A rotor dynamic model is built up for investigating the effects of tightening torque on dynamic characteristics of low pressure rotors connected by a spline coupling.The experimental rotor system is established using ...A rotor dynamic model is built up for investigating the effects of tightening torque on dynamic characteristics of low pressure rotors connected by a spline coupling.The experimental rotor system is established using a fluted disk and a speed sensor which is applied in an actual aero engine for speed measurement.Through simulating calculation and experiments,the effects of tightening torque on the dynamic characteristics of the rotor system connected by a spline coupling including critical speeds,vibration modes and unbalance responses are analyzed.The results show that when increasing the tightening torque,the first two critical speeds and the amplitudes of unbalance response gradually increase in varying degrees while the vibration modes are essentially unchanged.In addition,changing axial and circumferential positions of the mass unbalance can lead to various amplitudes of unbalance response and even the rates of change.展开更多
Background and Objectives: The Quercus (oak) fruit and especially the internal layer of the fruit (jaft) is rich in tannin (polyphenolic compound) and due to its astringent effects on the smooth muscles, we decided to...Background and Objectives: The Quercus (oak) fruit and especially the internal layer of the fruit (jaft) is rich in tannin (polyphenolic compound) and due to its astringent effects on the smooth muscles, we decided to evaluate this effect of extract of Oak Gall for vaginal tightening and rejuvenation in women with vaginal relaxation. Methods: This double blind clinical trial was performed on women with vaginal relaxation at Asali Hospital in Khorramabad from May to October 2012 and was candidate for colporrhaphy due to different types of pelvic organ prolapse. Sampling method was done on nonprobability basis according to the number of patients referred to clinic. Using blocked random allocation method, the participants were divided into 4 groups of 30 patients (three intervention group and one control group) who were age-matched. Then, an extract of Oak Gall in specified concentrations (10 - 15 and 20 grams in 1.5%, 2% and 2.5% jells) were administered to each intervention group. Finally, the obtained data were analyzed with Chi-square, Pearson, Fisher’s exact test and ANOVA using SPSS software version 19. Results: A total of 120 patients entered into the study with mean age of 36 ± 5.4 years. The evaluation of mean scores showed that sense of sexual satisfaction and orgasm, sense of vaginal tightness during intercourse, sense of vaginal lubrication and loss of vaginal dryness was significantly improved in patients in intervention group. Also other parameters including urinary incontinence, sense of vaginal mass exit, lack of orgasm, sense of air outflow during intercourse, sense of calmness after sex and loss of libido were significantly reduced in the group of patients who received jell 2.5% compared to other groups (P Conclusion: Our findings show that using topical jell of Oak Gall not only is associated with contracting effects, but also improves vaginal lubrication and reduces its dryness. Regarding the lack of previous studies in this field and considering some limitations of this study, we suggest that Oak Gall to be used for management of women with vaginal relaxation.展开更多
42 patients with broad age and ethnic demographics where treated with a novel, non-excisional, minimally invasive device to coagulate a very thin layer of sub-dermal septo-fascial fat, denature the deep reticular derm...42 patients with broad age and ethnic demographics where treated with a novel, non-excisional, minimally invasive device to coagulate a very thin layer of sub-dermal septo-fascial fat, denature the deep reticular dermis and tighten the skin and sub-dermal matrix of connective tissue. The detailed treatment protocol and results are presented. Patients were observed for up to 6 month following the procedure. No major side effects were observed. The aesthetic outcome of this non-excisional procedure includes improvement of the position and shape of the cheek, lower lid-cheek junction, jawline and neck. The overall aesthetic results deliver a noticeable and impressive tightening of the soft-tissue and may be compared with a conservative, small excisional procedure. The authors propose this versatile device and treatment as a non-excisional, moderate facial rejuvenation procedure on its own, or as an adjunct to open procedures performed simultaneously, or as a simplified treatment for secondary skin laxity in combination with a lift procedure.展开更多
Lax crepey skin is a major unsightly finding throughout the face and body that occurs from chronological aging and environmental photodamage. Surgical lifting procedures are unable to induce sufficient neocollagenesis...Lax crepey skin is a major unsightly finding throughout the face and body that occurs from chronological aging and environmental photodamage. Surgical lifting procedures are unable to induce sufficient neocollagenesis and also associated with visible scars, risks and recovery time. In this preliminary report, non-invasive delivery of microfocused ultrasonic thermal coagulation points at two levels of the dermis outside the orbital rims was effective in reduction of crepey, wrinkled and sagging skin for about 1 ? years in nineteen treated patients. Matched Orientation Mirror Imaging produced an average brow height elevation of 1 - 2 mm. Microfocused thermal coagulation points at multiple tissue levels also induced tissue tightening and reduction of crepey wrinkled skin in the décolletage, brachium, periumbilicus, inner thigh and knees. Investigator and Subject Global Aesthetic Improvement Scale graded responses that correlated to the severity of the degree of crepiness and laxity. Pain management during the procedure included the use of infiltration of local anesthesia. No permanent adverse events were observed. Further innovations in the current technology are needed for more effective and safer delivery of energy to improve the appearance of crepey and lax tissue in the head, neck and body.展开更多
Background: A novel Radiofrequency-Assisted Liposuction (RFAL) technology was evaluated clinically. Parallel original histological studies were conducted to substantiate the technology’s efficacy in skin tightening, ...Background: A novel Radiofrequency-Assisted Liposuction (RFAL) technology was evaluated clinically. Parallel original histological studies were conducted to substantiate the technology’s efficacy in skin tightening, and cellulite improvement. Methods: BodyTiteTM system, utilizing the RFAL technology, was used for treating patients on abdomen, hips, flanks and arms. Clinical results were measured on 53 patients up to 6 months follow-up. Histological and biochemical studies were conducted on 10 donors by using a unique GREDECO model of skin fragments cultured under survival conditions. Fragments from RFAL treated and control areas were examined immediately and after 10 days in culture, representing long-term results. Skin fragments from patients with cellulite were also examined. Results: Gradual improvement in circumference reduction (3.9 - 4.9 cm) and linear contraction (8% - 38%) was observed until the third month. These results stabilized at 6 months. No adverse events were recorded. Results were graded as excellent by most patients, including the satisfaction from minimal pain, bleeding, and downtime. Histological analysis of skin fragments immediately following RFAL treatment showed hypodermal coagulation of fat and blood vessels, and structural changes in dermal fibers. After 20 days in culture, fibroblast fibers metabolism was stimulated. Histological changes following cellulite treatment were also noted. Conclusions: The novel RFAL technology offers immediate skin tightening effect that is stable over time. The histological results correlated with the clinical observations of circumference reduction and skin tightening, as expressed by tissue fibers modulation. Moreover, RFAL offers an effective treatment for cellulite by formation of a thick collagen band at the dermal-hypodermal junction.展开更多
The corrosive properties of PVD TiN-Ti-Al type composite titanium nitride layer with titanium and aluminium sub-layers system on the AZ91D magnesium alloy and its sub-layers were investigated by using polarization met...The corrosive properties of PVD TiN-Ti-Al type composite titanium nitride layer with titanium and aluminium sub-layers system on the AZ91D magnesium alloy and its sub-layers were investigated by using polarization method and impedance spectroscopy, specifically, in terms of the hydrothermal tightening effect. The aim was to explain the mechanisms which contribute to high anticorrosive properties obtained by hydrothermal tightening. It was stated that the hydrothermal treatment changes the surface topography of the examined layers, most probably due to the formation of a continuous titanium oxides film. Tightening significantly modifies the corrosion resistance of the particular component sub-layers of the TiN-Ti-Al layer which exhibits optimum electrochemical parameters. It was shown that the increase of the electrochemical parameters is controlled by tightening of the outside titanium nitride layer, whereas the aluminium sub-layer plays a critical role in creating proper conditions for the hydrothermal tightening of titanium nitride.展开更多
The periorbital area is the third highest-ranking area for cosmetic surgery. However, surgery in this area presents a number of difficulties and safety concerns. First generation Monopolar RF treatments in this area w...The periorbital area is the third highest-ranking area for cosmetic surgery. However, surgery in this area presents a number of difficulties and safety concerns. First generation Monopolar RF treatments in this area were usually associated with considerable pain and long downtime. In the present clinical study, we used the iFine handpiece of the EndyMed PRO, multi-source phase-controlled radiofrequency (RF) for Non-invasive, pain free, skin rejuvenation of the periorbital area. The study included eleven (11) subjects, treated for periorbital signs of aging (iFine handpiece, EndyMed PRO platform, EndyMed Medical, Caesarea, Israel). The degree of clinical improvement was assessed by the global aesthetic improvement scale (GAIS) and subjects satisfaction by post treatment questionnaires. 91% of patients showed good to excellent improvement as a result of the treatment. Subjects satisfaction showed that 55% of patients reported that they were very satisfied, 45% were satisfied while none were dissatisfied. There were no incidences of infections, scarring, hypopigmentation, or any other serious complications.展开更多
Background: Acoustic wave has been used for many medical purposes, and although it is widely applied in cosmetic procedures, it has not been conducted for facial rejuvenation and tightening. Acoustic wave has been pro...Background: Acoustic wave has been used for many medical purposes, and although it is widely applied in cosmetic procedures, it has not been conducted for facial rejuvenation and tightening. Acoustic wave has been proven to penetrate deeper than subcutaneous tissue, independent of skin color, and to be beneficial for skin tightening and body contouring. Objective: To evaluate the effectiveness of a single acoustic wave treatment session using unique focused and radial acoustic waves for facial tightening. Participants: Sixty Asian patients were treated between the years 2016 and 2018. The single acoustic wave treatment session consists of focused long planar acoustic pulses thought to have an effect on cells and their metabolism resulting in an increased release of fat, and radial short acoustic pulses thought to have an effect on tissues activating blood and lymphatic flow. Patients did not undergo any form of medical aesthetic treatment during the study. Measurements: Digital photographs and three-dimensional imaging were used to evaluate the results. Results: Objective assessments with digital photographs and superimposed three-dimensional color images showed preferable facial tightening effects and marked volumetric reduction on the lower one-third of the face. These results were obtained without the edematous reactions observed in laser and radiofrequency therapies, and were sustained up to 12 months. All of the patients reported satisfaction with the results and convenience of the procedure. Complications were minor and transitory, consisting of a slight tingly sensation to the teeth during the treatment, and mild erythema resolving within 5 hours. Side effects were not observed. Conclusions: The advantages of the single acoustic wave treatment are the high potency of facial tightening effects, reduction of discomfort and side effects. Taken together, these characteristics facilitate the ability to give repeated treatments and provide an alternative or adjunct treatment for patients with improved results.展开更多
In a bid to prevent financial crisis andalleviate its impact to Chinese enonomy,thegovernment is studying on an early warningsystem for financial risk management.
ChinAfrica: The Tanzam Railway is a symbol of Sino-Tanzanian friendship. What's your opinion on the development of the bilateral relations now?Abdulrahaman A. Shimbo: Yes indeed, the "Tanzania-Zambia Railway," f...ChinAfrica: The Tanzam Railway is a symbol of Sino-Tanzanian friendship. What's your opinion on the development of the bilateral relations now?Abdulrahaman A. Shimbo: Yes indeed, the "Tanzania-Zambia Railway," famously known as the TAZARA, is the most iconic symbol of our two countries' unwavering and close brotherly relations, It is truly a remarkable example of China's selfless act toward its friends, at a time when China itself had fewer economic, technological and military capacities.展开更多
Background: Skin aging is an unavoidable process aggravated by environmental agents. Among other energy devices, non-invasive radiofrequency (RF) technology is widely used for skin tightening and body contouring as it...Background: Skin aging is an unavoidable process aggravated by environmental agents. Among other energy devices, non-invasive radiofrequency (RF) technology is widely used for skin tightening and body contouring as it is simpler and more affordable than other technologies that also minimize pain and side-effects. However, most of the current RF devices do not provide automatic skin temperature control and it is difficult to achieve controlled, deep, and harmless thermal increase, so treatment performance and safety is dependent on the operator’s movements and expertise. Objective: To show the potential of numerical simulations for optimizing the design of monopolar and bipolar RF electrodes that are capable of providing homogeneous, deep and controlled heating. Materials and methods: In-silico models were developed and analyzed using Comsol Multiphysics software to simulate the RF effect produced in tissue by rotating monopolar and bipolar electrodes with different geometries from the Sculpt & Shape RF device (Sinclair, Spain), operating at frequencies of 0.5 and 1 MHz. Ex-vivo and in-vivo proof-of-concept tests were carried out to validate the simulations. Finally, treatments were performed on 16 subjects and a total of 78 body areas to assess the clinical results generated by the RF electrodes for skin tightening and body contouring. Results: In-silico studies emulated the superficial and deep dispersion of heat due to the release of RF energy into human skin tissue. The rotating electrodes (monopolar and bipolar) and the selected RF frequency (0.5 and 1 MHz) determined the homogeneity of the thermal distribution, the penetration depth (between 4.37 mm and 25.0 mm) and the heating dynamics (between 30 and 100 seconds to reach the target skin temperature), which were confirmed by ex-vivo and in-vivo tests. In addition, real treatments on facial and body areas using skin temperatures of between 43˚C and 44˚C showed consistent results with good clinical efficacy for skin tightening, circumference reduction and cellulite reduction, with no adverse effects and high subject satisfaction. Conclusions: New monopolar and bipolar RF electrodes with rotating technology have been designed and optimized using numerical simulations. The use of in-silico studies and accurate models that reproduce the thermal behavior of human biological tissues can be used to better understand RF devices and to develop superior, efficient, and safer products more quickly.展开更多
Background: Non-ablative radiofrequency (RF) technology is widely used for the treatment of signs of aging, skin laxity, localized fat and cellulite. However, many RF devices suffer from technical limitations that mak...Background: Non-ablative radiofrequency (RF) technology is widely used for the treatment of signs of aging, skin laxity, localized fat and cellulite. However, many RF devices suffer from technical limitations that make the results highly dependent on the user’s experience or clinical limitations that compromise safety, efficacy and comfort. Objective: To evaluate the efficacy and safety of a novel semi-automatic non-ablative RF device for skin tightening, body shaping and cellulite reduction. Materials and methods: A retrospective multicenter study was performed using a novel rotative RF device with temperature and impedance control (Sculpt&Shape<sup>®</sup>, Sinclair, Spain). 58 subjects underwent a minimum of 4 treatments every 1-2 weeks. A total of 120 treatments (56.7% body and 43.3% facial) and 1034 sessions were performed. Efficacy was evaluated by 3 researchers using the Global Aesthetic Improvement Scale (GAIS) and anthropometric measurements were collected. Subject and practitioner satisfaction were recorded. Safety was evaluated by analyzing the perception of pain during the treatment and the side and adverse effects immediately after treatment and over the next 48 hours. Results: Between 25% and 50% improvement was achieved according to the GAIS. Statistically significant (p < 0.01) abdominal fold reduction of 5.1 mm and circumference reduction of 32.0 mm, 16.4 mm and 13.9 mm were recorded for the abdomen, legs and arms, respectively. 77.5% of subjects and 94.9% of practitioners were either satisfied or very satisfied. Minor adverse effects were found in 0.97% of the sessions. Conclusion: This novel semi-automatic rotative RF device has been found to provide treatments that are effective, safe and comfortable for both practitioners and subjects. .展开更多
文摘A rotor dynamic model is built up for investigating the effects of tightening torque on dynamic characteristics of low pressure rotors connected by a spline coupling.The experimental rotor system is established using a fluted disk and a speed sensor which is applied in an actual aero engine for speed measurement.Through simulating calculation and experiments,the effects of tightening torque on the dynamic characteristics of the rotor system connected by a spline coupling including critical speeds,vibration modes and unbalance responses are analyzed.The results show that when increasing the tightening torque,the first two critical speeds and the amplitudes of unbalance response gradually increase in varying degrees while the vibration modes are essentially unchanged.In addition,changing axial and circumferential positions of the mass unbalance can lead to various amplitudes of unbalance response and even the rates of change.
文摘Background and Objectives: The Quercus (oak) fruit and especially the internal layer of the fruit (jaft) is rich in tannin (polyphenolic compound) and due to its astringent effects on the smooth muscles, we decided to evaluate this effect of extract of Oak Gall for vaginal tightening and rejuvenation in women with vaginal relaxation. Methods: This double blind clinical trial was performed on women with vaginal relaxation at Asali Hospital in Khorramabad from May to October 2012 and was candidate for colporrhaphy due to different types of pelvic organ prolapse. Sampling method was done on nonprobability basis according to the number of patients referred to clinic. Using blocked random allocation method, the participants were divided into 4 groups of 30 patients (three intervention group and one control group) who were age-matched. Then, an extract of Oak Gall in specified concentrations (10 - 15 and 20 grams in 1.5%, 2% and 2.5% jells) were administered to each intervention group. Finally, the obtained data were analyzed with Chi-square, Pearson, Fisher’s exact test and ANOVA using SPSS software version 19. Results: A total of 120 patients entered into the study with mean age of 36 ± 5.4 years. The evaluation of mean scores showed that sense of sexual satisfaction and orgasm, sense of vaginal tightness during intercourse, sense of vaginal lubrication and loss of vaginal dryness was significantly improved in patients in intervention group. Also other parameters including urinary incontinence, sense of vaginal mass exit, lack of orgasm, sense of air outflow during intercourse, sense of calmness after sex and loss of libido were significantly reduced in the group of patients who received jell 2.5% compared to other groups (P Conclusion: Our findings show that using topical jell of Oak Gall not only is associated with contracting effects, but also improves vaginal lubrication and reduces its dryness. Regarding the lack of previous studies in this field and considering some limitations of this study, we suggest that Oak Gall to be used for management of women with vaginal relaxation.
文摘42 patients with broad age and ethnic demographics where treated with a novel, non-excisional, minimally invasive device to coagulate a very thin layer of sub-dermal septo-fascial fat, denature the deep reticular dermis and tighten the skin and sub-dermal matrix of connective tissue. The detailed treatment protocol and results are presented. Patients were observed for up to 6 month following the procedure. No major side effects were observed. The aesthetic outcome of this non-excisional procedure includes improvement of the position and shape of the cheek, lower lid-cheek junction, jawline and neck. The overall aesthetic results deliver a noticeable and impressive tightening of the soft-tissue and may be compared with a conservative, small excisional procedure. The authors propose this versatile device and treatment as a non-excisional, moderate facial rejuvenation procedure on its own, or as an adjunct to open procedures performed simultaneously, or as a simplified treatment for secondary skin laxity in combination with a lift procedure.
文摘Lax crepey skin is a major unsightly finding throughout the face and body that occurs from chronological aging and environmental photodamage. Surgical lifting procedures are unable to induce sufficient neocollagenesis and also associated with visible scars, risks and recovery time. In this preliminary report, non-invasive delivery of microfocused ultrasonic thermal coagulation points at two levels of the dermis outside the orbital rims was effective in reduction of crepey, wrinkled and sagging skin for about 1 ? years in nineteen treated patients. Matched Orientation Mirror Imaging produced an average brow height elevation of 1 - 2 mm. Microfocused thermal coagulation points at multiple tissue levels also induced tissue tightening and reduction of crepey wrinkled skin in the décolletage, brachium, periumbilicus, inner thigh and knees. Investigator and Subject Global Aesthetic Improvement Scale graded responses that correlated to the severity of the degree of crepiness and laxity. Pain management during the procedure included the use of infiltration of local anesthesia. No permanent adverse events were observed. Further innovations in the current technology are needed for more effective and safer delivery of energy to improve the appearance of crepey and lax tissue in the head, neck and body.
文摘Background: A novel Radiofrequency-Assisted Liposuction (RFAL) technology was evaluated clinically. Parallel original histological studies were conducted to substantiate the technology’s efficacy in skin tightening, and cellulite improvement. Methods: BodyTiteTM system, utilizing the RFAL technology, was used for treating patients on abdomen, hips, flanks and arms. Clinical results were measured on 53 patients up to 6 months follow-up. Histological and biochemical studies were conducted on 10 donors by using a unique GREDECO model of skin fragments cultured under survival conditions. Fragments from RFAL treated and control areas were examined immediately and after 10 days in culture, representing long-term results. Skin fragments from patients with cellulite were also examined. Results: Gradual improvement in circumference reduction (3.9 - 4.9 cm) and linear contraction (8% - 38%) was observed until the third month. These results stabilized at 6 months. No adverse events were recorded. Results were graded as excellent by most patients, including the satisfaction from minimal pain, bleeding, and downtime. Histological analysis of skin fragments immediately following RFAL treatment showed hypodermal coagulation of fat and blood vessels, and structural changes in dermal fibers. After 20 days in culture, fibroblast fibers metabolism was stimulated. Histological changes following cellulite treatment were also noted. Conclusions: The novel RFAL technology offers immediate skin tightening effect that is stable over time. The histological results correlated with the clinical observations of circumference reduction and skin tightening, as expressed by tissue fibers modulation. Moreover, RFAL offers an effective treatment for cellulite by formation of a thick collagen band at the dermal-hypodermal junction.
文摘The corrosive properties of PVD TiN-Ti-Al type composite titanium nitride layer with titanium and aluminium sub-layers system on the AZ91D magnesium alloy and its sub-layers were investigated by using polarization method and impedance spectroscopy, specifically, in terms of the hydrothermal tightening effect. The aim was to explain the mechanisms which contribute to high anticorrosive properties obtained by hydrothermal tightening. It was stated that the hydrothermal treatment changes the surface topography of the examined layers, most probably due to the formation of a continuous titanium oxides film. Tightening significantly modifies the corrosion resistance of the particular component sub-layers of the TiN-Ti-Al layer which exhibits optimum electrochemical parameters. It was shown that the increase of the electrochemical parameters is controlled by tightening of the outside titanium nitride layer, whereas the aluminium sub-layer plays a critical role in creating proper conditions for the hydrothermal tightening of titanium nitride.
文摘The periorbital area is the third highest-ranking area for cosmetic surgery. However, surgery in this area presents a number of difficulties and safety concerns. First generation Monopolar RF treatments in this area were usually associated with considerable pain and long downtime. In the present clinical study, we used the iFine handpiece of the EndyMed PRO, multi-source phase-controlled radiofrequency (RF) for Non-invasive, pain free, skin rejuvenation of the periorbital area. The study included eleven (11) subjects, treated for periorbital signs of aging (iFine handpiece, EndyMed PRO platform, EndyMed Medical, Caesarea, Israel). The degree of clinical improvement was assessed by the global aesthetic improvement scale (GAIS) and subjects satisfaction by post treatment questionnaires. 91% of patients showed good to excellent improvement as a result of the treatment. Subjects satisfaction showed that 55% of patients reported that they were very satisfied, 45% were satisfied while none were dissatisfied. There were no incidences of infections, scarring, hypopigmentation, or any other serious complications.
文摘Background: Acoustic wave has been used for many medical purposes, and although it is widely applied in cosmetic procedures, it has not been conducted for facial rejuvenation and tightening. Acoustic wave has been proven to penetrate deeper than subcutaneous tissue, independent of skin color, and to be beneficial for skin tightening and body contouring. Objective: To evaluate the effectiveness of a single acoustic wave treatment session using unique focused and radial acoustic waves for facial tightening. Participants: Sixty Asian patients were treated between the years 2016 and 2018. The single acoustic wave treatment session consists of focused long planar acoustic pulses thought to have an effect on cells and their metabolism resulting in an increased release of fat, and radial short acoustic pulses thought to have an effect on tissues activating blood and lymphatic flow. Patients did not undergo any form of medical aesthetic treatment during the study. Measurements: Digital photographs and three-dimensional imaging were used to evaluate the results. Results: Objective assessments with digital photographs and superimposed three-dimensional color images showed preferable facial tightening effects and marked volumetric reduction on the lower one-third of the face. These results were obtained without the edematous reactions observed in laser and radiofrequency therapies, and were sustained up to 12 months. All of the patients reported satisfaction with the results and convenience of the procedure. Complications were minor and transitory, consisting of a slight tingly sensation to the teeth during the treatment, and mild erythema resolving within 5 hours. Side effects were not observed. Conclusions: The advantages of the single acoustic wave treatment are the high potency of facial tightening effects, reduction of discomfort and side effects. Taken together, these characteristics facilitate the ability to give repeated treatments and provide an alternative or adjunct treatment for patients with improved results.
文摘In a bid to prevent financial crisis andalleviate its impact to Chinese enonomy,thegovernment is studying on an early warningsystem for financial risk management.
文摘ChinAfrica: The Tanzam Railway is a symbol of Sino-Tanzanian friendship. What's your opinion on the development of the bilateral relations now?Abdulrahaman A. Shimbo: Yes indeed, the "Tanzania-Zambia Railway," famously known as the TAZARA, is the most iconic symbol of our two countries' unwavering and close brotherly relations, It is truly a remarkable example of China's selfless act toward its friends, at a time when China itself had fewer economic, technological and military capacities.
文摘Background: Skin aging is an unavoidable process aggravated by environmental agents. Among other energy devices, non-invasive radiofrequency (RF) technology is widely used for skin tightening and body contouring as it is simpler and more affordable than other technologies that also minimize pain and side-effects. However, most of the current RF devices do not provide automatic skin temperature control and it is difficult to achieve controlled, deep, and harmless thermal increase, so treatment performance and safety is dependent on the operator’s movements and expertise. Objective: To show the potential of numerical simulations for optimizing the design of monopolar and bipolar RF electrodes that are capable of providing homogeneous, deep and controlled heating. Materials and methods: In-silico models were developed and analyzed using Comsol Multiphysics software to simulate the RF effect produced in tissue by rotating monopolar and bipolar electrodes with different geometries from the Sculpt & Shape RF device (Sinclair, Spain), operating at frequencies of 0.5 and 1 MHz. Ex-vivo and in-vivo proof-of-concept tests were carried out to validate the simulations. Finally, treatments were performed on 16 subjects and a total of 78 body areas to assess the clinical results generated by the RF electrodes for skin tightening and body contouring. Results: In-silico studies emulated the superficial and deep dispersion of heat due to the release of RF energy into human skin tissue. The rotating electrodes (monopolar and bipolar) and the selected RF frequency (0.5 and 1 MHz) determined the homogeneity of the thermal distribution, the penetration depth (between 4.37 mm and 25.0 mm) and the heating dynamics (between 30 and 100 seconds to reach the target skin temperature), which were confirmed by ex-vivo and in-vivo tests. In addition, real treatments on facial and body areas using skin temperatures of between 43˚C and 44˚C showed consistent results with good clinical efficacy for skin tightening, circumference reduction and cellulite reduction, with no adverse effects and high subject satisfaction. Conclusions: New monopolar and bipolar RF electrodes with rotating technology have been designed and optimized using numerical simulations. The use of in-silico studies and accurate models that reproduce the thermal behavior of human biological tissues can be used to better understand RF devices and to develop superior, efficient, and safer products more quickly.
文摘Background: Non-ablative radiofrequency (RF) technology is widely used for the treatment of signs of aging, skin laxity, localized fat and cellulite. However, many RF devices suffer from technical limitations that make the results highly dependent on the user’s experience or clinical limitations that compromise safety, efficacy and comfort. Objective: To evaluate the efficacy and safety of a novel semi-automatic non-ablative RF device for skin tightening, body shaping and cellulite reduction. Materials and methods: A retrospective multicenter study was performed using a novel rotative RF device with temperature and impedance control (Sculpt&Shape<sup>®</sup>, Sinclair, Spain). 58 subjects underwent a minimum of 4 treatments every 1-2 weeks. A total of 120 treatments (56.7% body and 43.3% facial) and 1034 sessions were performed. Efficacy was evaluated by 3 researchers using the Global Aesthetic Improvement Scale (GAIS) and anthropometric measurements were collected. Subject and practitioner satisfaction were recorded. Safety was evaluated by analyzing the perception of pain during the treatment and the side and adverse effects immediately after treatment and over the next 48 hours. Results: Between 25% and 50% improvement was achieved according to the GAIS. Statistically significant (p < 0.01) abdominal fold reduction of 5.1 mm and circumference reduction of 32.0 mm, 16.4 mm and 13.9 mm were recorded for the abdomen, legs and arms, respectively. 77.5% of subjects and 94.9% of practitioners were either satisfied or very satisfied. Minor adverse effects were found in 0.97% of the sessions. Conclusion: This novel semi-automatic rotative RF device has been found to provide treatments that are effective, safe and comfortable for both practitioners and subjects. .