Accurate 3D to 2D Object Distance Estimation from the Mapped Point Cloud Data.

Distance estimation is one of the oldest and most challenging tasks in computer vision using only a monocular camera. This can be challenging owing to the presence of occlusions, noise, and variations in the lighting, texture, and shape of objects. Additionally, the motion of the camera and objects in the scene can affect the accuracy of the distance estimation. Various techniques have been proposed to overcome these challenges, including stereo matching, structured light, depth from focus, depth from defocus, depth from motion, and time of flight. The addition of information from a high-resolution 3D view of the surroundings simplifies the distance calculation. This paper describes a novel distance estimation method that operates with converted point cloud data. The proposed method is a reliable map-based bird's eye view (BEV) that calculates the distance to the detected objects. Using the help of the Euler-region proposal network (E-RPN) model, a LiDAR-to-image-based method for metric distance estimation with 3D bounding box projections onto the image was proposed. We demonstrate that despite the general difficulty of the BEV representation in understanding features related to the height coordinate, it is possible to extract all parameters characterizing the bounding boxes of the objects, including their height and elevation. Finally, we applied the triangulation method to calculate the accurate distance to the objects and statistically proved that our methodology is one of the best in terms of accuracy and robustness.

Correlation of soft palate length with velum obstruction and severity of obstructive sleep apnea syndrome.

OBJECTIVE: Our aim in this study was to analyze whether soft palate length and velum obstruction during sleep are correlated and to determine the effects of related parameters on obstructive sleep apnea syndrome (OSAS) severity. We used computed tomography to measure soft palate length and drug-induced sleep endoscopy (DISE) to evaluate velum obstruction severity. Patients also underwent polysomnography (PSG) for evaluation of OSAS severity. METHODS: A retrospective cohort of 67 patients with OSAS treated between May 1st, 2013 and July 31st, 2016 was analyzed. Each patient underwent DISE, PSG, and computed tomography. Using DISE, velum obstruction was categorized by the VOTE classification method. Using computed tomography, soft palate length was measured as the length of the posterior nasal spine to the uvula. Correlations of velum obstruction in DISE and PSG parameters (obstructive apnea, hypopnea, apnea hypopnea index (AHI), respiratory effort related arousal (RERA), respiratory disturbance index (RDI), baseline SaO2, and minimum SaO2) with soft palate length were also analyzed. RESULTS: Among the 67 patients, the average PNS-U length was 39.90±4.19mm. Length was significantly different by age but not by other demographic characteristics such as sex, past history, or BMI. DISE revealed a statistically significant difference of velum obstruction degree; the cutoff value for PNS-U was 39.47mm. The PSG results, obstructive apnea, AHI, RDI, baseline SaO2, and minimum SaO2 were correlated with PNS-U length, while other results such as hypopnea and RERA showed no correlation. CONCLUSION: Analysis of soft palate length showed that increased PNS-U length was associated with higher rates of obstructive apnea, AHI, and RDI as assessed by PSG. In contrast, lower baseline SaO2 and minimum SaO2 values were seen by PSG; more severe velum obstruction was seen by DISE. We propose that when a soft palate is suspected in OSAS, computed tomography measurement of soft palate length is a valid method for estimating the degree of velum obstruction and the severity of OSAS.

Engraftment and regenerative effects of bone marrow stromal cell transplantation on damaged rat olfactory mucosa.

To develop a new therapeutic method to treat olfactory deficits, we investigated the engraftment and regenerative effects of transplanted bone marrow stromal cells (BMSCs) on damaged rat olfactory mucosa. To induce olfactory nerve degeneration, one side of the olfactory mucosa of Sprague-Dawley rats was damaged via Triton X-100 irrigation. Phosphate-buffered saline containing syngeneic BMSCs was injected into the olfactory mucosa for transplantation. PKH fluorescent cell dye labeling of BMSCs was used to monitor the transplanted cells. After transplantation of BMSCs, the thickness and regeneration of olfactory mucosa were analyzed using hematoxylin-eosin (H&E) staining. S100 immunohistochemical staining was used to measure nerve sheath regeneration. The increase in NGF (nerve growth factor) level in the olfactory mucosa was measured by Western blot analysis. Transplanted bone marrow stromal cells were engrafted to the lamia propria of damaged mucosa. The mean time for normalization of thickness and morphological recovery of the olfactory mucosa was 4 weeks in the therapeutic group and 9 weeks in the control group. S100 immunoreactivity was higher on the BMSC-treated side than on the control side. During regeneration, the expression of NGF increased in the olfactory mucosa of the experimental group. Based on these results, BMSC transplantation accelerated regeneration of olfactory mucosa damaged by Triton X-100, and NGF may be essential to this regenerative process.

An absorbable thread suture technique to treat snoring.

We investigated a novel, minimally invasive surgery that uses an absorbable suture technique to treat snoring and mild obstructive sleep apnea. This simple procedure was developed to increase the stiffness of the soft palate and to promote uvula elevation with sutures. Thirty-five snorer and mild obstructive sleep apnea syndrome patients were included in this study. The palate was sutured with the newly developed technique. The results of our surgery were evaluated using polysomnography (PSG), the Epworth sleepiness scale (ESS), and a visual analogue scale (VAS) before surgery and 90 days after surgery. One year after surgery, telephone interviews were performed to assess patient satisfaction. Postoperative physical examinations of all patients showed increased stiffness of the soft palate and superiorly displaced uvula. These findings were consistent after the postoperative day 90. The patients' snoring symptoms and their bed partners' complaints, assessed by ESS and VAS, significantly improved compared to the pre-treatment value (p < 0.05). Additionally, the apnea-hypopnea index (AHI), assessed by PSG, was significantly improved compared to the pre-treatment value (p < 0.05). Based on the results from the telephone interviews analyzed 1 year after surgery, about 88 % of patients were satisfied with the outcome. This minimally invasive snoreplasty that uses absorbable suture material is an effective and simple procedure for treating snoring and mild obstructive sleep apnea.

A new nose tip-defining technique for Asians using autologous cartilage prefabricated with octyl-2-cyanoacrylate adhesive.

OBJECTIVES: To form and test a prefabricated, 3-dimensional tip graft structure from autologous cartilage pieces and octyl-2-cyanoacrylate adhesive (Dermabond). Displacement and instability of grafted cartilage are common drawbacks of endonasal tip surgery, and we evaluated the feasibility and efficacy of octyl-2-cyanoacrylate adhesive for clinical use. METHODS: Three New Zealand rabbits were examined in this study. We cut auricular cartilage into pieces of approximately 1 x 2 cm and glued them together with octyl-2-cyanoacrylate. Three months after subcutaneous implantation in the rabbits, we histopathologically analyzed foreign body reactions, histotoxic effects, and the structure of the regenerative tissue in the implanted cartilage. Furthermore, from human patients we harvested small pieces of autologous cartilage and cemented them together with octyl-2-cyanoacrylate adhesive to prefabricate 3-dimensional tip grafts, which we then inserted into the nasal tips of patients via an endonasal approach to project and contour the nasal tip. The changes in tip definition of 42 Asian patients were analyzed. RESULTS: Octyl-2-cyanoacrylate adhesive interacts well with cartilage tissues with no systemic or local adverse effects. Its ability to bond cartilage instantaneously allows for the fabrication of intricate cartilage implant components. The aesthetic results in 42 cases were excellent, and the implants were both safe and effective. CONCLUSION: Our results demonstrate that octyl-2-cyanoacrylate can be safely used in endonasal tip surgery to produce excellent cosmetic outcomes in Asian subjects.

Are Cross-hatching Incisions Mandatory for Correction of Cartilaginous Septal Deviation?

OBJECTIVES: Cross-hatching incisions have been considered mandatory for correcting cartilaginous septal deviation. We evaluated the clinical outcome of septoplasty without cross-hatching incisions to determine the necessity for making septal cartilage incisions. METHODS: THE RECONSTRUCTED SEPTAL COMPONENTS DURING SEPTOPLASTY WERE CATEGORIZED INTO FOUR ANATOMICAL AREAS: vomer, maxillary crest, perpendicular plate of ethmoid (PPE) and septal cartilage (the area for cross-hatching incisions). During septoplasty, we attempted to complete the surgery only by removing or fracturing the bony part of the septum without cross-hatching incisions on the cartilage. Only in the cases that the deviation was not immediately corrected, the cross-hatching incisions were made onto the cartilage at the end of the procedure. We analyzed the frequency of manipulating the septal components. The changes of symptoms were evaluated using a modified nasal obstruction symptom evaluation (NOSE) scale and a visual analog scale (VAS) preoperatively, 1 and 3 months after the surgery. RESULTS: Seventy five percents of the deviated septums were immediately corrected only by removing or fracturing of the bony septal components. In decreasing order of frequency, the sepal components for correcting septal deviation were the vomer (59%), maxillary crest (49%), septal cartilage (cross-hatching only: 25%) and PPE (15%). The modified NOSE scale and the VAS demonstrated significant improvement of the nasal symptoms postoperatively (P<0.05). CONCLUSION: Most of septal deviations could be corrected by manipulating only the bony septum. The results of this procedure were not different from conventional septoplasty with cross-hatching incisions. Our data suggest cross-hatching incisions during septoplasty might have been overemphasized and that the main cause for cartilaginous deviation may be the extrinsic forces that are generated by the neighboring bony structures.

Tissue-engineered bone formation with gene transfer and mesenchymal stem cells in a minimally invasive technique.

BACKGROUND: The objective of this study was to use a chitosan-alginate gel to implant bone marrow-derived mesenchymal stem cells subcutaneously in a minimally invasive manner and promote bone formation by the simultaneously transferred osteogenic protein (OP)-1 (bone morphogenic protein-7) gene. METHOD AND RESULTS: The complex of polyethylenimine/luciferase plasmid DNA embedded in the gel was able to transfect HEK 293 cells on a culture dish or co-encapsulated in the gel. When injected into the subcutaneous space of mice, luciferase expression was two to three orders of magnitude increased above the background. To examine the efficacy of gene-, cell-, and combined gene- and cell-encapsulated gels in tissue generation, samples were injected into the subcutaneous space of 6-week-old athymic nude mice, and the OP-1 plasmid was studied. At 8 weeks after the injection, the gels only maintained their volumetric shape when human mesenchymal stem cells (hMSCs) were encapsulated, but otherwise the gels were partially dissolved. Transgene expression of OP-1 was clearly detected in the samples after 4 weeks but not after 8 weeks. Type II collagen was detected in all the gels containing the OP-1 plasmid, with or without hMSCs. The samples with the combination of OP-1 DNA and hMSCs revealed strong type II collagen expression as well as osteoid foci. CONCLUSION: These results suggest that combined gene and hMSC delivery within a chitosan-alginate gel could be an interesting approach for tissue engineering.