**5. Discussion and conclusion**

The process of bone drilling is characterized by a set of input and output parameters. The input parameters define the conditions under which the process takes place, while the output parameters determine the outcome of the process.

Many scientific investigations are done concerning input parameters as drill speed, feed rate, different types of drill bit, its diameter, bone type and drilling methods. These parameters are responsible for heat generation, micro cracks, hole delamination, breakthrough detection and penetration. The results are reported only for the case when one of the parameters has a fixed value (drill speed) and the other one has a discrete variation (feed rate) or vise versa.

The experiments are made by Computer Numerical Control (CNC) machines or CNC milling machines [39–41]. The purpose is to find such combinations of input parameters which may guarantee optimal output parameters during the process of bone drilling.

The difference between the experimental results of various studies arise for the sake of the wide variety of test conditions used by researchers regarding drill-bit diameter, drill bit type, rotational speed, feed rate and bone type. [42]. However, the following dependencies stand out:

Increasing the feed rate leads to:


Summarizing, to minimize heat generation during drilling (avoid thermal osteonecrosis) one should work with the highest possible value of feed rate and the lowest possible value of drill speed. To avoid traumatic osteonecrosis it is necessary to work with the lowest possible value of feed rate and with the highest possible value of drill speed.

Therefore, there are conflicting requirements regarding the values of the parameters drill speed and feed rate, which should be maintained (implemented) during the bone drilling process in order to obtain an optimal result.

During the manual drilling these parameters are controlled by the surgeon on the base of his practical skills. But the optimal results of the manipulations can be assured only when the input parameters are under control during the automatic execution of the drilling process. This is the main reason for the appearance of the handheld robotized systems.

**149**

**Author details**

Tony Boiadjiev1

and Roumen Kastelov4

**Acknowledgements**

**Conflict of interest**

Sciences, Sofia, Bulgaria

, George Boiadjiev2

The authors declare no conflict of interest.

\*Address all correspondence to: george@fmi.uni-sofia.bg

provided the original work is properly cited.

\*, Kamen Delchev2,3, Ivan Chavdarov2

1 Institute of Information and Communication Technologies, Bulgarian Academy of

2 Faculty of Mathematics and Informatics, Sofia University, Sofia, Bulgaria

4 Orthopedic and Trauma Clinical Centre, Ministry of Interior, Sofia, Bulgaria

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

3 Institute of Mechanics, Bulgarian Academy of Sciences, Sofia, Bulgaria

*Orthopedic Bone Drilling Robot ODRO: Basic Characteristics and Areas of Applications*

but many additional drilling working modes which were already discussed.

This research is supported by the National Scientific Program eHealth in Bulgaria.

As it was said, the purpose of handheld robotized systems development is to reach the accuracy and precise working of the stationary multifunctional robots. In addition, these systems combine robotic drilling technology with the familiarity of traditional, handheld medical drills. Among the important characteristics of the handheld robotized systems must be underlined no requirements of pre-operative planning, calibration, intraoperative navigation systems. Moreover, they are cheaper, easy and convenient for working and maintenance which allows their mass application in surgery practice. ODRO has some advantages in comparison to other considered systems: an algorithm for synthesis of the referenced feed rate during drilling, ability for far cortex detection from inside the bone, various specialized working regimes. Up to now, according to the author's knowledge, there are no reports for automatic bone drilling handheld systems that do not use a fixed feed rate during the whole drilling process. The only two systems available in the market which are used in hospitals - SMARTdrillR and IntelliSense orthopedic surgical drill device, also work in fixed feed rate mode. It is important to underline again that the other systems ability of work report only for bicortical drilling. The ODRO system has not only such ability

*DOI: http://dx.doi.org/10.5772/intechopen.96768*

*Orthopedic Bone Drilling Robot ODRO: Basic Characteristics and Areas of Applications DOI: http://dx.doi.org/10.5772/intechopen.96768*

As it was said, the purpose of handheld robotized systems development is to reach the accuracy and precise working of the stationary multifunctional robots. In addition, these systems combine robotic drilling technology with the familiarity of traditional, handheld medical drills. Among the important characteristics of the handheld robotized systems must be underlined no requirements of pre-operative planning, calibration, intraoperative navigation systems. Moreover, they are cheaper, easy and convenient for working and maintenance which allows their mass application in surgery practice.

ODRO has some advantages in comparison to other considered systems: an algorithm for synthesis of the referenced feed rate during drilling, ability for far cortex detection from inside the bone, various specialized working regimes. Up to now, according to the author's knowledge, there are no reports for automatic bone drilling handheld systems that do not use a fixed feed rate during the whole drilling process. The only two systems available in the market which are used in hospitals - SMARTdrillR and IntelliSense orthopedic surgical drill device, also work in fixed feed rate mode. It is important to underline again that the other systems ability of work report only for bicortical drilling. The ODRO system has not only such ability but many additional drilling working modes which were already discussed.
