Application Of Rapid Prototyping Techniques Research Articles

Democratizing science with the aid of parametric design and additive manufacturing: Design and fabrication of a versatile and low-cost optical instrument for scattering measurement.

This paper focuses on the application of rapid prototyping techniques using additive manufacturing in combination with parametric design to create low-cost, yet accurate and reliable instruments. The methodology followed makes it possible to make instruments with a degree of customization until now available only to a narrow audience, helping democratize science. The proposal discusses a holistic design-for-manufacturing approach that comprises advanced modeling techniques, open-source design strategies, and an optimization algorithm using free parametric software for both professional and educational purposes. The design and fabrication of an instrument for scattering measurement is used as a case of study to present the previous concepts.

Rapid prototyping technology and its application in bone tissue engineering.

Bone defects arising from a variety of reasons cannot be treated effectively without bone tissue reconstruction. Autografts and allografts have been used in clinical application for some time, but they have disadvantages. With the inherent drawback in the precision and reproducibility of conventional scaffold fabrication techniques, the results of bone surgery may not be ideal. This is despite the introduction of bone tissue engineering which provides a powerful approach for bone repair. Rapid prototyping technologies have emerged as an alternative and have been widely used in bone tissue engineering, enhancing bone tissue regeneration in terms of mechanical strength, pore geometry, and bioactive factors, and overcoming some of the disadvantages of conventional technologies. This review focuses on the basic principles and characteristics of various fabrication technologies, such as stereolithography, selective laser sintering, and fused deposition modeling, and reviews the application of rapid prototyping techniques to scaffolds for bone tissue engineering. In the near future, the use of scaffolds for bone tissue engineering prepared by rapid prototyping technology might be an effective therapeutic strategy for bone defects.

Application of Rapid Prototyping Technique and Intraoperative Navigation System for the Repair and Reconstruction of Orbital Wall Fractures.

BackgroundRestoring the orbital cavity in large blow out fractures is a challenge for surgeons due to the anatomical complexity. This study evaluated the clinical outcomes and orbital volume after orbital wall fracture repair using a rapid prototyping (RP) technique and intraoperative navigation system.MethodsThis prospective study was conducted on the medical records and radiology records of 12 patients who had undergone a unilateral blow out fracture reconstruction using a RP technique and an intraoperative navigation system from November 2014 to March 2015. The surgical results were assessed by an ophthalmic examination and a comparison of the preoperative and postoperative orbital volume ratio (OVR) values.ResultsAll patients had a successful treatment outcome without complications. Volumetric analysis revealed a significant decrease in the mean OVR from 1.0952±0.0662 (ranging from 0.9917 to 1.2509) preoperatively to 0.9942±0.0427 (ranging from 0.9394 to 1.0680) postoperatively.ConclusionThe application of a RP technique for the repair of orbital wall fractures is a useful tool that may help improve the clinical outcomes by understanding the individual anatomy, determining the operability, and restoring the orbital cavity volume through optimal implant positioning along with an intraoperative navigation system.

Rapid prototyping model for the manufacturing by thermoforming of occlusal splints

Purpose – This paper aims to present an optimal prototyping technology for the manufacture of occlusal splints. Design/methodology/approach – To carry out this study, a comparative technique was used to analyze models obtained by different prototyping techniques. Subsequently, further tests were carried out with respect to the manufacturing of splints by means of thermoforming in a vacuum. This involved an analysis of the most important variables such as prototype material, geometric accuracy, surface finish and costs. Findings – It was found that there is a group of prototyping technologies that are suitable for the manufacture of the models used in the thermoforming of correction splints, the most appropriate technologies being based on ink jet printing (IJP-Objet), ultraviolet photo polymerization and fused deposition modelling due to the fact that they offer an optimal relationship between the cost and the quality of the model required for thermoforming. Practical implications – The application of rapid prototyping techniques in medicine makes the production of physical models from three-dimensional medical image processing and their subsequent use in different specialties possible. It also makes preoperative planning processes, the production of prostheses and the preparation of surgical templates possible, thereby offering a higher quality of diagnosis, safer surgery and cost and time savings compared to conventional manufacturing technologies. Originality/value – This paper suggests that there exists a group of prototyping technologies for the manufacture of splints that offer advantages over existing technologies. The results also suggest that, in many cases, the most expensive technology is not the most appropriate: there are other options that provide an optimal model in terms of the cost and the quality needed for thermoforming.

Accuracy and Safety Assessment of Pedicle Screw Placement Using the Rapid Prototyping Technique in Severe Congenital Scoliosis

The application of rapid prototyping (RP) technique for improving accuracy of pedicle screw placement in congenital scoliosis is described in this study. To compare the accuracy and safety of pedicle screw placement in congenital scoliosis using the RP technique versus the conventional fluoroscopy. Maldeveloped vertebral components in congenital scoliosis leads to prolonged operation time and higher rate of screw misplacement. RP technique can enhance preoperative and perioperative planning. No data are available on the accuracy of pedicle screw fixation using the RP technique. Sixty-two consecutive patients with hemivertebra had undergone posterior-only hemivertebra resection. Pedicle screws were implanted either by the conventional intraoperative fluoroscopy technique (C-arm group; n=28) or the RP technique (RP group; n=34). Accuracy of pedicle screw placement was compared by postoperative computed tomographic scan. Seventy of 677 inserted screws were found to be misplaced, showing an overall accuracy of 89.7% (90.8% in the thoracic spine and 87.4% in the lumbar spine). In the C-arm group, 86.1% (167 of 194) and 82.0% (82 of 100) of screws were accurately placed in the thoracic and lumbar spine, respectively. While in the RP group, the respective screw placement accuracies were 94.4% (238 of 252) and 91.6% (120 of 131). In the C-arm and the RP groups, 94.8% (279 of 294) and 97.9% (375 of 383) of the screws were within the safety zone, respectively. Compared with the fluoroscopy method, the RP-assisted technique showed a shorter operation time and higher scoliosis correction rate. No neurovascular-related complication was observed with this technique during the study. The application of RP technique in congenital scoliosis can reduce the operation time, the risk of screw misplacement and its consequent complications. The use of RP technique in congenital scoliosis is safe and efficacious.

Application of 3-D skull models and guide plates in the treatment of unilateral orbitozygomatic deformity after fracture

To discuss the application of 3-D skull models and guide plates in treatment of unilateral orbitozygomatic deformity after fracture. Each patient underwent CT scan and DICOM data was obtained preoperatively. Two 3-D resin skull models were produced by rapid prototyping technique. The first model was produced based on the patient's original data and the second was the reshaped model by mirroring the unaffected facial side to the traumatic side. The original model was used for measurement of the fracture displacement in three directions and model surgery. On the second model, one 2.0 mm miniplate (Synthes Inc) was bended along the orbital rim as the repositioning guide plate. During the operation, osteotomy and reduction of zygomatic and the periorbital fractures was guided by prepared repositioning guide plate, following by orbital wall reconstruction and bone grafting. From March 2007 to February 2009, 7 cases (6 males and 1 female) were treated successfully with no infection or graft extrusion. One week after operation, the patient received CT examination again. The shape and location of zygomatic bone and arch was good. Three cases were followed up for 3 months. Among them, facial symmetry was achieved in 2 cases. Cicatricial contracture and temporal soft tissue atrophy occurred in one case. Reliable therapeutic effect can be achieved by application of rapid prototyping technique and repositioning guide plate in the treatment of complicated posttraumatic orbitozygomatic deformity.

The Application of Rapid Prototyping Technique in Chin Augmentation

This article discusses the application of computer-aided design and rapid prototyping techniques in prosthetic chin augmentation for mild microgenia. Nine cases of mild microgenia underwent an electrobeam computer tomography scan. Then we performed three-dimensional reconstruction and operative design using computer software. According to the design, we determined the shape and size of the prostheses and made an individualized prosthesis for each chin augmentation with the rapid prototyping technique. With the application of computer-aided design and a rapid prototyping technique, we could determine the shape, size, and embedding location accurately. Prefabricating the individual prosthesis model is useful in improving the accuracy of treatment. In the nine cases of mild microgenia, three received a silicone implant, four received an ePTFE implant, and two received a Medpor implant. All patients were satisfied with the results. During follow-up at 6-12 months, all patients remained satisfied. The application of computer-aided design and rapid prototyping techniques can offer surgeons the ability to design an individualized ideal prosthesis for each patient.

Use of Rapid Prototyping in Prosthetic Auricular Restoration

Reconstructing auricular defects is a challenging task for facial reconstructive surgeons. Although autologous reconstruction is the first choice for reconstruction, there may be circumstances of inconvenience such as previously attempted surgery, radiotherapy, systemic conditions, or patient's wish. Auricular restorations with facial prosthesis have produced promising results, but there are still problems to be tackled for improved results. Rapid prototyping in the production of an auricular prosthesis uses the mirror image of contralateral ear and produces excellent forms, eliminating the subjective perception of the prosthodontist. Rapid prototyping also lowers the production costs by reducing the need for several sessions in the process of producing the prostheses. Between 2004 and 2007, 10 patients applied to our department with the absence of an ear on a single side. All patients were male, with an average age of 23.1 years. The etiology for the loss of the ear was mostly tumors, followed by congenital deformities and trauma, respectively. In this study, we present our application of rapid prototyping technique and report our case series of 10 patients, two of which are presented in detail.

Application of rapid prototyping technique in diagnosis and treatment of complicated pelvic fractures

目的 探讨快速成形(RP)技术在复杂骨盆骨折诊断治疗中的应用价值.方法 2003年10月～2004年5月收治6例严重骨盆骨折患者,经电子束CT(EBT)检查,将所得数据经过转化输入RP机,制作出骨盆骨折模型;根据模型诊断骨折类型,指导临床手术治疗.将本组5例手术患者的出血量、输血量及手术时间与常规手术的11例类似患者进行对比.结果 本组6例患者均成功制备出1∶1等大的RP模型,通过在模型上进行术前手术方案的制定,使手术操作更加简便和微创化.本组5例手术患者的平均出血量、输血量及手术时间分别为800 mL、600 mL及3.2 h,11例常规手术患者分别为1300 mL、1000 mL及4.5 h.结论 采用RP技术可获得与患者骨盆骨折真实情况完全相同的骨盆模型,有利于直观、准确地了解骨折伤情.可根据骨折模型选择手术方案及内固定方式,并可对内固定钢板进行预先塑形,有利于减少手术创伤、缩短手术时间、提高手术质量。

Fabricating auricular prostheses based on rapid prototyping and the FreeForm modelling system

In this paper, a novel method for reconstructing and fabricating a missing ear is presented based on rapid prototyping (RP) and the FreeForm modelling system. Using the method, the image of the normal ear is extracted, mirrored, and positioned onto the image of the deformed side of the face precisely, and the undersurface of the ear prosthesis can match the remnant tissue of deformed side perfectly without making a wax ear. In the clinic, six ear prostheses have been produced and applied successfully. The results suggest that high accuracy has been achieved in shape, size, and protrusion of the ear prostheses, which indicates that the application of RP techniques in conjunction with the FreeForm modelling system is a suitable approach for fabricating ear prosthesis.

The application of rapid prototyping techniques in cranial reconstruction and preoperative planning in neurosurgery.

The value of rapid prototype models of the skull in our craniofacial and neurosurgical practice was analyzed. Individual skull models of 52 patients were produced by means of rapid prototyping techniques and used in various procedures. Patients were divided into three groups as follows: group I (26 patients) requiring corrective cranioplasty 1) after resection of osseous tumors (15 patients) and 2) with congenital and posttraumatic craniofacial deformities (11 patients), group II (10 patients) requiring reconstructive cranioplasty, and group III (16 patients) requiring planning of difficult skull base approaches. The utility of the stereolithographic models was assessed using the Gillespie scoring system. The esthetic and clinical outcomes were assessed by means of the esthetic outcome score and the Glasgow Outcome Score, respectively. Simulation of osteotomies for advancement plasty and craniofacial reassembly in the model before surgery in group I reduced operating time and intraoperative errors. In group II, the usefulness of the models depended directly on the size and configuration of the cranial defect. The planning of approaches to uncommon and complex skull base tumors (group III) was significantly influenced by the stereolithographic models. The esthetic outcome was pleasing. The indications for the manufacture of individual three-dimensional models could be cases of craniofacial dysmorphism that require meticulous preoperative planning and skull base surgery with difficult anatomical and reconstructive problems. The stereolithographic models provide 1) better understanding of the anatomy, 2) presurgical simulation, 3) intraoperative accuracy in localization of lesions, 4) accurate fabrication of implants, and 5) improved education of trainees.

Development of a direct metal freeform fabrication technique using CO 2 laser welding and milling technology

Since the first introduction of rapid prototyping in 1986, several techniques have been developed and successfully commercialized in the market. However, most commercial systems currently use resins or waxes as the raw materials. Thus, the limited mechanical strength for functional testing is regarded as an obstacle towards broader application of rapid prototyping techniques. To overcome this problem, direct metal deposition methods are being investigated worldwide for rapid prototyping and even for rapid tooling applications. As a contribution to this development, a fundamental study on a process combination of wire welding technology using CO 2 laser radiation with milling was carried out and is reported in this paper. Laser welding enables accurate deposition of metals and the subsequent milling increases the surface quality and accuracy to machining standard. Compared to powder, the use of wire is of advantage in terms of a simple feeding mechanism as well as a higher deposition rate. The main focus of the experimental investigation is to find the basic process characteristics. For this purpose, basic parts were fabricated as a function of process parameters such as laser power, welding speed and bead distance. The microstructure, hardness and tensile strength are then examined as a function of these process parameters. In conclusion, the advantages and disadvantages of this process are discussed in comparison with other direct metal fabrication techniques.

Rapid Product Development in the USA, Europe and Japan

Reviews, for the USA, Europe and Japan, the current state of development and application of rapid prototyping techniques and their impact on time‐to‐market for new products. These techniques, which are still undergoing rapid development, have already had a dramatic effect on reducing the time‐to‐market for new products by between 60 per cent and per cent and on reducing the cost‐to‐market by between 40 per cent and 70 per cent. Concludes that although the US is ahead of the rest of the world in terms of depth of experience and range of techniques, Europe and Japan are catching up fast in terms of experience and applications. Gives guidelines for the managers of manufacturing companies on the importance of the techniques, the selection of the most appropriate system and how to obtain most of the techniques adopted.