For the development of medical micro-robotics and robotic manipulation of catheter it is necessary to ensure tissue integrity. In-vitro evaluation of tissue manipulation can be achieved using photoelastic stress analysis and vasculature modeling with photoelastic materials. In this research we propose epoxy resin as photoelastic material for vasculature modeling as it has a larger photoelastic coefficient than previously studied materials and it has a young modulus similar to human vasculature. A model of a saccular aneurysm with bleb was built with the purpose of measuring stress overshoots that enable to differentiate embolization techniques according to the respect for tissue integrity. During embolization using a coil with smaller size than the aneurysm dome diameter, an average area of 0.72 mm2with stress above 90 kPa was measured. This area increased to 0.77 mm2when the dome was touched with the release mechanism of the coil, and to 0.74 mm2for embolization with larger size coil. The presented modeling material and measurement technique is useful for tissue respect quantification for micro-mechanisms evaluation.

Quantification of human skills is a challenge for simulator based medical training, particularly for endovascular intervention. For that purpose it is needed to measure different biometric parameters from the user and additionally measure the interaction between endovascular instruments and vasculature models membrane. For that purpose in this research we present an optical sensor for encoding linear and rotational motion of the catheter through the insertion port. Additionally we present two studies for measuring tissue integrity, time to complete a task, reaction time, and wasting motion using two populations of expert and beginner. The optical encoder showed an average error of 0.39mm and 10.78deg. In both studies the presented cyber-physical system is useful to identify the users with qualities closer to the expert among users with low performance.

For the development of artificial intelligent diagnosis for cerebrovascular intervention, it is desirable to forecast the growth of cerebral aneurysms. In order to achieve such purpose, it is needed to evaluate wall shear stress, strain, pressure, deformation and flow velocity in the aneurysm region. In this research, we focus on in-vitro strain and deformation measurements of cerebral aneurysm models, and propose a cyber-physical system, in which a scaled-up membranous silicone model of cerebral aneurysm was built and integrated with a specialized pump for the pulsatile blood flow simulation, and a vision system was constructed to measure the strain on different regions on the model with pulsatile blood flow circulated inside. Experimental results show that both distance and area strain maxima were larger for the aneurysm neck (0.042 and 0.052), followed by the aneurysm dome (0.023 and 0.04) and then by the main blood vessel section (0.01 and 0.014), which were complemented with computer fluid dynamics simulation for the inclusion of wall shear stress, oscillatory shear index and aneurysm formation index. Medical imaging data of the cerebral aneurysm in 2008 and 2011 was obtained. Diagnosis results have concordance with the aneurysm growth in 2011. The presented measurement method offers an option for measuring strain and deformation to be complementary with computer fluid dynamics and photoelastic stress analysis for advanced diagnostic in the endovascular surgery.

We have fabricated a micro touch sensor array. Every touch sensor unit is composed of Ti substrate and PZT thin film. The PZT thin film was synthesized by a hydrothermal method and used as both micro sensor and micro actuator. The micro actuator is driven at the resonant frequency point of the structure. The impedance change can be detected before and after contact by the micro sensor. This micro touch sensor array can be used as the controlling touch sensor pad of a car instead of the conventional capacity type touch pad, because it can resist high temperature. In order to improve the property of the micro touch sensor, the mechanics model, which is used to analyze the relationship between the input voltage and output voltage, was set up. According to cantilever beam theory, the response of the micro touch sensor to electric input has been discussed. Based on the model, the structural characterization of the micro touch sensor has been evaluated. The parameters that affect the output voltage have been analyzed.

This paper proposes a new tactile display to present shear deformation to the skin of human finger. For presenting the shear deformation of the finger, we fabricated a three-dimensional moving stage driven by the hydraulic actuators. For presenting different deformation under the condition of the same normal pressure, we used an air suction pad that can suck air. Using this air pad and the hydraulic display system, we performed experiments to present shear deformation. From these experiments, large deformation was achieved under the condition of the same normal pressure.