• Title, Summary, Keyword: Peristaltic flow

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A Development of the electronic controlled vaporizer for low flow anesthesia (저유량 마취를 위한 전자제어식 기화기 개발)

  • Oh, Yeong-Taek;Park, Jae-Hoon;Chang, In-Bae
    • Journal of Industrial Technology
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    • v.29 no.B
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    • pp.107-113
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    • 2009
  • For the environmental safety of the operating room and patient healthcare, the closed type rebreathing system is widely adopted. In order to reduce the anesthesia gas during surgery, the mixing ratio of anesthesia gas with breathing air should be precisely controlled. Generally, the breathing air passes through the vaporizer to mix the anesthesia gas, but there is a difficulty in controlling the mixing ratio precisely. In this paper, the stand-alone style vaporizer is designed and the operating characteristics are investigated. The vaporizer measures the temperature and pressure in the vaporizing chamber and chamber temperature is precisely controlled by proportional controlled heater. Exact quantity of anesthesia media is feeded by PID controlled peristaltic pump and vaporized gas is mixed with breathing air flow by PWM controlled solenoid valve. The experimental result shows that the vaporizer has an excellent command following performances that it can be applied to the low flow anesthesia system.

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The Motility of Esophagus in Acute Hemorrhage (급성실혈시의 식도운동)

  • Park, Soon-Il;Shin, Dong-Hoon
    • The Korean journal of physiology & pharmacology
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    • v.6 no.2
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    • pp.39-48
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    • 1972
  • Two polyethylene tubes were inserted into the esophagus of anesthetized rabbit in order to record the fluctuation of the intraluminal pressure through the orifices located near the tips of the tubes. The orifice of the first tube was 10 cm apart from the incisor of the rabbit and the orifice of the second tube was 5 cm below that of the first one. The tubes were filled with saline solution running at various rates ranging from 1.5 ml/min. to 4.2 ml/min. The tubes were connected to the pressure transducers and the electrical signals were recorded by the physiograph. When the peristaltic wave approached to the orifice a rise in the pressure was recorded, returning to the base line when the portion of the orifice was quiescent. The frequency of the peristaltic motion and the velocity of the wave were studied in connection with the flow rate of saline solution through the tubes and in the case of massive acute hemorrhage. The results obtained were as follows: 1. There was reflux of fluid induced during the procedure of the experiment. This outwrad flow through the pharynx seemed to elicite swallowing reflexes. Accordingly, the frequency of peristalsis of the esophagus was largely dependent on the flow rate of the fluid through the inserted tubes. By the flow rate of 1.5 ml/min., 2.5 ml/min., or 4.2 ml/min., the frequencies of the peristalsis were revealed to be $8.6{\pm}3.6/10min.,\;14.5{\pm}4.8/10min.\;or\;21.1{\pm}6.3/10min.,$ respectively. The velocity of peristalsis also coincided with the enhanced motility of the esophagus, showing $6.6{\pm}1.5\;cm/sec.,\;8.9{\pm}3.9\;cm/sec.,\;or\;12.4{\pm}4.6\;cm/sec.,$ respectively. 2. By acute hemorrhage, amounting to 2% of the body weight, the frequency of the peristalsis increased to twofold of the control and the propagation velocity also increased by 52 percent. 3. Retransfusion of the shed blood resulted in divergent responses. In some cases there were noticable ameliorations of the effects brought by acute hemorrhage, and in the others there were still increasing tendenies of the motility after the transfusion. 4. Some speculation was made about the possibility of a kind of relationship between the irreversibility of the hemorrhagic shock and the absence of responses by transfusion. 5. The peristalsis persisted even after complete disconnection at the midportion of the esophagus, reaffirming the view of a central regulation of the spatiotemporally coordinated motility, peristalsis.

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Effect of Slurry Flow in Spray Slurry Nozzle System on Cu CMP (스프레이 슬러리 노즐 시스템에서 슬러리 유동이 Cu CMP에 미치는 영향)

  • Lee, Da Sol;Jeong, Seon Ho;Lee, Jong Woo;Jeong, Jin Yeop;Jeong, Hae Do
    • Journal of the Korean Society for Precision Engineering
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    • v.34 no.2
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    • pp.101-106
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    • 2017
  • The chemical mechanical planarization (CMP) process combines the chemical effect of slurry with the mechanical effect of abrasive (slurry)-wafer-pads The slurry delivery system has a notable effect on polishing results, because the slurry distribution is changed by the supply method. Thus, the investigation of slurry pumps and nozzles with regard to the slurry delivery system becomes important. This paper investigated the effect of a centrifugal slurry pump on a spray nozzle system in terms of uniform slurry supply under a rotating copper (Cu) wafer, based on experimental results and computational fluid dynamics (CFD). In conventional tools, the slurry is unevenly and discontinuously supplied to the pad, due to a pulsed flow caused by the peristaltic pump and distributed in a narrow area by the tube nozzle. Adopting the proposed slurry delivery system provides a higher uniformity and lowered shear stress than usual methods. Therefore, the newly developed slurry delivery system can improve the CMP performance.

Aging and Gasroenterrogi Changes (노화에 따른 위장관 기능의 변화)

  • 조우균
    • The Korean Journal of Food And Nutrition
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    • v.6 no.3
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    • pp.219-230
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    • 1993
  • This research aims to study the changes In gastrointestinal function attributed to aging In human. The thresholds for recognition and detection of flavors became elevated and salivary gland acinar cells decreased in the old age. But most esophageal function remained relatively Intact. Although gastric emptying time has been slowed with aging, the total intestinal transit time did not differ. Atropic gastritis due to H. pylori in old man decreased secretion of acid and Intrinsic factor and absorbability of calcium and iron. Pancreatic secretion is droned in older persons. Prevalence of gallstones rised with age. Liver size and portal blood flow decreased significantly with age. Mucosal surface area has been reported to be slightly diminished in the aging man. Glucose transporters decreased and Insulin tolerance Increased. Absorption of aromatic amino acid is diminished with age. Dietary protein In that aging human increased fecal nitrogen excretion. Vitamin A tolerance increased. Vitamin D receptor concentration decreased and resistance to 1,25-(OH)2D3 action increased. Permeability of aging small Intestine Increased. Zinc balance dirt not differ Copper absorption appeared not to be significantly affected by age. Neurotensin secretion decreased thus slowed colonic peristaltic movements and Intestinal mucosal growth.

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Disinfection of harmful organism for ballast water using electrolytic treatment system (전해처리를 통한 밸러스트수의 유해생물 살균처리)

  • 박상호;김인수
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.227-232
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    • 2004
  • Ballast water from ship harmful microorganism sterilized use of electrolytic sterilization system. The experimental methods were use of peristaltic flow pump upward on electrode pole. Due to reaction time, HRT were unlike microorganism on flow rate. In electrolysis, dioxide iridium coated titanium(Ti/IrO$_2$) and stainless steel plate were used for anode and cathode respectively. Current density controls make use of D.C Power supply on 250V 100Amper. Experimental use of current density between 0.1 and 0.5A was able to disinfect microorganism at 5 seconds by the reaction time. This study shows that the electrolyzed water has a potential for the sterilization of ballast water.

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Feasibility of Streaming Potential Signal on Estimation of Solute Transport Characteristics

  • Kabir, Mohammad Lutful;Ji, Sung- Hoon;Lee, Jin-Yong;Koh, Yong- Kwon
    • Journal of Soil and Groundwater Environment
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    • v.20 no.2
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    • pp.41-46
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    • 2015
  • The drag of the excess charge in an electrical double layer at the solid fluid interface due to water flow induces the streaming current, i.e., the streaming potential (SP). Here we introduce a sandbox experiment to study this hydroelectric coupling in case of a tracer test. An acrylic tank was filled up with homogeneous sand as a sand aquifer, and the upstream and downstream reservoirs were connected to the sand aquifer to control the hydraulic gradient. Under a steady-state water flow condition, a tracer test was performed in the sandbox with the help of peristaltic pump, and tracer samples were collected from the same interval of five screened wells in the sandbox. During the tracer test, SP signals resulting from the distribution of 20 nonpolarizable electrodes were measured at the top of the tank by a multichannel meter. The results showed that there were changes in the observed SP after injection of tracer, which indicated that the SP was likely to be related to the solute transport.

Development of the Pulsatile Pump System for a Perfusion Bioreactor (관류형 바이오리액터를 위한 박동 펌프 시스템 개발)

  • Kim, Hak-Jun;Kim, Sun-Hong;Chung, Ho-Yun;Yun, Won-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.4
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    • pp.526-533
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    • 2011
  • This research is about the pulsatile pump system utilized in the perfusion bioreactor for the in vitro human tissue culture. A pulsatile pump system which can be applied to the culture of the vascular tissues including blood vessel is developed by using the idea of human heart's blood pumping into organs as followings: culture chamber, a pressurizing device which generates laminar pulsatile flow by controlling the x-sectional area of the culture media delivering tubing, a compliance chamber which supplies the pressuring device with a constant pressure, and a peristaltic pump which circulates the culture media in a circuit ranging from the culture chamber to the compliance chamber. The developed pulsatile pump system shows that a physiology of the human heart's blood pumping including pulsatile pressure waveform of systolic-diastolic pressure is well represented. Not only time domain but also frequency domain characteristics of pulsatile pump system which are necessary for the vascular tissue culture such as pulsatile pressure waveform's shape, the frequency, and the magnitude can be easily generated and manipulated by using the proposed system.

On-Line Measurement System for the Determination of Chemical Oxygen Demand (화학적 산소 요구량 측정을 위한 On-Line 측정 시스템에 관한 연구)

  • 정형근;차기철
    • Journal of Environmental Science International
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    • v.7 no.2
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    • pp.203-208
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    • 1998
  • A simple on-line measurement system consisting of a conventional peristaltic pump, a HPLC-type heater, and a flow-through spectrophotometer is introduced for the determination of chemical oxygen demand(CODI. The system was configured such that the reaction mixture in the highly concentrated surffuric acrid medium flowing through the PTFE reaction tubing was heated at 150℃ and the absorbance of dichromate was continuously moutored at 445 m. The same addation principle as in the standard procedure was employed akcept the use of CoSO4 as a new effective catalyst. To test the system, potassium hydrogen phthalate was selected as a COD standard material. With suitably optimized reaction condition, the applicable concentration range depends on the concentration of potassium dichromate in the oxidizing reagent. With 2.0×10-3 M and 5.0×10-4M dichromate, the linear dynamic range was observed up to 400 ppm and 100 ppm, respectively. The standards in the Unear ranges were shown to be completely oxidized, which was confirmed with sodium oxalate or Mohr's salt. In all cases, the typical reproduclbility for betweenruns was 2% or less. The proposed measurement system provides the valuable in- formation for the further development of automated analysis system based on the present standard procedure.

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Disinfection of harmful organisms for sea water using electrolytic treatment system (전해처리를 통한 해수의 유해생물 살균처리)

  • Park Sang-Ho;Kim In-Soo
    • Journal of Navigation and Port Research
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    • v.28 no.10
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    • pp.955-960
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    • 2004
  • The treated ballast water from previous treatment contains microorganisms and pathogenic organisms in an electrolytic treatment system. The experimental methods included using a peristaltic flow pump placed upward on an electrode pole. Due to the reaction time, the hydraulic retention time indicated unlike microorganisms on the flow rate. In electrolysis, dioxide iridium-coated titanium (Ti/Ir02) and stainless steel plates were used for the anode and cathode, respectively. Current density controls make use of a DC power supply on 250V, 100Amper. Experimental use of a current density between 0.1 and 1.0A/dm2 was able to disinfect the microorganism (E. coli, Bacteria, Bacillus sp.) in seawater for 5 seconds of reaction time. The removal rate was approximately $90\%,$ while the current density was 2.0A/dm2 and the electrode distance was 75mm. This study shows that the electrolytic treatment system has a potential for the sterilization of ballast water.

Impact of Complex Hemodynamics to the Management of ArterioVenous(AV) Fistula (동정맥루의 복합성 혈류학 소견이 그 관리에 미치는 영향)

  • Lee Byung-Boons
    • Proceedings of the KSME Conference
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    • pp.9-10
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    • 2002
  • Human circulatory system between heart and tissue is not directly connected in normal condition but mandatory to go through the capillary system in order to fulfill its physiologic aim to deliver oxygen and nutrients, etc. to the tissue and retrieve used blood together with waste products from the tissue properly. When abnormal connection between arterial and venous system (AV fistula), these two circulatory systems respond differently to the hemodynamic impact of this abnormal connection between high pressure (artery) and low pressure (vein) system. Depending upon the location and/or degree (e.g. size and flow) of fistulous condition, each circulatory system exerts different compensatory hemodynamic response to this newly developed abnormal inter-relationship between two systems in order to minimize its hemodynamic impact to own system of different hemodynamic characteristics. Pump action of the heart can assist the failing arterial system directly to maintain arterial circulation against newly established low peripheral resistance by the AV fistula during the compensation period, while it affects venous system in negative way with increased venous loading. However, the negative impact of increased heart action to the venous system is partly compensated by the lymphatic system which is the third circulatory system to assist venous system independently with different hemodynamics. The lymphatic system with own unique Iymphodynamics based on peristaltic circulation from low resistance to high resistance condition, also increases its circulation to assist the compensation of overloaded venous system. Once these compensation mechanisms should fail to fight to newly established hemodynamic condition due to this abnormal AV connection, each system start to show different physiologic ${\underline{de}compensation}$ including heart and lymphatic system. The vicious cycle of decompensation between arterial and vein, two circulatory system affecting each other by mutually negative way steadily progresses to show series of hemodynamic change throughout entire circulation system altogether including heart. Clinical outcome of AV fistula from the compensated status to decompensated status is closely affected by various biological and mechanical factors to make the hemodynmic status more complicated. Proper understanding of these crucial biomechanical factors iii particular on hemodyanmic point of view is mandatory for the advanced assessment of biomechanical impact of AV fistula, since this new advanced concept of AY fistula based on blomechanical information will be able to improve clinical control of the complicated AV fistula, either congenital or acquired.

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