A Twin Spiral Planar Antenna for UWB Medical Radars

A planar-spiral antenna to be used in an ultrawideband (UWB) radar system for heart activity monitoring is presented. The antenna, named “twin,” is constituted by two spiral dipoles in a compact structure. The reflection coefficient at the feed point of the dipoles is lower than −8 dB over the 3–12 GHz band, while the two-dipoles coupling is about −20 dB. The radiated beam is perpendicular to the plane of the spiral, so the antenna is wearable and it may be an optimal radiator for a medical UWB radar for heart rate detection. The designed antenna has been also used to check some hypotheses about the UWB radar heart activity detection mechanism. The radiation impedance variation, caused by the thorax vibrations associated with heart activity, seems to be the most likely explanation of the UWB radar operation

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

Implant primary stability and occlusion

In this chapter, we have focused on the primary implant stability not only from a biomechanical bone-implant perspective but also taking into account the neuromotor functions that could generate occlusal dynamic, asymmetric, and extra-axial loads.From the biomechanical bone-implant perspective, a microcomputed tomography image-based approach combined with the finite element method has been used to investigate the effect of the drill size on the biomechanics stability of the dental implant technique.In the case of neuromotor functions, to achieve a complete clinical evaluation of mastication, an in-depth neurophysiopathological assessment of masticatory muscle control has been described through the trigeminal electrophysiological approach.In conclusion, the implant-prosthetic primary stability is a biomechanical result in a "complex system" in which the direct components can coexist, such as the bone-implant relationship (press-fit phenomenon), and indirect components such as the occlusal loads are determined by the neuromuscular forces where the symmetry and synchronicity of the occlusal contacts are determined