RESUMO
Objective To investigate the feasibility and accuracy of a patient-special template for antegrade pubic branch screwing and sacroiliac screwing which is 3D printed and based on the external fixation for treatment of pelvic fractures.Methods From January to April 2017,5 patients with Tile B fracture of the pelvis were treated by external fixation for damage control and closed reduction of the fracture at the first stage.They were 4 males and one female,aged from 42 to 65 years(average,54.8 years).By the Tile classification,there were one case of type B1 and 4 cases of type B2.After the CT scan data following external fixation were reconstructed and the screw trajectories were designed in 3D format,an individual template for the pelvic model was 3D printed.After the feasibility was confirmed by the preoperative operation,the patient-special template was used to insert antegrade pubic branch screws and sacroiliac screws in the surgery.The accuracy and safety of the actual screwing aided by the template were evaluated by comparing postoperative CT scans and preplanned trajectories of the screws.Results The individualized 3D printing templates based on external fixation led to precise screw placements into the superior ramus of the pubis and the sacroiliac joint.All the patient-special templates matched the external fixation well.Screw placement time ranged frown 5.1 to 17.5 min,averaging 10.3 min.The fluoroscopy frequency ranged from 6 to 16 times,averaging 9 times.The wound healed primarily.There was no damnage to the vessels or nerves.Verification of preoperative and postoperative CT scans showed an axial displacement deviation of 1.60 + 0.21 mm and an angle deviation of 2.0° ± 0.3°.The screws were basically in the bone channel without penetrating the cortex of important parts.Conclusion In the treatment of pelvic fractures,a patient-special screw template 3D printed based on external fixation can help accurate and safe insertion of the screws in a minimally invasive manner,significantly reducing the operation time and radiation exposure.
RESUMO
Imaging brain oxygenation is crucial for preventing brain lesions in preterm infants. Our aim is to build and validate a near-infrared optical tomography (NIROT) sensor for the head of neonates. This sensor, combined with an optoacoustic device, will enable quantitative monitoring of the structural and functional information of the brain. Since the head of preterm infants is small and fragile great care must be taken to produce a comfortable and compact device in which a sufficient number of light sources and detectors can be implemented. Here we demonstrate our first prototype. Heterogeneous silicone phantoms were produced to validate the prototype's data acquisition, data processing, and image reconstruction. Reconstructed optical properties agree well with the target values. The mechanical performance of the new NIROT sensor prototype confirms its suitability for the clinical application.
