Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference
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Conf Proc IEEE Eng Med Biol Soc · Jan 2010
In vitro kinematic measurements of the patellar tendon in two different types of posterior-stabilized total knee arthroplasties.
Fixed-bearing posterior-stabilized (PS) total knee arthroplasty (TKA) has been used in Asian countries for several years, but few studies have investigated differences in the kinematic properties of the patellar tendon after standard PS TKA as compared to high-flex PS TKA. ⋯ We believe the changes observed in the sagittal plane and coronal plane angles of the patellar tendon after PS TKAs may influence the extensor mechanism and be an important cause of patella-femoral complications. These data may be used to assess patella-femoral complications after surgery so as to improve the design of high-flexion TKAs for Asians and achieve long-term stability.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2010
Electroconvulsive therapy in the presence of deep brain stimulation implants: electric field effects.
The safety of electroconvulsive therapy (ECT) in patients who have deep brain stimulation (DBS) implants represents a significant clinical issue. A major safety concern is the presence of burr holes and electrode anchoring devices in the skull, which may alter the induced electric field distribution in the brain. We simulated the electric field using finite-element method in a five-shell spherical head model. ⋯ We compared electric field strength and focality among the DBS implantation techniques and ECT electrode configurations. The simulation results show an increase in the electric field strength in the brain due to conduction through the burr holes, especially when the burr holes are not fitted with nonconductive caps. For typical burr hole placement for subthalamic nucleus DBS, the effect on the electric field strength and focality is strongest for BF ECT, which runs contrary to the belief that more anterior ECT electrode placements are safer in patients with DBS implants.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2010
Development of modified intraoperative examination monitor for awake surgery (IEMAS) system for awake craniotomy during brain tumor resection.
Gliomas represent the most frequent type of primary intracranial tumors, which originate from the brain tissue itself, have infiltrative growth, unclear borders, and usually affect functionally-important cerebral structures. From March 2000 till March 2010, 839 neurosurgical procedures directed on resection of such neoplasms were performed in the intelligent operating theater of Tokyo Women's Medical University with the use of intraoperative MRI, real-time updated neuronavigation system, and Hi-vision operative microscope. To facilitate maximal possible tumor resection with minimal risk of neurological morbidity a special device, called Intraoperative Examination Monitor for Awake Surgery (IEMAS) was developed by us. ⋯ The clinical testing of t- - his system was initiated on February 1, 2010, but quickly revealed crossed line effect between transmitters and receivers. To overcome this obstacle and to isolate transmitters, one channel was changed from wireless connection into wired, which resulted in significant improvement of the clearness of both transmitted images and sounds, and provides an opportunity for effective clinical use of the device. In perspective we wish to make IEMAS system fully wireless, using several types of frequency range transmitters.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2010
Development of a data acquisition and analysis system for nociceptive withdrawal reflex and reflex receptive fields in humans.
A system for data acquisition and analysis of nociceptive withdrawal reflex (NWR) and reflex receptive field (RRF) is introduced. The system is constituted by hardware and software components. ⋯ These programs were developed to maximize the potential of the hardware, turning it into a complete stimulation system capable of automatic quantification of NWR and RRF. In this article, a brief review of NWR and RRF analysis is presented, the system features are described in detail and its present and future applications are discussed.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2010
Robust closed-loop control of propofol administration using WAVCNS index as the controlled variable.
This paper presents a robust closed-loop strategy for control of depth of hypnosis. The proposed method regulates the electroencephalogram (EEG)-derived WAVCNS index as a hypnosis measure by manipulating intravenous propofol administration. ⋯ This closed-loop control was evaluated using simulated surgical procedures in 44 patient models whose PK and PD were identified from real clinical data. The controller can deliver consistent and acceptable closed-loop induction and maintenance phase responses for patients with wide-ranging PK and PD differences.