Isolated Heart Perfusion Apparatus
Description|
Isolated Heart Perfusion Apparatus The 1 Liter Reservoir supplies a constant head of perfusate. The perfusate flow rate is controlled by on of two methods. If the reservoir cap is off, the flow rate is controlled directly by a pinch clamp on the outlet tubing. If the reservoir cap is tightly sealed, a mariotte flask is created and the flow rate is set by the perfusion pressure. The height of the reservoir determines this pressure which in turn sets the rate of air allowed to enter the reservoir. As air enters, the perfusate flows out. This reservoir is placed in the three prong spring clip reservoir holder that has a 20cm (8 inch) long tube that slip on the top of a rod and lock in place by a knurled set screw. Using this set screw the height of the reservoir can be varied from 15cm (6 inch) above the top of the rod down to the top of the rod. If it is necessary to lower the reservoir even more, the holder has a clamp mounted on one side that can locate the holder at any point on the rod. The total vertical movement of the reservoir is 62.5cm (24 inch) above the top of the fluid warming coil. The Aeration Reservoir is mounted to the side of the reservoir holder. The perfusing fluid is led from the main reservoir to the Aeration Reservoir by tubing provided. The Aeration Stone is mounted on the end of 2 m (6.6 ft) tubing. This Aeration Stone fits inside the Aeration Reservoir and provides a high level of oxygenation to the perfusant. The transparent, heavy plastic Water Bath which warms the perfusant measures, H x W x D, 15.5 x 16.5 x 14cm ( 6-1/4 x 6-1/2 x 5-1/2 inch ) and has a capacity of 3.6 liters. The bath is heated by two simple sturdy cartridge elements that are mounted through the front of the tank near the bottom and extend 5cm (2 inch) into it. These heating elements have a combined rating of 80 watts. The temperature of the water is controlled by a front panel dial graduated from 15O to 45 OC by 5OC graduations. A metal tube mounted inside the bath carries a sensitive thermistor sensing bead. Once stabilized, this maintains the water temperature with 0.5OC of the desired temperature. The front panel of the water bath has two indicator lights. One illuminates when the bath is plugged into the AC line. The second illuminates whenever the heating circuit is energized. A screw in fuse holder is also mounted on the front panel for easy access. A drain hole with tubing, a plug and a tapered plastic cone are located in the bottom of the water tank. The soft rubber bung that carries the stem of the warming coil fits into the cone making a leak proof joint. The glass warming coil for the perfusing fluid is 5cm (2 inch) in diameter by 9cm (3-1/2 inch) long. It has a capacity of approximately 35ml. The stem of the warming coil connects to the Heart Cannula with tubing and a pinch clamp controls the flow of the warmed perfusate. A clamp and grooved rod are supplied for securing the bottom of the excised mammalian heart. The Heart Cannula has openings to accommodate both a Manometer and Thermometer. The Manometer has a fixed clamp for mounting it directly to a crossbar and is connected to the Cannula by tubing. The scale read 0 to 250 mmHg and is free to move up and down behind the tubing to facilitate zero adjustment. The glass Thermometer is straight, 10cm (4 inch) long and graduated from 0O to 50OC by 0.1OC increments. It is mounted in a rubber bung and fits into the side arm of the heart cannula. All of the clamp, stands and rods supplied with this Apparatus. Two light pulleys are supplied and carry a thread from the heart to a transducer (not supplied) or writing point. |
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