Titanium and its alloys are currently considered as one of the most important metallic materials used in the biomedical applications, due to their excellent mechanical properties and superior biocompatibility. In the ...Titanium and its alloys are currently considered as one of the most important metallic materials used in the biomedical applications, due to their excellent mechanical properties and superior biocompatibility. In the present study, a new effective method for fabricating high porosity titanium alloy scaffolds was developed. Porous Ti-6Al-4V scaffolds are successfully fabricated with porosities ranging from 30% to 70% using spaceholder and powder sintering technique. Based on its acceptable properties, spherical carbamide particles with different diameters （0.56, 0.8, and 1mm） were used as the space-holder material in the present investigation. The Ti-6Al-4V scaffolds porosity is characterized by using scanning electron microscopy. The results show that the scaffolds spherical-shaped pores are depending on the shape, size and distribution of the space-holder particles. This investigation shows that the present new manufacturing technique is promising to fabricate a controlled high porosity and high purity Ti-6Al-4V scaffolds for hard tissue replacement.展开更多
Background:Applying ultrasonic imaging system during surgery requires the poring of saline,performing the measurement,and acquiring data from its display—which requires time and is highly“performer dependent,”i.e.,...Background:Applying ultrasonic imaging system during surgery requires the poring of saline,performing the measurement,and acquiring data from its display—which requires time and is highly“performer dependent,”i.e.,the measure is of a subjective nature.A new ultrasonic device was recently developed that overcomes most of these drawbacks and was successfully applied during tumor-in-brain neurosurgeries.The purpose of this study was to compare the two types of US devices and demonstrate their properties.Methods:The study was performed in the following stages:(i)an ex vivo experiment,where slices of the muscle and brain of a young porcine were laid one on top the other.Thicknesses and border depths were measured and compared,using the two types of US instruments.(ii)During human clinical neurosurgeries,tumor depth was compared by measuring it with both devices.(iii)Following the success of stages(i)and(ii),using solely the new US device,the tumor thickness was monitored while its resection.Correlation,Pearson’s coefficient,average,mean,and standard deviation were applied for statistical tests.Results:A high correlation was obtained for the distances of tissue borders and for their respective thicknesses.Applying these ultrasonic devices during neurosurgeries,tumor depths were monitored with high similarity(87%),which was also obtained by Pearson’s correlation coefficient(0.44).The new US device,thanks to its small footprint,its remote measurement,and the capability of monitoring intraoperatively and in real-time,provides the approach to tumor’s border before its complete resection.Conclusions:The new US device provides better accuracy than an ultrasonic imaging system;its data is objective;it enables to control the residual tumor thickness during its resection,and it is especially useful in restricted areas.These features were found of great help during a tumor-in-brain surgery and especially in the final stages of tumor’s resection.展开更多
基金supported by the Korea Research Foundation (KRF)
文摘Titanium and its alloys are currently considered as one of the most important metallic materials used in the biomedical applications, due to their excellent mechanical properties and superior biocompatibility. In the present study, a new effective method for fabricating high porosity titanium alloy scaffolds was developed. Porous Ti-6Al-4V scaffolds are successfully fabricated with porosities ranging from 30% to 70% using spaceholder and powder sintering technique. Based on its acceptable properties, spherical carbamide particles with different diameters （0.56, 0.8, and 1mm） were used as the space-holder material in the present investigation. The Ti-6Al-4V scaffolds porosity is characterized by using scanning electron microscopy. The results show that the scaffolds spherical-shaped pores are depending on the shape, size and distribution of the space-holder particles. This investigation shows that the present new manufacturing technique is promising to fabricate a controlled high porosity and high purity Ti-6Al-4V scaffolds for hard tissue replacement.
文摘Background:Applying ultrasonic imaging system during surgery requires the poring of saline,performing the measurement,and acquiring data from its display—which requires time and is highly“performer dependent,”i.e.,the measure is of a subjective nature.A new ultrasonic device was recently developed that overcomes most of these drawbacks and was successfully applied during tumor-in-brain neurosurgeries.The purpose of this study was to compare the two types of US devices and demonstrate their properties.Methods:The study was performed in the following stages:(i)an ex vivo experiment,where slices of the muscle and brain of a young porcine were laid one on top the other.Thicknesses and border depths were measured and compared,using the two types of US instruments.(ii)During human clinical neurosurgeries,tumor depth was compared by measuring it with both devices.(iii)Following the success of stages(i)and(ii),using solely the new US device,the tumor thickness was monitored while its resection.Correlation,Pearson’s coefficient,average,mean,and standard deviation were applied for statistical tests.Results:A high correlation was obtained for the distances of tissue borders and for their respective thicknesses.Applying these ultrasonic devices during neurosurgeries,tumor depths were monitored with high similarity(87%),which was also obtained by Pearson’s correlation coefficient(0.44).The new US device,thanks to its small footprint,its remote measurement,and the capability of monitoring intraoperatively and in real-time,provides the approach to tumor’s border before its complete resection.Conclusions:The new US device provides better accuracy than an ultrasonic imaging system;its data is objective;it enables to control the residual tumor thickness during its resection,and it is especially useful in restricted areas.These features were found of great help during a tumor-in-brain surgery and especially in the final stages of tumor’s resection.
