Bone Grinding Research Articles

Force model of robot bone grinding based on finite element analysis

Bone grinding represents a formidable challenge during open epiphyseal surgery, as grinding force may result in potential damage to bone and surrounding tissues. To address this issue, this study establishes a correlation between grinding force and bone density, as well as feed rate and rotational speed. Given the limited availability of experimental data on bone grinding, a finite element analysis (FEA) model is developed. Subsequently, the impact of bone density, feed rate and rotational speed on grinding force is determined through linear regression method. The accuracy and sensitivity of the grinding force model are then assessed, revealing a maximum prediction deviation of 4.87%. Finally, based on the established model, safe operating parameters and boundary conditions for robot bone grinding are identified.

A novel surgical diamond spherical wheel to prevent bone adhesion with superhydrophobic and super-slippery coatings

Ordinary commercial diamond spherical wheels are extensively used in bone grinding surgeries. However, a persistent issue arises from bone debris adhering to the wheel surface, leading to elevated temperatures during the bone grinding process. To address this, the study developed a novel spherical wheel with a superhydrophobic and super-slippery coating to prevent the bone debris adhesion. Initially, a superhydrophobic and super-slippery coating was successfully designed and fabricated with mixture of ODA-GO, PDMS, KH-550, and epoxy resin E44. The coating's surface morphology, chemical composition, and durability were comprehensively characterized. Subsequently, the coating was applied to diamond spherical grinding wheels for bone grinding experiments. The results demonstrate that a coating with exposed ODA-GO forms a rough structure with optimal component parameters, achieving a contact angle of 158° and a sliding angle of 4.2°. Furthermore, the superhydrophobic and super-slippery coating exhibits exceptional wear and slipperiness resistance even after 100 cycles, maintaining a contact angle of 135° and a sliding angle of 8.5°. The use of this novel spherical wheel significantly mitigates bone debris adhesion. This study not only provides valuable insights into the mechanisms of anti-adhesion but also introduces a promising technique for enhancing the performance of diamond spherical wheels.

Advancements and Challenges in Robot-Assisted Bone Processing in Neurosurgical Procedures.

Practical applications of nerve decompression using neurosurgical robots remain unexplored. Our ongoing research and development initiatives, utilizing industrial robots, aim to establish a secure and efficient neurosurgical robotic system. The principal objective of this study was to automate bone grinding, which is a pivotal component of neurosurgical procedures. To achieve this goal, we integrated an endoscope system into a manipulator and conducted precision bone machining using a neurosurgical drill, recording the grinding resistance values across 3 axes. Our study encompassed 2 core tasks: linear grinding, such as laminectomy, and cylindrical grinding, such as foraminotomy, with each task yielding unique measurement data. In linear grinding, we observed a proportional increase in grinding resistance values in the machining direction with acceleration. This observation suggests that 3-axis resistance measurements are a valuable tool for gauging and predicting deep cortical penetration. However, problems occurred in cylindrical grinding, and a significant error of 10% was detected. The analysis revealed that multiple factors, including the tool tip efficiency, machining speed, teaching methods, and deflection in the robot arm and jig joints, contributed to this error. We successfully measured the resistance exerted on the tool tip during bone machining with a robotic arm across 3 axes. The resistance ranged from 3 to 8 Nm, with the measurement conducted at a processing speed approximately twice that of manual surgery performed by a surgeon. During the simulation of foraminotomy under endoscopic grinding conditions, we encountered a -10% error margin.

Microanatomical Investigation of the Subtemporal Transtentorial Approach

To study the microanatomic structure of the subtemporal transtentorial approach to the lateral side of the brainstem, and to provide anatomical information that will assist clinicians to perform surgeries on the lateral, circumferential, and petroclival regions of the brainstem. Anatomical investigations were conducted on 8 cadaveric head specimens (16 sides) using the infratemporal transtentorial approach. The heads were tilted to one side, with the zygomatic arch at its highest point. Then, a horseshoe incision was made above the auricle. The incision extended from the midpoint of the zygomatic arch to one third of the mesolateral length of the transverse sinus, with the flap turned towards the temporal part. After removing the bone, the arachnoid and the soft meninges were carefully stripped under the microscope. The exposure range of the surgical approach was observed and the positional relationships of relevant nerves and blood vessels in the approach were clarified. Important structures were photographed and the relevant parameters were measured. The upper edge of the zygomatic arch root could be used to accurately locate the base of the middle cranial fossa. The average distances of the star point to the apex of mastoid, the star point to the superior ridge of external auditory canal, the anterior angle of parietomastoid suture to the superior ridge of external auditory canal, and the anterior angle of parietomastoid suture to the star point of the 10 adult skull specimens were 47.23 mm, 45.27 mm, 26.16 mm, and 23.08 mm, respectively. The subtemporal approach could fully expose the area from as high as the posterior clinoid process to as low as the petrous ridge and the arcuate protuberance after cutting through the cerebellar tentorium. The approach makes it possible to handle lesions on the ventral or lateral sides of the middle clivus, the cistern ambiens, the midbrain, midbrain, and pons. In addition, the approach can significantly expand the exposure area of the upper part of the tentorium cerebelli through cheekbone excision and expand the exposure range of the lower part of the tentorium cerebelli through rock bone grinding technology. The total length of the trochlear nerve, distance of the trochlear nerve to the tentorial edge of cerebellum, length of its shape in the tentorial mezzanine, and its lower part of entering into the tentorium cerebelli to the petrosal ridge were (16.95±4.74) mm, (1.27±0.73) mm, (5.72±1.37) mm, and (4.51±0.39) mm, respectively. The cerebellar tentorium could be safely opened through the posterior clinoid process or arcuate protrusion for localization. The oculomotor nerve could serve as an anatomical landmark to locate the posterior cerebral artery and superior cerebellar artery. Through microanatomic investigation, the exposure range and intraoperative difficulties of the infratemporal transtentorial approach can be clarified, which facilitates clinicians to accurately and safely plan surgical methods and reduce surgical complications.

Medical Imaging and Analysis of Thermal Necrosis During Bone Grinding: Implementation of Non-dominated Sorting Genetic Algorithm (NSGA-III) in Healthcare.

Medical imaging plays a key role in neurosurgery; thereby, imaging and analysis of the soft and hard tissues during bone grinding is of paramount importance for neurosurgeons. Bone grinding, a minimally invasive operation in the field of neurosurgery amid osteotomy, has been used during brain cancer surgery. With increasing attention to neural tissue damage in machining operations, imaging of these neural tissues becomes vital and reducing temperature is imperative. In the present study, a novel attempt has been made to perform the imaging of bone tissues during the bone grinding procedure and further investigate the relationship between rotational speed, feed rate, depth of cut with cutting forces, and temperature. The role of cutting forces and temperature has been addressed as per the requirements of neurosurgeons. Firstly, a three-factor, three-level design was constructed with a full factorial design. Regression models were employed to construct the models between input parameters and response characteristics. Medical imaging techniques were used to perform a thorough analysis of thermal necrosis and damage to the bone. Subsequently, the non-dominated sorting genetic algorithm (NSGA-III) was used to optimize the parameters for reduction in the cutting forces and temperature during bone grinding while reducing neural tissue damage. The results revealed that the maximum value of tangential force was 21.32 N, thrust force was 9.25 N, grinding force ratio was 0.453, torque was 4.55 N-mm, and temperature was 59.3°C. It has been observed that maximum temperature was generated at a rotational speed of 55000 rpm, feed rate of 60 mm/min, and depth of cut of 1.0 mm. Histopathological imaging analysis revealed the presence of viable lacunas, empty lacunas, haversian canals, and osteocytes in the bone samples. Furthermore, the elemental composition of the bone highlights the presence of carbon (c) 59.49%, oxygen (O) 35.82%, sodium (Na) 0.11%, phosphorous 1.50%, sulphur 0.33%, chlorine 0.98%, and calcium 1.77%. The study revealed that compared to the initial scenario, NSGA-III can produce better results without compromising the trial results. According to a statistical study, the rise in temperature during bone grinding was significantly influenced by rotating speed. The density of osteocytes in the lacunas was higher at lower temperatures. Furthermore, the results of surface electron microscopy and energy dispersive spectroscopy revealed the presence of bone over the surface of the grinding burr, which resulted in the loading of the grinding burr. The results of the present investigation will be beneficial for researchers and clinical practitioners worldwide.

Tactile Perception-Based Depth and Angle Control During Robot-Assisted Bent Bone Grinding

During bent bone grinding, the robot often needs to adjust its grinding depth and angle in real-time to ensure surgical quality. Optical- or vision-based navigation methods are no longer applicable due to the interference caused by splashing cooling water in the operating field. Inspired by orthopedic surgeons, this manuscript presents a tactile perception-based method to solve this problem. The effect of grinding parameters on the cutter's current and vibration is analyzed, and current and vibration signals are further processed to predict depth and angle. Depth and angle estimation models were calibrated on homogeneous artificial bone. Grinding control experiments were carried out on femur models, and the statistical mean and standard deviation results of the measured depth show that the accuracy of depth control can be further improved by adding angle estimation and proper adjustment when depth is indirectly estimated based on sensing signals. The proposed approach relies solely on the estimation of the relative position and posture between the tool and the bone surface and is expected to improve the safety of automatic grinding with orthopedic robots.

Multi-objective optimization of cortical bone grinding parameters based on particle swarm optimization.

Grinding is a fundamental operation in craniotomy. Suitable grinding parameters will not only reduce force damage, but also ensure grinding efficiency. In this study, the regression equations of material removal rate and grinding force were obtained based on the theory of cortical bone grinding and full factorial test results, a multi-objective optimization based on the particle swarm algorithm was proposed for optimizing the grinding parameters: spindle speed, feed speed, and grinding depth in the grinding process. Two conflicting objectives, minimum grinding force and maximum material removal rate, were optimized simultaneously. The results revealed that the optimal grinding parameter combination and optimization results were as follows: spindle speed of 5000 rpm, feed rate of 60 mm/min, grinding depth of 0.6 mm, grinding force of 15.1 N, and material removal rate of 113.8 mm3/min. The parameter optimization result can provide theoretical guidance for selecting cortical bone grinding parameters in actual craniotomy.

Material Removal Mechanism and Force Modeling in Ultrasonic Vibration-Assisted Micro-Grinding Biological Bone

Micro-grinding with a spherical grinding head has been deemed an indispensable method in high-risk surgeries, such as neurosurgery and spine surgery, where bone grinding has long been plagued by the technical bottleneck of mechanical stress-induced crack damage. In response to this challenge, the ultrasound-assisted biological bone micro-grinding novel process with a spherical grinding head has been proposed by researchers. Force modeling is a prerequisite for process parameter determination in orthopedic surgery, and the difficulty in establishing and accurately predicting bone micro-grinding force prediction models is due to the geometric distribution of abrasive grains and the dynamic changes in geometry and kinematics during the cutting process. In addressing these critical needs and technical problems, the shape and protrusion heights of the wear particle of the spherical grinding head were first studied, and the gradual rule of the contact arc length under the action of high-speed rotating ultrasonic vibration was proposed. Second, the mathematical model of the maximum thickness of undeformed chips under ultrasonic vibration of the spherical grinding head was established. Results showed that ultrasonic vibration can reduce the maximum thickness of undeformed chips and increase the range of ductile and bone meal removals, revealing the mechanism of reducing grinding force. Further, the dynamic grinding behavior of different layers of abrasive particles under different instantaneous interaction states was studied. Finally, a prediction model of micro-grinding force was established in accordance with the relationship between grinding force and cutting depth, revealing the mechanism of micro-grinding force transfer under ultrasonic vibration. The theoretical model’s average deviations are 10.37% in x-axis direction, 6.85% in y-axis direction, and 7.81% in z-axis direction compared with the experimental results. This study provides theoretical guidance and technical support for clinical bone micro-grinding.

A Protocol for Large-Scale Isolation of Rat Primary Osteoblasts Suitable for Exosome Extraction

Objective: This study aims to introduce an optimized method for the large-scale isolation of rat primary osteoblasts, suitable for exosome extraction. Methods: An advancement on the traditional secondary enzyme digestion method, manual bone grinding to clean connective tissue and ophthalmic cutting into fragments have been replaced with oscillating vortex rinsing and a 14 cm straight head shear in a centrifuge tube to cut bone fragments, significantly reducing the experimental time. The experiment was conducted on forty suckling rats. The experimental time of both the optimized and traditional methods were compared. The osteoblasts obtained through the optimized method were observed morphologically, identified by Alkaline phosphatase and alizarin red staining, and their proliferation activity was detected using the EdU method. Sufficient cell supernatant was collected to extract osteoblast-derived exosomes, identified by employing transmission electron microscopy, nanoparticle tracking analysis, and Western blot. Result: The total experimental time of the improved method (5.5±0.17 hours) was significantly shorter than the traditional method (7.25±0.23 hours) with a notable statistical difference (P <0.001); the osteoblasts obtained by the improved method displayed good growth status. On the seventh day, the cells matured and exhibited positive ALP staining. By the 21st day, mineralized nodules were formed, and alizarin red staining was positive. The EdU results showed that osteoblasts demonstrated healthy growth at both 24 and 48 hours, with a proliferation rate of (96.2%±1.3%) at 48 hours, slightly higher than that of (94.6%±2.8%) at 24 hours, with no significant statistical difference (P >0.05); Western blot showed positive results for CD9, CD63, and TSG101, and negative results for Calnexin. Conclusion: The optimized primary osteoblast isolation method can significantly improve experimental efficiency and is suitable for extracting osteoblast-derived exosomes.

Influence of Cooling and Lubrication Parameters on Robot Bone Grinding Temperature and Prediction Modeling

In the process of robot bone grinding, a large amount of heat is generated, which will cause mechanical and thermal damage to bone tissues and nerves. It is necessary to study the influence of cooling and lubrication parameters on the robot bone grinding temperature and establish the prediction models among them. The FE model of single abrasive bone grinding was established to explore the influence of cooling and lubrication parameters on the bone grinding temperature. Response surface design of experiment was carried out to obtain the simulation results, and Design-Expert was used to establish a multiple regression prediction models of grinding temperature under the condition of different cooling and lubrication. Through the variance and response surface comparative analysis of the prediction model, the influence rules of the bone grinding parameters and the cooling and lubrication parameters on the bone grinding temperature was obtained. A robot bone grinding experiment was performed to prove the accuracy of FE simulation and prediction model. The research results show that the relationship between grinding temperature and cooling lubrication parameters obtained by FE simulation, RSM prediction and experiment verification is consistent, and the simulation model and prediction model of cooling and lubrication parameters are proven to be correct and effective. The influence rules and prediction effects obtained in this study will provide a reasonable scheme for doctors to implement robot bone grinding with high efficiency and low damage, and establish the theoretical basis for the effective control of robot bone grinding force thermal damage.

Investigation of Infrared Thermography of Cortical Bone Grinding in Neurosurgery

Investigation of Infrared Thermography of Cortical Bone Grinding in Neurosurgery

Was it ground? A closer look at various prehistoric bone grinding techniques – An experimental and traceological study

This article presents the results of an experimental program, and traceological analyses of bone tools that were ground using various stone materials. Using multifaceted characterisation and classification of traces, we show that distinctive micro-wear patterns (e.g., striations, polish) are associated with different grinding techniques and corresponding stone materials. At the same time, we underline that it is not possible to distinguish between the different stone materials used during the grinding process. The results of our study highlight the potential for microscopic wear analysis in determining the origin of micro-wear traces on archaeological bone tools.

Bone grinding using coarse-grained diamond wheels to suppress thermal damage

Bones, which are hard tissues in the human body, are frequently removed during spine, joint, and brain surgeries. Diamond grinding wheels are widely used for the careful removal of bones during surgeries such as an endoscopic surgery. However, the wheels generate a considerable amount of heat, causing thermal damage, such as thermal bone necrosis and thermal injury to adjacent tissues. Considerable research has been conducted to suppress this heat generation using #120–#200 (grit size) wheels; notably, #30–#120 wheels are often used in actual surgeries to reduce the operating time. In this study, the bone grinding characteristics associated with a temperature increase were studied when using a coarse-grained wheel, i.e., a #30 wheel. Results showed that the temperature increased owing to the large grain size of the wheel. Furthermore, a decrease in the rotation speed of the wheel effectively suppressed the temperature increase. Consequently, an increase in the grain depth of cut and a decrease in the generated frictional heat between bone and grains effectively suppressed the temperature increase.

The role of operating variables in improving the performance of skull base grinding.

Control of the thermal and physical damage during skull base grinding is of great importance. We assess the effects of bur material (3 materials), angle of the bur (10 angles), bur diameter (10 diameters), gas coolant (4 coolants), and grinding time (10 times) to evaluate the role of operating variables in thermal and physical damage during skull bone grinding. After validation of finite element analysis (FEA) results with experimental data, the temperature in the grinding site and axial force are calculated using FEA. The use of a diamond bur leads to at least 24.48 and 12.9% reduction in thermal and physical damage, respectively. A change in angle of the bur from 0º to 90º leads to a 19.76-31.62 times increment in axial force. An increase in bur diameter from 1 to 5.5mm led to 10.78-14.36% and 23.43-43.90% increase in maximum temperature and axial force, respectively. However, a bur diameter between 2.5 and 4mm could provide enough grinding force with less thermal damage. Skull base grinding with dry (D) and normal saline (NS) coolants was always accompanied with thermal damage. The results of maximum and duration of temperature, axial force, and surface defect evaluation show CO2 coolants (especially internal CO2 coolant) are the best options to decrease thermal damage. The equations of temperature and axial force were estimated by regression analysis. This may be used as a guideline for neurosurgeons to control damage during skull base grinding and can also be helpful for the programming of robot-assisted skull grinding during surgery.

Cortical bone grinding mechanism modeling and experimental studyfor damage minimization in craniotomy.

Craniotomy, as a part of neurosurgery, implies a safe opening of the skull with mechanical equipment. Grinding is a traditional machining method that can accurately and efficiently remove bone tissue. Aiming at low-damage and high-efficiency bone grinding, this study analyzed the kinematic law of a single abrasive grain during the grinding process. The theoretical model of grinding force was established based on the calculation of specific energy and friction force. The grinding test platform was set up, and the full factorial experimental design was performed to link the grinding force evolution with different processing parameters. The experimental results obtained on porcine femurs validated the model predictions where the grinding force grew with feed speed and grinding depth; it exhibited a decreasing trend with rotation speed, followed by increasing one.

Circular Ribbon Antenna Array Design For Imaging Application

Our goal is to develop THz module on chip to visualize bone grinding atthe early stage so that arthritis can be visualized and treated early. A criticalcomponent of such module is antenna. A compact 4 by 4 beamformingantenna array for biomedical application is presented in this paper. Weare proposing a novel antenna which is in the form of a circular ribbonshape with a gold patch. Gold material for the patch is used to enhance itsconductivity and to cut down backward radiation. Differential port pin usedto increase the bandwidth. Au-posts are finally used for output connection.The proposed antenna operates over the frequency band from 201 GHz tomore than 228 GHz. Directivity and gain of the proposed antenna are 13dB and 7 dB respectively. This makes it applicable for imaging systemsbecause of the frequency band for biomedical imaging. Index Terms—Beamforming antenna, antenna array, Advanced design system (ADS),Biomedical imaging.

Non-Fourier bioheat model for bone grinding with application to skull base neurosurgery.

Bone grinding is used to remove the skull bone and access tumors through the nasal passage during cranial base neurosurgery. The generated heat of the spherical diamond tool propagates and could damage the nerves or coagulate the arteries blood. Little is known about the non-Fourier behavior of heat propagation during bone grinding. Therefore, this study develops an analytical model of the hyperbolic Pennes bioheat transfer equation (HPBTE) to calculate the three-dimensional temperature and necrosis in the grinding region. In vitro experimental investigations were carried out, and the contact zone temperature was measured using an infrared thermography system to validate the proposed thermal model. The results demonstrate that the HPBTE provides more reliable temperature evaluation and thermal damage than Fourier or parabolic heat transfer equation (PHTE). Due to the low thermal diffusivity of the bone, the lower grinding feed rate leads to higher temperature amplitude and a smaller radius of the affected zone in the surface and depth of the bone. Also, the intensity of bone necrosis decreases with the increase of the feed rate, and the shape of the damage zone becomes stretched. This analytical model can assess the potential risk of the surgery before clinical trials. Also, it could be used for comparing the different operating conditions to minimize bone necrosis and improve the control process in neurosurgeries.

EXPERIMENTAL INVESTIGATION AND PARAMETRIC OPTIMIZATION OF NEUROSURGICAL BONE GRINDING UNDER BIO-MIMIC ENVIRONMENT

Bone grinding is a craniotomy procedure which is used to remove a bone flap from the skull to expose and create an access for the dissection of tumors. In this study, a computer-controlled neurosurgical bone grinding has been used to explore the effect of various neurosurgical bone grinding parameters, such as cutting forces, torque, grinding force ratio, and temperature generated during bone grinding have been investigated. Bone samples after grinding have been assessed for morphological analysis. Based on the outcomes, a multi-attribute decision-making methodology based on grey relational analysis has been adopted. Regression models have been developed and then validated to ensure the adequacy of the developed models. Subsequently, a comparative analysis of experimental and predicted results have been presented. It is revealed that grinding forces and torque decreased with the escalation of rotational speed from 35,000 revolutions per minute (rpm) to 55,000[Formula: see text]rpm. The optimum combination of process parameters found as rotational speed of 55,000[Formula: see text]rpm, feed rate of 20[Formula: see text]mm/min, and depth of cut of 0.50[Formula: see text]mm.

Experimental analysis of wear and multi-shape burr loading during neurosurgical bone grinding

Amid bone grinding, a part of the hard tissue (i.e. bone) is usually removed to gain clearer operative excess to the tumours present beneath the bone. The tool wear and tool loading influence the thermal as well as mechanical conditions of surgery. The rise in temperature during osteotomy may cause severe consequence like thermogenesis and damage to optic nerves, cervical, and sciatic nerves. Therefore, the present study has been carried out to investigate the burr wear with different shaped grinding burrs. The burr wear is characterized in terms of burr loading, dislodging and fracture in abrasives. The burr loading is further quantified on the amount of bone adhered over the surface of the burr. The results of surface characterization revealed that minimum wear occurred in case of convex shape burr whereas cylindrical burr caused the highest wear in terms of abrasive fragmentation, dislodging, and wear flats. The minimum percentage of weight reduction observed with the convex burr i.e., 1.68% including 0.4196 g weight of dislodged abrasive (Wab) and corresponding burr loading is observed as 0.1464 g. The maximum burr loading was seen in the case of the spherical burr (Wb) i.e. 0.5907 g.

Finite element simulation and integration of CEM43 °C and Arrhenius Models for ultrasonic-assisted skull bone grinding: A thermal dose model

The aim of the study was to develop a novel automated setup for bone grinding to limit the temperature to below 43 °C. The feasibility of using ultrasonic actuation during bone osteotomy was explored with different machining variables, such as rotational speed, feed rate and ultrasonic frequency, in terms of the criterion variable (i.e., temperature). A thermal dose model based on the CEM43 °C and the Arrhenius model was developed for the prediction of tissue damage during bone grinding. CEM43 °C is a normalizing method to convert the time-temperature relationship into an equivalent number of minutes at 43 °C. For every degree rise in temperature above 43 °C, the cell viability significantly increased. The temperature generated during bone grinding was measured with an infrared thermography technique. The increase in temperature above threshold levels of 43 °C and 47 °C may harm the bone tissues and cause thermogenesis and osteonecrosis, respectively. A finite-element simulation was conducted to visualise the spatial and temporal distribution of temperature on the bone surface after bone grinding. Furthermore, simulation results were used to measure the depth of thermogenesis and osteonecrosis at the grinding site. Evaluation of the optimised set of bone grinding process parameters was supported with analysis of variance at the 95% confidence level.