Tissue pad degradation of ultrasonic device may enhance thermal injury and impair its sealing performance in liver surgery

BACKGROUND Ultrasonic devices are widely used in many surgical fields,including hepatectomy;however,the negative effects of tissue pad degradation of ultrasonic devices,including those in liver surgery,remain unknown.The Harmonic®1100(H-1100)scalpel has advanced heat control technology than previous models,such as the Harmonic®HD1000i(H-HD1000i).We hypothesized that,because of its advanced temperature-control technology,the H-1100 scalpel would show less tissue pad degradation,resulting in superior sealing performance,compared to that with the H-HD1000i scalpel.AIM To elucidate ultrasonic device tissue pad degradation effects on instrument temperature and sealing performance using ex vivo porcine liver/vessel models.METHODS Two different harmonic scalpels were used and compared:A newer model,the H-1100 scalpel,and an older model,the H-HD1000i scalpel.Using ex vivo porcine livers,each instrument was activated until the liver parenchyma was dissected.The device temperature(passive jaw temperature)was measured after every 10 consecutive activations,until 300 transections of the porcine liver were performed.Tissue pad degradation was evaluated after 300 activations.Sealing performance was evaluated using excised porcine carotid vessels;vessel sealing speed and frequency of vessel burst pressure below 700 mmHg were determined after 300 transections of porcine liver parenchyma.RESULTS The temperature of the H-HD1000i scalpel was approximately 10℃higher than that of the H-1100 scalpel,and gradually increased as the number of activations increased.The median passive jaw temperature of the H-HD1000i scalpel was significantly higher than that of the H-1100 scalpel(73.4℃vs 65.1℃;P<0.001).After 300 transections of porcine liver parenchyma,less tissue pad degradation was observed with the H-1100 scalpel than with the H-HD1000i scalpel(0.08 mm vs 0.51 mm).The H-1100 scalpel demonstrated faster vessel-sealing speed(4.9 sec.vs 5.1 sec.)and less frequent vessel burst pressure<700 mmHg(0%vs 40%)after 300 activations than the H-HD1000i scalpel;however,the difference did not reach statistical significance(P=0.21 and P=0.09,respectively).CONCLUSION In an ex vivo porcine hepatectomy model,the H-1100 scalpel shows lower passive jaw temperature and maintains its sealing performance by avoiding tissue pad degradation compared to that with the H-HD1000i.

Lack of repellency of three commercial ultrasonic devices to the German cockroach （Blattodea： Blattellidae）

Three commercial ultrasonic devices （A, B, and C） were tested for their ability to repel the German cockroach, Blattella germanica （L.） （Blattodea： Blattellidae）, in Plexiglas enclosures. Device A generated peak frequencies at 26 kHz and 34 kHz, and produced a 95 ±1 dB sound pressure level （SPL） at 50 cm distance （0 dB = 20 log 10[20 μPa/ 20 μPa]）. Device B generated peak frequencies at 27 kHz and 35 kHz, and produced a 92 ± 4 dB SPL. Device C generated a wide range of frequencies between 28-42 kHz and produced an 88 ±2 dB SPL. Ultrasound from any of the three devices did not demonstrate sufficient repelling ability against the German cockroach in the tests. The result failed to provide evidence that ultrasonic technology could be used as an effective pest management tool to repel or eliminate the German cockroach.

Comparison of dispersion of nanoparticles ultrasonicated with probe and cup horn

This study aims to investigate the effects of a probe and a cup horn on the de-agglomeration efficiency in ultrasound vibration processes. TiO2 and Al2O3 nanoparticle dispersions were prepared in distilled water at a concentration of 50.0 mg/mL followed by treatment with a dispersion stabilizer （100% FBS） and ultrasound vibration at 20 kHz and 35% amplitude for 10 min by a probe and a cup horn, respectively. The average sizes of dispersed TiO2 and Al2O3 nanoparticles were measured by a dynamic light scattering device. Compared to dispersion with the probe sonicating, the average sizes of TiO2 and Al2O3 particles sonicated by the cup horn are markedly smaller at time points of 30, 60, 120, and 180 min. The TiOe and Al2O3 particle size distributions of cup horn-treated suspensions were narrower than those of probe-treated suspensions at time points of 120 and 180 min. It is suggested that the cup horn has a higher efficiency than the probe in dispersing nanoparticles, The cup horn is better than the probe for processing multiple small sample vessels simultaneously. Indirect cup horn sonication is ideal for processing pathogenic and sterile samples.

Elastic twisting metamaterial for perfect longitudinal-torsional wave mode conversion

In this work,we design a twisting metamaterial for longitudinal-torsional(L-T)mode conversion in pipes through exploring the theory of perfect transmodal FabryPerot interference(TFPI).Assuming that the axial and radial motions in pipes can be decoupled,we find that the metamaterial can be designed in a rectangular coordinate system,which is much more convenient than that in a cylindrical system.Numerical calculation with detailed microstructures shows that an efficient L-T mode conversion can be obtained in pipes with different radii.In addition,we fabricate mode-converting microstructures on an aluminum pipe and conduct ultrasonic experiments,and the results are in good agreement with the numerical calculations.We expect that the proposed LT mode-converting metamaterial and its design methodology can be applied in various ultrasonic devices.

Vibration coupling effects and machining behavior of ultrasonic vibration plate device for creep-feed grinding of Inconel 718 nickel-based superalloy

Ultrasonic vibration-assisted grinding(UVAG)is an effective and promising method for machining of hard-to-cut materials.This article proposed an ultrasonic vibration plate device enabling the longitudinal full-wave and transverse half-wave(L2T1)vibration mode for UVAG.The characteristics of two-dimensional coupled vibration in different directions were analyzed on the basis of apparent elastic method and finite element method.Furthermore,a correction factor was applied to correct the frequency error caused by the apparent elastic method.Finally,the comparative experiments between the conventional creep-feed grinding and UVAG of Inconel 718 nickel-based superalloy were carried out.The results indicate that the apparent elastic method with the correction factor is accurate for the design of plate device under the L2T1 vibration mode.Compared with the conventional creep-feed grinding,the UVAG causes the reduction of grinding force and the improvement of machined surface quality of Inconel 718 nickel-based superalloy.Furthermore,under the current experimental conditions,the optimal ultrasonic vibration amplitude is determined as 6μm,with which the minimum surface roughness is achieved.

Safety and Performance of Harmonic®HD 1000i Shears in Thoracoscopic Procedures: A Retrospective Study

Background: Ultrasonic energy devices are utilized for transection, incision, and hemostasis in traditional open and laparoscopic procedures. The Harmonic HD 1000i Shears, designed to deliver a precise amount of thermal energy during tissue transection and vessel sealing, has been utilized in many specialties. This study aimed to confirm real-world safety and performance of the Harmonic device in two thoracoscopic procedures: lobectomy and segmentectomy. Methods: The primary endpoint of this retrospective, observational, single-arm study was rate of post-operative blood transfusions related to study device or procedure. Secondary endpoints included occurrence of intra- and post-operative adverse events (AEs) or complications device- or procedure-related, and rate of required additional hemostatic measures. Adults included those who underwent thoracoscopic lobectomy or segmentectomy where HD 1000i shears were used while excluding those where additional advanced energy devices were used. The study was conducted at Severance Hospital, Yonsei University Health System, South Korea from May 1, 2018, to November 30, 2020. Results: Subjects included n = 766 lobectomies (mean age 63.79, 52% male) and n = 215 segmentectomies (mean age 63.19, 54% male). Estimated blood loss was 50 mL (0 min, 3200 max) and 20 mL (0 min, 800 max), intraoperative transfusion rate 0.001% and 0%, intraoperative complication/AE rate 1% and 2%, and post-operative complication/AE rate 9% and 4% in the lobectomy and segmentectomy groups, respectively. Median operative times were 108 min. (35 min, 395 max) for lobectomies and 105 min. (32 min, 574 max) for segmentectomies. Conclusion: Given the low rate of blood loss and intra- and post-operative complication/AE rates, HD 1000i can be used confidently for thoracoscopic pulmonary resection in adults.

A novel in-plane mode rotary ultrasonic motor

Ultrasonic motors have the merits of high ratio of torque to volume, high positioning precision, intrinsic holding torque, etc., compared to the conventional electromagnetic motors. There have been several potential applications for this type of motor in aerospace exploration, but bearings and bonding mechanism of the piezoelectric ring in the motors limit the performance of them in the space operation conditions. It is known that the Langevin type transducer has excel- lent energy efficiency and reliability. Hence using the Langevin type transducer in ultrasonic motors may improve the reliability of piezoelectric motors for space applications. In this study, a novel in-plane mode rotary ultrasonic motor is designed, fabricated, and characterized. The proposed motor operates in in-plane vibration mode which is excited by four Langevin-type bending vibra- tors separately placed around a ring-shaped stator. Two tapered rotors are assembled to the inner ring of the stator and clamped together by a screw nut. In order to make the motor more stable and convenient to fix, a thin cylindrical support is placed under the stator ring. Due to its no-bearing structure and Langevin transducer excitation, the prototype ultrasonic motor may operate well in aeronautic and astronautic environments.