Water Veil Effect to Control Splashing from the Pulsed Water Jet Device: Minimizing the Potential Risk of Dissemination Using Surgical Aspirators

2018 ◽  
Vol 79 (04) ◽  
pp. 309-315 ◽  
Author(s):  
Atsushi Nakayashiki ◽  
Atsuhiro Nakagawa ◽  
Motohiko Sato ◽  
Fusako Mochizuki ◽  
Toshiki Endo ◽  
...  

Objective Maximum resection with minimum damage to normal structures is required for a better clinical outcome. Several efficient surgical devices such as the Cavitron ultrasonic surgical aspirator are available. Our group developed the actuator-driven pulsed water jet (ADPJ) to dissect soft tissue with vessel preservation. Although these devices are very effective for resection, tumor seeding is a potential risk. The present study investigated the control of splashing during ADPJ use. We demonstrate the effect of additional water flow around the instrument tip to veil the splashing. Methods Pulsed water jet was ejected from the tip of the ADPJ nozzle. Effects of ADPJ parameters such as input voltage, suction pressure, and distance between the nozzle and the target (standoff distance) on the amount of splashing were analyzed. Methylene blue solution was ejected on photo paper, gelatin brain phantom, and porcine brain harvested and subsequently immersed into physiologic saline to quantify the amount of splashing. Results High-input voltage and a long standoff distance had significant correlations with large amounts of splashing (r > 0.5; p < 0.01). However, suction pressure had no correlation (r = 0.23). Additional water flow combined with the ADPJ decreased the amount of splashing. A high-speed camera recording revealed that the additional water flow formed a water veil that prevented droplet dispersion, as confirmed with experiments using the brain phantom and porcine brain, in which the irregularity and elasticity are specific. Conclusions The veil effect of additional water flow is important to reduce splashing during ADPJ use and can minimize the potential risk of dissemination and enhance the safety of the ADPJ.

2013 ◽  
Vol 448-453 ◽  
pp. 1173-1178 ◽  
Author(s):  
Xing Dong ◽  
Wei Yang ◽  
Hai Lu Zhang

In order to achieve movement rule of post-mixed water jet outflow field, post-mixed water jet peening nozzle flow field were simulated by FLUENT software, according to their turbulent characteristics, the mathematical model adopted Euler model, turbulence model adopted the standard kε model. Analyzed the peening pressure and peening standoff distance on the influence of outflow field of liquid-solid two phases-flow axial dynamic pressure and axial velocity, the results show that in different peening pressure, water flow field and pill flow field of axial velocity and the axial dynamic pressure both are symmetrical distribution, and their value increased with the increase of peening pressure to raise, decreases with the increase of peening standoff distance, even, with the increase of length of pill nozzle water flow field of axial velocity decreases, and pill flow field of axial velocity increases. When the peening pressure is 14 MPa, peening standoff distance is 30 mm, length of pill nozzle is 55 mm, maximum axial dynamic pressure of the outflow field is 3.18 MPa, the maximum axial velocity of water flow field and pill flow field respectively are 71.3 m/s and 69.6 m/s.


2016 ◽  
Vol 78 (02) ◽  
pp. 137-143
Author(s):  
Jia Wenting ◽  
Atsuhiro Nakagawa ◽  
Hidenori Endo ◽  
Yuto Sagae ◽  
Masaki Iwasaki ◽  
...  

Author(s):  
M. J. Jackson

This paper discusses water jet machining of selected materials using a non-traditional way of delivering water jets in the form of a series of discrete pulses. The theory of water jet impact has been used to demonstrate the principle of removing material by exploiting the existence of a Rayleigh wave that excites the formation of surface cracks and the lateral outflow of water that extends the cracks and removes material. A mathematical model has been developed that predicts changes in the response characteristics of materials owing to an idealised representation of a finite jet of water impacting a plane surface. The analytical approach used is applicable to the first stages of impact where the compressibility of water in the droplet is significant. The predicted response characteristics are compared with experimental data generated using controlled water jet impacts produced by a specially constructed pulsed water jet machining centre. The predicted response of selected materials compare well with experimental data. The results presented in this paper illustrate the importance of using pulsed water jets as a way of machining materials in a non-traditional manner.


LASER THERAPY ◽  
2016 ◽  
Vol 25 (3) ◽  
pp. 185-191
Author(s):  
T Nakano ◽  
C Sato ◽  
M Yamada ◽  
A Nakagawa ◽  
H Yamamoto ◽  
...  

2013 ◽  
Vol 543 ◽  
pp. 491-494 ◽  
Author(s):  
Maria Vesna Nikolic ◽  
Obrad.S. Aleksic ◽  
Branka M. Radojcic ◽  
Miloljub D. Lukovic ◽  
Nenad Nikolic ◽  
...  

NTC thermistor paste for printing thermal sensors on alumina was formed of very fine Ni0.5Cu0.2Zn1.0Mn1.3O4 thermistor powder obtained by a combined mechanical activation/thermal treatment process, organic vehicle and glass frit. Sheet resistivity was measured using an R-test matrix and it was much lower than the value determined for pure nickel manganite thermistors. The thermistor exponential coefficient was calculated from the R[ diagram measured in the temperature range-30 to +120°C in a climatic chamber. Thick film segmented thermistors with reduced dimensions (optimized construction) were printed sequentially layer by layer, dried and fired at 850°C/10 min in air. Electrodes were printed of PdAg conductive and solderable paste. The samples obtained were characterized by electrical and thermal measurements. The obtained NTC segmented thermistors with reduced dimensions were applied in a thermal sensor for water flow in the water mains. It contained a cold thermistor for measuring input water temperature and a self-heating thermistor for measuring the dependence of water current on water flow rate at a set input voltage power. Initial measurements show that the thermal sensor system requires a low input voltage power making it much easier and safer for operation.


Author(s):  
Koji Yamane ◽  
Hiromitsu Sasaki ◽  
Yuzuru Shimamoto

One of the authors has developed a high-pressure fuel injection system using an oil hammer for diesel engines in 1993. In the present study, we applied this novel principle of the fuel injection system to the water-jet cutting system, and a pulsed water jet cutting system by means of water hammer in convergent pipeline caused by strong spool acceleration was developed. The system consisted of a pump having a small size plunger and spool, a convergent pipeline, and automatic injector having a hole-type nozzle with a small orifice. This pump, generating strong compression waves at the convergent pipeline inlet by strong acceleration of spool and plunger, is controlled by the low source oil pressure and electromagnetic valve. The wave propagated in the convergent pipeline is dynamically intensified by water hammering in the pipeline. High pressure is then developed at the nozzle. The injection pressure and injection frequency are fully controllable by the source pressure, and by the valve-opening frequency of the electromagnetic valve (EMPV). A computer simulation demonstrated that an operation and the injection pressure are satisfactory as a water jet cutting system. It is shown that a pressure of 140 MPa is obtained in nozzle inlet by a source pressure of 11.8MPa in experiments. The dimension of the nozzle orifice was determined by visualizing the spray origin using a laser-sheet imaging technique. Stagnation force and its spectrum of water jet on work was measured to evaluate effects of injection period and standoff distance on punching time and area. Practical feasibility of water jet cutting system was demonstrated by cutting/punching tests for soft/no-heating materials or metal plates and by paint removing tests.


2014 ◽  
Vol 21 (11) ◽  
pp. 1181-1182 ◽  
Author(s):  
Shinichi Yamashita ◽  
Yoshihiro Kamiyama ◽  
Atsuhiro Nakagawa ◽  
Yasuhiro Kaiho ◽  
Teiji Tominaga ◽  
...  

2012 ◽  
Vol 602-604 ◽  
pp. 1667-1671
Author(s):  
Feng Li ◽  
Duan Feng Han

Experiment of aluminum block erosion using organ-pipe nozzle was carried out in air. The erosion effects of water jet were used to evaluate the performance of organ-pipe nozzle. The experiment and corresponding data were used to analyze the effects of nozzle configuration, jet pressure, standoff distance. Results have shown that the organ-pipe water jets are much more effective in aluminum block erosion.


Sign in / Sign up

Export Citation Format

Share Document