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Numerical criteria for evaluating stress on vasculature models have applications in evaluating medical tools and surgical skills enabling better endovascular surgery training and the development of better medical techniques and tools. We propose using the stress produced by blood pressure simulation in the vasculature model wall for this criterion and use photoelastic effect for measuring the principal stress magnitude component. We simulated human blood pressure with 5.6% average error and developed shielded urethane model of vasculature enabling water circulation and avoiding plastic deformation at pressures below 182 mmHg. We developed software to calculate model wall stress. We quantitatively compared in four ranges stress produced on the model wall by blood pressure simulation and a guide wire.

Endovascular intervention using interventional radiology (IVR) is most commonly used in cerebralvascular treatment. Medical imaging such as digital subtraction angiography (DSA) and vascular mapping make vasculature and catheters easier to read from fluoroscopy during endovascular intervention. We propose simulating IVR using augmented reality, reproducing fluoroscopic images and a patient-specific blood vessel model without X-ray imaging. The advantages of the patient-specific vascular model reproducing the human vasculature lumen with 13 μm resolution include 1) a realistic “feel,” 2) excellent tool behavior simulation during intervention, and 3) surgical training alternative to physician training in-vitro. Simulated fluoroscopic images are created in two steps: First, the blood vessel model refraction index is matched to surrounding glycerin solution to conceal the vascular model, making the silicone vasculature appear human as seen in endovascular intervention. Second, an augmented reality (AR) environment is created using image subtraction and overlap, making model-based endovascular simulation more understandable for catheter use and fluoroscopy use and reading.

Magnetic motion capture sensors (MMCS) are not commonly used for robot control due to the need for complex, resource-consuming calibration to correct error introduced by the magnetic sensor. We propose avoiding such calibration using a rule-based controller that only uses spatial coordinates from the magnetic sensor. This controller uses a sparse look-up table of spatial coordinates and actions conducted by the robot and reacts to the presence of the sensor near reference points. The control method was applied to manipulate a robotic camera to track a catheter-shaped sensor inside vessels silicone models. A second evaluation was done guiding a mechanism to reconstruct catheter insertion in major silicone vasculature models. The robotic camera tracked the catheter by reacting to the sensor within 10 mm of each reference point. The catheter insertion mechanism reconstructed the catheter trajectory by reacting to the sensor within 6 mm of each reference point. We found that the proposed method allowed robot control in a bounded space without having to correct for the magnetic tracker output distortion.

We have been developing scaffolds of three-dimensional (3D) synthetic vascular prosthesis in tailor-made. Human umbilical vein endothelial cells (HUVECs) attached on the inner surface of the scaffold have anticoagulant effects. Asperity structures of the inner surface are important to cell adhesion. It is important to quantify the inner surface asperity condition of the scaffold by observing HUVECs behavior and morphology. For this purpose, we recreated the inner surface profile of the scaffold on a poly(dimethilsiloxane) (PDMS) substrate by microfabrication. We made semiround convex patterns of resist that had 8 µm in diameter and 5 µm high using photolithography, and the concave pattern on the PDMS substrate by printing. We observed HUVECs adhering to the PDMS substrate having concave pattern on it surface. The distribution density of the concaves of the tested pattern is 1600 /mm2or 40,000 in a 25 mm2area. In addition, we fabricated an arteriole model by photolithography, creating an arteriole tube model that had 1.1 cm long and 300-400 µm in diameter. We confirmed that the arteriole model had no leakage using a methylene blue solution flow in the channel.

We propose an in vitro patient-specific anatomical model of the human cerebral artery and its simulation of endovascular intervention, a potent treatment modality for cerebrovascular diseases. Our proposed model reproduces the 3-dimensional vasculature lumen, using computed tomography (CT) and magnetic resonance (MR) fluoroscopic information, within a thin artery-like membranous configuration having material properties close to arterial tissue. This cerebral arterial model reproduces an exceedingly realistic surgical feel, dynamic vascular deformation and, other important aspects involving endovascular intervention, realizing a highly realistic surgical simulation. We also propose another vasculature model that reproduces the subarachnoid space around the cerebral arteries. This version simulates endovascular intervention realistically. The model is compatible with current major imaging modalities such as CT, MR, and transcranial Doppler (TDC), and should provide effective platforms for applications, such as diagnosis, surgical planning, medical training, hemodynamic analysis and medical system development and evaluation, especially surgical robots.