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An analytical method to create patient-specific deformed bone models using X-ray images and a healthy bone model
摘要： Generation of patient-specific bone models from X-ray images is useful for various medical applications such as total hip replacement, implant manufacturing, knee kinematic studies and deformity correction. These models may provide valuable information required for a more reliable operation. In this work, we propose a new algorithm for generating patient-specific 3D models of femur and tibia with deformity, using only a generic healthy bone model and some simple measurements taken on the X-ray images of the diseased bone. Using the X-ray measurements, an interpolation function (a polynomial or a cubic spline) is fit to the mid-diaphyseal curve of the actual bone and the generic bone model is deformed in the guidance of this function with free form deformation method. The created models are intended to be used mainly for the visualization of fixation procedure in software-supported external fixation systems. An error measure is defined to quantify the error in this matching procedure. The method is found to be capable of producing deformed tibia models that satisfactorily reflect the actual bones, as confirmed by two orthopaedic surgeons who use software-supported external fixation systems regularly.
关键词： Deformity,3D bone modeling,Free form deformation,External fixation,Patient-specific bone models,Mathematical modeling
更新于2025-09-23 15:21:21
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[IEEE 2018 9th International Conference on Computing, Communication and Networking Technologies (ICCCNT) - Bangalore (2018.7.10-2018.7.12)] 2018 9th International Conference on Computing, Communication and Networking Technologies (ICCCNT) - A Perceptual Field of Vision, Using Image Processing
摘要： Currently, estimated facts state that there are more than 285 million visually impaired people around the globe, of which 39 million are blind and the others have a low vision [1]. Approximately 90% of people suffering from blindness are from low-income backgrounds [2]. The main aim of this paper is to provide an efficient visual platform to enhance the perception of the surroundings for a visually impaired user. This is achieved by using the concept of real-time image and video processing. This data is analyzed and compared along with the database which consists of pre-stored data that aids in recognition of the captured image. A head mount camera is used to capture an image on a real-time basis whenever desired. The camera is placed to provide a maximum field of vision and to eliminate the blind spot. The captured image is then processed and compared with the information stored in the database, providing an audio output indicating the desired information. Audio output is provided through bone conduction headphones which communicate audio signals directly with the inner ear. This keeps the outer ear free to be sensitive to the surroundings. A distress alert mechanism is also included as a safety measure to the blind at times of danger. It helps in sending messages containing distress alert signal which contains current location of the user.
关键词： virtual vision,computer vision,audio processing,distress alert,bone conduction,image processing,database
更新于2025-09-23 15:21:21
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High-Resolution Shortwave Infrared Imaging of Vascular Disorders Using Gold Nanoclusters
摘要： We synthesized a generation of water-soluble, atomically precise gold nanoclusters (Au NCs) with anisotropic surface containing short dithiol pegylated chain (AuMHA/TDT). These AuMHA/TDT exhibit a high brightness (QY～6%) in the shortwave infrared (SWIR) spectrum with a detection above 1250 nm. Furthermore, they show an extended half-life in blood (t1/2? = 19.54 ±0.05 h) and a very weak accumulation in organs. We also developed a non-invasive, whole-body vascular imaging system in the SWIR window with high-resolution, benefiting from a series of Monte Carlo image processing of the images. The imaging process enabled to improve contrast by one order of magnitude and enhance by 59% the spatial resolution. After systemic administration of these nanoprobes in mice, we can quantify vessel complexity in depth (> 4 mm) allowing to detect very subtle vascular disorders non-invasively in bone morphogenetic 9 (Bmp9) deficient mice. The combination of these anisotropic surface charged gold nanoclusters plus an improved SWIR imaging device allows then a precise mapping at high resolution and in depth of the organization of the vascular network in live animals.
关键词： shortwave infrared fluorescence,bone morphogenetic 9 (Bmp9),gold nanoclusters,vascular disorder,monte carlo restoration imaging processing
更新于2025-09-23 15:21:01
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The effect of low-level laser radiation and doxycycline on the levels of osteoprotegerin and receptor activator of nuclear factor kappa-B ligand
摘要： The present in vitro study was conducted to investigate the effect of low-level laser (LLL) radiation and doxycycline on the levels of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) derived from MG-63 osteosarcoma cell line. MG-63 cells were divided into four groups. In the first group, 2 mg/mL of doxycycline was injected into the cell culture medium. Diode laser (810 nm, 100 mw, 75 s) was radiated to the culture medium of the second group. The third group received both doxycycline and laser radiation. In the fourth group (control), the culture medium was replaced daily, similar to the above three groups. Mentioned interventions were performed once a day for 4 consecutive days. Then, on the sixth day, the levels of OPG and RANKL mediators were measured using real-time polymerase chain reaction by isolating the cells from the samples. OPG expression had the highest to lowest levels in the laser + doxycycline, doxycycline, laser, and control groups, respectively. The level of OPG was significantly different between all the study groups (p < 0.05) except in the doxycycline + laser and doxycycline groups (p = 0.061). The highest to lowest levels of RANKL was observed in the doxycycline, laser + doxycycline, control, and laser groups, respectively. The RANKL expression was not significantly different between all the study groups (p > 0.05). The results of this study revealed that LLL and doxycycline reduced the RANKL/OPG ratio derived from the MG-63 osteosarcoma cell line, which may result in the diminished activity of osteoclasts and osteoclastogenesis.
关键词： OPG,Remodeling,RANKL,Laser,Doxycycline,Bone
更新于2025-09-23 15:21:01
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Clinical and radiographics results at 3 years of RCT with split-mouth design of submerged vs. nonsubmerged single laser-microgrooved implants in posterior areas
摘要： Aim: To evaluate and compare radiographic crestal bone loss (CBL) and soft tissue parameters around submerged/two-stage and nonsubmerged/one-stage single implants with the same endosseous portion (body design and surface, thread design and distance) and identical intramucosal laser-microgrooved surface, after 3 years of loading. Materials and methods: Twenty submerged/two-stage implants and 20 nonsubmerged/one-stage implants were placed randomly with a split-mouth design in the posterior areas of 20 partially edentulous patients. Radiographic and clinical examinations were carried out at the implant placement, at the delivery of prosthetic restorations, and at each year of the follow-up period. Plaque index (PI), probing depth (PD), bleeding on probing (BOP), and gingival recession (REC) were recorded. Radiographic crestal bone levels were assessed at the mesial and distal aspect of the implant sites. In addition, the influence of the vertical keratinized tissue thickness (KTT) on CBL was investigated. Results: At the delivery of prosthetic restorations, a statistically significant difference (P = 0.013) was found in radiographic mean CBL between submerged and nonsubmerged implants (0.15 ± 0.05 mm vs. 0.11 ± 0.04 mm). At the end of the follow-up period, no statistical difference (P = 0.741) was found in the mean CBL between submerged and nonsubmerged implants (0.27 ± 04 mm vs. 0.26 ± 0.5 mm). The changes in the soft tissues including PI, PD, BOP, and REC had no significant differences in either group. Moreover, KTT did not show a statistical correlation with CBL. Conclusions: After 3 years of loading, no statistical difference was noted in CBL and soft tissue conditions between single submerged two-stage and nonsubmerged one-stage laser-microgrooved implants.
关键词： Submerged two-stage,Nonsubmerged one-stage,Dental implants,Marginal bone loss
更新于2025-09-23 15:21:01
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Laser fabrication of structural bone: surface morphology and biomineralization assessment
摘要： The current work explores the surface morphology of the laser-ablated bone using Yb-fiber coupled Nd:YAG laser (λ = 1064 nm) in continuous wave mode. As the laser-ablated region contains physiochemically modified carbonized and nonstructural region, it becomes unknown material for the body. Thus, biomineralization on such a laser-ablated region was assessed by in vitro immersion test in noncellular simulated body fluid. The presence of hydroxyapatite was detected in the precipitated mineral product using scanning electron microscopy equipped with energy dispersive spectroscopy, and X-ray diffraction analysis. The effect of varying laser parameters on distribution of surface morphology features was identified and its corresponding effect on biomineralization was studied.
关键词： Laser-bone interaction,Surface morphology,Finite element method (FEM) modeling,Laser ablation
更新于2025-09-23 15:21:01
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Role of laser ablation in multimodal treatment of radioiodine- refractory bone metastases of thyroid cancer: a retrospective study
摘要： Purpose To assess the efficacy, safety, and pain benefits of imaging-guided laser ablation (IGLA) in patients with radioiodine-refractory (RR) bone metastases from differentiated thyroid carcinoma (DTC). Patients and methods The institutional medical records of patients with bone metastases from DTC treated with laser ablation (LA) were reviewed retrospectively. Local response, complications, and effects on pain relief were investigated. Results Six osteolytic lesions in five patients (one male, four females; mean age 65.4 ± 5.1 years, range 58–72) were treated with IGLA. All lesions were osteolytic and all have had previous treatments with high-dose radioiodine therapy followed by external radiotherapy (EBRT). All patients assumed opioid analgesics for severe pain. Overall, the lesions (mean size 5.8 ± 3.2 cm; median 5.0 cm, range 3.0–12.0 cm) underwent nine IGLA sessions (mean 1.8 ± 0.4 sessions; median 2.0 sessions, range 1–2). In four (80%) out five lesions, cross-sectional imaging showed a nearly complete response (CR) while the largest lesion was ablated by 80%. Pain changes were assessed with the Brief Pain Inventory-Short Form, that was administered before IGLA and during a 6-month follow-up. Patients experienced significant reduction in worst pain, average pain, and pain interference. Following IGLA, the average daily opioid requirement rapidly and progressively decreased. Treatments were well-tolerated and no major complications occurred. Conclusions IGLA is an effective and safe debulking procedure and provides significant pain relief in patients suffering from DTC bone metastases that are not responsive to standard treatments. So, IGLA could be considered as part of a multi-modality management of advanced thyroid cancer with RR metastatic skeletal involvement.
关键词： Minimally invasive techniques,Laser ablation,Differentiated thyroid cancer,Thermal ablation therapies,Radioiodine-refractory thyroid cancer,Bone metastases
更新于2025-09-23 15:21:01
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Nanostructured apatites grown by laser floating zone
摘要： Apatites (AP) ceramics are important due to their application in the orthopaedics field as bioceramic material. Several processes to produce apatites such as oxyapatite (OAP) and hydroxyapatite (HA) materials are used to apply as a temporary substitute for human bone. In the present work, AP powders were prepared by high-energy ball milling and then by laser floating zone (LFZ) technique to transform into a dense cylinder (fibre). The effect of LFZ processing conditions was assessed by structural and electric characterization. Fibres present strong densification and a uniform polycrystalline microstructure, which could favour the use for natural bone treatments and as bio-sensors. However, further work must be assessed to optimize laser processing conditions.
关键词： Bioceramic,Apatites,Laser floating zone,Bio-sensors,Bone treatment,Hydroxyapatite,Oxyapatite
更新于2025-09-23 15:21:01
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Bone quality assessment of osteogenic cell cultures by Raman microscopy
摘要： The use of autologous stem/progenitor cells represents a promising approach to the repair of craniofacial bone defects. The calvarium is recognized as a viable source of stem/progenitor cells that can be transplanted in vitro to form bone. However, it is unclear if bone formed in cell culture is similar in quality to that found in native bone. In this study, the quality of bone mineral formed in osteogenic cell cultures were compared against calvarial bone from postnatal mice. Given the spectroscopic resemblance that exists between cell and collagen spectra, the feasibility of extracting information on cell activity and bone matrix quality were also examined. Stem/progenitor cells isolated from fetal mouse calvaria were cultured onto fused‐quartz slides under osteogenic differentiation conditions for 28 days. At specific time intervals, slides were removed and analyzed by Raman microscopy and mineral staining techniques. We show that bone formed in culture at Day 28 resembled calvarial bone from 1‐day‐old postnatal mice with comparable mineralization, mineral crystallinity, and collagen crosslinks ratios. In contrast, bone formed at Day 28 contained a lower degree of ordered collagen fibrils compared with 1‐day‐old postnatal bone. Taken together, bone formed in osteogenic cell culture exhibited progressive matrix maturation and mineralization but could not fully replicate the high degree of collagen fibril order found in native bone.
关键词： Raman microscopy,osteogenic differentiation,tissue engineering,stem cells,bone quality
更新于2025-09-23 15:21:01
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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI, USA (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Evaluation of Bone Conduction Vibration System Using Photoacoustic Effect
摘要： This article proposes a novel bone conduction vibrator based on an interesting phenomenon where audible sound can be perceived when a vibration is produced using a laser beam that is synchronized to the sound and this vibration is transmitted to an auricular cartilage. To study this phenomenon, we measured the effect using a rubber sheet with similar properties to those of soft tissue, together with an acceleration sensor, and found that audible sound was produced in the sample. We also calculated the force level based on the mechanical impedance and the acceleration in the proposed system. It is expected that a force level equal to the reference equivalent threshold force level can be achieved at a light intensity below the safety limit for human skin exposure by choosing an irradiation wavelength at which a larger degree of optical absorption occurs. This novel application of the photoacoustic effect is promising for bone conduction hearing aids.
关键词： bone conduction,hearing aids,laser,vibration,photoacoustic effect
更新于2025-09-23 15:21:01