Point-of-care manufacturing: a single university hospital's initial experience

Tablet-based Augmented reality and 3D printed templates in fully guided Microtia Reconstruction: a clinical workflow

BACKGROUND

Microtia is a congenital malformation of the auricle that affects approximately 4 of every 10,000 live newborns. Radiographic film paper is traditionally employed to bidimensionally trace the structures of the contralateral healthy ear in a quasi-artistic manner. Anatomical points provide linear and angular measurements. However, this technique proves time-consuming, subjectivity-rich, and greatly dependent on surgeon expertise. Hence, it's susceptible to shape errors and misplacement.

METHODS

We present an innovative clinical workflow that combines 3D printing and augmented reality (AR) to increase objectivity and reproducibility of these procedures. Specifically, we introduce patient-specific 3D cutting templates and remodeling molds to carve and construct the cartilaginous framework that will conform the new ear. Moreover, we developed an in-house AR application compatible with any commercial Android tablet. It precisely guides the positioning of the new ear during surgery, ensuring symmetrical alignment with the healthy one and avoiding time-consuming intraoperative linear or angular measurements. Our solution was evaluated in one case, first with controlled experiments in a simulation scenario and finally during surgery.

RESULTS

Overall, the ears placed in the simulation scenario had a mean absolute deviation of 2.2 ± 1.7 mm with respect to the reference plan. During the surgical intervention, the reconstructed ear was 3.1 mm longer and 1.3 mm wider with respect to the ideal plan and had a positioning error of 2.7 ± 2.4 mm relative to the contralateral side. Note that in this case, additional morphometric variations were induced from inflammation and other issues intended to be addressed in a subsequent stage of surgery, which are independent of our proposed solution.

CONCLUSIONS

In this work we propose an innovative workflow that combines 3D printing and AR to improve ear reconstruction and positioning in microtia correction procedures. Our implementation in the surgical workflow showed good accuracy, empowering surgeons to attain consistent and objective outcomes.

Accelerating neurotechnology development using an Agile methodology

Novel bioelectronic medical devices that target neural control of visceral organs (e.g., liver, gut, spleen) or inflammatory reflex pathways are innovative class III medical devices like implantable cardiac pacemakers that are lifesaving and life-sustaining medical devices. Bringing innovative neurotechnologies early into the market and the hands of treatment providers would benefit a large population of patients inflicted with autonomic and chronic immune disorders. Medical device manufacturers and software developers widely use the Waterfall methodology to implement design controls through verification and validation. In the Waterfall methodology, after identifying user needs, a functional unit is fabricated following the verification loop (design, build, and verify) and then validated against user needs. Considerable time can lapse in building, verifying, and validating the product because this methodology has limitations for adjusting to unanticipated changes. The time lost in device development can cause significant delays in final production, increase costs, and may even result in the abandonment of the device development. Software developers have successfully implemented an Agile methodology that overcomes these limitations in developing medical software. However, Agile methodology is not routinely used to develop medical devices with implantable hardware because of the increased regulatory burden of the need to conduct animal and human studies. Here, we provide the pros and cons of the Waterfall methodology and make a case for adopting the Agile methodology in developing medical devices with physical components. We utilize a peripheral nerve interface as an example device to illustrate the use of the Agile approach to develop neurotechnologies.

Does using 3D printed models for pre-operative planning improve surgical outcomes of foot and ankle fracture fixation? A systematic review and meta-analysis

PURPOSE

The systematic review aims to establish the value of using 3D printing-assisted pre-operative planning, compared to conventional planning, for the operative management of foot and ankle fractures.

METHODS

The systematic review was performed according to PRISMA guidelines. Two authors performed searches on three electronic databases. Studies were included if they conformed to pre-established eligibility criteria. Primary outcome measures included intraoperative blood loss, operation duration, and fluoroscopy time. The American orthopaedic foot and ankle score (AOFAS) was used as a secondary outcome. Quality assessment was completed using the Cochrane RoB2 form and a meta-analysis was performed to assess heterogeneity.

RESULTS

Five studies met the inclusion and exclusion criteria and were eventually included in the review. A meta-analysis established that using 3D printed models for pre-operative planning resulted in a significant reduction in operation duration (mean difference [MD] = - 23.52 min, 95% CI [- 39.31, - 7.74], p = 0.003), intraoperative blood loss (MD = - 30.59 mL, 95% CI [- 46.31, - 14.87], p = 0.0001), and number of times fluoroscopy was used (MD = - 3.20 times, 95% CI [- 4.69, - 1.72], p < 0.0001). Using 3D printed models also significantly increased AOFAS score results (MD = 2.24, 95% CI [0.69, 3.78], p = 0.005), demonstrating improved ankle health.

CONCLUSION

The systematic review provides promising evidence that 3D printing-assisted surgery significantly improves treatment for foot and ankle fractures in terms of operation duration, intraoperative blood loss, number of times fluoroscopy was used intraoperatively, and improved overall ankle health as measured by the AOFAS score.

Point-of-Care Orthopedic Oncology Device Development

BACKGROUND

The triad of 3D design, 3D printing, and xReality technologies is explored and exploited to collaboratively realize patient-specific products in a timely manner with an emphasis on designs with meta-(bio)materials.

METHODS

A case study on pelvic reconstruction after oncological resection (osteosarcoma) was selected and conducted to evaluate the applicability and performance of an inter-epistemic workflow and the feasibility and potential of 3D technologies for modeling, optimizing, and materializing individualized orthopedic devices at the point of care (PoC).

RESULTS

Image-based diagnosis and treatment at the PoC can be readily deployed to develop orthopedic devices for pre-operative planning, training, intra-operative navigation, and bone substitution.

CONCLUSIONS

Inter-epistemic symbiosis between orthopedic surgeons and (bio)mechanical engineers at the PoC, fostered by appropriate quality management systems and end-to-end workflows under suitable scientifically amalgamated synergies, could maximize the potential benefits. However, increased awareness is recommended to explore and exploit the full potential of 3D technologies at the PoC to deliver medical devices with greater customization, innovation in design, cost-effectiveness, and high quality.

Utilization of accessible resources in the fabrication of an affordable, portable, high-resolution, 3D printed, digital microscope for Philippine diagnostic applications

Philippine clinical laboratory licensing requirements mandate that diagnostic microscopy for Tuberculosis (TB) sputum microscopy, urinalysis, pap smears, wet smears, an option for complete blood count, stool exams, and malaria thick and thin smears should be accessible and available in health facilities including primary care centers. However, access to these essential diagnostics is hampered by the lack of trained personnel, relatively high costs for supplies and equipment especially in rural and underserved areas. This served as motivation for our team to utilize accessible resources in the form of affordable 3D printers, available CAD software, and components to build our low-cost Openflexure microscope (OFM) prototype. We successfully fabricated our prototype for a total of 310$ with a weight of 525g. We used pathology teaching slides from the Ateneo School of Medicine and Public Health and examined the OFM prototype imaging capabilities. The calculated image resolution was 13% higher compared to an LED light microscope sample captured by a mobile phone at 40x and 15% for 100x. The sampled slide images had adequate clarity with some identifiable cellular features for Rheumatic Heart Disease (RHD), Tuberculosis in soft tissue, and Ascariasis. We were able to correct the color aberrations of the OFM we built and was able to scan images up to 1000x magnification without using oil. Given the features and cost, the OFM prototype can be an attractive and affordable option as an alternative or augmentation to diagnostic microscopy in Philippine primary care. Moreover, it may enable telepathology to support diagnostic microscopy in frontline care.

Can Steam Sterilization Affect the Accuracy of Point-of-Care 3D Printed Polyetheretherketone (PEEK) Customized Cranial Implants? An Investigative Analysis

Polyetheretherketone (PEEK) has become the biomaterial of choice for repairing craniofacial defects over time. Prospects for the point-of-care (POC) fabrication of PEEK customized implants have surfaced thanks to the developments in three-dimensional (3D) printing systems. Consequently, it has become essential to investigate the characteristics of these in-house fabricated implants so that they meet the necessary standards and eventually provide the intended clinical benefits. This study aimed to investigate the effects of the steam sterilization method on the dimensional accuracy of POC 3D-printed PEEK customized cranial implants. The objective was to assess the influence of standard sterilization procedures on material extrusion-based 3D-printed PEEK customized implants with non-destructive material testing. Fifteen PEEK customized cranial implants were fabricated using an in-house material extrusion-based 3D printer. After fabrication, the cranial implants were digitalized with a professional-grade optical scanner before and after sterilization. The dimensional changes for the 3D-printed PEEK cranial implants were analyzed using medically certified 3D image-based engineering software. The material extrusion 3D-printed PEEK customized cranial implants displayed no statistically significant dimensional difference with steam sterilization (p > 0.05). Evaluation of the cranial implants’ accuracy revealed that the dimensions were within the clinically acceptable accuracy level with deviations under 1.00 mm. Steam sterilization does not significantly alter the dimensional accuracy of the in-house 3D-printed PEEK customized cranial implants.

Digital workflow for fabrication of bespoke facemask in burn rehabilitation with smartphone 3D scanner and desktop 3D printing: clinical case study

We present a digital workflow for the production of custom facial orthosis used for burn scar management using smartphone three-dimensional (3D) scanner and desktop 3D printing. 3D facial scan of a 48-year-old lady with facial burn scars was obtained. 3D modeling with open-source programs were used to create facemask then 3D printed using rigid polylactic acid (PLA) filament and semi-rigid thermoplastic polyurethane (TPU). Conventional facemask was used as a control. Each mask was worn for 7 days. Primary outcomes were level of comfort, and adherence to treatment. The conventional facemask was the most convenient followed by the TPU-facemask (mean comfort score of 9/10 and 8.7/10, respectively). Patient's compliance was high for both TPU and conventional masks, each was worn for at least 21 hours/day for 7 days. On the contrary, PLA-facemask was not well tolerated. The proposed digital workflow is simple, patient-friendly and can be adopted for resource-intensive healthcare.

Vital Role of In-House 3D Lab to Create Unprecedented Solutions for Challenges in Spinal Surgery, Practical Guidelines and Clinical Case Series

For decades, the advantages of rapid prototyping for clinical use have been recognized. However, demonstrations of potential solutions to treat spinal problems that cannot be solved otherwise are scarce. In this paper, we describe the development, regulatory process, and clinical application of two types of patient specific 3D-printed devices that were developed at an in-house 3D point-of-care facility. This 3D lab made it possible to elegantly treat patients with spinal problems that could not have been treated in a conventional manner. The first device, applied in three patients, is a printed nylon drill guide, with such accuracy that it can be used for insertion of cervical pedicle screws in very young children, which has been applied even in semi-acute settings. The other is a 3D-printed titanium spinal column prosthesis that was used to treat progressive and severe deformities due to lysis of the anterior column in three patients. The unique opportunity to control size, shape, and material characteristics allowed a relatively easy solution for these patients, who were developing paraplegia. In this paper, we discuss the pathway toward the design and final application, including technical file creation for dossier building and challenges within a point-of-care lab.

Design and 3D-printing of MRI-compatible cradle for imaging mouse tumors

BACKGROUND

The ability of 3D printing using plastics and resins that are magnetic resonance imaging (MRI) compatible provides opportunities to tailor design features to specific imaging needs. In this study an MRI compatible cradle was designed to fit the need for repeatable serial images of mice within a mouse specific low field MRI.

METHODS

Several designs were reviewed which resulted in an open style stereotaxic cradle to fit within specific bore tolerances and allow maximum flexibility with interchangeable radiofrequency (RF) coils. CAD drawings were generated, cradle was printed and tested with phantom material and animals. Images were analyzed for quality and optimized using the new cradle. Testing with multiple phantoms was done to affirm that material choice did not create unwanted image artifact and to optimize imaging parameters. Once phantom testing was satisfied, mouse imaging began.

RESULTS

The 3D printed cradle fit instrument tolerances, accommodated multiple coil configurations and physiological monitoring equipment, and allowed for improved image quality and reproducibility while also reducing overall imaging time and animal safety.

CONCLUSIONS

The generation of a 3D printed stereotaxic cradle was a low-cost option which functioned well for our laboratory.

Quantitative Assessment of Point-of-Care 3D-Printed Patient-Specific Polyetheretherketone (PEEK) Cranial Implants

Recent advancements in medical imaging, virtual surgical planning (VSP), and three-dimensional (3D) printing have potentially changed how today's craniomaxillofacial surgeons use patient information for customized treatments. Over the years, polyetheretherketone (PEEK) has emerged as the biomaterial of choice to reconstruct craniofacial defects. With advancements in additive manufacturing (AM) systems, prospects for the point-of-care (POC) 3D printing of PEEK patient-specific implants (PSIs) have emerged. Consequently, investigating the clinical reliability of POC-manufactured PEEK implants has become a necessary endeavor. Therefore, this paper aims to provide a quantitative assessment of POC-manufactured, 3D-printed PEEK PSIs for cranial reconstruction through characterization of the geometrical, morphological, and biomechanical aspects of the in-hospital 3D-printed PEEK cranial implants. The study results revealed that the printed customized cranial implants had high dimensional accuracy and repeatability, displaying clinically acceptable morphologic similarity concerning fit and contours continuity. From a biomechanical standpoint, it was noticed that the tested implants had variable peak load values with discrete fracture patterns and failed at a mean (SD) peak load of 798.38 ± 211.45 N. In conclusion, the results of this preclinical study are in line with cranial implant expectations; however, specific attributes have scope for further improvements.