Research on Positioning Accuracy of Mobile Robot in Indoor Environment Based on Improved RTABMAP Algorithm.

Visual simultaneous localization and mapping is a widely used technology for mobile robots to carry out precise positioning in the environment of GNSS technology failure. However, as the robot moves around indoors, its position accuracy will gradually decrease over time due to common and unavoidable environmental factors. In this paper, we propose an improved method called RTABMAP-VIWO, which is based on RTABMAP. The basic idea is to use an Extended Kalman Filter (EKF) framework for fusion attitude estimates from the wheel odometry and IMU, and provide new prediction values. This helps to reduce the local cumulative error of RTABMAP and make it more accurate. We compare and evaluate three kinds of SLAM methods using both public datasets and real indoor scenes. In the dataset experiments, our proposed method reduces the Root-Mean-Square Error (RMSE) coefficient by 48.1% compared to the RTABMAP, and the coefficient is also reduced by at least 29.4% in the real environment experiments. The results demonstrate that the improved method is feasible. By incorporating the IMU into the RTABMAP method, the trajectory and posture errors of the mobile robot are significantly improved.

Metal surface defect detection based on improved YOLOv5.

During the production of metal material, various complex defects may come into being on the surface, together with large amount of background texture information, causing false or missing detection in the process of small defect detection. To resolve those problems, this paper introduces a new model which combines the advantages of CSPlayer module and Global Attention Enhancement Mechanism based on the YOLOv5s model. First of all, we replace C3 module with CSPlayer module to augment the neural network model, so as to improve its flexibility and adaptability. Then, we introduce the Global Attention Mechanism (GAM) and build the generalized additive model. In the meanwhile, the attention weights of all dimensions are weighted and averaged as output to promote the detection speed and accuracy. The results of the experiment in which the GC10-DET augmented dataset is involved, show that the improved algorithm model performs better than YOLOv5s in precision, mAP@0.5 and mAP@0.5: 0.95 by 5.3%, 1.4% and 1.7% respectively, and it also has a higher reasoning speed.

Global contextual attention augmented YOLO with ConvMixer prediction heads for PCB surface defect detection.

To solve the problem of missed and false detection caused by the large number of tiny targets and complex background textures in a printed circuit board (PCB), we propose a global contextual attention augmented YOLO model with ConvMixer prediction heads (GCC-YOLO). In this study, we apply a high-resolution feature layer (P2) to gain more details and positional information of small targets. Moreover, in order to suppress the background noisy information and further enhance the feature extraction capability, a global contextual attention module (GC) is introduced in the backbone network and combined with a C3 module. Furthermore, in order to reduce the loss of shallow feature information due to the deepening of network layers, a bi-directional weighted feature pyramid (BiFPN) feature fusion structure is introduced. Finally, a ConvMixer module is introduced and combined with the C3 module to create a new prediction head, which improves the small target detection capability of the model while reducing the parameters. Test results on the PCB dataset show that GCC-YOLO improved the Precision, Recall, mAP@0.5, and mAP@0.5:0.95 by 0.2%, 1.8%, 0.5%, and 8.3%, respectively, compared to YOLOv5s; moreover, it has a smaller model volume and faster reasoning speed compared to other algorithms.

Mixed Receptive Fields Augmented YOLO with Multi-Path Spatial Pyramid Pooling for Steel Surface Defect Detection.

Aiming at the problems of low detection efficiency and poor detection accuracy caused by texture feature interference and dramatic changes in the scale of defect on steel surfaces, an improved YOLOv5s model is proposed. In this study, we propose a novel re-parameterized large kernel C3 module, which enables the model to obtain a larger effective receptive field and improve the ability of feature extraction under complex texture interference. Moreover, we construct a feature fusion structure with a multi-path spatial pyramid pooling module to adapt to the scale variation of steel surface defects. Finally, we propose a training strategy that applies different kernel sizes for feature maps of different scales so that the receptive field of the model can adapt to the scale changes of the feature maps to the greatest extent. The experiment on the NEU-DET dataset shows that our model improved the detection accuracy of crazing and rolled in-scale, which contain a large number of weak texture features and are densely distributed by 14.4% and 11.1%, respectively. Additionally, the detection accuracy of inclusion and scratched defects with prominent scale changes and significant shape features was improved by 10.5% and 6.6%, respectively. Meanwhile, the mean average precision value reaches 76.8%, compared with the YOLOv5s and YOLOv8s, which increased by 8.6% and 3.7%, respectively.

Use of Buried Guide Needle to Fix Inferior Eyelid Orbital Septum Fat for Tear Trough Depression Filling.

ABSTRACT: Fat fixation is a key step in filling tear trough depression with inferior eyelid orbital septum fat. The ideal position for inferior eyelid fat fixation is to cross the tear trough ligament causing tear trough depression and the orbicularis retaining ligament, with the distal end fixed at the farthest end of the dissected lacuna deep down the inferior orbicularis oculi muscle. Traditional suturing is difficult in the deep narrow lacunae, but a buried guide needle can be used to suture and fix the fat in the deepest lacuna. In this study, 264 patients who underwent tear trough filling using a buried guide needle to fix the released inferior eyelid orbital septum fat from 2017 to 2020 were followed up. The preoperative and postoperative imaging findings were compared to evaluate the effectiveness of the operation and postoperative complications. The inferior eyelid bulging, loose skin, and tear trough depression significantly improved than that before the operation. None of the patients had any severe complications, such as inferior eyelid ectropion, lagophthalmos, scar hyperplasia, and diplopia, in the long term (6 months) postoperatively. Five patients showed mild eyelid-eyeball separation and recovered in 1 month. Four patients had diplopia, and 3 patients had chemosis; all recovered in 7 days. The tear trough depression was not corrected completely in 2 patients. The operation showed satisfactory results in the improvement of tear trough depression in addition to alleviation of inferior eyelid bulging and loose inferior eyelid skin that is caused by the traditional inferior eyelid pouch removal.

Vaginal delivery combined with vaginal tightening surgery and perineal body repair: 5 case reports.

The present study aimed to investigate the feasibility of vaginal delivery combined with vaginal tightening surgery and perineal body repair.From January 2017 to April 2017, 5 cases underwent vaginal delivery combined with vaginal tightening surgery and perineal body repair. We retrospectively analyzed the clinical data.The incisions of 5 cases were all primary healing; vulva form was improved, and there were no postoperative hematoma, infection or vaginal mucosa prolapse. Sexual function was improved to different degrees. The pelvic muscle force test showed that both the type I and type II myofiber scores were increased.It is feasible to perform vaginal delivery combined with vaginal tightening surgery and perineal body repair, which is a safe and effective method for improving sex life and pelvic floor function.

Corrective Strategies for a Complex Deformity Caused by "European-Style Double Eyelid" Blepharoplasty in Asians.

BACKGROUND: "European-style double eyelid" blepharoplasty often leads to a complex deformity, which includes one or more of the following features: a high fold, upper eyelid depression, multiple folds, an obvious scar, blepharoptosis, and lower flap tumidness. However, there is still a lack of comprehensive research on evaluation and treatment strategies for this complex deformity. METHODS: During a 6-year period, 65 patients (106 eyes) with a high fold and upper eyelid depression underwent corrective blepharoplasty. The authors classified this complex deformity as mild, moderate, or severe based on the extent of adhesion and tissue insufficiency, and we performed preaponeurotic fat flap transfer in 47 eyes (44.3%), free fat graft in 35 eyes (33%), and free dermis-fat graft in 24 eyes (22.6%), respectively. RESULTS: The outcomes in 87 eyelids were judged as excellent; and the grading was excellent in 41 eyes (87.2%) that underwent preaponeurotic fat flap transfer, 30 eyes (85.7%) that received a free fat graft, and 16 eyes (66.7%) that received a free dermis-fat graft. The outcomes in only 3 eyes (2.8%) were evaluated as unsatisfactory. CONCLUSIONS: The fundamental reasons behind this deformity were adhesion and tissue insufficiency above the supratarsal crease. The purpose of correction was to reconstruct the gliding system and restore the volume. The authors performed preaponeurotic fat flap transfer, free fat graft, and free dermis-fat graft and achieved satisfactory results. Great improvement in ptosis was achieved by releasing the adhesion and lowering the fold in patients with normal levator muscle function. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Autologous Buccal Micro-Mucosa Free Graft combined with Posterior Scrotal Flap Transfer for Vaginoplasty in Male-To-Female Transsexuals: A Pilot Study.

BACKGROUND: The inverted peno-scrotal flap method is considered the standard method of vaginoplasty in male-to-female genital reassignment surgery. Though with numerous advantages, the method has its limitations regarding skin texture, lack of inherent lubrication, and that the tissues for creating the labia depend on the amount of tissues remaining after vaginoplasty. Our purpose was to describe the procedure and outcome of vaginoplasty applying a new technique: autologous buccal micro-mucosa free graft combined with posterior scrotal flap transfer, which could solve some of the problems the previous methods had. METHODS: Nine male-to-female transsexual patients received our new method of vaginoplasty from July 2010-October 2015. We described the details of the surgical procedure and evaluated the long-term anatomical and functional outcomes. RESULTS: In a mean clinical follow-up period of 25.3 months and phone interview follow-up of 50.3 months, we observed that the neovaginas in the nine cases were all of sufficient volume, lined with mucosa, with natural mucosal discharge. The oral donor sites resulted in no visible scars or malfunction. Eight patients experienced uneventful postoperative periods, while one patient suffered from scrotal flap prolapse. All the patients were sexually active and reported sexual satisfaction, with no need of lubrication. CONCLUSION: The reported technique achieves the outcomes of creating a neovagina of sufficient volume, without serious stenosis in long-term follow-up. The neovagina is lined with mucosa and has appropriate lubrication as well as good sexual sensation. The reported method is easy and economical to perform and retains enough tissues for vulvoplasty to achieve a superior cosmetic appearance, with rare risk of complications and donor area malfunction. Additionally, this technique is feasible and advantageous to the patients who have insufficient peno-scrotal skin for neovaginal lining as well as those with unfavorable previous vaginoplasty. All of these indicate that this technique is a promising option for vaginoplasty in male-to-female transsexual surgery. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Scrotal-Septal Fasciocutaneous Flap Used as a Multifunctional Coverage for Prior Failed Hypospadias Repair.

OBJECTIVES: The study aims to report the method and outcome of using scrotal-septal fasciocutaneous flap as a multifunctional coverage for prior failed hypospadias repair. METHODS: From January 2014 to June 2015, 18 hypospadias patients who have undergone repeated failed surgeries were enrolled. Their penile skin, urethral plate and dartos fascia are not enough to reconstruct the urethra, but have well-developed scrota. We performed urethroplasty by buccal mucosa free grafting and tubularized anastomosis 6 months after the urethroplasty. Then, scrotal-septal fasciocutaneous flap was used to be a multifunctional coverage on the surface of anastomotic urethra, which was a waterproof layer and cutaneous coverage. RESULTS: The skin flaps survived and the incisions healed in 18 patients. No fistula and stricture occurred. The scar of donor site seemed like a new scrotal raphe. The flap can slip slightly along with the preputial movement and retain the original sense of touch. All patients were followed up at 1 and 6 months by telephone or in person and gained good recoveries. CONCLUSION: Scrotal-septal fasciocutaneous flap, including sufficient fascia tissue, reliable blood supply and skin coverage, is a good choice for the coverage of anastomotic urethra as both the waterproof layer and skin coverage, especially for hypospadias patients who have undergone several failed operations.

[EFFECTIVENESS OF VAGINOPLASTY WITH ACELLULAR DERMAL MATRIX AND MIXED PARTICLES GRAFT].

OBJECTIVE: To evaluate the effectiveness or acellular dermal matrix (ADM) with autologous buccal micro mucosa and micro skin graft in vaginoplasty. METHODS: A retrospective analysis was made on the clinical data of 67 patients with vaginal agenesis treated between July 2006 and June 2013. ADM and mixed particles were used in 20 cases (ADM group) and mixed particles graft in 47 cases (control group) in vaginoplasty. There was no significant difference in age between 2 groups (t=0.233, P=0.816). The depth, diameter, and volume of neovagina, epithelization time, stent needing time, and female sexual function index (FSFI) score were compared between 2 groups. RESULTS: There was no significant difference in operation time and amount of bleeding between 2 groups (t = -1.922, P = 0.059; t = 0.398, P = 0.692). The patients were followed up 11-38 months (mean, 16.08 months). Fifteen cases in ADM group and 29 cases in control group had sexual life after operation. Bleeding after operation occurred in 6 cases (2 in ADM group and 4 in control group). No stenosis was observed. Difference in epithelization time was not statistically significant (t = -1.938, P = 0.057). However, the stent needing time of ADM group was significantly shorter than that of control group (t = 7.020, P = 0.000). The neovagina was ideal in wetness degree, smoothness, flexibility, and hairlessness during follow-up. The depth, diameter, and volume of vagina had no significant difference between 2 groups (P > 0.05) at last follow-up, which were close to normal vagina. The other patients had normal sexual function except 1 patient whose FSFI score was less than 23; no statistically significant difference was found in FSFI score between 2 groups (P > 0.05). CONCLUSION: On the basis of mixed particles grafting, the ADM could improve trestle structure for resisting contracture. The effectiveness is better than merely mixed particles graft. The procedure has satisfactory anatomical and functional results.

[Vaginoplasty with autologous buccal micromucosa combined with acellular allogenic dermal matrix].

OBJECTIVE: To introduce and evaluate the technical feasibility and anatomical and functional outcomes of one-stage vaginoplasty with autologous buccal micromucosa combined with acellular allogenic dermis. METHODS: We retrospectively reviewed our experiences with 17 patients with Mayer- Rokitansky-Kuster-Hauser syndrome treated with primary surgery from September 2010 to April 2013. All patients underwent vaginoplasty with autologous buccal micromucosa combined with acellular allogenic dermis. We describe the details of this technique, observe the time of epithelization and evaluate the long- term anatomical, functional, and sexual outcomes. RESULTS: The time of epithelization was 13 d (range: 12-15 d). At a mean follow-up of 15 months (range: 12-24 months), the mean postoperative dependence on the vaginal stent was 11.7 ± 1.64 months (range: 9-15 months), the mean depth of the neovagina was (9.0 ± 0.94) cm (range: 7-11 cm), the mean circumference was (12.3 ± 1.36) cm (range: 10.0-14.5 cm) and the mean volume was (105 ± 10) ml (range 85-120 ml). The mean female sexual function index score of the 12 sexually active patients was 29.5 ± 2.6. No spouse reported discomfort during intercourse. CONCLUSIONS: Vaginoplasty with autologous buccal micromucosa combined with acellular allogenic dermis is an effective and feasible approach for patients with Mayer-Rokitansky-Kuster-Hauser syndrome. The procedure has satisfactory long-term anatomical and functional results. The use of the acellular allogenic dermis is limited by the high price and the potential infection.

A new surgical technique of hymenoplasty.

OBJECTIVE: To review data from patients who have undergone hymenoplasty with a novel surgical technique, termed the STSI (suture three stratums around the introitus) method. METHODS: In a retrospective study, data were reviewed from patients who underwent hymenoplasty by STSI at a center in Beijing, China, between January 2010 and January 2014. Patients were scheduled to attend a follow-up appointment 1 month after surgery. Long-term follow-up was conducted by telephone. Follow-up data and preoperative and postoperative photos were assessed. RESULTS: Overall, 125 patients had undergone hymenoplasty using the STSI method. Only 1 (0.8%) patient had an early postoperative complication (uncontrolled bleeding). Among the 99 patients who returned for follow-up at 1 month, healing was recorded for 91 (91.9%). Long-term follow-up suggested that no patient had persistent dyspareunia, menstruation changes, or other health problems after the surgery. Among 51 patients who reported sexual intercourse since the surgery, 47 (92.2%) were satisfied with the outcome and 28 (54.9%) reported blood loss during the first intercourse. CONCLUSION: The STSI method seems to be an effective, enduring, and safe technique of hymenoplasty.

Measurements of female genital appearance in Chinese adults seeking genital cosmetic surgery: a preliminary report from a gynecological center.

INTRODUCTION AND HYPOTHESIS: Accurate and comprehensive measurements of the external genitalia in female adults are of great significance in surgery designs and for aesthetic evaluation in genital plastic surgeries. The authors carried out a 319-case study and provided baseline data and morphometric reference for plastic surgery involving the genital deformity caused by trauma or burns and male-to-female transsexual operations. METHODS: Our study design recruited 319 women referred to the out-patient clinic from August 2010 to August 2013. From each individual we measured 16 parameters and assessed the significance of variations in age, height, weight, BMI, and marital status (as a proxy for parity). We tried to establish a female external genitalia database of the population presenting for cosmetic surgery and define the general proportions of female genitalia in Chinese adults from the data we obtained. RESULTS: A wide range of values was noted in female genital measurements especially in labia minora parameters. Four parameters, including clitoral prepuce length, clitoris to urethra, labial length, and perineal body length had a proportional relationship to some extent. The position of the clitoris and urethral orifice was found to be regular in female adults. Compared with unmarried women, perineal body length decreased (P = 0.048), while the apex to perineum (bilateral) and labial length increased (P = 0.005, 0.006, <0.0001) in those who were married. Several parameters were statistically significantly associated with age, height, weight, BMI, and marital status. CONCLUSIONS: We presented an external genitalia database of Chinese female adults asking for cosmetic surgery. Although the ranges of genital measurements vary, there is a proportional relationship in female genital appearance, which should be heeded in surgical designs and genital aesthetic evaluation.

Aesthetic Labia Minora Reduction with Combined Wedge-edge Resection: A Modified Approach of Labiaplasty.

BACKGROUND: Nowadays, the demand for female genital rejuvenation procedures especially for labiaplasty is surging. Labia minora reduction has been the most practiced esthetic procedure for the female genitalia in China. Gynecological plastic surgeons have proposed several methods for labia reduction, but there is no consensus on which one is the best choice. Patients often receive re-operations for inadequate resection and asymmetry with existing methods. Here we present a modified method of labiaplasty combined wedge and edge resection and to discuss the appropriate indications of this method. METHODS: From January 2009 to March 2014, we performed 524 labia esthetic surgeries. The methods we used mainly include simple edge resection, wedge resection, modified de-epithelialization, and the combined method discussed in this article. Forty-nine patients aged from 25 to 45 years were selected to receive combined wedge-edge labial resection and were retrospectively reviewed. Patients were required to come back for follow-up assessment at 1 and 6 months. RESULTS: Twenty-one of forty-nine (42.9 %) patients underwent unilateral labial reduction. The average time for the procedures was 56 min. The mean follow-up was 4.5 months. All the surgeries were successfully performed and 47 patients experienced an uneventful postoperative period. A minor dehiscence occurred in two patients. One of the patients received a revision surgery correcting a postoperative asymmetry malformation. Finally, all the patients were satisfied with the esthetic appearance. CONCLUSION: The combined wedge-edge reduction of the labia minora is a simple and safe method associated with high satisfaction and a low complication rate. Therefore, we propose this combined procedure for bi-dimensional and/or unilateral hypertrophied labia minora especially in those who require removal of the dark margin of the labia.

Three-layer reconstruction of large urethrocutaneous fistulas using scrotal-septal flaps.

INTRODUCTON: The repair of large urethrocutaneous fistulas (UCFs) commonly involves reconstruction of the urethra, waterproof layer and skin coverage, which deploy different tissues from different flaps. To simplify the multiple procedures, we explored to use one flap (a scrotal-septal flap) to reconstruct three layers in UCF repairing in one stage. METHODS: Between January 2011 and July 2012, 29 patients with large UCFs (ranging from 1.0 to 2.0 cm) were treated using scrotal-septal flaps for three-layer reconstruction. Every patient has an unbroken scrotum. The hair follicles in the donor site were destroyed using a radiosurgical knife 2 months before the operation. The flap was divided into three zones, which were flipped, folded, and extended respectively to form the urethra, waterproof layer and skin coverage. RESULTS: The patients were followed up between 6 to 12 months. No fistula recurrence was observed. All flaps survived, except in one case, in which the distal skin flap was lost but stenosis or fistula did not develop. Two patients underwent second operations to refine the aesthetic results. CONCLUSIONS: The scrotal-septal flap can be transferred in an overturning-folding-advancement fashion and can simultaneously involve the reconstruction of the urethra, waterproof barrier and skin coverage. This is a simple and reliable alternative for large UCFs (≤2 cm) repairing at the penoscrotal junction; however, it cannot be used in patients with a damaged scrotal septum.

Ten years' experience for hypospadias repair: combined buccal mucosa graft and local flap for urethral reconstruction.

OBJECTIVES: To share our experience in hypospadias repair and discuss the clinical implications of our method, which consists of a combined buccal mucosa graft and local flap for urethroplasty. PATIENTS AND METHODS: 1,394 cases (median age 11.3 years, age range 5 months to 53 years) of hypospadias which were repaired using our method between July 2000 and December 2010 in our department were included in this study. The patients who had a short penis or did not have chordee were excluded from the data. 588 cases (42.2%) had previously undergone surgery in other hospitals but failed; 806 (57.8%) cases had undergone the first treatment in our department. RESULTS: Of the 806 cases which had undergone the first treatment in our department, we successfully reconstructed the urethra for 747 patients (92.3%), and 59 patients had complications (7.7%); of the 588 cases which had previously undergone surgery but failed, we successfully reconstructed the urethra for 522 patients (88.8%), and 66 patients had complications (11.2%). The most common complication was urethra fistula (70; 5%); other complications include necrosis of the skin flap and infection resulting in wound disruption (19; 1.4%), urethral diverticula (11; 0.8%) and urethral stricture (25; 1.8%). CONCLUSIONS: Our method appears to be a safe, simple and satisfactory surgical procedure and can provide relatively enough tissue to reconstruct the urethra with a higher success rate.

Long-term outcomes of vaginoplasty with autologous buccal micromucosa.

OBJECTIVE: To evaluate the technical feasibility and anatomical and functional outcomes of one-stage vaginoplasty with autologous buccal micromucosa. METHODS: We retrospectively reviewed our experiences with 38 patients with vaginal agenesis treated with primary surgery from June 2006 to April 2012. All patients underwent transvestibular vaginoplasty with autologous buccal micromucosa. We describe the details of this technique and evaluate the long-term anatomical, functional, and sexual outcomes. RESULTS: A total of 38 patients (33 with Mayer-Rokitansky-Kuster-Hauser syndrome and five with complete androgen insensitivity syndrome) were included in the present study. The mean operative time was 86.4 minutes (range 75-120 minutes). The mean blood loss was 68.5 mL (range 40-80 mL). At a mean follow-up of 33.5 months (range 15-76 months), the mean depth of the neovagina was 8.5±0.66 cm (range 7-10 cm), the mean circumference was 12.3±1.24 cm (range 10-15 cm), and the mean volume was 100±8 mL (range 85-120 mL). By histologic examination, we found the neovaginal mucosa was stratified nonkeratinized squamous mucosa and had secretory function. The mean female sexual function index score of the 32 sexually active patients was 28.8±2.1. No spouse reported discomfort during intercourse. The mean postoperative dependence on the vaginal stent was 15±2.1 months (range 9-20 months). CONCLUSION: Transvestibular vaginoplasty with autologous buccal micromucosa is an effective and feasible approach for patients with Mayer-Rokitansky-Kuster-Hauser syndrome and complete androgen insensitivity syndrome. The procedure has satisfactory long-term anatomical and functional results. LEVEL OF EVIDENCE: III.

Spontaneous ventral urethral fistula in a young man whose mother had a retained IUD in uterus during the gestation.

Urethral fistula is rare and is usually a complication of penile and urethral surgery. A few congenital cases have been reported. To our knowledge, there are only 2 reports about spontaneous ventral urethral fistula in the English literature. We present what we believe is the first case of a patient with spontaneous ventral urethral fistula whose mother had a retained IUD in uterus during the gestation.

'Expansion in-situ' concept as a new technique for expanding skin and soft tissue.

Techniques for expanding skin and soft tissue are widely used to repair damaged areas since they facilitate the provision of new, additional skin tissue with similar quality, texture and color to that surrounding the defective area. Conventional expansion techniques involve placing expanders under the normal skin adjacent to a lesion. However, these techniques may involve additional incisions, complications with blood supply and 'dog-ear' deformities and may result in a low utilization rate of the expanded tissue. When reconstructing small defects that may not be sutured directly, these shortcomings, particularly the requirement to make additional incisions, limit the application of conventional techniques. The current study presents a novel approach to expansion called the 'expansion in-situ' technique. In this technique, the lesion is used as the center for expansion and expanders of optimal size are implanted under the lesion and surrounding normal soft tissue. Following expansion, the damaged area is excised directly. In order to avoid poor healing of the incision made during expander implantation, the overlapping suturing of both cut sides is conducted. This enlarges the contact area of both sides of the incision, thereby avoiding incision dehiscence and increasing wound healing during the expansion process. Between August 2006 and July 2011, the expansion in-situ technique was applied in 10 cases involving either nevus excision or scar removal. All 10 cases were treated successfully. Five of the cases were followed up over 1-3 years. The 'expansion in-situ' technique is likely to be useful for avoiding additional incisions and improving the utilization rate of expanded skin flaps.