Robotic System for Catheter Navigation during Medical Procedures

Abstract

Lung cancer is the most common cancer globally with over 2 million new cases diagnosed every year. Fortunately, if caught early, the likelihood of survival is greatly improved. If diagnosed in Stage I, survival rates are >75% over 5 years, vs. just 1% if diagnosed in Stage IV. Early diagnosis requires finding and sampling (biopsy) small, peripheral nodules that are located in the parenchima of the lung and predominately outside small airways. Currently, for early diagnosis a bronchoscope is inserted into the lung airway but due to large size it cannot reach the small airways. Therefore, the doctor has to advance a sharp biopsy needle blindly from the tip of the bronchoscope and into the lung tissue in the approximate direction of the nodule. This blind procedure has low accuracy and carries a high risk of misdiagnosis. Currently, to improve the accuracy, real time x-ray (fluoroscopy) is use which causes exposure of the patient and physician to harmful radiation. Computer and image assisted surgery and medical robotics present viable solutions but are not optimal at present. The scope of our research was to develop a robotic solution for increased precision and accuracy of early diagnosis and treatment of lung cancer, to increase procedure success rate, decrease patient radiation and stress exposure, and reduce the procedure cost. For this purpose, we developed an advanced prototype of a robotic system which is small in size, easy to use and effective. To demonstrate its effectiveness in navigating to peripheral small size lung cancer lesions, we performed laboratory tests or a realistic lung airway model. The preliminary tests of a novel medical robot using a complex lung airway model proved that our catheter driving robotic system is working as designed and allows navigation, through a complex 3D channels structure like the bronchial tree, in both manipulator and robotic modes without fluoroscopy scanning. The robotic system is more precise and stable, and can avoid patient injury and instrument damage due to accidental impact with the airway wall. Because it could be controlled from a different room via the software platform, using this robotic system can drastically reduce radiation exposure of the patient and totally avoid the exposure of the doctor. Another benefit of the proposed robotic system is that it uses currently available catheters in which a reusable electromagnetic guide wire is temporarily inserted to guide the tip of the catheter towards hard to reach targets. After the target is confirmed, the sensor can be retracted and the catheter can be used for its routine function such as biopsy collection. Future development will include placement of a force sensor at the tip of the catheter to “feel” the wall and adapt the speed of insertion in order to avoid wall damage and an improved algorithm to increase the speed in the automatic mode.