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 2007
Local control of temperature in a theoretical human model of selective brain cooling.
A method of feedback control of local brain temperature during therapeutic intracarotid cold saline infusion is presented and tested on a theoretical cerebral heat transfer model based on the Pennes bioheat equation. In this temperature control method, the infusion rate of cold saline is varied based on the rate of temperature change, and the deviation of temperature to a target, within a voxel in the treated region of brain. ⋯ Two hours of treatment decreased the required inflow of ice-cold saline from 30 ml/min to 21 and 7 ml/min in the non-ice and ice cases, respectively. Intracarotid hematocrit had higher values in the non-ice case.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
The complete electrode model for imaging and electrode contact compensation in electrical impedance tomography.
Electrical Impedance Tomography (EIT) is an imaging modality which currently shows promise for the detection and characterization of breast cancer. A very significant problem in EIT imaging is the proper modeling of the interface between the body and the electrodes. We have found empirically that it is very difficult, in a clinical setting, to assure that all electrodes make satisfactory contact with the body. ⋯ To compensate for these problems, we have developed a hybrid nonlinear-linear reconstruction algorithm in which we first estimate electrode surface impedances, using a Newton-type iterative optimization procedure with an analytically computed Jacobian matrix. We subsequently make use of a linearized algorithm to perform a three-dimensional reconstruction of perturbations in both contact impedances and in the spatial distributions of conductivity and permittivity. Results show that, using this procedure, artifacts due to electrodes making poor contact can be greatly reduced.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
Optimizing the tactile display of physiological information: vibro-tactile vs. electro-tactile stimulation, and forearm or wrist location.
Anesthesiologists use physiological data monitoring systems with visual and auditory displays of information to monitor patients in the operating room (OR). The efficacy of visual-audio systems may impose an increase in patient risk when the demand for constant switching of attention between the patient and the visual monitoring system is high. This is evidenced by auditory alarms frequently being neglected in a noisy OR environment. ⋯ A post-study questionnaire was completed by each subject to assess the comfort and usability of the three prototypes. We found that both VF and VW were superior to the EF in both accuracy and comfort and, that there were no differences between the wrist and the forearm. In conclusion, the tactile-display prototypes designed to alert the clinician of adverse changes in a patient's physiological state efficaciously and unobtrusively delivered these data and warranted further investigation and development.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
A simple and efficient algorithm with a coarse to fine approach for arterial beat pulse detection.
This paper presents a simple algorithm for arterial beat pulse detection. It consists in a coarse to fine approach : the first step is performed with a lifting Haar wavelet transform with thresholding and provides search intervals, the second step is to localize the beat pulse in the original signal within these areas. Thanks to online available database, the performance of this algorithm can be compared to others and its ability to detect peaks is sufficient considering its low amount of calculation.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
Clinical TrialA system for analyzing intraoperative B-Mode ultrasound scans of the liver.
In this article, a system for automatic analysis of intraoperative B-Mode ultrasound images of the liver is presented. The system is part of an assistance system for open liver surgery. ⋯ With this segmentation results, an ultrasound based 3D-model of the vascular structure is extracted and manually registered to a preoperative CT-based model. Anatomical landmarks like bifurcations of vessels are automatically extracted in the ultrasound-based model and will be used for an automatic registration process in further developments.