[Automatic registration of patients with A-mode ultrasound for computer-assisted surgery. Laboratory proof of concept]. / Automatische Registration des Patienten mit A-Mode-Ultraschall für computerunterstützte Chirurgie. Funktionsnachweis im Labor.

BACKGROUND: The main source of error in 3D navigation is the patient-to-image registration process. Anatomical landmarks or adhesive markers perform sub-optimally. Bone-anchored invasive markers significantly change the clinical workflow of navigated ENT surgery, are invasive and cause patient discomfort. In order to minimize registration errors and to further streamline the clinical use of intraoperative 3D navigation we demonstrate that A-mode ultrasound allows an accurate 3D surface profile of the os occipitale to be created which can be reliably registered on preoperative patient CT data. METHODS: The transducer is mechanically positioned with sub-millimeter accuracy on the patient's occiput. From the sound echos a 3D surface is generated and registered to the preoperative CT images with the iterative closest point (ICP) algorithm. The evaluation of our setup was performed on three anatomic specimens and one bony skull. RESULTS: The ultrasound echoes from the occiput allowed the creation of an adequate 3D surface which could be registered to a segmentation of the CT image with an accuracy greater than 1.5 mm. The experiments were evaluated by an intuitive representation of the spatial deviation between CT and ultrasound data as a color-coded map. CONCLUSION: The approach to scan the posterior skull with A-mode ultrasound enables automatic intraoperative registration and can be integrated into the intraoperative setup.

[Physical methods (ultrasound) and disinfecting agents for decontaminating the water in poultry meat processing]. / Izsledvaniia vurkhu fizichni metodi (ultrazvuk) i dezinfektsionni sredstva za dekontaminirane na vodata pri dobiva na ptitche meso.

Productional and laboratory experiments were carried out to study the effect of ultra sound with a view to decontaminating the water in the vats for cooling poultry carcasses and skin cover as well as that of disinfection means (inkosan, actofor, yomil S, chalamide, and chloramin). In vitro studies revealed that the use of ultra sound in the decontamination of cooling water and poultry meat surface did not produce the necessary effect. The iodofor preparations inkosan and yomil S as well as the agents chalamide and chloramine added in fixed concentrations to the water in cooling vats were not shown to be able to inactivate Salmonella organisms on the surface of experimentally contaminated poultry carcasses. Inkosan at the rate of 1:1000, and yomil S at 0.2 and 0.4 per cent produced a 100 per cent bactericidal effect against the microflora in vat waters regardless of their initial contamination. Except for yomil S at 0.4 per cent these agents did not affect the organoleptic properties of poultry meat.