelling time. The exit detector responses to the LPB are obtained by processing returned detector signals resulting from the predefined leaf patterns for each jaw setting. Through forward transformation, detector signal can be predicted given a delivery plan. An equivalent leaf open time (LOT) sinogram containing output variation information can also be inversely calculated from the measured detector signals. Twelve patient plans were delivered in air. The equivalent LOT sinograms were compared with their planned sinograms. Results: The whole calibration process was done in 20 minutes. For two randomly generated leaf patterns, 98.5% of the active channels showed differences within 0.5% of the local maximum between the predicted and measured signals. Averaged over the twelve plans, 90% of LOT errors were within +/−10 ms. The LOT systematic error increases and shows an oscillating pattern when LOT is shorter than 50 ms. Conclusion: The LPB method models the MLC-detector response accurately, which improves patient specific delivery QA and in-vivo dosimetry for TomoTherapy systems. It is sensitive enough to detect systematic LOT errors as small as 10 ms.

  16. Development and preliminary evaluation of a prototype audiovisual biofeedback device incorporating a patient-specific guiding waveform

    Energy Technology Data Exchange (ETDEWEB)

    Venkat, Raghu B; Sawant, Amit; Suh, Yelin; Keall, Paul J [Department of Radiation Oncology, Stanford University, Stanford, CA 94305-5847 (United States); George, Rohini [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA (United States)], E-mail: Paul.Keall@stanford.edu

    2008-06-07

    The aim of this research was to investigate the effectiveness of a novel audio-visual biofeedback respiratory training tool to reduce respiratory irregularity. The audiovisual biofeedback system acquires sample respiratory waveforms of a particular patient and computes a patient-specific waveform to guide the patient's subsequent breathing. Two visual feedback models with different displays and cognitive loads were investigated: a bar model and a wave model. The audio instructions were ascending/descending musical tones played at inhale and exhale respectively to assist in maintaining the breathing period. Free-breathing, bar model and wave model training was performed on ten volunteers for 5 min for three repeat sessions. A total of 90 respiratory waveforms were acquired. It was found that the bar model was superior to free breathing with overall rms displacement variations of 0.10 and 0.16 cm, respectively, and rms period variations of 0.77 and 0.33 s, respectively. The wave model was superior to the bar model and free breathing for all volunteers, with an overall rms displacement of 0.08 cm and rms periods of 0.2 s. The reduction in the displacement and period variations for the bar model compared with free breathing was statistically significant (p = 0.005 and 0.002, respectively); the wave model was significantly better than the bar model (p = 0.006 and 0.005, respectively). Audiovisual biofeedback with a patient-specific guiding waveform significantly reduces variations in breathing. The wave model approach reduces cycle-to-cycle variations in displacement by greater than 50% and variations in period by over 70% compared with free breathing. The planned application of this device is anatomic and functional imaging procedures and radiation therapy delivery. (note)

  17. Laparoscopic cholecystectomy causes less sleep disturbance than open abdominal surgery

    DEFF Research Database (Denmark)

    Gögenur, I; Rosenberg-Adamsen, S; Kiil, C;

    2001-01-01

    BACKGROUND: The aim of this study was to examine subjective sleep quality before and after laparoscopic vs open abdominal surgery. METHODS: Twelve patients undergoing laparoscopic cholecystectomy and 15 patients undergoing laparotomy were evaluated with the aid of a sleep questionnaire from 4 day...

  18. Development of plastic surgery

    Directory of Open Access Journals (Sweden)

    Pećanac Marija Đ.

    2015-01-01

    Full Text Available Introduction. Plastic surgery is a medical specialty dealing with corrections of defects, improvements in appearance and restoration of lost function. Ancient Times. The first recorded account of reconstructive plastic surgery was found in ancient Indian Sanskrit texts, which described reconstructive surgeries of the nose and ears. In ancient Greece and Rome, many medicine men performed simple plastic cosmetic surgeries to repair damaged parts of the body caused by war mutilation, punishment or humiliation. In the Middle Ages, the development of all medical braches, including plastic surgery was hindered. New age. The interest in surgical reconstruction of mutilated body parts was renewed in the XVIII century by a great number of enthusiastic and charismatic surgeons, who mastered surgical disciplines and became true artists that created new forms. Modern Era. In the XX century, plastic surgery developed as a modern branch in medicine including many types of reconstructive surgery, hand, head and neck surgery, microsurgery and replantation, treatment of burns and their sequelae, and esthetic surgery. Contemporary and future plastic surgery will continue to evolve and improve with regenerative medicine and tissue engineering resulting in a lot of benefits to be gained by patients in reconstruction after body trauma, oncology amputation, and for congenital disfigurement and dysfunction.

  19. Aid and Growth

    DEFF Research Database (Denmark)

    Tarp, Finn; Mekasha, Tseday Jemaneh

    2013-01-01

    Recent litterature in the meta-analysis category where results from a range of studies are brought together throws doubt on the ability of foreign aid to foster economic growth and development. This article assesses what meta-analysis has to contribute to the litterature on the effectiveness...... of foreign aid in terms of growth impact. We re-examine key hypotheses, and find that the effect of aid on growth is positive and statistically significant. This significant effect is genuine, and not an artefact of publication selection. We also show why our results differ from those published elsewhere....

  20. Aid Supplies Over Time

    DEFF Research Database (Denmark)

    Jones, Edward Samuel

    2015-01-01

    What determines how much foreign aid donors provide? Existing answers to this question point to a complex range of influences. However, the tasks of distinguishing between long- and short-run factors, as well as differences between donors, have not been adequately addressed. Taking advantage...... of data spanning nearly 50 years, this paper uses panel cointegration techniques to consider these issues. The analysis provides clear evidence for heterogeneity both between donors and over time, bandwagon effects, and a growing influence of security considerations in aid provision. Domestic...... macroeconomic shocks have a moderate but delayed effect on aid disbursements....

  1. Aid and Growth

    DEFF Research Database (Denmark)

    Mekasha, Tseday Jemaneh; Tarp, Finn

    Some recent literature in the meta-analysis category where results from a range of studies are brought together throws doubt on the ability of foreign aid to foster economic growth and development. This paper assesses what meta-analysis has to say about the effectiveness of foreign aid in terms...... of the growth impact. We re-examine key hypotheses, and find that the effect of aid on growth is positive and statistically significant. This significant effect is genuine, and not an artefact of publication selection. We also show why our results differ from those published elsewhere....

  2. The patient’s perspective of the feasibility of a patient-specific instrument in physiotherapy goal setting: a qualitative study

    OpenAIRE

    2016-01-01

    Background: Patient participation in goal setting is important to deliver client-centered care. In daily practice, however, patient involvement in goal setting is not optimal. Patient-specific instruments, such as the Patient Specific Complaints (PSC) instrument, can support the goal-setting process because patients can identify and rate their own problems. The aim of this study is to explore patients’ experiences with the feasibility of the PSC, in the physiotherapy goal setting. Method: We ...

  3. Pulmonary complications of AIDS: radiologic features. [AIDS

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, B.A.; Pomeranz, S.; Rabinowitz, J.G.; Rosen, M.J.; Train, J.S.; Norton, K.I.; Mendelson, D.S.

    1984-07-01

    Fifty-two patients with pulmonary complications of acquired immunodeficiency syndrome (AIDS) were studied over a 3-year period. The vast majority of the patients were homosexual; however, a significant number were intravenous drug abusers. Thirteen different organisms were noted, of which Pneumocystis carinii was by far the most common. Five patients had neoplasia. Most patients had initial abnormal chest films; however, eight patients subsequently shown to have Pneumocystis carinii pneumonia had normal chest films. A significant overlap in chest radiographic findings was noted among patients with different or multiple organisms. Lung biopsy should be an early consideration for all patients with a clinical history consistent with the pulmonary complications of AIDS. Of the 52 patients, 41 had died by the time this report was completed.

  4. Clinical Pearls in Anaesthesia for Endoscopic Endonasal Transsphenoid Pituitary Macroadenoma Surgery

    Directory of Open Access Journals (Sweden)

    Shah Shagun B

    2015-11-01

    Full Text Available Endoscopic Endonasal Trans-sphenoid Surgery (EETS aided by avant-garde neuro-navigation techniques, ultrasonic aspirators and bone curettes has come of age. Endoscopic surgery supersedes conventional microscopic approach due to better visualization, avoidance of craniotomy, brain retraction and undue neurovascular manipulation with less morbidity, blood loss and improved safety. Anaesthetic techniques must be tailored to cater for such advances in surgery.

  5. HIV/AIDS

    Science.gov (United States)

    ... equity (covering the populations in need of services). Financing for sustainability (covering the costs of services). Innovation for acceleration (looking towards the future). WHO is a cosponsor of the Joint United Nations Programme on AIDS (UNAIDS). Within UNAIDS, WHO leads ...

  6. First Aid: Croup

    Science.gov (United States)

    ... Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life First Aid & Safety Doctors & ... with each breath has a pale or bluish color around the mouth drools or has difficulty swallowing ...

  7. Buying a Hearing Aid

    Science.gov (United States)

    ... Contact Us Calendar ENTCareers Marketplace ENT Careers Marketplace Log in b Log in Toggle navigation b Join Now Donate Now ... using your hearing aids in quiet surroundings, gradually building up to noisier environments. Then eventually work up ...

  8. HIV/AIDS

    Science.gov (United States)

    HIV stands for human immunodeficiency virus. It harms your immune system by destroying the white blood cells ... It is the final stage of infection with HIV. Not everyone with HIV develops AIDS. HIV most ...

  9. AidData

    Data.gov (United States)

    US Agency for International Development — AidData is a research and innovation lab making information on development finance more accessible and actionable. Tracking more than $6 trillion dollars from 90+...

  10. Convulsions - first aid - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100212.htm Convulsions - first aid - series—Procedure, part 1 To use ... slide 2 out of 2 Overview When a seizure occurs, the main goal is to protect the ...

  11. Hypophyseal pathology in AIDS

    OpenAIRE

    Mosca, L; Costanzi, G; Antonacci, C.; Boldorini, R; Carboni, N.; Cristina, S; Liberani, C.; Parravicini, C.; Pirolo, A.; Vago, L

    1992-01-01

    One hundred and eleven pituitary glands of patients (93 males, 18 females; mean age 32 years, 5 months) who died of fully developed AIDS or ARC were examined under light microscopy with the aid of immunohistochemistry. On post mortem (p.m.) examination a wide series of multiorgan alterations was noticed. Microscopically vanous lesions in both adeno- and neurohypophysis were seen. These ranged from vessel damage to secondaries to systemic infections, neoplas...

  12. Plasma-aided manufacturing

    Science.gov (United States)

    Shohet, J. L.

    1993-12-01

    Plasma-aided manufacturing is used for producing new materials with unusual and superior properties, for developing new chemical compounds and processes, for machining, and for altering and refining materials and surfaces. Plasma-aided manufacturing has direct applications to semiconductor fabrication, materials synthesis, welding, lighting, polymers, anti-corrosion coatings, machine tools, metallurgy, electrical and electronics devices, hazardous waste removal, high performance ceramics, and many other items in both the high-technology and the more traditional industries in the United States.

  13. Ergonomics in laparoscopic surgery

    Directory of Open Access Journals (Sweden)

    Supe Avinash

    2010-01-01

    Full Text Available Laparoscopic surgery provides patients with less painful surgery but is more demanding for the surgeon. The increased technological complexity and sometimes poorly adapted equipment have led to increased complaints of surgeon fatigue and discomfort during laparoscopic surgery. Ergonomic integration and suitable laparoscopic operating room environment are essential to improve efficiency, safety, and comfort for the operating team. Understanding ergonomics can not only make life of surgeon comfortable in the operating room but also reduce physical strains on surgeon.

  14. Ergonomics in Laparoscopic Surgery

    OpenAIRE

    Supe Avinash; Kulkarni Gaurav; Supe Pradnya

    2016-01-01

    Laparoscopic surgery provides patients with less painful surgery but is more demanding for the surgeon. The increased technological complexity and sometimes poorly adapted equipment have led to increased complaints of surgeon fatigue and discomfort during laparoscopic surgery. Ergonomic integration and suitable laparoscopic operating room environment are essential to improve efficiency, safety, and comfort for the operating team. Understanding ergonomics can not only make life of surgeon comf...

  15. THE AIDS HANDBOOK

    Directory of Open Access Journals (Sweden)

    Z Khan

    1997-12-01

    Full Text Available HIV infection and AIDS is increasingly becoming a major public health problem in our country. Currently, the reported cases represent only the 'tip of the iceberg' of the problem. In view of the fact that no cure or vaccine for the disease has yet been found, spreading knowledge and removing misconceptions is about the only way that AIDS can be effectively tackled.This handbook, developed by Prof. Shankar Chowdhury and associates, seeks to address all levels of medical and non-medical AIDS workers, as well as the layman. It deals with topics ranging from biology of the virus, symptoms and transmission of disease, to prevention, counselling for infected persons and action plan for AIDS education.The biology of the virus and the immune system is described in simple terms, as well as methods of testing for HIV, and what these test results mean. The progression of disease in adults and children, development of symptoms, diagnostic criteria for AIDS, treatment and outcome of disease is dealt with. How AIDS spreads between people, and the health risk for health workers and families is examined. The various ways in which transmission of HIV can be prevented is looked at in detail, including public health measures, national and internatonal action, and ethical and human rights issues involved.

  16. Surgery center joint ventures.

    Science.gov (United States)

    Zasa, R J

    1999-01-01

    Surgery centers have been accepted as a cost effective, patient friendly vehicle for delivery of quality ambulatory care. Hospitals and physician groups also have made them the vehicles for coming together. Surgery centers allow hospitals and physicians to align incentives and share benefits. It is one of the few types of health care businesses physicians can own without anti-fraud and abuse violation. As a result, many surgery center ventures are now jointly owned by hospitals and physician groups. This article outlines common structures that have been used successfully to allow both to own and govern surgery centers.

  17. Abdominal aortic aneurysm surgery

    DEFF Research Database (Denmark)

    Gefke, K; Schroeder, T V; Thisted, B

    1994-01-01

    The goal of this study was to identify patients who need longer care in the ICU (more than 48 hours) following abdominal aortic aneurysm (AAA) surgery and to evaluate the influence of perioperative complications on short- and long-term survival and quality of life. AAA surgery was performed in 553......, 78% stated that their quality of life had improved or was unchanged after surgery and had resumed working. These data justify a therapeutically aggressive approach, including ICU therapy following AAA surgery, despite failure of one or more organ systems....

  18. Complications of strabismus surgery

    Directory of Open Access Journals (Sweden)

    Scott E Olitsky

    2015-01-01

    Full Text Available All surgeries carry risks of complications, and there is no way to avoid ever having a complication. Strabismus surgery is no different in this regard. There are methods to reduce the risk of a complication during or after surgery, and these steps should always be taken. When a complication occurs, it is important to first recognize it and then manage it appropriately to allow for the best outcome possible. This article will discuss some of the more common and/or most devastating complications that can occur during or after strabismus surgery as well as thoughts on how to avoid them and manage them should they happen.

  19. Integrated bariatric surgery residency

    Directory of Open Access Journals (Sweden)

    Eltorai AE

    2014-11-01

    Full Text Available Adam EM Eltorai Warren Alpert Medical School of Brown University, RI, USA Abstract: Obesity is a major public health concern. Given its lasting efficacy for improving obesity and obesity-related diseases, bariatric surgery is an increasingly common treatment option. As the implementation of the Affordable Care Act progresses, the impending physician shortage will become more severe. Thus there will be an even greater need for doctors specialized in the management and treatment of obese patients. The development of integrated bariatric surgery residency programs could be considered and is discussed herein. Keywords: obesity, bariatric surgery, integrated residency, surgery education

  20. Hyperoxaluria and Bariatric Surgery

    Science.gov (United States)

    Asplin, John R.

    2007-04-01

    Bariatric surgery as a means to treat obesity is becoming increasingly common in the United States. An early form of bariatric surgery, the jejunoileal bypass, had to be abandoned in 1980 due to numerous complications, including hyperoxaluria and kidney stones. Current bariatric procedures have not been systematically evaluated to determine if they cause hyperoxaluria. Presented here are data showing that hyperoxaluria is the major metabolic abnormality in patients with bariatric surgery who form kidney stones. Further studies are needed to assess the prevalence of hyperoxaluria in all patients with bariatric surgery.

  1. Multilateral Aid | L’aide multilatérale

    Directory of Open Access Journals (Sweden)

    2012-05-01

    Full Text Available Bilateral and Multilateral Aid, DAC Members, 1960–2010 (in million USD constant, 2009Aide bilatérale et multilatérale des pays membres du CAD, 1960-2010 (en millions USD constants de 2009­Bilateral and Multilateral Aid by Recipient Region, DAC Members, 2008 (in percentage of total aid by RegionAide bilatérale et multilatérale des pays membres du CAD par region de destination, 2008 (en pourcentage de l’aide totale par régionSources: OECD (2010 2010 DAC Report on Multilateral Aid (Paris: O...

  2. Less extensive surgery compared to extensive surgery

    DEFF Research Database (Denmark)

    Lauszus, Finn F; Petersen, Astrid Christine; Neumann, Gudrun

    2014-01-01

    OBJECTIVE: To describe the outcome of adult granulosa cell tumor (AGCT) with respect to initial clinical findings, methods of surgery, and perioperative treatment. STUDY DESIGN: Retrospective follow-up study. Setting: All hospitals in Jutland. Sample: 163 women diagnosed with AGCT. Methods: Follow......-up by hospital data files, general practitioner, death certificate, and autopsy report. Revision of histopathology by a single pathologist. Main outcome measures: Survival and relapse by clinical data, stage, and type of surgery. RESULTS: The incidence of AGCT was 1.37 per year per 100,000 women (95% CI: 1.08, 1...... in postmenopausal women was associated with surgery including hysterectomy and bilateral oophorectomy (psurgery. Endometrial carcinoma was found 138 times (95% CI: 48, 275) more prevalent than the expected rate. CONCLUSION...

  3. Characterization of a novel 2D array dosimeter for patient-specific quality assurance with volumetric arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Stathakis, Sotirios; Myers, Pamela; Esquivel, Carlos; Mavroidis, Panayiotis; Papanikolaou, Nikos [Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 (United States)

    2013-07-15

    Purpose: In this study, the authors are evaluating a new, commercially available 2D array that offers 3D dose reconstruction for patient specific intensity modulated radiation therapy quality assurance (IMRT QA).Methods: The OCTAVIUS 4D system and its accompanying software (VERISOFT) by PTW were evaluated for the accuracy of the dose reconstruction for patient specific pretreatment IMRT QA. OCTAVIUS 4D measures the dose plane at the linac isocenter as the phantom rotates synchronously with the gantry, maintaining perpendicularity with the beam, by means of an inclinometer and a motor. The measurements collected during a volumetric modulated arc therapy delivery (VMAT) are reconstructed into a 3D dose volume. The VERISOFT application is used to perform the analysis, by comparing the reconstructed dose against the 3D dose matrix from the treatment planning system (TPS) that is computed for the same geometry and beam arrangement as that of the measurement. In this study, the authors evaluated the 3D dose reconstruction algorithm of this new system using a series of tests. Using the Octavius 4D phantom as the patient, dose distributions for various field sizes, beam orientations, shapes, and combination of fields were calculated using the Pinnacle3, TPS, and the respective DICOMRT dose was exported to the VERISOFT analysis software. Measurements were obtained by delivering the test treatment plans and comparisons were made based on gamma index, dose profiles, and isodose distribution analysis. In addition, output factors were measured and the dose linearity of the array was assessed. Those measurements were compared against measurements in water using a single, calibrated ionization chamber as well as calculations from Pinnacle for the same delivery geometries.Results: The number of voxels that met the 3%/3 mm criteria for the volumetric 3D gamma index analysis ranged from 92.3% to 98.9% for all the patient plans that the authors evaluated. 2D gamma analysis in the

  4. Generic method for automatic bladder segmentation on cone beam CT using a patient-specific bladder shape model

    Energy Technology Data Exchange (ETDEWEB)

    Schoot, A. J. A. J. van de, E-mail: a.j.schootvande@amc.uva.nl; Schooneveldt, G.; Wognum, S.; Stalpers, L. J. A.; Rasch, C. R. N.; Bel, A. [Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Hoogeman, M. S. [Department of Radiation Oncology, Daniel den Hoed Cancer Center, Erasmus Medical Center, Groene Hilledijk 301, 3075 EA Rotterdam (Netherlands); Chai, X. [Department of Radiation Oncology, Stanford University School of Medicine, 875 Blake Wilbur Drive, Palo Alto, California 94305 (United States)

    2014-03-15

    Purpose: The aim of this study is to develop and validate a generic method for automatic bladder segmentation on cone beam computed tomography (CBCT), independent of gender and treatment position (prone or supine), using only pretreatment imaging data. Methods: Data of 20 patients, treated for tumors in the pelvic region with the entire bladder visible on CT and CBCT, were divided into four equally sized groups based on gender and treatment position. The full and empty bladder contour, that can be acquired with pretreatment CT imaging, were used to generate a patient-specific bladder shape model. This model was used to guide the segmentation process on CBCT. To obtain the bladder segmentation, the reference bladder contour was deformed iteratively by maximizing the cross-correlation between directional grey value gradients over the reference and CBCT bladder edge. To overcome incorrect segmentations caused by CBCT image artifacts, automatic adaptations were implemented. Moreover, locally incorrect segmentations could be adapted manually. After each adapted segmentation, the bladder shape model was expanded and new shape patterns were calculated for following segmentations. All available CBCTs were used to validate the segmentation algorithm. The bladder segmentations were validated by comparison with the manual delineations and the segmentation performance was quantified using the Dice similarity coefficient (DSC), surface distance error (SDE) and SD of contour-to-contour distances. Also, bladder volumes obtained by manual delineations and segmentations were compared using a Bland-Altman error analysis. Results: The mean DSC, mean SDE, and mean SD of contour-to-contour distances between segmentations and manual delineations were 0.87, 0.27 cm and 0.22 cm (female, prone), 0.85, 0.28 cm and 0.22 cm (female, supine), 0.89, 0.21 cm and 0.17 cm (male, supine) and 0.88, 0.23 cm and 0.17 cm (male, prone), respectively. Manual local adaptations improved the segmentation

  5. Cardiac Procedures and Surgeries

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Cardiac Procedures and Surgeries Updated:Sep 16,2016 If you've had ... degree of coronary artery disease (CAD) you have. Cardiac Procedures and Surgeries Angioplasty Also known as Percutaneous Coronary Interventions [PCI], ...

  6. [Robotic surgery in gynecology].

    Science.gov (United States)

    Csorba, Roland

    2012-06-24

    Minimally invasive surgery has revolutionized gynecological interventions over the past 30 years. The introduction of the da Vinci robotic surgery in 2005 has resulted in large changes in surgical management. The robotic platform allows less experienced laparoscopic surgeons to perform more complex procedures. It can be utilized mainly in general gynecology and reproductive gynecology. The robot is being increasingly used for procedures such as hysterectomy, myomectomy, adnexal surgery, and tubal anastomosis. In urogynecology, the robot is being utilized for sacrocolopexy as well. In the field of gynecologic oncology, the robot is being increasingly used for hysterectomy and lymphadenectomy in oncologic diseases. Despite the rapid and widespread adaption of robotic surgery in gynecology, there are no randomized trials comparing its efficacy and safety to other traditional surgical approaches. This article presents the development, technical aspects and indications of robotic surgery in gynecology, based on the previously published reviews. Robotic surgery can be highly advantageous with the right amount of training, along with appropriate patient selection. Patients will have less blood loss, less post-operative pain, faster recovery, and fewer complications compared to open surgery and laparoscopy. However, until larger randomized control trials are completed which report long-term outcomes, robotic surgery cannot be stated to have priority over other surgical methods.

  7. [Cognitive deterioration after surgery

    DEFF Research Database (Denmark)

    Steinmetz, J.; Rasmussen, L.S.

    2008-01-01

    Delirium and postoperative cognitive dysfunction are important and common complications after surgery. Risk factors are first of all increasing age and type of surgery, whereas the type of anaesthesia does not seem to play an important role. Mortality is higher among patients with cognitive...

  8. Women and AIDS: introduction.

    Science.gov (United States)

    Krieger, N; Margo, G

    1991-01-01

    Around the world, more and more women--principally poor women of color--are being diagnosed with and are dying of AIDS, the acquired immune deficiency syndrome. Yet, effective and appropriate prevention programs for women are sorely missing from the global program to control AIDS. To help us understand why this gap exists, and what we must do to close it, the three articles in this issue focus on women and AIDS. Examining the situation in such countries as Zimbabwe and South Africa, as well as in other economically underdeveloped and developed regions, the authors argue that women with the least control over their bodies and their lives are at greatest risk of acquiring AIDS. For example, the high rate of infection among women in Africa cannot be understood apart from the legacy of colonialism (including land expropriation and the forced introduction of a migrant labor system) and the insidious combination of traditional and European patriarchal values. Only by recognizing the socioeconomic and cultural determinants of both disease and sexual behavior, and only by incorporating these insights into our AIDS prevention programs, will we be able to curb the spread of this lethal disease.

  9. AIDS in Africa.

    Science.gov (United States)

    Mokhobo, D

    1989-03-01

    Numerous cultural practices and attitudes in Africa represent formidable obstacles to the prevention of the further spread of acquired immunodeficiency syndrome (AIDS). Polygamy and concubinage are still widely practiced throughout Africa. In fact, sexual promiscuity on the part of males is traditionally viewed as positive--a reflection of male supremacy and male sexual prowess. The disintegration of the rural African family, brought about by urbanization, the migrant labor system, and poverty, has resulted in widespread premarital promiscuity. Contraceptive practices are perceived by many as a white conspiracy aimed at limiting the growth of the black population and thereby diminishing its political power. Condom use is particularly in disfavor. Thus, AIDS prevention campaigns urging Africans to restrict the number of sexual partners and to use condoms are unlikely to be successful. Another problem is that most Africans cannot believe that AIDS is sexually linked in that the disease does not affect the sex organs as is the case with other sexually transmitted diseases. The degree to which African governments are able to allocate resources to AIDS education will determine whether the epidemic can be controlled. Even with a massive outpouring of resources, it may be difficult to arouse public alarm about AIDS since Africans are so acclimated to living with calamities of every kind.

  10. Automatic 4D reconstruction of patient-specific cardiac mesh with 1-to-1 vertex correspondence from segmented contours lines.

    Directory of Open Access Journals (Sweden)

    Chi Wan Lim

    Full Text Available We propose an automatic algorithm for the reconstruction of patient-specific cardiac mesh models with 1-to-1 vertex correspondence. In this framework, a series of 3D meshes depicting the endocardial surface of the heart at each time step is constructed, based on a set of border delineated magnetic resonance imaging (MRI data of the whole cardiac cycle. The key contribution in this work involves a novel reconstruction technique to generate a 4D (i.e., spatial-temporal model of the heart with 1-to-1 vertex mapping throughout the time frames. The reconstructed 3D model from the first time step is used as a base template model and then deformed to fit the segmented contours from the subsequent time steps. A method to determine a tree-based connectivity relationship is proposed to ensure robust mapping during mesh deformation. The novel feature is the ability to handle intra- and inter-frame 2D topology changes of the contours, which manifests as a series of merging and splitting of contours when the images are viewed either in a spatial or temporal sequence. Our algorithm has been tested on five acquisitions of cardiac MRI and can successfully reconstruct the full 4D heart model in around 30 minutes per subject. The generated 4D heart model conforms very well with the input segmented contours and the mesh element shape is of reasonably good quality. The work is important in the support of downstream computational simulation activities.

  11. In situ genetic correction of F8 intron 22 inversion in hemophilia A patient-specific iPSCs.

    Science.gov (United States)

    Wu, Yong; Hu, Zhiqing; Li, Zhuo; Pang, Jialun; Feng, Mai; Hu, Xuyun; Wang, Xiaolin; Lin-Peng, Siyuan; Liu, Bo; Chen, Fangping; Wu, Lingqian; Liang, Desheng

    2016-01-08

    Nearly half of severe Hemophilia A (HA) cases are caused by F8 intron 22 inversion (Inv22). This 0.6-Mb inversion splits the 186-kb F8 into two parts with opposite transcription directions. The inverted 5' part (141 kb) preserves the first 22 exons that are driven by the intrinsic F8 promoter, leading to a truncated F8 transcript due to the lack of the last 627 bp coding sequence of exons 23-26. Here we describe an in situ genetic correction of Inv22 in patient-specific induced pluripotent stem cells (iPSCs). By using TALENs, the 627 bp sequence plus a polyA signal was precisely targeted at the junction of exon 22 and intron 22 via homologous recombination (HR) with high targeting efficiencies of 62.5% and 52.9%. The gene-corrected iPSCs retained a normal karyotype following removal of drug selection cassette using a Cre-LoxP system. Importantly, both F8 transcription and FVIII secretion were rescued in the candidate cell types for HA gene therapy including endothelial cells (ECs) and mesenchymal stem cells (MSCs) derived from the gene-corrected iPSCs. This is the first report of an efficient in situ genetic correction of the large inversion mutation using a strategy of targeted gene addition.

  12. A Patient Specific Biomechanical Analysis of Custom Root Analogue Implant Designs on Alveolar Bone Stress: A Finite Element Study

    Directory of Open Access Journals (Sweden)

    David Anssari Moin

    2016-01-01

    Full Text Available Objectives. The aim of this study was to analyse by means of FEA the influence of 5 custom RAI designs on stress distribution of peri-implant bone and to evaluate the impact on microdisplacement for a specific patient case. Materials and Methods. A 3D surface model of a RAI for the upper right canine was constructed from the cone beam computed tomography data of one patient. Subsequently, five (targeted press-fit design modification FE models with five congruent bone models were designed: “Standard,” “Prism,” “Fins,” “Plug,” and “Bulbs,” respectively. Preprocessor software was applied to mesh the models. Two loads were applied: an oblique force (300 N and a vertical force (150 N. Analysis was performed to evaluate stress distributions and deformed contact separation at the peri-implant region. Results. The lowest von Mises stress levels were numerically observed for the Plug design. The lowest levels of contact separation were measured in the Fins model followed by the Bulbs design. Conclusions. Within the limitations of the applied methodology, adding targeted press-fit geometry to the RAI standard design will have a positive effect on stress distribution, lower concentration of bone stress, and will provide a better primary stability for this patient specific case.

  13. Towards personalised management of atherosclerosis via computational models in vascular clinics: technology based on patient-specific simulation approach.

    Science.gov (United States)

    Díaz-Zuccarini, Vanessa; Di Tomaso, Giulia; Agu, Obiekezie; Pichardo-Almarza, Cesar

    2014-01-01

    The development of a new technology based on patient-specific modelling for personalised healthcare in the case of atherosclerosis is presented. Atherosclerosis is the main cause of death in the world and it has become a burden on clinical services as it manifests itself in many diverse forms, such as coronary artery disease, cerebrovascular disease/stroke and peripheral arterial disease. It is also a multifactorial, chronic and systemic process that lasts for a lifetime, putting enormous financial and clinical pressure on national health systems. In this Letter, the postulate is that the development of new technologies for healthcare using computer simulations can, in the future, be developed as in-silico management and support systems. These new technologies will be based on predictive models (including the integration of observations, theories and predictions across a range of temporal and spatial scales, scientific disciplines, key risk factors and anatomical sub-systems) combined with digital patient data and visualisation tools. Although the problem is extremely complex, a simulation workflow and an exemplar application of this type of technology for clinical use is presented, which is currently being developed by a multidisciplinary team following the requirements and constraints of the Vascular Service Unit at the University College Hospital, London.

  14. Pretreatment Patient Specific Quality Assurance and Gamma Index Variation Study in Gantry Dependent EPID Positions for IMRT Prostate Treatments

    Directory of Open Access Journals (Sweden)

    Siji Cyriac

    2014-01-01

    Full Text Available Pretreatment quality assurance (QA is a major concern in complex radiation therapy treatment plans like intensity modulated radiation therapy (IMRT. Present study considers the variations in gamma index for gantry dependent pretreatment verification and commonly practiced zero gantry angle verifications for ten prostate IMRT plans using two commercial medical linear accelerators (Varian 2300 CD, Varian Clinac iX. Two verification plans (the one with all fields at the actual treatment angles and one with all fields merged to 0 degree gantry angles for all the patients were generated to obtain dose fluence mapping using amorphous silicon electronic portal imaging device (EPID. The gamma index was found depend on gantry angles but the difference between zero and the nonzero treatment angles is in the confidence level for clinical acceptance. The acceptance criteria of gamma method were always satisfied in both cases for two machines and are stable enough to execute the patient specific pretreatment quality assurance at 0 degree gantry angle for prostate IMRTs, where limited number of gantry angles are used.

  15. Novel genes associated with colorectal cancer are revealed by high resolution cytogenetic analysis in a patient specific manner.

    Directory of Open Access Journals (Sweden)

    Hisham Eldai

    Full Text Available Genomic abnormalities leading to colorectal cancer (CRC include somatic events causing copy number aberrations (CNAs as well as copy neutral manifestations such as loss of heterozygosity (LOH and uniparental disomy (UPD. We studied the causal effect of these events by analyzing high resolution cytogenetic microarray data of 15 tumor-normal paired samples. We detected 144 genes affected by CNAs. A subset of 91 genes are known to be CRC related yet high GISTIC scores indicate 24 genes on chromosomes 7, 8, 18 and 20 to be strongly relevant. Combining GISTIC ranking with functional analyses and degree of loss/gain we identify three genes in regions of significant loss (ATP8B1, NARS, and ATP5A1 and eight in regions of gain (CTCFL, SPO11, ZNF217, PLEKHA8, HOXA3, GPNMB, IGF2BP3 and PCAT1 as novel in their association with CRC. Pathway and target prediction analysis of CNA affected genes and microRNAs, respectively indicates TGF-β signaling pathway to be involved in causing CRC. Finally, LOH and UPD collectively affected nine cancer related genes. Transcription factor binding sites on regions of >35% copy number loss/gain influenced 16 CRC genes. Our analysis shows patient specific CRC manifestations at the genomic level and that these different events affect individual CRC patients differently.

  16. Physiological outflow boundary conditions methodology for small arteries with multiple outlets: a patient-specific hepatic artery haemodynamics case study.

    Science.gov (United States)

    Aramburu, Jorge; Antón, Raúl; Bernal, Nebai; Rivas, Alejandro; Ramos, Juan Carlos; Sangro, Bruno; Bilbao, José Ignacio

    2015-04-01

    Physiological outflow boundary conditions are necessary to carry out computational fluid dynamics simulations that reliably represent the blood flow through arteries. When dealing with complex three-dimensional trees of small arteries, and therefore with multiple outlets, the robustness and speed of convergence are also important. This study derives physiological outflow boundary conditions for cases in which the physiological values at those outlets are not known (neither in vivo measurements nor literature-based values are available) and in which the tree exhibits symmetry to some extent. The inputs of the methodology are the three-dimensional domain and the flow rate waveform and the systolic and diastolic pressures at the inlet. The derived physiological outflow boundary conditions, which are a physiological pressure waveform for each outlet, are based on the results of a zero-dimensional model simulation. The methodology assumes symmetrical branching and is able to tackle the flow distribution problem when the domain outlets are at branches with a different number of upstream bifurcations. The methodology is applied to a group of patient-specific arteries in the liver. The methodology is considered to be valid because the pulsatile computational fluid dynamics simulation with the inflow flow rate waveform (input of the methodology) and the derived outflow boundary conditions lead to physiological results, that is, the resulting systolic and diastolic pressures at the inlet match the inputs of the methodology, and the flow split is also physiological.

  17. Clinical Study of 3D Imaging and 3D Printing Technique for Patient-Specific Instrumentation in Total Knee Arthroplasty.

    Science.gov (United States)

    Qiu, Bing; Liu, Fei; Tang, Bensen; Deng, Biyong; Liu, Fang; Zhu, Weimin; Zhen, Dong; Xue, Mingyuan; Zhang, Mingjiao

    2017-01-25

    Patient-specific instrumentation (PSI) was designed to improve the accuracy of preoperative planning and postoperative prosthesis positioning in total knee arthroplasty (TKA). However, better understanding needs to be achieved due to the subtle nature of the PSI systems. In this study, 3D printing technique based on the image data of computed tomography (CT) has been utilized for optimal controlling of the surgical parameters. Two groups of TKA cases have been randomly selected as PSI group and control group with no significant difference of age and sex (p > 0.05). The PSI group is treated with 3D printed cutting guides whereas the control group is treated with conventional instrumentation (CI). By evaluating the proximal osteotomy amount, distal osteotomy amount, valgus angle, external rotation angle, and tibial posterior slope angle of patients, it can be found that the preoperative quantitative assessment and intraoperative changes can be controlled with PSI whereas CI is relied on experience. In terms of postoperative parameters, such as hip-knee-ankle (HKA), frontal femoral component (FFC), frontal tibial component (FTC), and lateral tibial component (LTC) angles, there is a significant improvement in achieving the desired implant position (p implantation compared against control method, which indicates potential for optimal HKA, FFC, and FTC angles.

  18. A comparative study of 1D and 3D hemodynamics in patient-specific hepatic portal vein networks

    Directory of Open Access Journals (Sweden)

    Jonášová A.

    2014-12-01

    Full Text Available The development of software for use in clinical practice is often associated with many requirements and restrictions set not only by the medical doctors, but also by the hospital’s budget. To meet the requirement of reliable software, which is able to provide results within a short time period and with minimal computational demand, a certain measure of modelling simplification is usually inevitable. In case of blood flow simulations carried out in large vascular networks such as the one created by the hepatic portal vein, simplifications are made by necessity. The most often employed simplification includes the approach in the form of dimensional reduction, when the 3D model of a large vascular network is substituted with its 1D counterpart. In this context, a question naturally arises, how this reduction can affect the simulation accuracy and its outcome. In this paper, we try to answer this question by performing a quantitative comparison of 3D and 1D flow models in two patient-specific hepatic portal vein networks. The numerical simulations are carried out under average flow conditions and with the application of the three-element Windkessel model, which is able to approximate the downstream flow resistance of real hepatic tissue. The obtained results show that, although the 1D model can never truly substitute the 3D model, its easy implementation, time-saving model preparation and almost no demands on computer technology dominate as advantages over obvious but moderate modelling errors arising from the performed dimensional reduction.

  19. Automated identification of brain tumours from single MR images based on segmentation with refined patient-specific priors

    Directory of Open Access Journals (Sweden)

    Ana eSanjuán

    2013-12-01

    Full Text Available Brain tumours can have different shapes or locations, making their identification very challenging. In functional MRI, it is not unusual that patients have only one anatomical image due to time and financial constraints. Here, we provide a modified automatic lesion identification (ALI procedure which enables brain tumour identification from single MR images. Our method rests on (A a modified segmentation-normalisation procedure with an explicit extra prior for the tumour and (B an outlier detection procedure for abnormal voxel (i.e. tumour classification. To minimise tissue misclassification, the segmentation-normalisation procedure requires prior information of the tumour location and extent. We therefore propose that ALI is run iteratively so that the output of Step B is used as a patient-specific prior in Step A. We test this procedure on real T1-weighted images from 18 patients, and the results were validated in comparison to two independent observers’ manual tracings. The automated procedure identified the tumours successfully with an excellent agreement with the manual segmentation (area under the ROC curve = 0.97 ± 0.03. The proposed procedure increases the flexibility and robustness of the ALI tool and will be particularly useful for lesion-behaviour mapping studies, or when lesion identification and/or spatial normalisation are problematic.

  20. Computational Modelling of Multi-folded Balloon Delivery Systems for Coronary Artery Stenting: Insights into Patient-Specific Stent Malapposition.

    Science.gov (United States)

    Ragkousis, Georgios E; Curzen, Nick; Bressloff, Neil W

    2015-08-01

    Despite the clinical effectiveness of coronary artery stenting, percutaneous coronary intervention or "stenting" is not free of complications. Stent malapposition (SM) is a common feature of "stenting" particularly in challenging anatomy, such as that characterized by long, tortuous and bifurcated segments. SM is an important risk factor for stent thrombosis and recently it has been associated with longitudinal stent deformation. SM is the result of many factors including reference diameter, vessel tapering, the deployment pressure and the eccentric anatomy of the vessel. For the purpose of the present paper, virtual multi-folded balloon models have been developed for simulated deployment in both constant and varying diameter vessels under uniform pressure. The virtual balloons have been compared to available compliance charts to ensure realistic inflation response at nominal pressures. Thereafter, patient-specific simulations of stenting have been conducted aiming to reduce SM. Different scalar indicators, which allow a more global quantitative judgement of the mechanical performance of each delivery system, have been implemented. The results indicate that at constant pressure, the proposed balloon models can increase the minimum stent lumen area and thereby significantly decrease SM.

  1. Fluid mechanics of blood flow in human fetal left ventricles based on patient-specific 4D ultrasound scans.

    Science.gov (United States)

    Lai, Chang Quan; Lim, Guat Ling; Jamil, Muhammad; Mattar, Citra Nurfarah Zaini; Biswas, Arijit; Yap, Choon Hwai

    2016-10-01

    The mechanics of intracardiac blood flow and the epigenetic influence it exerts over the heart function have been the subjects of intense research lately. Fetal intracardiac flows are especially useful for gaining insights into the development of congenital heart diseases, but have not received due attention thus far, most likely because of technical difficulties in collecting sufficient intracardiac flow data in a safe manner. Here, we circumvent such obstacles by employing 4D STIC ultrasound scans to quantify the fetal heart motion in three normal 20-week fetuses, subsequently performing 3D computational fluid dynamics simulations on the left ventricles based on these patient-specific heart movements. Analysis of the simulation results shows that there are significant differences between fetal and adult ventricular blood flows which arise because of dissimilar heart morphology, E/A ratio, diastolic-systolic duration ratio, and heart rate. The formations of ventricular vortex rings were observed for both E- and A-wave in the flow simulations. These vortices had sufficient momentum to last until the end of diastole and were responsible for generating significant wall shear stresses on the myocardial endothelium, as well as helicity in systolic outflow. Based on findings from previous studies, we hypothesized that these vortex-induced flow properties play an important role in sustaining the efficiency of diastolic filling, systolic pumping, and cardiovascular flow in normal fetal hearts.

  2. Patient-specific modeling and analysis of dynamic behavior of individual sickle red blood cells under hypoxic conditions

    Science.gov (United States)

    Li, Xuejin; Du, E.; Li, Zhen; Tang, Yu-Hang; Lu, Lu; Dao, Ming; Karniadakis, George

    2015-11-01

    Sickle cell anemia is an inherited blood disorder exhibiting heterogeneous morphology and abnormal dynamics under hypoxic conditions. We developed a time-dependent cell model that is able to simulate the dynamic processes of repeated sickling and unsickling of red blood cells (RBCs) under physiological conditions. By using the kinetic cell model with parameters derived from patient-specific data, we present a mesoscopic computational study of the dynamic behavior of individual sickle RBCs flowing in a microfluidic channel with multiple microgates. We investigate how individual sickle RBCs behave differently from healthy ones in channel flow, and analyze the alteration of cellular behavior and response to single-cell capillary obstruction induced by cell rheologic rigidification and morphological change due to cell sickling under hypoxic conditions. We also simulate the flow dynamics of sickle RBCs treated with hydroxyurea (HU) and quantify the relative enhancement of hemodynamic performance of HU. This work was supported by the National Institutes of Health (NIH) Grant U01HL114476.

  3. Structural correlation method for model reduction and practical estimation of patient specific parameters illustrated on heart rate regulation.

    Science.gov (United States)

    Ottesen, Johnny T; Mehlsen, Jesper; Olufsen, Mette S

    2014-11-01

    We consider the inverse and patient specific problem of short term (seconds to minutes) heart rate regulation specified by a system of nonlinear ODEs and corresponding data. We show how a recent method termed the structural correlation method (SCM) can be used for model reduction and for obtaining a set of practically identifiable parameters. The structural correlation method includes two steps: sensitivity and correlation analysis. When combined with an optimization step, it is possible to estimate model parameters, enabling the model to fit dynamics observed in data. This method is illustrated in detail on a model predicting baroreflex regulation of heart rate and applied to analysis of data from a rat and healthy humans. Numerous mathematical models have been proposed for prediction of baroreflex regulation of heart rate, yet most of these have been designed to provide qualitative predictions of the phenomena though some recent models have been developed to fit observed data. In this study we show that the model put forward by Bugenhagen et al. can be simplified without loss of its ability to predict measured data and to be interpreted physiologically. Moreover, we show that with minimal changes in nominal parameter values the simplified model can be adapted to predict observations from both rats and humans. The use of these methods make the model suitable for estimation of parameters from individuals, allowing it to be adopted for diagnostic procedures.

  4. ROBOTIC SURGERY: BIOETHICAL ASPECTS

    Science.gov (United States)

    SIQUEIRA-BATISTA, Rodrigo; SOUZA, Camila Ribeiro; MAIA, Polyana Mendes; SIQUEIRA, Sávio Lana

    2016-01-01

    ABSTRACT Introduction: The use of robots in surgery has been increasingly common today, allowing the emergence of numerous bioethical issues in this area. Objective: To present review of the ethical aspects of robot use in surgery. Method: Search in Pubmed, SciELO and Lilacs crossing the headings "bioethics", "surgery", "ethics", "laparoscopy" and "robotic". Results: Of the citations obtained, were selected 17 articles, which were used for the preparation of the article. It contains brief presentation on robotics, its inclusion in health and bioethical aspects, and the use of robots in surgery. Conclusion: Robotic surgery is a reality today in many hospitals, which makes essential bioethical reflection on the relationship between health professionals, automata and patients. PMID:28076489

  5. AIDS ORPHANS GET SPECIAL VISITOR

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chinese Premier Wen Jiabao visits AIDS orphans in Shangcai County,central China’s Henan Province,on November 30,a day before the 20th World AIDS Day. The region of Shangcai has the highest concentration of people living with HIV/AIDS in China. The Chinese Government has released a package of policies that offer people living with HIV/AIDS free medicine,health checks and consultations,as well as free schooling to AIDS orphans.

  6. 计算机辅助外科中手术与计划空间标定以及视觉空间的误差校正%Calibration Between Operation Space and Plan Space and Error Correction of Visual Space in Computer-aided Surgery

    Institute of Scientific and Technical Information of China (English)

    郭锥; 周宇; 席文明

    2012-01-01

    In computer-aided surgery (CAS) system,many space integrates in together,in order to improve the precision of the system operation,the effective calibration method to correct the error between the space is needed. Using the robot characteristics motion errors in visual space of navigation system to establish the mapping of visual space and robot space,and to recursion correction the local transformation matrix of visual space and robot space. Using local transformation matrix to establish optimization equatipn.and then obtaining global optimal transformation matrix. This method for all the static and dynamic error correction. According to the coupling error exists in the operation and plan space,using the designed special structure force sensor and calibration piece of decoupling to calibration its error, and according to the transformation matrix to adjust the objects position and orientation in the plan space to ensure that the objects in the plan space have the same pose with it in the operation space. The experimental results show that the dynamic calibration method can make the visual space global error reduced to 5 pixels,and the force control calibration method can make the position error is reduced to 0. 25 mm and the posture error reduced to 0. 1%计算机辅助外科(CAS)系统中,多空间集成在一起,为了提高系统的操作精度,需要有效的标定方法校正空间之间的误差.利用机器人上特征在导航系统中视觉空间的运动误差,建立视觉空间与机器人空间的映射关系,递归校正两空间之间的局部转换矩阵.利用局部转换矩阵建立优化方程,求取全局最优转换矩阵.该方法对所有动态、静态误差进行校正.针对手术与计划空间中存在的耦合误差,利用设计的特殊结构力传感器和标定块解耦标定其误差,并根据求取的转换矩阵,调整计划空间中对象的位姿,保证计划空间与手术空间中的对象位姿一致.实验结果表明,动

  7. Factors influencing intraoperative blood loss in orthognathic surgery.

    Science.gov (United States)

    Thastum, M; Andersen, K; Rude, K; Nørholt, S E; Blomlöf, J

    2016-09-01

    This retrospective study aimed to identify factors of importance for intraoperative blood loss relative to total blood volume in patients undergoing orthognathic surgery. The study included 356 patients treated consecutively at a Danish university hospital between 1 January 2010 and 31 December 2012. Inclusion criteria were (1) patient age ≥18 years and (2) patient undergoing a three-piece Le Fort I osteotomy, a bilateral sagittal split osteotomy, or a combination of the two. The patient-specific relative blood loss was calculated as a percentage by dividing the intraoperative blood loss by the estimated preoperative total blood volume, and then correlated with body mass index (BMI), age, sex, operating time, and treatment modality in a multivariate stepwise regression analysis. Operating time (Psurgery, a prolonged operating time, and reduced BMI significantly increase the intraoperative relative blood loss in patients undergoing orthognathic surgery.

  8. Gamma knife surgery for craniopharyngioma.

    Science.gov (United States)

    Prasad, D; Steiner, M; Steiner, L

    1995-01-01

    We present our results of Gamma Knife surgery for craniopharyngioma in nine patients. The current status of surgery, radiation therapy, intracavitary instillation of radionucleides and Gamma Knife surgery in the management of craniopharyngiomas is discussed.

  9. Preparing for Breast Reconstruction Surgery

    Science.gov (United States)

    ... Cancer Breast Reconstruction Surgery Preparing for Breast Reconstruction Surgery Your surgeon can help you know what to ... The plan for follow-up Costs Understanding your surgery costs Health insurance policies often cover most or ...

  10. Tests and visits before surgery

    Science.gov (United States)

    Before surgery - tests; Before surgery - doctor visits ... Pre-op is the time before your surgery. It means "before operation." During this time, you will meet with one of your doctors. This may be your surgeon or primary care ...

  11. Cancer Surgery: Physically Removing Cancer

    Science.gov (United States)

    ... in cancer diagnosis, staging, treatment and symptom relief. Robotic surgery. In robotic surgery, the surgeon sits away from the operating table ... to maneuver surgical tools to perform the operation. Robotic surgery helps the surgeon operate in hard-to-reach ...

  12. Intracranial Hypertension: Medication and Surgery

    Science.gov (United States)

    ... Intracraneal en Espanol. STORE Shop the IHRF Store Medication and Surgery Medication and Surgery Both drugs and surgery are used ... to treat the headache that accompanies chronic IH. Medications for chronic headache like tricyclic anti-depressants, beta- ...

  13. SURGERY AND CARDIOVASCULAR SURGERY JOURNALS ANALYSIS

    Directory of Open Access Journals (Sweden)

    Alberto Schanaider

    2015-01-01

    Full Text Available Objective: To analyze critically the effectiveness and value of bibliometric indicators in journals of Surgery or Cardiovacular Surgery in the context of the postgraduate programs of CAPES Medicine III. Methods: A sampling with 16 academic programs and one professional master of Medicine III, encompassing the General and Digestive System Surgery, Cardiovascular Surgery and Multidisciplinary courses with such contents, was evaluated. Thomson Reuters/ISI (JCR, Elsevier/Scopus (SJR, and also Scielo databases were used. Results: Only in seven programs, the teachers had an average of Qualis A1 articles greater than the others strata. Eleven journals in the surgical area are in stratum A1 (5% and it reaches 25% in Cardiovascular Surgery. Among the six journals with the largest number of publications Qualis A1 in area Medicine III, five are from non-specific areas. The Acta Cirúrgica Brasileira represented 58% of the publications in the stratum A2. There are some obstacles in the Qualis classification with little uniformity among the Medicine areas I, II and III. Conclusions: A permanent committee should be set to update the Qualis, composed by the three medical areas. It should be considered using other index databases and the unification of the Qualis criteria for journals in medicine. Rating criteria of multi and transdisciplinary journals need to be reviewed. It is essential an institutional financial support for national journals chosen by peers aiming to provide a full computerization process and a professional reviewer of the English language, in order to increase the impact factor.

  14. AIDS in Colombia.

    Science.gov (United States)

    Boshell, J; Gacharná, M G; García, M; Jaramillo, L S; Márquez, G; Fergusson, M M; González, S; Prada, E Y; de Rangel, R; de Cabas, R

    1989-01-01

    Between January 1984 and December 1987 a total of 178 AIDS cases were reported to the Colombian Ministry of Health. The location of these cases suggests that the human immunodeficiency virus (HIV) is widely distributed in Colombia. Most of those afflicted (97%) have been adult males. HIV seroprevalence studies of selected population groups revealed the highest antibody prevalence (5.65% in females, 22.5% in males) among individuals involved in high-risk behaviors who participated in a free AIDS testing program. High prevalences (from 0.6% to 3.9% in females, and 14.6% to 15.9% in males) were also found in patients (primarily female prostitutes and male homosexuals) attending clinics for sexually transmitted diseases in several urban areas. The number of AIDS cases in Colombia has doubled or tripled annually since reporting began in 1984, a pattern similar to that observed worldwide.

  15. [AIDS mortality in France].

    Science.gov (United States)

    Hatton, F; Maguin, P; Nicaud, V; Renaud, G

    1986-01-01

    A study about mortality by AIDS had been undertaken since July 1st 1983, in the Service of Information on Medical causes of Death (INSERM SC8), which is in charge of developing mortality statistics in France. From July 1st 1983 to September 30th 1985, 243 deaths due to AIDS were recorded. Only the cases where this diagnosis was clearly mentioned were selected; more than 90% were notified by hospitals and mainly by highly specialized services. The number of deaths, which was low and varied rather irregularly at the beginning, then increased by successive stages. The first year, during which a tenth of deaths was recorded every three months, was followed by a great increase, doubling, then tripling the initial numbers. Lastly, a second and sudden rise occurred during the third trimester of 1985, the trimestrial number of deaths due to AIDS reaching 80.

  16. Computer aided control engineering

    DEFF Research Database (Denmark)

    Szymkat, Maciej; Ravn, Ole

    1997-01-01

    Current developments in the field of Computer Aided Control Engineering (CACE) have a visible impact on the design methodologies and the structure of the software tools supporting them. Today control engineers has at their disposal libraries, packages or programming environments that may be speci......Current developments in the field of Computer Aided Control Engineering (CACE) have a visible impact on the design methodologies and the structure of the software tools supporting them. Today control engineers has at their disposal libraries, packages or programming environments that may...

  17. Handheld micromanipulator for robot-assisted stapes footplate surgery.

    Science.gov (United States)

    Montes Grande, Gonzalo; Knisely, Anna J; Becker, Brian C; Yang, Sungwook; Hirsch, Barry E; Riviere, Cameron N

    2012-01-01

    Stapes footplate surgery is complex and delicate. This surgery is carried out in the middle ear to improve hearing. High accuracy is required to avoid critical tissues and structures near the surgical worksite. By suppressing the surgeon's tremor during the operation, accuracy can be improved. In this paper, a fully handheld active micromanipulator known as Micron is evaluated for its feasibility for this delicate operation. An ergonomic handle, a custom tip, and a brace attachment were designed for stapes footplate surgery and tested in a fenestration task through a fixed speculum. Accuracy was measured during simulated surgery in two different scenarios: Micron off (unaided) and Micron on (aided), both with image guidance. Preliminary results show that Micron significantly reduces the mean position error and the mean duration of time spent in specified dangerous zones.

  18. [Approach to the patient in the ambulatory surgery unit].

    Science.gov (United States)

    Cordero-Ponce, Montserrat; Romero-Sánchez, Isabel María; López-Barea, José; Martínez-Ramos, Pablo

    2008-01-01

    Ambulatory surgery aims to improve the quality of care, provide services in an environment closer to users' normal surroundings, reduce the risk of nosocomial infection and release hospital beds for other uses demanded by the population, thus reducing health costs. Nursing activity in these units should aim to restore health and aid the rapid recovery of patients in their homes. To achieve this, an effective health education program is required. Such programs should be simple and, at the same time, cover the care that these patients will require during the recovery period at home. The unit covers patients in the Virgen de Rocío University Hospital, The Fleming Peripheral Center for Specialties and the Virgen de los Reyes Peripheral Center for Specialties in Seville, Spain and the the specialties included are plastic surgery, otorhinolaryngology, orthopedic surgery, urology, and general surgery. The duration of the education program will be at most 14-17 h.

  19. The Plastic Surgery Compass: Navigating the Reconstructive Ladder in the Personalized Health Care Era

    Science.gov (United States)

    2016-01-01

    Summary: The reconstructive ladder and the reconstructive elevator have withstood the test of time as didactic tools for resident education. Over time, many alternative models have been suggested to incorporate the technological advances in plastic surgery, but none of them have focused on the patient. Changes in practice and the trend toward personalized health care demand a 360-degree evaluation and solution of surgical problems incorporating patient-specific characteristics. We, therefore, suggest the concept of the plastic surgery compass to navigate the ladder. PMID:27757348

  20. Single port laparoscopic surgery

    DEFF Research Database (Denmark)

    Springborg, Henrik; Istre, Olav

    2012-01-01

    LESS, or laparo-endoscopic single site surgery, is a promising new method in minimally invasive surgery. An increasing number of surgical procedures are being performed using this technique, however, its large-scale adoption awaits results of prospective randomized controlled studies confirming...... potential benefits. Theoretically, cosmetic outcomes, postoperative pain and complication rates could be improved with use of single site surgery. This study describes introduction of the method in a private hospital in Denmark, in which 40 patients have been treated for benign gynecologic conditions...

  1. Surveys on surgery theory

    CERN Document Server

    Cappell, Sylvain; Rosenberg, Jonathan

    2014-01-01

    Surgery theory, the basis for the classification theory of manifolds, is now about forty years old. There have been some extraordinary accomplishments in that time, which have led to enormously varied interactions with algebra, analysis, and geometry. Workers in many of these areas have often lamented the lack of a single source that surveys surgery theory and its applications. Indeed, no one person could write such a survey. The sixtieth birthday of C. T. C. Wall, one of the leaders of the founding generation of surgery theory, provided an opportunity to rectify the situation and produce a

  2. Surveys on surgery theory

    CERN Document Server

    Cappell, Sylvain; Rosenberg, Jonathan

    2014-01-01

    Surgery theory, the basis for the classification theory of manifolds, is now about forty years old. The sixtieth birthday (on December 14, 1996) of C.T.C. Wall, a leading member of the subject''s founding generation, led the editors of this volume to reflect on the extraordinary accomplishments of surgery theory as well as its current enormously varied interactions with algebra, analysis, and geometry. Workers in many of these areas have often lamented the lack of a single source surveying surgery theory and its applications. Because no one person could write such a survey, the editors ask

  3. Chair in Pediatric Surgery

    OpenAIRE

    Graña, Francisco; Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú

    2014-01-01

    Inaugural lecture of the course of 1922, Department of Paediatric Surgery, by Dr. Francisco Grana, Professor of Pediatric Surgery and Orthopedics at the Faculty of Medicine of Lima, the National Academy of Medicine, of the Peruvian Society of Surgery. Lección inaugural del curso de 1922, Cátedra de Cirugía Infantil, por el Dr. Francisco Graña, Catedrático de Cirugía Infantil y Ortopedia en la Facultad de Medicina de Lima, de la Academia Nacional de Medicina, de la Sociedad Peruana de Cirug...

  4. Stereo-particle image velocimetry measurements of a patient-specific Fontan physiology utilizing novel pressure augmentation stents.

    Science.gov (United States)

    Chopski, Steven G; Rangus, Owen M; Fox, Carson S; Moskowitz, William B; Throckmorton, Amy L

    2015-03-01

    Single ventricle anomalies are a challenging set of congenital heart defects that require lifelong clinical management due to progressive decline of cardiovascular function. Few therapeutic devices are available for these patients, and conventional blood pumps are not designed for the unique anatomy of the single ventricle physiology. To address this unmet need, we are developing an axial flow blood pump with a protective cage or stent for Fontan patients. This study investigates the 3-D particle image velocimetry measurements of two cage designs being deployed in a patient-specific Fontan anatomy. We considered a control case without a pump, impeller placed in the inferior vena cava, and two cases where the impeller has two protective stents with unique geometric characteristics. The experiments were evaluated at a cardiac output of 3 L/min, a fixed vena caval flow split of 40%/60%, a fixed pulmonary arterial flow split of 50%/50%, and for operating speeds of 1000-4000 rpm. The introduction of the cardiovascular stents had a substantial impact on the flow conditions leaving the pump and entering the cavopulmonary circulation. The findings indicated that rotational speeds above 4000 rpm for this pump could result in irregular flows in this specific circulatory condition. Although retrograde flow into the superior vena cava was not measured, the risk of this occurrence increases with higher pump speeds. The against-with stent geometry outperformed the other configurations by generating higher pressures and more energetic flows. These results provide further support for the viability of mechanical cavopulmonary assistance as a therapeutic treatment strategy for Fontan patients.

  5. Patient-specific reconstruction utilizing computer assisted 3D modelling for partial bone flap defect in hybrid cranioplasty

    Science.gov (United States)

    Hueh, Low Peh; Abdullah, Johari Yap; Abdullah, Abdul Manaf; Yahya, Suzana; Idris, Zamzuri; Mohamad, Dasmawati

    2016-12-01

    Autologous cranioplasty using a patient's original bone flap remain the commonest practice nowadays. However, partial bone flap defect is commonly encountered. Replacing the bone flap with pre-moulded synthetic bone flap is costly and not affordable to many patients. Hence most of the small to medium size defect was topped up with alloplastic material on a free hand basis intra-operatively which often resulted in inaccurate implant approximation with unsatisfactory cosmetic result. This study aims to evaluate implant accuracy and cosmetic outcome of cranioplasty candidates who underwent partial bone flap reconstruction utilising computer assisted 3D modelling. 3D images of the skull were obtained from post-craniectomy axial 1-mm spiral computed tomography (CT) scans and a virtual 3D model was generated using the Materialise Mimics software. The Materialise 3-Matic was then utilised to design a patient-specific implant. Prefabrication of the implant was performed by the 3D Objet printer, and a negative gypsum mold was created with the prefabricated cranial implant. Intraoperatively, a hybrid polymethyl methacrylate (PMMA)-autologous cranial implant was produced using the gypsum mold, and fit into the cranial defect. This study is still ongoing at the moment. To date, two men has underwent partial bone flap reconstruction utilising this technique and both revealed satisfactory implant alignment with favourable cosmesis. Mean implant size was 12cm2, and the mean duration of intraoperative reconstruction for the partial bone flap defect was 40 minutes. No significant complication was reported. As a conclusion, this new technique and approach resulted in satisfactory implant alignment and favourable cosmetic outcome. However, more study samples are needed to increase the validity of the study results.

  6. Patient specific quality assurance of RapidArc pre treatment plans using semiflex 0.125 cc ionization chamber

    Science.gov (United States)

    Kumar, S. A. Syam; Vivekanandan, Nagarajan

    2017-01-01

    Patient specific pre-treatment quality assurance for RapidArc plans were analyzed for hundred patients for different sites. Verification plan was created for each treatment plan in Eclipse 8.6 treatment planning system with the semiflex ionization chamber and the octavius phantom. Absolute point dose were measured for head and neck, thorax and abdomen cases using semiflex (0.125 cc) ionization chamber. Positive absolute mean dose variation of 0.56% was observed with thorax cases with a standard deviation (SD) of ±1.13 between the plans with a range of -1.78% to 2.70%. Negative percentage dose errors were found with head and neck and abdomen cases, with a mean variation of -0.43% (SD±1.50), (range -3.25% to 2.85%) and -0.35% (SD±1.48), (range -3.10% to 2.65%) for head and neck and abdomen cases respectively. Evaluation has been done using PTW verisoft software by keeping the passing criteria as 3 mm DTA, 3% DD, for 95% of the evaluated dose points. The maximum percentage value failed in gamma analysis was found to be 4.95, 4.75, and 4.88 for head and neck, thorax, and abdomen cases respectively. In all the cases analyzed the percentage dose points failed the gamma criteria is less than 5%. On the basis of the studies performed it can be concluded that the semiflex ionization chamber having a volume of 0.125 cc can be used efficiently for measuring the pre-treatment quality assurance of RapidArc plans for all the sites.

  7. Mechanical cavopulmonary assistance of a patient-specific Fontan physiology: numerical simulations, lumped parameter modeling, and suction experiments.

    Science.gov (United States)

    Throckmorton, Amy L; Carr, James P; Tahir, Sharjeel A; Tate, Ryan; Downs, Emily A; Bhavsar, Sonya S; Wu, Yi; Grizzard, John D; Moskowitz, William B

    2011-11-01

    This study investigated the performance of a magnetically levitated, intravascular axial flow blood pump for mechanical circulatory support of the thousands of Fontan patients in desperate need of a therapeutic alternative. Four models of the extracardiac, total cavopulmonary connection (TCPC) Fontan configuration were evaluated to formulate numerical predictions: an idealized TCPC, a patient-specific TCPC per magnetic resonance imaging data, and each of these two models having a blood pump in the inferior vena cava (IVC). A lumped parameter model of the Fontan physiology was used to specify boundary conditions. Pressure-flow characteristics, energy gain calculations, scalar stress levels, and blood damage estimations were executed for each model. Suction limitation experiments using the Sylgard elastomer tubing were also conducted. The pump produced pressures of 1-16 mm Hg for 2000-6000 rpm and flow rates of 0.5-4.5 L/min. The pump inlet or IVC pressure was found to decrease at higher rotational speeds. Maximum scalar stress estimations were 3 Pa for the nonpump models and 290 Pa for the pump-supported cases. The blood residence times for the pump-supported cases were shorter (0.9 s) as compared with the nonsupported configurations (2.5 s). However, the blood damage indices were higher (1.5%) for the anatomic model with pump support. The pump successfully augmented pressure in the TCPC junction and increased the hydraulic energy of the TCPC as a function of flow rate and rotational speed. The suction experiments revealed minimal deformation (<3%) at 9000 rpm. The findings of this study support the continued design and development of this blood pump.

  8. Application of a 3D custom printed patient specific spinal implant for C1/2 arthrodesis

    Science.gov (United States)

    Phan, Kevin; Sgro, Alessandro; Maharaj, Monish M.; D’Urso, Paul

    2016-01-01

    The study aims to describe a three-dimensional printed (3DP) posterior fixation implant used for C1/C2 fusion in a 65-year-old female. Spinal fusion remains a common intervention for a range of spinal pathologies including degenerative disc and facet disease when conservative methods are unsuccessful. However, fusion devices are not always entirely efficacious in providing the desired fixation, and surgeons rely on ‘off the shelf’ implants which may not provide an anatomical fit to address the particular pathology. 3DP refers to a process where three-dimensional objects are created through successive layering of material, so called ‘additive manufacturing’. Although this technology enables accurate fabrication of patient-specific orthopaedic and spinal implants, literature on its utilization in this regard is rare. A 65-year-old female, with severe facet arthropathy at the C1/C2 level, osteophyte formation and impingement of the exiting C2 nerve root underwent a C1/C2 posterior fusion and rhizolysis of the C2 nerve roots. A custom posterior fixation implant was designed and on-laid over the C2 spinous process and lamina, with screw holes made to a depth and angulation that was pre-calculated based on the preoperative CT based 3D modelling. The patient had an uneventful recovery and reported a significant reduction in occipital neuralgia and sub-occipital pain and 2-month follow-up. We report the first case of a customized 3DP spinal prosthesis for posterior C1/C2 fusion. The implant added significant value reducing the overall time of the procedure, and safety with a reduced risk of neurovascular compromise. PMID:28097249

  9. PD-1 identifies the patient-specific CD8⁺ tumor-reactive repertoire infiltrating human tumors.

    Science.gov (United States)

    Gros, Alena; Robbins, Paul F; Yao, Xin; Li, Yong F; Turcotte, Simon; Tran, Eric; Wunderlich, John R; Mixon, Arnold; Farid, Shawn; Dudley, Mark E; Hanada, Ken-Ichi; Almeida, Jorge R; Darko, Sam; Douek, Daniel C; Yang, James C; Rosenberg, Steven A

    2014-05-01

    Adoptive transfer of tumor-infiltrating lymphocytes (TILs) can mediate regression of metastatic melanoma; however, TILs are a heterogeneous population, and there are no effective markers to specifically identify and select the repertoire of tumor-reactive and mutation-specific CD8⁺ lymphocytes. The lack of biomarkers limits the ability to study these cells and develop strategies to enhance clinical efficacy and extend this therapy to other malignancies. Here, we evaluated unique phenotypic traits of CD8⁺ TILs and TCR β chain (TCRβ) clonotypic frequency in melanoma tumors to identify patient-specific repertoires of tumor-reactive CD8⁺ lymphocytes. In all 6 tumors studied, expression of the inhibitory receptors programmed cell death 1 (PD-1; also known as CD279), lymphocyte-activation gene 3 (LAG-3; also known as CD223), and T cell immunoglobulin and mucin domain 3 (TIM-3) on CD8⁺ TILs identified the autologous tumor-reactive repertoire, including mutated neoantigen-specific CD8⁺ lymphocytes, whereas only a fraction of the tumor-reactive population expressed the costimulatory receptor 4-1BB (also known as CD137). TCRβ deep sequencing revealed oligoclonal expansion of specific TCRβ clonotypes in CD8⁺PD-1⁺ compared with CD8⁺PD-1- TIL populations. Furthermore, the most highly expanded TCRβ clonotypes in the CD8⁺ and the CD8⁺PD-1⁺ populations recognized the autologous tumor and included clonotypes targeting mutated antigens. Thus, in addition to the well-documented negative regulatory role of PD-1 in T cells, our findings demonstrate that PD-1 expression on CD8⁺ TILs also accurately identifies the repertoire of clonally expanded tumor-reactive cells and reveal a dual importance of PD-1 expression in the tumor microenvironment.

  10. SU-F-BRE-08: Feasibility of 3D Printed Patient Specific Phantoms for IMRT/IGRT QA

    Energy Technology Data Exchange (ETDEWEB)

    Ehler, E; Higgins, P; Dusenbery, K [University of Minnesota, Minneapolis, MN (United States)

    2014-06-15

    Purpose: Test the feasibility of 3D printed, per-patient phantoms for IMRT QA to analyze the treatment delivery quality within the patient geometry. Methods: Using the head and neck region of an anthropomorphic phantom as a substitute for an actual patient, a soft-tissue equivalent model was constructed with the use of a 3D printer. A nine-field IMRT plan was constructed and dose verification measurements were performed for the 3D printed phantom. During the delivery of the IMRT QA on to the 3D printed phantom, the same patient positioning indexing system was used on the phantom and image guidance (cone beam CT) was used to localize the phantom, serving as a test of the IGRT system as well. The 3D printed phantom was designed to accommodate four radiochromic film planes (two axial, one coronal and one sagittal) and an ionization chamber measurement. As a frame of comparison, the IMRT QA was also performed on traditional phantoms. Dosimetric tolerance levels such as 3mm / 3% Gamma Index as well as 3% and 5% dose difference were considered. All detector systems were calibrated against a NIST traceable ionization chamber. Results: Comparison of results 3D printed patient phantom with the standard IMRT QA systems showed similar passing rates for the 3D printed phantom and the standard phantoms. However, the locations of the failing regions did not necessarily correlate. The 3D printed phantom was localized within 1 mm and 1° using on-board cone beam CT. Conclusion: A custom phantom was created using a 3D printer. It was determined that the use of patient specific phantoms to perform dosimetric verification and estimate the dose in the patient is feasible. In addition, end-to-end testing on a per-patient basis was possible with the 3D printed phantom. Further refinement of the phantom construction process is needed for routine clinical use.

  11. Studying Aid: Some Methods

    NARCIS (Netherlands)

    D.R. Gasper (Des)

    2003-01-01

    textabstractINVESTIGATING IDEAS, IDEOLOGIES AND PRACTICES This paper presents some methods for trying to make sense of international aid and of its study.1 Some of the methods may be deemed ethnographic; the others are important partners to them, but rather different. In the course of discussing q

  12. Hearing Aids Communication

    DEFF Research Database (Denmark)

    Globally, hearing loss is the second most frequent disability. About 80% of the persons affected by hearing loss do not use hearing aids. The goal of this edited volume is to present a theoretically founded, interdisciplinary approach geared at understanding and improving social interaction impac...

  13. Parent Hearing Aid Experiences

    Science.gov (United States)

    Munoz, Karen; Roberts, Mallory; Mullings, Day; Harward, Richard

    2012-01-01

    This study addresses parent experiences in obtaining and managing hearing aids for their young child. The purpose was to identify challenges parents encounter to determine what state agencies can do to improve parent access to amplification. Data were collected July through September of 2010; 40 parents of children ages birth to 3 years old…

  14. Hearing Aid Personalization

    DEFF Research Database (Denmark)

    Nielsen, Jens Brehm; Nielsen, Jakob; Jensen, Bjørn Sand

    2013-01-01

    Modern digital hearing aids require and offer a great level of personalization. Today, this personalization is not performed based directly on what the user actually perceives, but on a hearing-care professional’s interpretation of what the user explains about what is perceived. In this paper, an...

  15. Computer Aided Lecturing.

    Science.gov (United States)

    Van Meter, Donald E.

    1994-01-01

    Surveyed students taking a natural resource conservation course to determine the effects of computer software that provides tools for creating and managing visual presentations to students. Results indicated that 94% of the respondents believed computer-aided lectures helped them and recommended their continued use; note taking was more effective,…

  16. AIDS and associated malignancies

    Institute of Scientific and Technical Information of China (English)

    Charles WOOD; William HARRINGTON Jr

    2005-01-01

    AIDS associated malignancies (ARL) is a major complication associated with AIDS patients upon immunosuppression.Chronically immunocompromised patients have a markedly increased risk of developing lymphoproliferative disease. In the era of potent antiretrovirals therapy (ARV), the malignant complications due to HIV- 1 infection have decreased in developed nations where ARV is administered, but still poses a major problem in developing countries where HIV- 1incidence is high and ARV is still not yet widely available. Even in ARV treated individuals there is a concern that the prolonged survival of many HIV- 1 carriers is likely to eventually result in an increased number of malignancies diagnosed.Malignancies that were found to have high incidence in HIV-infected individuals are Kaposi's sarcoma (KS), Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). The incidence of NHL has increased nearly 200 fold in HIV-positive patients, and accounts for a greater percentage of AIDS defining illness in the US and Europe since the advent of HAART therapy. These AIDS related lymphomas are distinct from their counterparts seen in HIV- 1 seronegative patients.For example nearly half of all cases of ARL are associated with the presence of a gamma herpesvirus, Epstein Barr virus (EBV) or human herpesvirus-8 (HHV-8)/Kaposi's sarcoma associated herpesvirus (KSHV). The pathogenesis of ARLs is complex. B-cell proliferation driven by chronic antigenemia resulting in the induction of polyclonal and ultimately monoclonal lymphoproliferation may occur in the setting of severe immunosuppression.

  17. [Post-transfusional AIDS].

    Science.gov (United States)

    Azzini, M; Maccabruni, A; Marcellini, M; Michelone, G; Dei Cas, A

    1987-01-01

    Two cases of post-transfusional AIDS in two premature babies who received blood of the same seropositive donor, are reported. The risk of the susceptibility to HIV infection of these patients, in relation to the immaturity of immune system and to the transfusional treatment often necessary in premature newborns, is stressed.

  18. The CASPAR finding aids

    OpenAIRE

    Meghini, Carlo; Avancini, Henry; Versienti, Loredana

    2011-01-01

    One of the CASPAR key components is the FIND Components, which is implementing the Finding Aids of OAIS. According to OAIS, FIND manages Description Information that is associated to Information Packages in order to support the discovery of those Packages. FIND allows defining, creating, persisting, querying, browsing, and accessing both Description Information and the association between Information Packages and Description Information

  19. Coil Welding Aid

    Science.gov (United States)

    Wiesenbach, W. T.; Clark, M. C.

    1983-01-01

    Positioner holds coil inside cylinder during tack welding. Welding aid spaces turns of coil inside cylinder and applies contact pressure while coil is tack-welded to cylinder. Device facilitates fabrication of heat exchangers and other structures by eliminating hand-positioning and clamping of individual coil turns.

  20. Enteric parasites and AIDS

    Directory of Open Access Journals (Sweden)

    Sérgio Cimerman

    1999-11-01

    Full Text Available OBJECTIVE: To report on the importance of intestinal parasites in patients with AIDS, showing relevant data in the medical literature, with special emphasis on epidemiology, diagnosis and treatment of enteroparasitosis, especially cryptosporidiasis, isosporiasis, microsporidiasis and strongyloidiasis. DESIGN: Narrative review.

  1. Numerical predictions of hemodynamics following surgeries in cerebral aneurysms

    Science.gov (United States)

    Rayz, Vitaliy; Lawton, Michael; Boussel, Loic; Leach, Joseph; Acevedo, Gabriel; Halbach, Van; Saloner, David

    2014-11-01

    Large cerebral aneurysms present a danger of rupture or brain compression. In some cases, clinicians may attempt to change the pathological hemodynamics in order to inhibit disease progression. This can be achieved by changing the vascular geometry with an open surgery or by deploying a stent-like flow diverter device. Patient-specific CFD models can help evaluate treatment options by predicting flow regions that are likely to become occupied by thrombus (clot) following the procedure. In this study, alternative flow scenarios were modeled for several patients who underwent surgical treatment. Patient-specific geometries and flow boundary conditions were obtained from magnetic resonance angiography and velocimetry data. The Navier-Stokes equations were solved with a finite volume solver Fluent. A porous media approach was used to model flow-diverter devices. The advection-diffusion equation was solved in order to simulate contrast agent transport and the results were used to evaluate flow residence time changes. Thrombus layering was predicted in regions characterized by reduced velocities and shear stresses as well as increased flow residence time. The simulations indicated surgical options that could result in occlusion of vital arteries with thrombus. Numerical results were compared to experimental and clinical MRI data. The results demonstrate that image-based CFD models may help improve the outcome of surgeries in cerebral aneurysms. acknowledge R01HL115267.

  2. Intraoperative evaluation of device placement in spine surgery using known-component 3D-2D image registration.

    Science.gov (United States)

    Uneri, A; De Silva, T; Goerres, J; Jacobson, M W; Ketcha, M D; Reaungamornrat, S; Kleinszig, G; Vogt, S; Khanna, A J; Osgood, G M; Wolinsky, J-P; Siewerdsen, J H

    2017-04-21

    Intraoperative x-ray radiography/fluoroscopy is commonly used to assess the placement of surgical devices in the operating room (e.g. spine pedicle screws), but qualitative interpretation can fail to reliably detect suboptimal delivery and/or breach of adjacent critical structures. We present a 3D-2D image registration method wherein intraoperative radiographs are leveraged in combination with prior knowledge of the patient and surgical components for quantitative assessment of device placement and more rigorous quality assurance (QA) of the surgical product. The algorithm is based on known-component registration (KC-Reg) in which patient-specific preoperative CT and parametric component models are used. The registration performs optimization of gradient similarity, removes the need for offline geometric calibration of the C-arm, and simultaneously solves for multiple component bodies, thereby allowing QA in a single step (e.g. spinal construct with 4-20 screws). Performance was tested in a spine phantom, and first clinical results are reported for QA of transpedicle screws delivered in a patient undergoing thoracolumbar spine surgery. Simultaneous registration of ten pedicle screws (five contralateral pairs) demonstrated mean target registration error (TRE) of 1.1  ±  0.1 mm at the screw tip and 0.7  ±  0.4° in angulation when a prior geometric calibration was used. The calibration-free formulation, with the aid of component collision constraints, achieved TRE of 1.4  ±  0.6 mm. In all cases, a statistically significant improvement (p  <  0.05) was observed for the simultaneous solutions in comparison to previously reported sequential solution of individual components. Initial application in clinical data in spine surgery demonstrated TRE of 2.7  ±  2.6 mm and 1.5  ±  0.8°. The KC-Reg algorithm offers an independent check and quantitative QA of the surgical product using radiographic/fluoroscopic views

  3. Screening for AIDS.

    Science.gov (United States)

    1985-03-29

    Tests to detect serum antibody to human T-lymphotropic virus type III (HTLV-III), based on an enzyme-linked immunosorbent assay (ELISA) that uses whole disrupted HTLV-III virus antigens, are now commercially available in the US. Recent surveys of groups at high risk for acquired immunodeficiency syndrome (AIDS) have found that 22-65% of homosexual men, 87% of active intravenous drug users, 56-72% of hemophiliacs, and 35% of women who were sexual partners of men with AIDS have had postitive ELISA tests compared with fewer than 1% of those with no known risk factors. A positive ELISA test could be due to subclinical infection, immunity, or cross-reactivity with other viral antigens. Laboratory error can also produce false positive results. Thus, it is recommended that the ELISA test be repeated at least once on all seropositive specimens before the result is reported to the patient. The western blot test appears to be more specific and less sensitive than the ELISA. Studies of asymptomatic seropositive homosexual men followed for 2-5 years have found that over 50% remain asymptomatic, 5-19% develop full blown AIDS, and 25% develop signs suggestive of the AIDS-related complex. Asymptomatic patients with positive ELISA tests should be made aware of early signs and symptoms of AIDS. Other data suggest that seropositive patients have the HTLV-III virus in their blood, semen, and/or saliva and can transmit the infection. Precautions to prevent transmission, such as the use of condoms, should be taken by such patients. Physicians should be sensitive to the fear and anxiety that a positive ELISA test will create.

  4. Pain Medications After Surgery

    Science.gov (United States)

    ... aspx?id=23897. Accessed Dec. 16, 2013. Winn HR. Youmans Neurological Surgery. 6th ed. Philadelphia, Pa.: Saunders ... Terms and Conditions Privacy Policy Notice of Privacy Practices Notice of Nondiscrimination Advertising Mayo Clinic is a ...

  5. Surgery for pancreatic cancer

    Science.gov (United States)

    ... using a tiny video camera) or using a robot depends on: The extent of the surgery The ... Procedure Meet with your doctor to make sure medical problems, such as diabetes, high blood pressure, and ...

  6. Retrosternal thyroid surgery

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007558.htm Retrosternal thyroid surgery To use the sharing features on this page, please enable JavaScript. The thyroid gland is normally located at the front of ...

  7. Septoplasty and Turbinate Surgery

    Science.gov (United States)

    ... nose. Surgery on the septum can lead to stretching or injury to these nerves. This can lead ... a painless procedure that is performed in our office. A small endoscope is used to visualize the ...

  8. Abdominal wall surgery

    Science.gov (United States)

    ... pregnancy. Skin and muscle cannot regain its normal tone. This can be a problem for very overweight people who lost a lot of weight. Tummy tuck is major surgery. It is important to read about the procedure before having it. ...

  9. Blood donation before surgery

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000367.htm Blood donation before surgery To use the sharing features on ... described here. Blood From the Public (Volunteer Blood Donation) The most common source of blood given during ...

  10. INDIRECT MICROLARYNGOSTROBOSCOPIC SURGERY

    NARCIS (Netherlands)

    MAHIEU, HF; DIKKERS, FG

    1992-01-01

    Detailed preoperative laryngostroboscopic examination is a prerequisite for phonosurgical correction of organic dysphonia. Although suspension microlaryngoscopic surgery has proved its value in the past, it excludes functional control during the removal of vocal fold swellings. Using an indirect mic

  11. Robotics in Colorectal Surgery

    Science.gov (United States)

    Weaver, Allison; Steele, Scott

    2016-01-01

    Over the past few decades, robotic surgery has developed from a futuristic dream to a real, widely used technology. Today, robotic platforms are used for a range of procedures and have added a new facet to the development and implementation of minimally invasive surgeries. The potential advantages are enormous, but the current progress is impeded by high costs and limited technology. However, recent advances in haptic feedback systems and single-port surgical techniques demonstrate a clear role for robotics and are likely to improve surgical outcomes. Although robotic surgeries have become the gold standard for a number of procedures, the research in colorectal surgery is not definitive and more work needs to be done to prove its safety and efficacy to both surgeons and patients. PMID:27746895

  12. Knee microfracture surgery

    Science.gov (United States)

    Cartilage regeneration - knee ... Three types of anesthesia may be used for knee arthroscopy surgery: Medicine to relax you, and shots of painkillers to numb the knee Spinal (regional) anesthesia General anesthesia (you will be ...

  13. Is day surgery safe?

    DEFF Research Database (Denmark)

    Majholm, Birgitte; Engbæk, J; Bartholdy, Jens

    2012-01-01

    Day surgery is expanding in several countries, and it is important to collect information about quality. The aim of this study was to assess morbidity and unanticipated hospital visits 0-30 days post-operatively in a large cohort.......Day surgery is expanding in several countries, and it is important to collect information about quality. The aim of this study was to assess morbidity and unanticipated hospital visits 0-30 days post-operatively in a large cohort....

  14. Complications of pancreatic surgery

    Directory of Open Access Journals (Sweden)

    Åke Andrén-Sandberg

    2011-01-01

    Full Text Available Many diseases, including pancreatitis benign tumors and cancer, may require pancreas surgery. Pancreatic resection can lead to a prolonged survival in pancreatic cancer and even a potential chance for cure. However, the pancreatic surgery can result in complications, and high postoperative morbidity rates are still presence. This article reviews the pancreatic abstracts of American Pancreas Club 2011, which involves the more common complications, their prevention and treatment.

  15. Future of cosmetic surgery.

    Science.gov (United States)

    Goldberg, Robert Alan

    2014-04-01

    Changes in cosmetic surgery will be driven by several key forces. The patient's self-image, and perceived place in society, will continue to drive patients to the cosmetic surgeon as well as to demand newer and better treatments. Technological advances, especially those based on an enhanced understanding of cellular and tissue physiology, promise enhanced tools other than the scalpel for the surgeon. Conceptual advances in our understanding of beauty and patient psychology will lead to a more integrative approach to cosmetic surgery.

  16. Henan Surveys Blood Donors to Aid AIDS Prevention

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Central China's Henan Province, one of the worst AIDS-hit provinces in the country, launched a sweeping survey in September of past blood donors to ascertain tile number of HIV-infected individuals to aid AIDS prevention and control work.

  17. Perceptions of Aid and Actual Aid in Intergenerational Caregiving.

    Science.gov (United States)

    Walker, Alexis J.; And Others

    1991-01-01

    Compared pairs (n=174) of elderly mothers' and their caregiving daughters' perceptions of aid given to the mothers with actual caregiving activities. Results indicated nearly half of the mothers and daughters were accurate in their perceptions of aid given to the mothers; when mothers' perception of aid was inaccurate, mothers overestimated rather…

  18. Photobiomodulation in laser surgery

    Science.gov (United States)

    Liu, Timon Cheng-Yi; Rong, Dong-Liang; Huang, Jin; Deng, Xiao-Yuan; Liu, Song-Hao

    2006-01-01

    Laser surgery provides good exposure with clear operating fields and satisfactory preliminary functional results. In contrast to conventional excision, it was found that matrix metalloproteinases and the tissue inhibitors of metalloproteinases -1 mRNA expression is higher, myofibroblasts appeared and disappeared slower in laser excision wounds. It has been suggested that the better anatomical and functional results achieved following laser cordectomy may be explained by the fact that such procedures result in better, more rapid healing processes to recover vocal cord for early glottic tumors and better. In this paper, the role of photobiomodulation in laser surgery will be discussed by the cultured monolayer normal human skin fibroblast model of the photobiomodulation of marginal irradiation of high intensity laser beam, the photobiomodulation related to the irradiated tissue, the biological information model of photobiomodulation and the animal models of laser surgery. Although high intensity laser beam is so intense that it destroys the irradiated cells or tissue, its marginal irradiation intensity is so low that there is photobiomodulation on non-damage cells to modulate the regeneration of partly damaged tissue so that the surgery of laser of different parameters results in different post-surgical recovery. It was concluded that photobiomodulation might play an important role in the long-term effects of laser surgery, which might be used to design laser surgery.

  19. Robotic surgery in gynecology

    Directory of Open Access Journals (Sweden)

    Rooma Sinha

    2015-01-01

    Full Text Available FDA approved Da Vinci Surgical System in 2005 for gynecological surgery. It has been rapidly adopted and it has already assumed an important position at various centers where this is available. It comprises of three components: A surgeon′s console, a patient-side cart with four robotic arms and a high-definition three-dimensional (3D vision system. In this review we have discussed various robotic-assisted laparoscopic benign gynecological procedures like myomectomy, hysterectomy, endometriosis, tubal anastomosis and sacrocolpopexy. A PubMed search was done and relevant published studies were reviewed. Surgeries that can have future applications are also mentioned. At present most studies do not give significant advantage over conventional laparoscopic surgery in benign gynecological disease. However robotics do give an edge in more complex surgeries. The conversion rate to open surgery is lesser with robotic assistance when compared to laparoscopy. For myomectomy surgery, Endo wrist movement of robotic instrument allows better and precise suturing than conventional straight stick laparoscopy. The robotic platform is a logical step forward to laparoscopy and if cost considerations are addressed may become popular among gynecological surgeons world over.

  20. Fibrin Adhesive: Clinical Application in Coronary Artery Bypass Graft Surgery

    Science.gov (United States)

    Fundaró, Pino; Velardi, Antonio R.; Santoli, Carmine

    1985-01-01

    Fibrin adhesive was used 72 times in a group of 67 patients undergoing elective coronary artery bypass graft surgery. The indications were prophylactic sealing of potential sources of bleeding, topical hemostasis (control of bleeding sites dangerous or difficult to suture), and fixation of the graft in the optimal position. The method of glue application under varying circumstances is described and the results are reported. This experience suggests that in some cases the glue expedites the operation and makes it safer. We conclude that the fibrin sealing represents a valid aid in coronary artery bypass graft surgery. PMID:15227018