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Cooling Device (cooling + device)
Selected AbstractsCooling Device for Bradycardia Based on Peltier Element for Accurate Anastomosis of Off-Pump Coronary Artery Bypass GraftingARTIFICIAL ORGANS, Issue 10 2002Yukio Kuniyoshi Abstract: Upon introducing off-pump coronary artery bypass grafting (CABG), the indications for CABG were expanded to include patients who previously had no operative indications. For accurate anastomosis, various devices and methods have been developed. Bradycardia is easily induced by drug administration. However, this method of achieving bradycardia also has adverse effects on cardiac function. We have developed a new device to decrease the heart rate by regional cooling of the sino-atrial node. The new device is incorporated with Peltier's element, which uses an electric charge to create a temperature gradient on both of its surfaces. In terms of the cooling ability of this device, its cooling surface is chilled from 25°C to 0°C within 30 s. During in vivo animal experiments, this device has been shown to decrease the myocardial temperature around the sino-atrial node to 15°C and suppress sino-atrial node activity, resulting in bradycardia to 60 beats/min level. In summary, the simple and easily applicable device for local cooling in combination with the application of diltiazem for effective heart rate reduction may be very helpful for the surgeon and may avoid disadvantages for critically ill patients. [source] Laser Hair Removal: Long-Term Results with a 755 nm Alexandrite LaserDERMATOLOGIC SURGERY, Issue 11 2001Sorin Eremia MD Background. Hypertrichosis is a common problem for which laser hair removal is becoming the treatment of choice. Optimal wavelength, pulse duration, spot size, fluence, and skin cooling parameters for various skin types have not yet been firmly established. Objective. To evaluate the long-term efficacy and safety of a 3-msec 755 nm alexandrite laser equipped with a cryogen cooling device for patients with Fitzpatrick skin types I,V. Methods. Eighty-nine untanned patients with skin types I,V underwent a total of 492 treatments of laser hair removal over a 15-month period. Each patient in the study underwent a minimum of three treatment sessions spaced 4,6 weeks apart (mean treatments 5.6). Retrospective chart review and patient interviews were used to establish hair reduction results. Treatment sites included the axillae, bikini, extremities, face, and trunk. A 3-msec pulse width, 755 nm alexandrite laser equipped with a cryogen spray cooling device was used in this study. Spot sizes of 10,15 mm were used. A spot size of 10 mm was used for fluences greater than 40 J/cm2, a spot size of 12 mm was used for fluences of 35,40 J/cm2, and spot sizes of 12 and 15 mm were used for fluences less than 30 J/cm2. Fluences ranging from 20 to 50 J/cm2 (mean fluence 36 J/cm2) were used. Results. The patients had a mean 74% hair reduction. Skin type I patients had an average of 78.5% hair reduction using a mean fluence of 40 J/cm2 (35,50 J/cm2) and a 10,12 mm spot size (12 mm in more than 95% of treatments). Skin type II patients had a mean 74.3% hair reduction using a mean fluence of 38 J/cm2 (30,40 J/cm2) and a 12,15 mm spot size. Skin type III patients had a mean 73.4% hair reduction using a mean fluence of 37 J/cm2 (25,40 J/cm2) and a 12,15 mm spot size. Skin type IV patients had a mean 71.0% hair reduction using a mean fluence of 31 J/cm2 (25,35 J/cm2) and a 12,15 mm spot size. A patient with skin type V had a 60% hair reduction using a mean fluence of 23 J/cm2 (20,25 J/cm2) and a 12,15 mm spot size. The efficiency of hair removal directly correlates significantly with the fluence used. Rare side effects included transient postinflammatory hyperpigmentation (n = 9; 10%), burn with blisters (n = 1; 1%), and postinflammatory hypopigmentation (n = 2; 2%). All complications resolved without permanent scarring. Conclusion. The 3-msec cryogen cooling-equipped alexandrite laser can safely and effectively achieve long-term hair removal in patients with skin types I,V. The best results are achieved in untanned patients with skin types I,IV. [source] Relationship between ambient temperature and heat flux in the scrotal skinINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 4 2009G.-S. Song Summary Excessive scrotal heating or cooling may lead to the cessation of spermatogenesis. Data regarding heat exchange rates in scrotal skin can be used to control testicular temperature within the appropriate range. Heat flux (HF) in the scrotal skin surface is generated based on the surrounding environment. This study aims to elucidate the HF of scrotal skin by varying ambient temperature. Twenty college students including seven varicoceles volunteered as the subjects (mean age: 22.95 ± SD 1.96 years; height: 175.00 ± 5.17 cm; weight: 68.40 ± 8.65 kg; body mass index: 22.28 ± 2.15), and participated in the experiments from September 11 to October 4, 2006. The environmental temperature was controlled at 20 °C and 25 °C in the first and second experiment respectively. The HF and skin temperature on both sides of the scrotal surface were measured for 60 min in the environmental chamber. The results revealed that the HF was 87.64 ± 12.69 W/m2 and 78.91 ± 12.09 W/m2 in the left and right side of the scrotum respectively. The scrotal skin temperature (SST) was 30.28 ± 0.75 °C and 30.24 ± 0.62 °C on the left and right side of the scrotum in the 20 °C environment respectively. In the 25 °C environment the HF was 53.54 ± 8.86 W/m2 and 45.25 ± 8.32 W/m2, and the SST was 32.29 ± 0.61 °C and 32.07 ± 0.36 °C on the left and right side of the scrotum respectively. The cooling source power to decrease testicular temperature is suggested at 290 W/m2. This suggested value could be adopted a cooling device as clinical therapy for a heat stress patient to decrease testicular temperature affecting spermatogenesis. [source] Cryogen-induced arcuate shaped hyperpigmentation by dynamic cooling deviceJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 7 2008SJ Lee [source] Electrocaloric Materials for Solid-State RefrigerationADVANCED MATERIALS, Issue 19 2009Sheng-Guo Lu Abstract The electrocaloric effect (ECE) in dielectric materials has great potential in realizing solid-state cooling devices with compact size and high efficiency, which are highly desirable for a broad range of applications. This paper presents the general considerations for dielectric materials to achieve large ECE and reviews the experimental efforts investigating ECE in various polar dielectrics. For practical cooling devices, an ECE material must possess a large isothermal entropy change besides a large adiabatic temperature change. We show that polar dielectrics operated at temperatures near order,disorder transition have potential to achieve large ECE due to the possibility of large change in polarization induced by electric field and large entropy change associated with the polarization change. We further show that indeed the ferroelectric poly(vinylidene fluoride,trifluoroethylene)-based polymers display a large ECE, i.e., an isothermal entropy change of more than 55,J,(kgK),1 and an adiabatic temperature change of more than 12,°C, at temperatures above the order,disorder transition. [source] An investigation of thermoelectric cooling devices for small-scale space conditioning applications in buildingsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 9 2010Mark Gillott Abstract This paper presents the study of a thermoelectric cooler (TEC) designed for small-scale space conditioning applications in buildings. A theoretical study was undertaken to find the optimum operating conditions, which were then applied in the laboratory testing work. A TEC unit was assembled and tested under laboratory conditions. Eight pieces of UltraTEC were shown to generate up to 220,W of cooling with a COP of 0.46 under the input current of 4.8,A for each module. Thermo-economical analysis was carried out and results showed that a system with PV panel can compete with an equivalent system without a PV panel when PV costs fall down to or lower than £1.25 per Watt. For the cases without a PV panel, the system with a high level of TEC power input delivered a better performance in terms of the average cooling energy price than that system with a low level of TEC power input after critical interest rate (currently 4%). Copyright © 2009 John Wiley & Sons, Ltd. [source] A comparative study of a 595-nm with a 585-nm pulsed dye laser in refractory port wine stainsBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2005A. Yung Summary Background, The pulsed dye laser (PDL) is the treatment of choice for port wine stains (PWS); however, some patients' PWS become refractory to further treatments. Technological advances have enabled new machines with the advent of surface cooling devices to deliver longer wavelengths and higher fluence more safely. These advances have the potential to achieve improved response rates in refractory PWS. There are few studies comparing the efficacy of standard PDL treatments for refractory PWS with the wider choice of treatment variables available from newer PDL machines. Objectives, To determine if there is any advantage of using a longer wavelength (595 nm) and pulse widths (1·5 ms, 6 ms and 20 ms) over conventional PDL settings (wavelength 585 nm, pulse width 1·5 ms) in refractory PWS. Methods, Eighteen consecutive consenting patients with Fitzpatrick skin types 1,4 with a mean age 35 years (range 17,59 years) with refractory PWS were treated routinely with three separate test areas using 595-nm PDL (using three different pulse width settings of 1·5 ms, 6 ms and 20 ms), compared with test areas treated with 585-nm PDL (pulse width 1·5 ms). All test areas were treated with an identical fluence (15 J cm,2), spot size (7 mm) and cooling setting (dynamic cooling 60 ms, delay 60 ms). Results, We found a statistically significant advantage of 595-nm PDL (pulse width 1·5 ms) over 595-nm PDL (pulse width 6 ms) (P < 0·05) in the treatment of refractory PWS; however, we found no significant advantage using longer pulse widths of 20 ms compared with 1·5 ms with the 595-nm PDL. There was no statistically significant advantage in using a 595-nm PDL over a 585-nm PDL using identical pulse widths of 1·5 ms, spot size, fluence and cryogen cooling settings; however, the number of directly comparable test areas was smaller. Some individual patients in our study obtained a better response with certain 595-nm PDL settings (pulse width 1·5 ms and 6 ms) compared with 585-nm PDL (pulse width 1·5 ms). Conclusions, Our experience of high fluence PDL in the treatment of refractory PWS suggests patients treated with 585 nm (pulse width 1·5 ms) improve to a similar degree as patients treated with 595-nm PDL (pulse width 1·5 ms). However, the use of the 595-nm PDL with longer pulse widths yields no extra advantage. For those patients who have failed to improve with high-fluence 585-nm PDL (pulse width 1·5 ms), test areas using 595-nm PDL (pulse width 1·5 ms and 6 ms) should be undertaken to ascertain if individual patients may benefit from the longer pulse width 595-nm PDL. [source] | ||||||||||