Sequential drilling and drill angulation reduce the accuracy of drill hole start location in a synthetic bone model

The accuracy of drill hole location is critical for implant placement in orthopaedic surgery. Increasing drill bit size sequentially has been suggested as a method for improving the accuracy of drill hole start location. The aim of this study was to determine whether sequential drilling or drill angulation would alter accuracy of drill hole start location. Three specialist veterinary surgeons drilled holes in synthetic bone models either directly, or with sequentially increasing drill bit sizes. Drilling was performed at 0o, 10o and 20o to perpendicular to the bone models. Three synthetic bone models were used to mimic canine cancellous and cortical bones. Sequential drilling resulted in greater inaccuracy in drill hole location when assessing all drilling angles together. There was no influence of surgeon or synthetic bone density on drilling accuracy. The combination of drill angulation and sequential drilling increased inaccuracy in drill hole start location. We conclude that sequential drilling decreased accuracy of drill hole location in the synthetic bone model when drilling was angled. Inaccuracy associated with the drill hole start location should be taken into account when performing surgery, although the magnitude of inaccuracy is low when compared with other sources of error such as angulation.

Analytical Modeling of Ultrasonic Vibration Assisted Drilling of Bones for Medical Surgical Applications

This paper presents a new analytical modeling of ultrasonic vibration assisted drilling of bones for medical surgery operations. Due to the heterogeneous bone structure and the uneven bone surface, bone surgery cutting suffers from inaccuracy and difficulty in high precision bone surgery cutting. In this paper, a new method of ultrasonic vibration assisted drilling is proposed for bone surgery cutting. An analytical force modeling is presented for ultrasonic vibration assisted bone drilling. Experimental result validates the analytical modeling presented in the paper. Preliminary testing result also shows a significant improvement of drilling accuracy based on the proposed ultrasonic vibration assisted bone drilling. The proposed cutting techniques can be used in bone cutting surgery to increase the accuracy of born drilling position and reduce trauma damage of bone and surrounding soft tissues.

Application of Computer in the Directional Well Technology

The directional well technology is developing with the increasing demand for energy, and the computer science plays an important role, which not only decrease the design time of the directional well, but also improve the drilling accuracy. The application of computer in rotary steering system makes it possible to realize the intelligent Directional well system.