We have developed a new finite element (FE) model of human right ear, including the accurate geometry of middle ear ossicles, external ear canal, tympanic cavity, and mastoid cavity. The FE model would be suitable to study the dynamic behaviors of pathological middle ear conditions, including changes of stapedial ligament stiffness, tensor tympani ligament (TTL), and tympanic membrane (TM) stiffness and thickness. Increasing stiffness of stapedial ligament has substantial effect on stapes footplate movement, especially at low frequencies, but less effect on umbo movement. Softer TTL will result in increasing umbo and stapes footplate displacement, especially at low frequencies (f<1000Hz). When the TTL was detached, the vibration amplitude of umbo increased by 6dB at 600Hz and two peaks (300 and 600Hz) were found in the vibration amplitude of stapes footplate. Increasing the stiffness of tensor tympani resulted in a slightly decreased umbo amplitude at very low frequencies (f<500Hz) and significantly decreased displacement up to 12dB at middle frequencies (1000Hz1500Hz. As (TM) thickness was increased, the umbo displacement was reduced, especially at very low frequencies (f<600Hz). Otherwise, the stapes displacement was reduced at all frequencies.

Neurosurgeons are required to perform craniotomies to remove brain tumors, hemangiomas, cerebral aneurysms, blood clots in the brain, or relieve internal pressure in the brain. After a craniotomy, the cranial flaps removed from the skull must be set back and fixed appropriately. However, due to the different sizes and shapes of cranial flaps and the various fixation methods, in certain clinical cases, the fixed cranial flaps might be loosened or in dented condition after surgery. This study thus developed a cranioplasty surgical-planning platform to integrate medical imaging technology, computer-aided engineering, and a highperformance computing simulation and visualization. This platform provides an efficient approach to evaluate the structural strength of cranial flaps before an operation. Surgeons can execute preoperative biomechanical simulations of cranial flaps under different fixation methods to achieve optimal fixation planning.