Bone Drilling Process Research Articles

An in-vitro study of cutting force and torque during rotary ultrasonic bone drilling

Bone drilling is one of the steps in a typical surgical operation that is performed around the world for reconstruction and repair of the fractured bone. During the last decade, various techniques, such as two-step drilling, ultrasonic-assisted bone drilling and laser drilling, have been introduced to control the level of forces and torque during bone drilling. In this research, rotary ultrasonic bone drilling has been successfully attempted to minimize the forces and torque during bone drilling. The drilling experiments were planned and carried out on pig bones using the design of experiments (response surface methodology). Analysis of variance was carried out to find the effect of process factors such as rotational speed, feed rate, drill diameter and ultrasonic vibrational amplitude on the force and torque. Statistical models were developed for the force and torque with 95% confidential interval, and confirmation experiments have been carried out to validate the models. Microcracks developed during drilling process were characterized by scanning electron microscopy. The results revealed that rotary ultrasonic bone drilling process offered a lower force and torque making it a potential process for bone drilling in orthopedic surgery.

Far cortex automatic detection aimed for partial or full bone drilling by a robot system in orthopaedic surgery

ABSTRACTFar 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.

Experimental investigation and statistical modeling of temperature rise in rotary ultrasonic bone drilling

Thermal necrosis is one of the major problems associated with the bone drilling process in orthopedic/trauma surgical operations. To overcome this problem a new bone drilling method has been introduced recently. Studies have been carried out with rotary ultrasonic drilling (RUD) on pig bones using diamond coated abrasive hollow tools. In the present work, influence of process parameters (rotational speed, feed rate, drill diameter and vibrational amplitude) on change in the temperature was studied using design of experiment technique i.e., response surface methodology (RSM) and data analysis was carried out using analysis of variance (ANOVA). Temperature was recorded and measured by using embedded thermocouple technique at a distance of 0.5mm, 1.0mm, 1.5mm and 2.0mm from the drill site. Statistical model was developed to predict the maximum temperature at the drill tool and bone interface. It was observed that temperature increased with increase in the rotational speed, feed rate and drill diameter and decreased with increase in the vibrational amplitude.

A study of an assisting robot for mandible plastic surgery based on augmented reality

Background: Mandible plastic surgery plays an important role in conventional plastic surgery. However, its success depends on the experience of the surgeons. In order to improve the effectiveness of the surgery and release the burden of surgeons, a mandible plastic surgery assisting robot, based on an augmented reality technique, was developed.Material and methods: Augmented reality assists surgeons to realize positioning. Fuzzy control theory was used for the control of the motor. During the process of bone drilling, both the drill bit position and the force were measured by a force sensor which was used to estimate the position of the drilling procedure.Results: An animal experiment was performed to verify the effectiveness of the robotic system. The position error was 1.07 ± 0.27 mm and the angle error was 5.59 ± 3.15°. The results show that the system provides a sufficient accuracy with which a precise drilling procedure can be performed. In addition, under the supervision’s feedback of the sensor, an adequate safety level can be achieved for the robotic system.Conclusion: The system realizes accurate positioning and automatic drilling to solve the problems encountered in the drilling procedure, providing a method for future plastic surgery.

A predictive bone drilling force model for haptic rendering with experimental validation using fresh cadaveric bone.

Bone drilling simulators with virtual and haptic feedback provide a safe, cost-effective and repeatable alternative to traditional surgical training methods. To develop such a simulator, accurate haptic rendering based on a force model is required to feedback bone drilling forces based on user input. Current predictive bone drilling force models based on bovine bones with various drilling conditions and parameters are not representative of the bone drilling process in bone surgery. The objective of this study was to provide a bone drilling force model for haptic rendering based on calibration and validation experiments in fresh cadaveric bones with different bone densities. Using a commonly used drill bit geometry (2 mm diameter), feed rates (20-60mm/min) and spindle speeds (4000-6000rpm) in orthognathic surgeries, the bone drilling forces of specimens from two groups were measured and the calibration coefficients of the specific normal and frictional pressures were determined. The comparison of the predicted forces and the measured forces from validation experiments with a large range of feed rates and spindle speeds demonstrates that the proposed bone drilling forces can predict the trends and average forces well. The presented bone drilling force model can be used for haptic rendering in surgical simulators.

Optimization of bone drilling process based on finite element analysis

Bone drilling is frequently used in modern surgery operations, especially in fracture treatment. Drilling temperature should be strictly controlled, since when the temperature is 47°C higher over 60s, irreversible damages happen to bone. The study investigated the heat transfer of bone drilling by a three-dimensional model based on finite element method. Three principal drilling parameters were studied: feed rate, spindle speed and drill diameter. A parametric study proved that drilling temperature increases once any of three parameters rises. Parameters’ effects on drilling temperature are proved synergistic. An empirical formula of maximum drilling temperature depending on three drilling parameters is given with a sensitivity analysis. To a drilling process of surgical operations, this formula could be used for temperature prediction and optimization of parameters respecting drilling temperature. Furthermore, the intermittent feed drilling is proposed and demonstrated to be very efficient to reduce thermal necrosis to bone tissue.

Temperature in Bone Drilling Process: Mathematical Modeling and Optimization of Effective Parameters

Bone drilling process is the most prominent process in orthopedically surgeries and curing bone breakages. It is also very common in dentistry and bone sampling operations. Due to complexity of the material that is machined, bone, and the sensitivity of the process, bone drilling is one of the most important, common and sensitive processes in biomedical engineering field. The most critical problem which can occur during bone drilling is increasing the process temperature above the allowable limit (47°C) which causes thermal necrosis or cell death in the bone tissue. In this study, an empirical model is developed to enable the surgeon to predict the temperature of the process based on tool's rotational speed, feed rate, tool diameter and effective interactions between these parameters. Experiments were designed and modeled using response surface methodology and to ascertain operation conditions, optimization was performed. Results show that within the range of the investigated variables, with an increase in the tool diameter and cutting speed, the rate of temperature change increases. It is noted that the behavior of the feed rate is complex; in this paper it is investigated precisely. The response surface model is able to predict temperature behavior based on the input parameters. The allowable range of parameters in bone drilling operation is introduced to obtain a quick and swift desirable operation.

Thermal analysis during bone drilling using rigid polyurethane foams: numerical and experimental methodologies

Osteotomy or bone cutting is a common procedure in orthopaedic surgery, mainly in the treatment of fractures and reconstructive surgery. However, the excessive heat produced during the bone drilling process is a problem that counters the benefits of this type of surgery, because it can result in thermal osteonecrosis, bone reabsorption and damage the osseointegration of implants. The analysis of different drilling parameters and materials can allow to decrease the temperature during the bone drilling process and contribute to a greater success of this kind of surgical interventions. The main goal of this study was to build a numerical three-dimensional model to simulate the drilling process considering the type of bone, the influence of cooling and the bone density of the different composite materials with similar mechanical properties to the human bone and generally used in experimental biomechanics. The numerical methodology was coupled with an experimental methodology. The use of cooling proved to be essential to decrease the material damage during the drilling process. It was concluded that the materials with less porosity and density present less damage in drilling process. The developed numerical model proved to be a great tool in this kind of analysis.

Effect of Diamond Coating on Drilling Force and Temperature during High Speed Micro Drilling of Bone

Bone drilling commonly exists in clinical practice and the heat and force generated by the drilling process has a huge impact on the surgery effect and the recovery of patients. High speed drilling, proved to have less injury and be more efficient when compared to the traditional low speed drilling, is considered to be the development direction of bone drilling-related surgeries. In order to make a further study of the controlling of the heat and force during the bone drilling process, the experiment designed to examine the influence of the diamond coating has been conducted and the result indicates that the diamond coating generally has little influence on the drilling force, however, it can increase the drilling temperature to a certain extent which indicates that the diamond coating is not suitable to apply to bone drills under the conditions of the conducted experiments. The result of this research could be of some help to the development of new kinds of medical drills.

Evaluation of delamination in drilling of bone

In this paper, delamination of bone associated with drilling is investigated using design of experiments. Experiments have been planned based on L25 design of the orthogonal arrays with different conditions of drill bit, spindle speed and feed rate. Regression analysis is used to develop a mathematical model of delamination as a function of bone drilling process parameters. Analysis of variance (ANOVA) is carried out to find the significance of the developed model along with the percentage contribution of each factor on delamination. Optimum setting of bone drilling parameters for minimum delamination is determined using Taguchi optimization methodology. Finally, the results obtained are validated by conducting confirmation experiments.

Drill wear monitoring in cortical bone drilling

Medical drills are subject to intensive wear due to mechanical factors which occur during the bone drilling process, and potential thermal and chemical factors related to the sterilisation process. Intensive wear increases friction between the drill and the surrounding bone tissue, resulting in higher drilling temperatures and cutting forces. Therefore, the goal of this experimental research was to develop a drill wear classification model based on multi-sensor approach and artificial neural network algorithm. A required set of tool wear features were extracted from the following three types of signals: cutting forces, servomotor drive currents and acoustic emission. Their capacity to classify precisely one of three predefined drill wear levels has been established using a pattern recognition type of the Radial Basis Function Neural Network algorithm. Experiments were performed on a custom-made test bed system using fresh bovine bones and standard medical drills. Results have shown high classification success rate, together with the model robustness and insensitivity to variations of bone mechanical properties. Features extracted from acoustic emission and servomotor drive signals achieved the highest precision in drill wear level classification (92.8%), thus indicating their potential in the design of a new type of medical drilling machine with process monitoring capabilities.

Analysis of Bone Drilling Processes: A Review

Analysis of Bone Drilling Processes: A Review

An experimental evaluation of loads occurring during guided drilling for cochlear implantation.

During guided drilling for minimally invasive cochlear implantation and related applications, typically forces and torques act on the employed tool guides, which result from both the surgeon's interaction and the bone drilling process. Such loads propagate through the rigid mechanisms and result in deformations of compliant parts, which in turn affect the achievable accuracy. In this paper, the order of magnitude as well as the factors influencing such loads are studied experimentally to facilitate design and optimization of future drill guide prototypes. The experimental setup to evaluate the occurring loads comprises two six degree of freedom force/torque sensors: one mounted between a manually operated, linearly guided drill handpiece and one below the specimens into which the drilling is carried out. This setup is used to analyze the influences of drilling tool geometry, spindle speed as well as experience of the operator on the resulting loads. The results reveal that using a spiral drill results in lower process loads compared with a surgical Lindemann mill. Moreover, in this study, an experienced surgeon applied lower interaction forces compared with untrained volunteers. The measured values further indicate that both the intraoperative handling of the bone-attached drill guide as well as the tool removal after completing the hole can be expected to cause temporary load peaks which exceed the values acquired during the drilling procedure itself. The results obtained using the proposed experimental setup serve as realistic design criteria with respect to the development of future drill guide prototypes. Furthermore, the given values can be used to parameterize simulations for profound stiffness analyses of existing mechanisms.

Cortical bone drilling: An experimental and numerical study.

Bone drilling is a common surgical procedure in orthopedics, dental and neurosurgeries. In conventional bone drilling process, the surgeon exerts a considerable amount of pressure to penetrate the drill into the bone tissue. Controlled penetration of drill in the bone is necessary for safe and efficient drilling. Development of a validated Finite Element (FE) model of cortical bone drilling. Drilling experiments were conducted on bovine cortical bone. The FE model of the bone drilling was based on mechanical properties obtained from literature data and additionally conducted microindentation tests on the cortical bone. The magnitude of stress in bone was found to decrease exponentially away from the lips of the drill in simulations. Feed rate was found to be the main influential factor affecting the force and torque in the numerical simulations and experiments. The drilling thrust force and torque were found to be unaffected by the drilling speed in numerical simulations. Simulated forces and torques were compared with experimental results for similar drilling conditions and were found in good agreement.CONCLUSIONS: FE schemes may be successfully applied to model complex kinematics of bone drilling process.

A feasibility investigation for modeling and optimization of temperature in bone drilling using fuzzy logic and Taguchi optimization methodology.

Drilling of bone is a common procedure in orthopedic surgery to produce hole for screw insertion to fixate the fracture devices and implants. The increase in temperature during such a procedure increases the chances of thermal invasion of bone which can cause thermal osteonecrosis resulting in the increase of healing time or reduction in the stability and strength of the fixation. Therefore, drilling of bone with minimum temperature is a major challenge for orthopedic fracture treatment. This investigation discusses the use of fuzzy logic and Taguchi methodology for predicting and minimizing the temperature produced during bone drilling. The drilling experiments have been conducted on bovine bone using Taguchi's L25 experimental design. A fuzzy model is developed for predicting the temperature during orthopedic drilling as a function of the drilling process parameters (point angle, helix angle, feed rate and cutting speed). Optimum bone drilling process parameters for minimizing the temperature are determined using Taguchi method. The effect of individual cutting parameters on the temperature produced is evaluated using analysis of variance. The fuzzy model using triangular and trapezoidal membership predicts the temperature within a maximum error of ±7%. Taguchi analysis of the obtained results determined the optimal drilling conditions for minimizing the temperature as A3B5C1.The developed system will simplify the tedious task of modeling and determination of the optimal process parameters to minimize the bone drilling temperature. It will reduce the risk of thermal osteonecrosis and can be very effective for the online condition monitoring of the process.

THERMAL NECROSIS - EXPERIMENTAL INVESTIGATION ON THERMAL EXPOSURE DURING BONE DRILLING PROCESS

The process of bone drilling is an essential part of internal immobilization in orthopaedic and trauma surgery. So drill bit design also plays a vital role in surgery. Improper drill bit parameters will seriously affect the bone tissues and results thermal necrosis. This paper investigates the main concern of thermal necrosis during bone drilling.

Multi-performance optimization of bone drilling using Taguchi method based on membership function

In orthopaedic surgery, the thermal and mechanical invasion caused to the bone cells due to drilling can result in their damage or even death, leading to the loosening of the fixation and increase in healing time postoperatively. This article presents a hybrid algorithm (Taguchi combined with membership function) for the optimization of bone drilling process with multiple performance characteristics to minimize the drilling induced bone tissue damage. Taguchi method is a powerful optimization tool designed for the optimization of single performance characteristics, but most of the real engineering problems demands for multiple objective optimization. Therefore, a simple modification is incorporated in Taguchi method based on membership function to convert the optimization of the complex multiple performance characteristics into a single signal to noise as the performance index. Bone drilling investigations are carried out on bovine bone with spindle speed and feed rate as drilling parameters. The objective function is the simultaneous minimization of drilling temperature and thrust force. Analysis of variance (ANOVA) is employed to find out the effect of each parameter on the multiple performance signal to noise ratio. The effectiveness of the above approach is validated by the confirmation experiment.

Optimization of processing parameters of a developed new driller system for orthopedic surgery applications using Taguchi method

In bone drilling process during the surgical operations, heating increases due to high bone/drill contact friction that damages the bones and soft tissues. The overheating is usually recognized as the temperature rise exceeds 47 °C, a critical limit, above which the drilling causes osteonecrosis. In this study, a new driller system is developed to prevent the overheating in orthopedic surgeries. It has a closed-circuit cooling system to reduce the undesired temperature rise during the drilling process. It is also designed and manufactured as a prototype and tested experimentally in vitro by drilling fresh bovine bones using different processing parameters. In the drilling tests, the temperature levels of the bones are measured using thermocouple sensors. Based on the measured results, the driller system provides a valuable temperature reduction around 25 % to prevent necrosis in low spindle speeds (rpm) usually preferred by surgeons. The measured temperatures from the tests of the driller system with a cooling system were compared with the use of regular bone drilling process without cooling. The optimum processing parameters of the new driller system with/without coolant are calculated using the Taguchi method, and the most effective parameter is found as rpm.

Development of a new driller system to prevent the osteonecrosis in orthopedic surgery applications

In bone drilling process during the surgical operations, heating increases extremely due to undesired temperature rise that sometimes seriously damages the bones and soft tissues. The overheating is usually recog- nized as the temperature exceeds 47 C known as a critical limit above which the drilling causes osteonecrosis. In this study, a new driller system is developed to prevent the overheating in orthopedic surgical applications. The driller system has a closed-circuit cooling system to reduce the undesired temperature rise during the bone drilling process. The driller system is designed and manufactured as a prototype and tested experimentally in vitro by drilling fresh bovine bones using different processing parameters. A drill bit with a diameter of 10 mm is designed with a closed-circuit cooling channel internally and used in the bone drilling tests. In the drilling tests, the temperatures levels of the bones are measured using both non-contact and thermocouple sensors. Based on the results measured in the experiments, the developed driller system provides a valuable temperature reduction during the bone drilling process. Therefore, the bone temperature reduction was measured range of 20-25 % for lower spindle speeds (rpm) that is usually preferred by surgeons. The temperature levels measured from the drilling tests of the developed driller system having a cooling system are compared with the use of regular bone drilling process without cooling. A valuable temperature reduction is obtained using the driller system during the bone drilling tests.

3D finite element modeling and analysis of dynamic force in bone drilling for orthopedic surgery

Three-dimensional finite element modeling and analysis are made to simulate the dynamic process of bone drilling during the orthopedic surgery. This study is proposed to evaluate the performance of various surgical tools and the possible pre-operative biohazard. In the simulation, the strain-stress curve of the bone is divided into linear elastic region and nonlinear plastic region according to the strain range. Rigid-plasticity and elasto-plasticity are used as bone material. The performances of twist drill bit and hollow drill bit are evaluated. The results of finite element analysis give different patterns of stress distribution on the two types of bone models and drill bits. The FE simulations show dynamic drilling process that the drill bit penetrates through the bone model. In vitro drilling experiment on porcine femur is conducted to measure the drilling force for the validation of the FEM.