Radiofrequency devices for body shaping: a review and study of 12 patients

Simulation-guided development of advanced PID control algorithm for skin cooling in radiofrequency lipolysis

BACKGROUND

The clinical outcomes of bipolar radiofrequency (RF) lipolysis, a prevalent non-invasive fat reduction procedure, hinge on the delicate balance between effective lipolysis and patient safety, with skin overheating and subsequent tissue damage as primary concerns.

OBJECTIVE

This study aimed to investigate a novel bipolar radiofrequency lipolysis technique, safeguarding the skin through an innovative PID temperature control algorithm.

METHODS

Utilizing COMSOL Multiphysics simulation software, a two-dimensional fat and skin tissue model was established, simulating various PID temperature control schemes. The crux of the simulation involved a comparative analysis of different PID temperatures at 45 °C, 50 °C, and 55 °C and constant power strategies, assessing their implications on skin temperature. Concurrently, a custom bipolar radiofrequency lipolysis device was developed, with ex vivo experiments conducted using porcine tissue for empirical validation.

RESULTS

The findings indicated that with PID settings of Kp = 7, Ki = 2, and Kd = 0, and skin temperature control at 45 °C or 50 °C, the innovative PID-based epidermal temperature control strategy successfully maintained the epidermal temperature within a safe range. This maintenance was achieved without compromising the effectiveness of RF lipolysis, significantly reducing the risk of thermal damage to the skin layers.

CONCLUSION

Our research confirms the substantial practical utility of this advanced PID-based bipolar RF lipolysis technique in clinical aesthetic procedures, enhancing patient safety during adipose tissue ablation therapies.

Experimental evaluation of high intensity focused ultrasound for fat reduction of ex vivo porcine adipose tissue

PURPOSE

The present study was stimulated by the continuous growth of commercially available high intensity focused ultrasound (HIFU) systems for fat reduction. Herein, HIFU was utilised for fat ablation using a single-element ultrasonic transducer operating in thermal mode.

METHODS

The custom-made concave transducer that operates at 1.1 MHz was assessed on excised porcine adipose tissue for its ability to reduce fat. Ultrasonic sonications were executed on the adipose tissue utilising acoustical power between 14 and 75 W and sonication time in the range of 1-10 min. The mass of the adipose tissue sample was weighed afore and after ultrasonic sonications and the effect of the sonication on the mass change was recorded.

RESULTS

Mass change was linearly dependent with either increasing acoustical power or sonication time and was in the range of 0.46-1.9 g. High acoustical power of 62.5 W for a sonication time of 1 min and a power of 75 W for a sonication time of 5 min, respectively resulted in the formation of a lesion or possible cavitation on the piece of excised adipose tissue.

CONCLUSION

The study demonstrated the efficacy of the proposed transducer in achieving a reduction of excised fat tissue. The present findings indicate the potential use of the transducer in a HIFU system indicated for the reduction of subcutaneous adipose tissue where increased values of acoustical power can result in increased amounts of fat reduction.

Radiofrequency and skin rejuvenation: a systematic review

Increasingly, there is an attempt to minimize expression lines through esthetic procedures, and radiofrequency (RF) is one of the therapeutic modalities. This article aims to systematically review the literature on the different types of RF treatment in clinical trials and in variables related to the aging process. This systematic review included 21 articles that treated 354 people with different physical characteristics. The most used RF was the fractional followed by the non-ablative RF. There was a large discrepancy in relation to the types and parameters. A parameter that did not show so much divergence was the temperature, which was between 38°C and 44°C. The main temporary adverse reactions reported by the authors were as follows: discomfort, pain, erythema, hyperpigmentation, crusting, swelling, edema, and purple and acneic appearance of the skin. Finally, our study concluded that non-ablative and ablative RF was reported to rejuvenate and improve the features of skin in all skin types.

A Computational and Experimental Study to Compare the Effectiveness of Bipolar Mode With Phase-Shift Angle Mode in Radiofrequency Fat Dissolution on Subcutaneous Tissue

BACKGROUND AND OBJECTIVES

Radiofrequency (RF) energy exposure refers to a popular non-invasive method employed to generate heat in cutaneous and subcutaneous tissues. RF thermal stimulation of adipose tissue has been considered to cause adipocyte metabolism and enzymatic degradation of triglycerides into free fatty acids and glycerol. Bipolar mode (BM) has achieved extensive applications in clinical studies on RF fat dissolution, whereas BM has a less penetration depth than monopolar, result in a higher RF voltage that may be required to increase power to the deeper fat layer of the subcutaneous tissue, and improper power control may easily cause the skin layer to be thermally damaged. To tackle down the mentioned defect, a novel phase-shift angle mode (PM) was proposed in this study based on double-channel bipolar RF. By employing the finite element method (FEM) and performing the ex vivo experiment, the effectiveness of BM was compared with that of PM in RF fat dissolution on subcutaneous tissue. In addition, this study attempted to develop reasonable phase-shift angles capable of achieving fat dissolution effects, while the RF energy of which would not cause the skin layer to be thermally damaged.

STUDY DESIGN/MATERIALS AND METHODS

Two electrode spacings (1 and 2 cm) were applied in BM (BM-1 cm and BM-2 cm, respectively), and six phase-shift angles (i.e., 30°, 60°, 90°, 120°, 150°, and 180°) were set in PM (i.e., PM-30°, PM-60°, PM-90°, PM-120°, PM-150°, and PM-180°). In addition, COMSOL was adopted to conduct a finite element analysis for achieving thermoelectric coupling. Ex vivo experiments were performed with a self-developed double-channel bipolar RF device, through which up to two adjustable phase-shift angle sinusoidal voltages could be generated. Such a device was isolated with a transformer and then connected to four electrodes with a 5 mm diameter contacting the ex vivo porcine abdominal tissue.

RESULTS

Under the RF voltage amplitude of 30 V, and after 1800 seconds of RF heating, no thermally damaged area was formed in the tissue in BM-1 cm and BM-2 cm; in PM-30°, PM-60°, and PM-90°, thermally damaged areas were formed in the fat layer, while the skin layer was not located in the thermally damaged area. Moreover, the temperature in the thermally damaged area attributed to the mentioned three conditions may satisfy the requirement of fat dissolution temperature.

CONCLUSIONS

Under the identical RF voltage and heating time, PM is easier to cause the fat layer of the subcutaneous tissue to be thermally damaged as compared with BM. Accordingly, PM may be enabled to achieve the fat dissolution effect under a relatively low RF voltage as opposed to BM, thus avoiding the possibility of thermal damage of the skin layer attributed to the use of higher RF voltage. In PM, different phase-shift angle significantly affects the electrical and thermal properties of RF energy applied on subcutaneous tissue; the phase-shift angle of RF voltage is likely to be regulated for fat dissolution effect, while the RF energy of which will not cause the skin layer to be thermally damaged.© 2021 Wiley Periodicals LLC.

Efficacy of focused radiofrequency with ultrasound in body contouring: A study of 64 patients

BACKGROUND

Energy-based devices are increasingly used for noninvasive body contouring. Our aim was to investigate the clinical efficacy of combined radiofrequency and ultrasound device for reduction in body circumference in various body parts.

AIMS

The aim of our study was to investigate the clinical efficacy of combined focused radiofrequency and ultrasound device for reduction in body circumference in various body parts. We aimed to report objective measurements in terms of circumference reduction and patient satisfaction scores.

METHODS

We retrospectively analyzed data of 64 patients who were treated with focused radiofrequency and ultrasound device during August 2017-December 2019. All patients had received 4 sessions at one-week interval. Body circumference measurements were done before treatment and one month after the last session. Patients were also asked to score their satisfaction with the result of treatment on a scale of 1 to 5.

RESULTS

Abdomen was treated in 40 patients, thighs in 18 patients, and arms in 7 patients. One patient had received treatments to both abdomen and thighs. Circumference measurements in all body parts differed significantly between baseline and one month after the 4th session. Patients were satisfied with the result of treatment (score: 4.48 ± 0.66). No adverse events were noted.

CONCLUSIONS

Focused radiofrequency and ultrasound combination is a safe and effective treatment modality for body contouring. Patients should be informed about moderate degrees of improvement.

Effect of an aerobic exercise session combined with abdominal radiofrequency on lipolytic activity in women: Randomized control trial

BACKGROUND

Abdominal adiposity is a cardiovascular risk factor; it is assumed that the combination of radiofrequency and physical exercise may decrease this excess of adipose tissue.

PURPOSE

To understand whether an aerobic physical exercise session associated with abdominal radiofrequency increases the level of lipolytic activity.

METHODOLOGY

The study analyzes the effect of a combined aerobic exercise session with radiofrequency. Participants were 30 healthy female volunteers, aged 18-28 years, randomly assigned to an experimental group and placebo group. They were characterized by a sociodemographic questionnaire, the International Physical Activity Questionnaire and the Food Frequency Questionnaire. The groups performed an abdominal radiofrequency session followed by moderate aerobic exercise, assessing glycerol concentration and lipid profile values before and after the intervention. In the experimental group, a percentage of potency was used that allowed to maintain the temperature between 40º C and 42º C to the epidermis. In the placebo group, the power of the radiofrequency was 0 Watt. To compare results, Student's t test was used for a significance level of 0.05.

RESULTS

There were no significant changes in glycerol concentrations between groups (P > 0.05). There were no changes in the lipid profile of both groups after the intervention (P > 0.05).

CONCLUSION

The association of exercise with radiofrequency did not present an increased effect on lipolytic activity when compared to the isolated exercise. The application of this technique is a safe intervention.

Quantitative evaluation of skin shrinkage associated with non-invasive skin tightening: a simple method for reproducible linear measurement using microtattoos

Non-invasive skin-tightening devices can induce thermal denaturation and skin shrinkage via externally applied radiofrequency emissions or high-frequency ultrasound. Therefore, the purpose of this study is to develop and test a method for measurement of skin reduction associated with application of such energy devices. Twenty-five healthy participants with mild to moderate skin laxity of the arms were enrolled. Pinpoint microtattoos were placed at each of the treatment sites to delineate two 6 × 12 cm rectangles per subject. A non-stretchable filament, tape and marking pen apparatus was used to measure the size of each rectangle before treatment and at follow-up visit by two blinded investigators. After randomization, one side received a single pass with a radiofrequency device (6.78 MHz), while the contralateral side received multiple passes. Participants underwent two treatment sessions to each side 2 weeks apart, and returned for follow-up 4 weeks after the second treatment. Length and area measurement were analyzed to assess precision and accuracy of measurements and to compare efficacy of treatment between pre- and post-treatment. Concordance correlation coefficients (CCC) demonstrated substantial inter-investigator reliability and precision in length measurements (CCC, 0.94 to 0.98 in pre-treatment; 0.95 to 0.98 in post-treatment). Measurements at the 6-week post-treatment follow-up demonstrated a statistically significant skin reduction in all six of the measured parameters. A simple skin measurement method requiring minimal instrumentation can quantitatively evaluate skin shrinkage associated with non-invasive skin-tightening devices.

Multi-channeling optimized radiofrequency energy: A new age in well-established radiofrequency technology

AIM

To evaluate the safety and efficacy of Viora’s new multi-polar radiofrequency (RF) handpiece.

METHODS

A group of twelve volunteers (11 females and 1 male) participated in the current study, ranging in age from 23-70 years with Fitzpatrick skin type II-V. The inclusion criteria for the enrollment were no contraindications for the treatment, body mass index (BMI) < 35 and local fat accumulation or cellulite formation. A total of 19 treatment areas were treated in the study: 9 abdomen, 2 abdomen plus flanks, 2 arms and 6 thighs. The treatment performed with new multi-polar RF handpiece (V-FORM) with 4 levels of RF power (up to 50 W), 4 levels of vacuum pressure intensity (up to 500 mbar) and 4 operational modes (0.8, 1.7 and 2.45 MHz). Circumferential reduction and cellulite reduction treatments were performed once a week (7 ± 1 d) for a treatment series of 3-8 sessions. The clinical assessment of the treatment outcomes included skin moisture level, skin impedance, body temperature, circumferential measurements, clinical photographic assessment and BMI.

RESULTS

Ten of twelve patients completed the treatment course. No side effects were recorded during the study. The skin responded with slight erythema and sometimes edema, which is considered a positive end-point. All patients maintained a stable weight during the entire period of the study. No patient underwent any treatments or took medications for fat volume reduction during the study. A moderate positive correlation was found between the patient’s age and BMI (correlation coefficient 0.54). The initial body temperature increased in average to 34.0 °C from 31.9 °C, the initial skin moisture level increased to an average 40.98% from 38.9% and the initial skin impedance decreased by 3.8%-35.9% by the end of the treatment course. The pre-heating time for all body areas ranged between 1-6 min with negative correlation to the body’s end-point temperature (correlation coefficient -0.31). All patients responded to the treatment and showed some degree of circumferential reduction (up to 15 cm), on at least one of two-three measured points.

CONCLUSION

According to clinical data collected in this study, the new V-FORM handpiece represents an effective treatment with 100% response rate, with the safest treatment profile.

Radiofrequency for the treatment of skin laxity: mith or truth

The nonablative radiofrequency is a procedure commonly used for the treatment of skin laxity from an increase in tissue temperature. The goal is to induce thermal damage to thus stimulate neocollagenesis in deep layers of the skin and subcutaneous tissue. However, many of these devices haven't been tested and their parameters are still not accepted by the scientific community. Because of this, it is necessary to review the literature regarding the physiological effects and parameters for application of radiofrequency and methodological quality and level of evidence of studies. A literature search was performed in MEDLINE, PEDro, SciELO, PubMed, LILACS and CAPES and experimental studies in humans, which used radiofrequency devices as treatment for facial or body laxity, were selected. The results showed that the main physiological effect is to stimulate collagen synthesis. There was no homogeneity between studies in relation to most of the parameters used and the methodological quality of studies and level of evidence for using radiofrequency are low. This fact complicates the determination of effective parameters for clinical use of this device in the treatment of skin laxity. The analyzed studies suggest that radiofrequency is effective, however the physiological mechanisms and the required parameters are not clear in the literature.

The evidence behind noninvasive body contouring devices

The demand for body contouring is rapidly increasing, and interest in noninvasive approaches has also grown. The author reviewed the evidence base behind the currently available devices and methods for nonsurgical body contouring. There is little high-level evidence in the present literature to support the effectiveness of any of these devices.

Non-contact radiofrequency-induced reduction of subcutaneous abdominal fat correlates with initial cardiovascular autonomic balance and fat tissue hormones: safety analysis

Background and objective: The non-invasive reduction of subcutaneous abdominal fat became popular in the last decade. Radiofrequency (RF), non-contact, selective-field device Vanquish® has been developed to selectively induce deep fat tissue heating to reduce waist circumference. Our analysis evaluates immediate and sustained effects of this treatment on cardiovascular autonomic function and on selected metabolic parameters.

Study design/patients and methods: A retrospective proof-of-concept analysis of RF treatment effects was conducted in 20 individuals with metabolic syndrome, to reduce the subcutaneous abdominal fat. Four 30-minutes treatment sessions (manufacturer´s standard protocol) were performed in 1-week intervals. Vital signs, ECG, lab screening, body composition, subcutaneous fat thickness and spectral analysis of heart rate variability (HRV) have been examined before, after the 1 ^st and 4 ^th treatment, and at follow-up visits 1 month and 3 months after the treatment.

Results: The RF treatment led to a significant reduction of abdominal circumference after the 4 ^th session (p<0.001), and during follow-up after 1 and 3 months (p<0.001 and p<0.02, resp.). There was a significant correlation (r=-0.58, p=0.007) between reduction of abdominal circumference and initial very-low frequency (VLF) spectral power at 1 month follow-up. A significant increase of cumulative spectral power in low frequency (p=0.02) and reduction in high frequency (p=0.05) band have been observed immediately (20 +14 minutes) after the treatment. On the contrary, no sustained impact on autonomic balance has been recorded 39 +18 days after the treatment. A significant correlation between the initial adiponectin values and immediate autonomic response to one treatment was observed in VLF and total spectral bands (r>0.59, p<0.04).

Conclusions: Our analysis shows that the selective-field RF treatment is safe and efficient for reduction of subcutaneous abdominal fat. While the treatment increases the immediate sympathetic response of the body to deep tissue heating, no sustained change in autonomic function could be recorded at 1 month follow-up. The observed correlation between initial VLF spectral power and waist circumference reduction at follow-up, as well as the association of initial adiponectin values and immediate autonomic response to the treatment might be instrumental for decisions on body contouring strategies.

Liposuction devices: technology update

Since its introduction by Illouz and others over 30 years ago, suction-assisted lipectomy/liposuction/lipoplasty has evolved tremendously and has developed into one of the most popular procedures in aesthetic plastic surgery. Liposuction is an effective procedure employed to treat localized adipose deposits in patients not suffering from generalized obesity. These accumulations of subcutaneous fat often occur in predictable distributions in both men and women. A cannula connected to a suction-generating source allows for small incisions to be strategically placed and large volumes of fat to be removed. This fat removal leads to improved harmonious balance of a patient's physique and improved body contour. Various surgical techniques are available and have evolved as technology has improved. Current technology for liposuction includes suction-assisted lipectomy, ultrasound-assisted, power-assisted, laser-assisted, and radiofrequency-assisted. The choice of technology and technique often depends on patient characteristics and surgeon preference. The objective of this review is to provide a thorough assessment of current technologies available to plastic surgeons performing liposuction.

Cellulite - an overview of non-invasive therapy with energy-based systems

Cellulite is one of the most common skin care concerns seen in modern dermatology. The presence of cellulite in the 21(st) century is now considered a major "problem" whose treatment options are varied and numerous, all with hopes of improving the appearance of cellulite and maintaining its response over a period of time. The purpose of this article is to review cellulite, its predisposing factors, its classification, and some of the more common devices now in use to treat the disorder.