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The orthopedic manipulation of bone drilling is performed during the osteosynthesis of bone fractures. It is characterized by a set of input and output parameters. The temperature in the tool-bone interaction zone is one of the most important output parameters of the drilling process. The increase in temperature above a certain threshold causes thermal osteonecrosis of bone cells and all the resulting negative consequences. This work presents a way of drill-bit upper limit temperature calculation during robotized bone drilling process. The temperature estimation and temperature calculation methodology is based on the energy conversion in the bone-robot system, preserving the overall energy balance according to the universal energy conservation law. The bone drilling is performed by using of robot ODRO. Fresh porcine femur bones are used as specimens in the experiments which validate the theoretical results. The real time temperature data during drilling are obtained using a non-contact temperature sensor. A computational approach is developed for estimating the temperature in the drilling zone on the base of the obtained data.The temperature estimation data can be used to control of the cutting condition during a robotic bone drilling process in order to obtain an optimal outcome.

A serious problem associated with orthopedic bone drilling manipulation is the so-called thermal osteonecrosis (TO). This problem occurs because the drilling manipulation generates heat, and the amount of heat depends on the drilling conditions. This work presents the experimental evaluation of the temperature during automated bone drilling by using a handheld Orthopedic bone Drilling Robot ODRO. Up to now, such experimental results related to temperature evaluation in bone drilling by robots have not been presented. Fresh porcine and bovine femur bones were specimens in the experiments. The increase in bone temperature during drilling was measured by a thermal infrared camera. Thermographic sequence images were recorded, processed and visualized using specialized software, which allows to capture accurately the moment of drill bit penetration through the bone and its extraction when going back to initial position. The results showed that under given feed rate and drill speed, when using a new drill bit, the temperature value during porcine femur drilling exceeded the critical threshold of 50 °C for less than 2 s, and thermal osteonecrosis does not occur. When using a worn-out drill bit, the temperature value during bovine femur drilling significantly exceeded the threshold of 50 °C, and thermal osteonecrosis occurs. Thus, to guarantee bone drilling without the risk of thermal osteonecrosis, the automated drilling should be executed with the simultaneous control of speed of drill bit and feed rate. This is possible to be achieved only by robotic execution of the manipulation.

There is an increase in the incidence of hip fractures worldwide in recent years, associated with the upward trend in the life expectancy of the human population. Hip fractures occur mostly in patients aged over 60 years. Therefore, the task for optimization of hip fracture treatment and maximal patients’ recovery is of serious social importance. Many scientists devote their efforts to improving the solutions to such cases. This work presents a specific algorithm developed for registration of human femoral head far cortex and human femoral head end. Its realization is a very successful robot application in the orthopaedic surgery – automatic bone drilling. The experimental specimens are human hip heads obtained during hip-joint excision arthroplasty. The device indicates the maximal hole depths which could be reached. Such information helps to determine and calculate the accurate implant size to ensure its positioning in the desired area of the hip head and reaching maximal fixation strength. The risk of penetration into the joint capsule is eliminated by software defence that the robot is responsible for. The proposed solution is a promising approach towards improvement of the precision and outcome of hip fracture treatment.

Far cortex detection during the bone-drilling process is a specific task in orthopaedic surgery. Any errors in its execution could damage the cortex wall from the inside, which often causes additional trauma even with a fatal result. Here we present some functionality enhancements of the drilling orthopaedic robot ODRO concerning the solution of the far cortex detection problem. The solution is based on software control of the thrust force applied to the bone during the drilling process. A new algorithm is created and its software realisation is provided. Experimental results are presented which verify and confirm the new functional characteristics of the robot. The risk of far cortex damage may be avoided by robot application and such precise operations may guarantee better success.