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Biomedical subjects

E D Voy

Publications and source records attributed to E D Voy.

At least 19 recordsLinked to original sources
PubMed1995

[Diagnostic imaging of microcirculation of pedicled flap-plasties of the mandibulofacial area using the laser Doppler scanner].

Objective, non-invasive examination techniques in addition to clinical parameters are required to monitor the wound healing of flaps. With the new Laser-Doppler Scanner (LDI, PIM 1.0 Lisca Development AB, Sweden) it is possible to measure and visualize microcirculation continuously, non-invasively and without contact to the wound in an area of 12 x 12 cm. We performed measurements and simultaneous two-dimensional imaging of microcirculation 24, 48, 72 hours and five and 14 days postoperatively in 22 patients, who received reconstruction procedures with random or axial pattern flaps. The perfusion diagrams were correlated to the clinical aspect. Necrotic areas, venous stasis, and normal course of wound healing can be clearly visualized and differentiated. The new Laser-Doppler Imaging System (LDI) serves as an excellent aid for control and planning of flaps in plastic and reconstructive surgery.

Adolescent↗
PubMed1992

Pediatric craniofacial surgery: comparison of milling and stereolithography for 3D model manufacturing.

To improve the planning phase for pediatric craniofacial surgery, 3D reconstructions of CT image series were performed on a personal computer. For construction of true models of the surgical site, two concepts were pursued. CT image data of six patients were used for model manufacturing by a conventional 2 1/2 axis milling system. The material used was polyurethane foam. Alternatively, in one patient a stereolithography was produced on the basis of the 3D reconstructed CT data. This new manufacturing device uses a photocurable monomer, hardened by a UV-laser. The spatial resolution of the system is about 0.1 mm. 3D-reconstructions were performed on a personal computer. Data were then transferred into a surface oriented structure to control a stereolithographic modeling device. Time for transfer was 70 min. The production of the modelled cranium took a total time of 59 h. Accuracy was found to be much higher in stereolithography than in milled models. The model served for surgical planning. The long time for production was caused by inadequate computer capacities, which are configured for much less complex objects in computer aided design. Furthermore the programs for the machine control are optimized for technical purposes. If these conditions are improved, stereolithography could be an attractive alternative to milling of medical models.

Child↗
PubMed1992

[Stereolithographic model construction based on 3-dimensional reconstructed CT sectional image sequences].

Techniques for 3D reconstruction of medical objects and production of models by CAM have been markedly improved. Milling tools have limited abilities to reproduce complex anatomical structures. Even if 5-axis milling systems are used, the problem of collisions between tool and object is not yet under control. An alternative is offered here by stereolithography. We performed a computed tomography (Somatom DRH, Siemens/Erlangen) of a child with extensive maxillary bone defect after surgical treatment of a congenital tumour. The bone defect was covered by an alloplastic implant. 3D reconstructions were performed by the aid of a conventional personal computer. Generated 3D volume data sets were transferred to a stereolithography system (3D Systems GmbH, Darmstadt/FRG). The produced model revealed high accuracy of the anatomical structures. Intraoperatively, the alloplastic prosthesis was removed and the shape of the new implant could be designed using the stereolithographic model.

Child↗
PubMed1992

[Methods for simulation of surgical interventions in head and neck surgery].

Preoperative evaluation of the operating site is essential in planning surgical procedures. The relationship of pathology to adjacent tissues and vital anatomical structures needs to be analyzed to determine the intraoperative procedures required. For this the surgeon mentally simulates the procedure planned. For complicated conditions or reconstructive surgery in extensive bony defects, surgery can be simulated with three-dimensional reconstruction on either a monitor screen or on an individually manufactured plastic model of the patient. For this purpose different procedures for 3 D representation and manipulation of tomographic image data have been developed in our departments and the technique of stereolithography used experimentally to create custom-made plastic model of patients. A computerized video image manipulator was also developed for simulation of aesthetic plastic surgical procedures.

Computer Graphics↗
PubMed1985

[Vascularization and resorption of different supporting tissues by the greater omentum in the formation of compound microvascular transplants].

In former investigations the author described the use of omentum majus in building microsurgical compound island flaps employing supporting tissue. Now different kinds of hard tissue, such as autogenous bone and cartilage, allogenous bone and cartilage (preserved by Cialit-solution), Teflon-Fluorocarbon Polymer (Proplast) and tri-calcium phosphate were presented in omentum-sandwich flaps in a histological investigation. We paid special attention to resorption and vascularisation of hard tissue. Allogenous cartilage grafts or artificial materials like Proplast were the most suitable to put into a compound omental island flap. There was good vascularisation with no resorption, especially with Proplast.

Animals↗
PubMed1984

[Formation of a microvascular, multilayer constructed transplant using the greater omentum].

The high potential for vascularisation of the greater omentum, described in the literature and in our own investigations was used to build microsurgical compound island flaps containing hard tissue grafts like Proplast. In the first operative procedure Proplast was inserted into the omentum and a flap was formed pedicled on the right gastro-epiploic vessels and transposed into the subcutaneous layer. Two to three weeks later the vascularized Proplast could be removed together with the overlying skin and fat. In another experiment Proplast was inserted into the pedicled omentum and put back into the belly. A second laparotomy was performed 14 days later to cover the omentum-Proplast sandwich with a split skin allograft. In both experiments the total compound sandwich flap was supplied only by the right gastro-epiploic vessels, which allowed a microsurgical transplantation.

Animals↗
PubMed1980

[Rational interpretation of the lateral teleradiograph by means of the principle of magnetostriction].

A new method for the pick up and processing of cephalometric data from teleradiographs was reported. The possibilities for error with the method were objectified by comparative measurements using traditional methods; no significant differences or disadvantages could be established in comparison with other methods of measurement. The errors due to the projection and technical imperfections in the roentgenograms remained unaltered in the assessment. The basic advantage therefore is the efficient function, which is particularly effective when combined with automatic data processing systems.

Cephalometry↗