SUMMARY: Due to the complexity of head shape, limited 1D or 2D head anthropometry fail to fully capture its shape characteristics. Currently, there is limited research on clustering analysis of head shape from a shape difference perspective, especially for the head shape of Chinese people. Head shape is influenced by factors such as race, sex, and age, making it imperative to create a head shape database for Chinese individuals. In this study, three-dimensional head data of 339 Chinese young adult were collected, and the head shapes were clustered into 7 clusters using an improved k-medoids algorithm. The differences between clusters and the average head shape were further analyzed. It can be foreseen that the head shape database for Chinese young adult constructed in this study has important reference value for the ergonomic design of head-related products and head morphology research, among other fields.

RESUMEN: Debido a la complejidad de la forma de la cabeza, la antropometría limitada de ésta, en 1D o 2D, no logra capturar completamente sus características de forma. Actualmente, existen estudios limitados sobre el análisis de agrupamiento de la forma de la cabeza, desde una perspectiva de diferencia de forma, especialmente en el caso de la población china. La forma de la cabeza está influenciada por factores como la raza, el sexo y la edad, por lo que resulta imperativo crear una base de datos sobre la forma de la cabeza de los individuos chinos. En este estudio, se recopilaron datos tridimensionales de la cabeza de 339 adultos jóvenes chinos, y las formas de la cabeza se agruparon en 7 grupos utilizando un algoritmo k-medoids mejorado. Las diferencias entre los grupos y la forma promedio de la cabeza se analizaron a profundidad. Se puede prever que la base de datos sobre la forma de la cabeza de adultos jóvenes chinos construida en este estudio, tiene un valor de referencia importante para el diseño ergonómico de productos relacionados con la morfología de la cabeza, entre otros campos.

ABSTRACTPurpose:To evaluate the clinical efficacy of flexible ureteroscope (F-URS) combined with holmium laser lithotripter in treating renal calculi in horseshoe kidney.Materials and Methods:From November 2010 to December 2013, the medical history and charts of sixteen patients (mean age 42.9±11.6 years, range 26-66 years), including 13 males and 3 females were analyzed retrospectively. Mean stone burden was 29±8 mm (range 17-42 mm2). Mean stone digitized surface area (DSA) was 321±94 mm2 (range 180-538 mm2). Under spinal anesthesia in a modified lithotomy position with the head down, rigid ureteroscope was placed firstly into the ureter to reach the level of the pelvis, a zebra guide wire was inserted and following the removal of the rigid ureteroscope, an ureteral access sheath was positioned along the guide wire, then passed the URF P-5 flexible ureteroscope into the renal cavities over the guidewire. After locating the stones, holmium laser lithotripsy was performed.Results:The average operative time was 92±16 minutes (range 74-127 min.). No major complications were encountered. Ten patients obtained stone-free status with one session, four obtained stone-free status after two sessions. Single session stone-free rate was 62.5%, overall stone-free rate was 87.5%. Two patients have small residual stones in the lower pole.Conclusions:F-URS combined with holmium laser lithotripter and nitinol basket, is safe and effective in dealing with moderate stone diameter (<30 mm) in HSKs with high clearance rates and low complication rates.