• Archives of Plastic Surgery
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• 제47권1호
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• pp.20-25
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• 2020

Background Ultrasonic dissection devices cause less thermal damage to the surrounding tissue than monopolar electrosurgical devices. We compared the effects of using an ultrasonic dissection device or an electrocautery device during prosthetic breast reconstruction on seroma development and short-term postoperative complications. Methods We retrospectively reviewed the medical records of patients who underwent implant-based reconstruction following mastectomy between March 2017 and September 2018. Mastectomy was performed by general surgeons and reconstruction by plastic surgeons. From March 2017 to January 2018, a monopolar electrosurgical device was used, and an ultrasonic dissection device was used thereafter. The other surgical methods were the same in both groups. Results The incidence of seroma was lower in the ultrasonic dissection device group than in the electrocautery group (11 [17.2%] vs. 18 [31.0%]; P=0.090). The duration of surgery, total drainage volume, duration of drainage, overall complication rate, surgical site infection rate, and flap necrosis rate were comparable between the groups. Multivariate analysis revealed that the risk of seroma development was significantly lower in the ultrasonic dissection device group than in the electrocautery group (odds ratio for electrocautery, 3.252; 95% confidence interval, 1.242-8.516; P=0.016). Conclusions The findings of this study suggest that the incidence of seroma can be reduced slightly by using an ultrasonic dissection device for prosthesis-based breast reconstruction. However, further randomized controlled studies are required to verify our results and to assess the cost-effectiveness of this technique.

• ETRI Journal
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• 제39권1호
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• pp.87-96
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• 2017

Ultrasonic surgical devices are routinely used for surgical procedures. The incision and coagulation of tissue generate a temperature of $40^{\circ}C-150^{\circ}C$ and depend on the controllable output power level of the surgical device. Recently, research on the classification of grasped tissues to automatically control the power level was published. However, this research did not consider the specific characteristics of the surgical device, tissue denaturalization, and so on. Therefore, this research proposes a robust algorithm that simulates noise to resemble real situations and classifies tissue using conventional classifier algorithms. In this research, the bioimpedance spectrum for six tissues (liver, large intestine, kidney, lung, muscle, and fat) is measured, and five classifier algorithms are used. A signal-to-noise ratio of additive white Gaussian noise diversifies the testing sets, and as a result, each classifier's performance exhibits a difference. The k-nearest neighbors algorithm shows the highest classification rate of 92.09% (p < 0.01) and a standard deviation of 1.92%, which confirms high reproducibility.

• 대한의용생체공학회:의공학회지
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• 제34권3호
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• pp.141-147
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• 2013

Ultrasonic shears is currently in wide use as an energy device for minimal invasive surgery. There is an advantage of minimizing the carbonization behavior of the tissue due to the vibrational energy transfer system of the transducer by applying a piezoelectric ceramic. However, the vibrational energy transfer system has a pitfall in energy consumption. When the movement of the forceps is interrupted by the tissue, the horn which transfers the vibrational energy of the transducer will be affected. A study was performed to recognize different tissues by measuring the impedance of the transducer of the ultrasonic shears in order to find the factor of energy consumption according to the tissue. In the first stage of the study, the voltage and current of the transducer connecting portion were measured, along with the phase changes. Subsequently, in the second stage, the impedance of the transducer was directly measured. In the final stage, using the handpiece, we grasped the tissue and observed the impedance differences appeared in the transducer To verify the proposed tissue distinguishing method, we used the handpiece to apply a force between 5N and 10N to pork while increasing the value of the impedance of the transducer from 400 ${\Omega}$.. It was found that fat and skin tissue, tendon, liver and protein all have different impedance values of 420 ${\Omega}$, 490 ${\Omega}$, 530 ${\Omega}$, and 580 ${\Omega}$, respectively. Thus, the impedance value can be used to distinguish the type of tissues grasped by the forceps. In the future study, this relationship will be used to improve the energy efficiency of ultrasonic shears.

• 대한의용생체공학회:의공학회지
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• 제41권5호
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• pp.210-218
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• 2020

Vessel sealing is a medical device that converts electrical or ultrasonic energy into thermal energy and leads to seal, coagulate, and cut the vessel by protein modification within the walls or surrounding connective tissues. As most of surgeries have recently been conducted with minimally invasive surgery, the demand and market for vessel sealing are expected to get bigger. However, there is a problem that electrosurgical or ultrasonic surgical is applied and we have a high risk to evaluate the strength of seal, because the collateral and particular standards currently in force follows have not been establish. Therefore, in this study, we investigated some papers studied on the efficacy and safety of the device, the guidance of FDA and test papers previously conducted from 3 individual subject device made in Korea. We found there is a relationship between burst pressure and the performance of the device, therefore, we propose the vascular bursting pressure test for evaluating the safety and performance of the vessel sealing.

• Journal of Periodontal and Implant Science
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• 제35권4호
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• pp.1109-1116
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• 2005

The purpose of this study was to observe the effects of periodontal therapy, including nonsurgical periodontal therapy with azithromycin, surgical therapy, and maintenace therapy on the drug-induced gingival enlargement, by means of measuring gingival thickness. The test group of 18 patients with drug-induced gingival enlargement received scaling, root planing with azithromycin for 5 days, with or without surgical periodontal treatment. The control group of 18 patients who had not taken any medication, received scaling and root planing, with or without surgical periodontal treatment. Both groups received supportive periodontal therapy every 3 months for 2 years. The mean period of total treatment is 32 months in the test group and 31 months in the control group. The thickness of the buccal gingiva was measured using an ultrasonic device of $SDM^{(R)}$(Krupp Corp., Essen, Germany). The results revealed that the test $group(1.21{\pm}0.51mm)$ showed statistically thicker buccal gingiva than the control $group(1.01{\pm}0.3mm)$. In the test group, the buccal gingiva was thickest on 2nd molars and was thinnest on canines of both dental arches. In the control group, the buccal gingiva was thickest on central incisors in the maxilla and 2nd molars in the mandible, while the thinnest areas were on canines in the maxilla and 1st premolars in the mandible. It would be concluded that the periodontal treatment with azithromycin aids in decreasing the degree of the gingival enlargement but cannot prevent the recurrence completely.