Skull Prosthesis Research Articles

Process capabilities and future scope of Incremental Sheet Forming (ISF)

The Incremental Sheet Forming process (ISF) is a versatile forming process that is widely used in various advanced manufacturing areas such as for making the skull prosthesis, automobile, electronics and aerospace components etc. In the present paper methods, chronology of ISF and its classifications have been discussed, considering the effect of various factors such as stress triaxiality, bending stress and fracture strain. In addition, the effect of process parameters and its interaction on forming force, formability, surface roughness, spring back, failure and fracture etc. are also studied. It is observed that the study of two degree of freedom manipulator of robot with ISF and its effect on the formability surface roughness are highly recommended. Also, a future scope of ISF is also included in this investigation.

Solving the Prosthesis Modeling for Skull Repair Through Differential Evolution Algorithm

Cranial defects can result in compromised physical protection for the brain and a how risky the brain infection is. Cranioplasty is commonly performed by doing the bone graft onto the deficient area or areas and/or using the metal to support them for restoring the cranial cavity integrity and maintain the physiological intracranial pressure stability. Nowadays, the suitable shape of skull prosthesis can be created and operated precisely and efficiently during cranioplasty process, because the technological development of additive manufacturing or 3D printing. Additive manufacturing has great potential in regard to addressing irregular cranial defects because it can be used to create customized shapes rapidly. However, an unsuitable cranial prosthesis that made from synthetic polymer or a metal implantation will cause a serious infections, and required additional surgery. This paper proposes a geometric model of skull defects by using the superellipse and Differential Evolution (DE). The defects of skill bones in each tomography slice can be modeled by superellipse. The DE optimizes the parameters of superellipse to emulate and compensate the suitable curvature. In a rapid 2D image process and 3D cranial model construction system, the clinical surgeons’ ability is determining, processing, and implanting a customized prosthesis for patients just in a short time in surgery and with maximum surgical quality, especially in emergency cases.

Development of an Automatic Robotic Procedure for Machining of Skull Prosthesis

The project presented in this paper develops within the field of automation in the medical-surgical sector. It aims at automating the process for the realization of prosthetic devices for the skull in cranioplasty, following a craniotomy intervention for brain tumor removal. The paper puts emphasis on the possibility to create the prosthetic device in run-time during the surgery, in order to ease the work that surgeons have to do during the operation. Generally, a skull prosthesis is realized before the day of the intervention, based on the plan of the medical operation, on the results of computed tomography, and through image processing software. However, after the surgery is performed, a non-negligible geometrical uncertainty can be found between the part of the skull actually removed and the cut planned during the preliminary analysis, so that the realized prosthesis (or even the skull, at worse) may need to be retouched. This paper demonstrates the possibility to introduce a fully automated process in a hospital environment, to manufacture in runtime the prosthetic operculum, relying on the actual geometry of the incision of the skull detected during the intervention. By processing a 3D scan of the skull after the craniectomy, a digital model of the prosthesis can be created and then used as an input to generate the code to be run by a robotic system in charge of the workpiece machining. Focusing on this second step, i.e., the manufacturing process, the work describes the way the dimensions of the raw material block are automatically selected, and the way robot trajectories for milling operation are automatically generated. Experimental validation demonstrates the possibility to complete the prosthesis within the surgery time, thus increasing the accuracy of the produced prosthesis and consequently reducing the time needed to complete the operation.

Effect of Ambient Temperature Changes on Blood Flow in Anterior Cerebral Artery of Patients with Skull Prosthesis

In many cases, an injury to the head leads to the replacement of a part of the skull with materials such as titanium and polyether ether ketone. Three-dimensional heads model of 15 healthy individuals and 13 patients were prepared. The models were simulated using thermal fluid structure interaction analysis to evaluate the effects of cold (5°C) and hot (55°C) temperatures of the skull on the conditions of blood flow in the anterior cerebral artery. The results showed negligible changes (<3%) in wall shear stress (WSS) vessel and von Mises stress between the healthy individuals and patients both at 25°C and 55°C. However, at 5°C, the values of these 2 parameters in the patients were 2.1 and 2.5 times those in healthy individuals, respectively. The value of WSS in healthy individuals and the patients in cold temperature was 1.2 and 2.9 times those at normal temperature. The corresponding values for von Mises stress were 1.1 and 2.2, respectively. Accordingly, the stress changes between cold and hot ambient temperatures were found to be negligible in all samples. The changes in stress were significant only for the patients when exposed to cold ambient temperature, and only in patients, exposure to a cold ambient temperature significantly increased the risks of vascular aneurysm and damage to the brain tissue surrounding the blood vessels. These risks were found to be negligible for both healthy individuals and patients when exposed to hot ambient temperature and also for healthy individuals exposed to cold ambient temperature.

Hot incremental forming of titanium human skull prosthesis by using cartridge heaters: a reverse engineering approach

The single-point incremental forming process is an emerging process, which presents an alternative to the conventional sheet metal-forming processes like stamping and drawing. It is known to be perfectly suited for prototyping and small series. The incremental forming process offers the possibility of manufacturing medical prosthesis or implants specific to each patient, which are more comfortable and guarantee better performance. A reverse engineering approach associated with single-point incremental forming process in order to produce a titanium prosthesis of human skull is developed. It allows guaranteeing the high degree of customization required. In this paper, several novel warm forming experimental setup equipped with instruments to measure efforts and temperature monitoring is proposed. This new warm setup is feasible and makes it easy to monitor force and temperature sheet at forming; it gives it the ability to be exploited in the industry of manufacturing titanium alloy medical shapes. The real geometry of a skull prosthesis is re-constructed from a laser scanning technique, and specific treatments are performed until a CAD model is obtained. From it, the forming punch trajectories have been defined, and skull prostheses are manufactured using the technology of single-point incremental forming in titanium material at different temperatures.

The Development of Skull Prosthesis Through Active Contour Model.

Skull defects result in brain infection and inadequate brain protection and pose a general danger to patient health. To avoid these situations and prevent re-injury, a prosthesis must be constructed and grafted onto the deficient region. With the development of rapid customization through additive manufacturing and 3D printing technology, skull prostheses can be fabricated accurately and efficiently prior to cranioplasty. However, an unfitted skull prosthesis made with a metal implant can cause repeated infection, potentially necessitating secondary surgery. This paper presents a method of creating suitably geometric graphics of skull defects to be applied in skull repair through active contour models. These models can be adjusted in each computed tomography slice according to the graphic features, and the curves representing the skull defect can be modeled. The generated graphics can adequately mimic the natural curvature of the complete skull. This method will enable clinical surgeons to rapidly implant customized prostheses, which is of particular importance in emergency surgery. The findings of this research can help surgeons provide patients with skull defects with treatment of the highest quality.

Skull Repair Using Active Contour Models

Skull defects will result in high risk of brain infection and low brain protection. In order to avoid risks and re-injury, we need to reconstruct the defect by grafting bone onto the deficient region. With rapid customization manufacturing of additive manufacturing (AM) and 3D printing (3DP) technology, the fitted shape of a skull prosthesis can be fabricated accurately and efficiently during cranioplasty surgery. However, an unfitted skull prosthesis made of artificial polymer or a metal implant can cause repeated infection, which may need an additional surgery. This paper presents a method to create suitable geometric graphics of skull defects to be applied in skull repair by using active contour models. The active contour models can be adjusted in every tomography slice, and the curves that represent the defect in the skull bone can be modeled. The generated graphics can adequately mimic and compensate for a fitted curvature. Clinical surgeons will be able to define, process, and implant a customized prosthesis to patients very quickly in surgery with this research. Especially, patients who have urgently skull defect problem can be solved and obtained maximum surgical quality.

Implant-retained skull prosthesis to cover a large defect of the hairy skull resulting from treatment of a basal cell carcinoma: A clinical report

Skin carcinoma, particularly basal cell carcinoma, and its treatment can result in large defects of the hairy skull. A 53-year-old man is described who was surgically treated for a large basal cell carcinoma invading the skin and underlying tissue at the top of the hairy skull. Treatment consisted of resecting the tumor and external part of the skull bone. To protect the brain and to cover the defect of the hairy skull, an acrylic resin skull prosthesis with hair was designed to mask the defect. The skull prosthesis was retained on 8 extraoral implants placed at the margins of the defect in the skull bone. The patient was satisfied with the treatment outcome.

Fabrication of hybrid Ti/PMMA materials for skull prosthesis reconstruction

Fabrication of hybrid Ti/PMMA materials for skull prosthesis reconstruction

Forming Approaches Comparison for High Customised Skull Manufacturing

The production of prostheses is still not completely optimized, especially for those districts where both functional and aesthetic requirements have to be combined with the urgency of intervention. The prostheses manufactured by machining using CAD/CAM techniques represent the conventional way to obtain a “custom-made” part. However, the above-mentioned solutions are penalized by the too long manufacturing time. This limit can be overcome by using an innovative metal-forming process, i.e. the Incremental Sheet Forming (ISF), which also allows to obtain complex patient-specific geometries even if characterized by a lower precision compared to the conventional process. In this paper, alternative approaches to manufacture a skull prosthesis (i.e. conventional milling and ISF) are compared from technological and economical points of view.

Design Method of the Skull Restoration Based on User-Centered

The user needs during the skull restoration design were classified into functional requirement, physiological requirement and emotional requirement. The diagram of user-centered design in the skull prosthesis was drawn. The skull restoration formulas of titanium plate strength, compressive stiffness, bending stiffness and skull prosthesis manufacturing error were established. The hierarchy of the emotional design in the skull prosthesis was drawn. Through the analysis and research on the functional requirement, physiological requirement and emotional requirement, the user-centered design idea was shown, which had an important guiding significance for the development of the skull prosthesis design. Keywords: User-centered design, Skull restoration, Functional requirement, Physiological requirement, Emotional requirement

Parameter Mapping Method of the Skull Restoration Based on User Demand

Parameter mapping method was put forward, through the skull restoration design and manufacture based on user demand. Considering the cost, time, resource utilization rate and feasibility, the conversion of the skull prosthesis design parameters and mapping between the design parameters of user needs were realized. The effectiveness of the method was verified through the example analysis, which provided a basis for the design and scheme of the skull restoration.

A PSO Application in Skull Prosthesis Modelling by Superellipse

This paper presents a method to create the geometric model of skull defects to be applied in anatomic prosthesis modelling. The approach is to generate an image that represents the missing information in the skull when bone`s defect is non-symmetric. We are proposing the use of superellipse concept to recover the parameters that represents the geometric shape of a skull bone curvature in tomography. If the superellipse is properly adjusted in each computed tomography slice, the arcs that represent the piece of missing bone can be modelled in 3D. The problem is that many similar ellipses can be created, and the best solution must be found. This research applies the Particle Swarm Optimization (PSO) algorithm in order to find the best solution for each tomographic slice. Once the solution found for each slice, the whole 3D missing information can be virtually rebuilt as an adjusted prosthesis model image.

Does Early Decompressive Craniectomy Improve Outcome? Experience from an Active UK Recruiter Centre.

Introduction. The results of the recent DECRA study suggest that although craniectomy decreases ICP and ICU length of stay, it is also associated with worst outcomes. Our experience, illustrated by these two striking cases, supports that early decompressive craniectomy may significantly improve the outcome in selected patients. Case Reports. The first patient, a 20-year-old man who suffered severe brain contusion and subarachnoid haemorrhage after a fall downstairs, with refractory ICP of 35 mmHg, despite maximal medical therapy, eventually underwent decompressive craniectomy. After 18 days in intensive care, he was discharged for rehabilitation. The second patient, a 23-year-old man was found at the scene of a road accident with a GCS of 3 and fixed, dilated pupils who underwent extensive unilateral decompressive craniectomy for refractory intracranial hypertension. After three weeks of cooling, paralysis, and neuroprotection, he eventually left ICU for rehabilitation. Outcomes. Four months after leaving ICU, the first patient abseiled 40 m down the main building of St. Mary's Hospital to raise money for the Trauma Unit. He has returned to part-time work. The second patient, was decannulated less than a month later and made a full cognitive recovery. A year later, with a titanium skull prosthesis, he is back to part-time work and to playing football. Conclusions. Despite the conclusions of the DECRA study, our experience of the use of early decompressive craniectomy has been associated with outstanding outcomes. We are currently actively recruiting patients into the RESCUEicp trial and have high hopes that it will clarify the role of the decompressive craniectomy in traumatic brain injury and whether it effectively improves outcomes.

Electroconvulsive Therapy in Patients With Skull Defects or Metallic Implants

Head injury is often associated with psychiatric morbidity. While it is well understood that the loss of critical areas of the brain may play a role in cognitive dysfunction and change in personality, head injury can also have profound effects on mood and cognition. The role of medications in the treatment of mood disorders associated with brain injury is well documented, and there is also evidence favoring the use of electroconvulsive therapy (ECT) in this context. However, data are limited on the use of ECT in patients with skull defects or metallic head implants. First, a review of the literature on use of ECT in patients with metallic head implants is provided. Electronic databases and online sites, including PubMed, Cochrane Library of Systematic Reviews, and UpToDate, were used to search for relevant articles and case reports on the use of ECT in patients with and without metallic implants in the head (1964 to 2009). The search terms electroconvulsive, electroconvulsive therapy, ECT, electroshock therapy, EST, head injury, brain injury, metallic plates, metallic implants, skull prosthesis, and depression were used interchangeably. The search produced 7 articles discussing exclusively the use of ECT in patients with a metallic skull plate. Second, the case of the successful and safe use of ECT in an individual with a previous history of brain trauma and metallic plate implantation is described. Most cases of head injury are managed by neurologists and rehabilitation consultants; the more severe cases of depression and other mood disorders tend to be referred for specialist psychiatric care. With greater degrees of deficit following head injury, management becomes more complicated. Our patient showed positive results with ECT, including improvement in depressive features and resolution of suicidal ideas/plans. ECT is an effective and safe alternative in patients with a history of brain trauma and metallic plate implantation who subsequently develop treatment-resistant depression and associated suicidal ideas or plans refractory to management with medications.

Research on the Digital Design and Manufacture Technology in the Manufacturing of Titanium Alloy Cranial Prosthesis

It is a new design and manufacturing method which forming medical image data processing technology and multi-point forming technology for titanium alloy cranial prosthesis digital design and manufacturing. First, the head of the CT data of patients according to medical image segmentation approach to the skull and scalp, brain image segmentation boundaries, using registration method to segment the skull CT image registration, and application of 3D visualization technology in patients with skull reconstruction of the mathematical model. Then on this basis, the use of thin-plate spline interpolation in accordance with the health side of the skull surface extension of the transition to be a mathematical model of the skull prosthesis. Finally, the mathematical model of the skull prosthesis passed to the multi-point forming CAD / CAM software system, so that multi-point forming the basic body to adjust the upper and lower press out the skull prosthesis forming surface, and processing the required titanium alloy cranial prosthesis. The technical solution of the skull repair system prepared in the presence of low precision machining, production costs are high, long cycle and so on, while improving the prosthesis fit and the precision of the edge defects.

A Digital Manufacture Technology for Skull Prosthesis Using Incremental Sheet Forming Method

In order to alleviate the suffering of the patients with skull defects, this paper presents a detailed analysis of incremental sheet forming (ISF) method to shape skull prosthesis of titanium alloy meshed plate. In the study, we emphasized the following points: First, we designed and made skull model based on computed tomography image, and extracted the skull defect data using reverse engineering technology, then we reconstructed the surface of the prosthesis and designed it’s three dimentional model, finally, we adjusted tool path repeatedly and then imported the tool path into incremental sheet forming system to shape skull prosthesis. This paper provides a fast and accurate prosthesis manufacture method of titanium alloy meshed plate, which can improve the level of the skull repair technique.

Post-traumatic cholesteatoma

Post-traumatic cholesteatoma often presents many years after the original injury. This case occurred 24 years after a head injury which represents the longest recorded interval. A further interesting feature was that the patient presented with an infected skull prosthesis that was inserted at the time of the original injury.