Disposable blood oxygenators

No. 276 Disposable blood oxygenator set 1. Extractive substances i. Transparency and appearance ii> Foam teat ill. pH (The difference to the blank solution) iv. Potassium permanganate-reducing substances V. Residue on evaporation Vi. Zink vii. Lead 2. Hemolysis test 3. Pyrogen test... 

Recently developed blood oxygenators are disposable, used only once, and can be presterilized and coated with anticoagulant (e.g., heparin) when they are constructed. Normally, membranes with high gas permeabilities, such as silicone rubber membranes, are used. In the case of microporous membranes, which are also used widely, the membrane materials themselves are not gas permeable, but gas-liquid interfaces are formed in the pores of the membrane. The blood does not leak from the pores for at least several hours, due to its surface tension. Composite membranes consisting of microporous polypropylene and silicone rubber have also been developed. 

Disposable syringes, blood oxygenator membrane, suture, nonwoven fabric, and artificial vascular grafts... 

Another microcell has been proposed that may be used as a microcell for pseudo-continuous sensing, or as a disposable blood gas analyzer [13], Three sensor spots, responsive to, respectively, pH, oxygen and carbon dioxide, are placed in a 30-pL... 

Lung function Relating to the transfer of oxygen from air into the blood and the disposal of carbon dioxide from the blood to the air. 

The major functions of the red blood ceil are relatively simple, consisting of dehvering oxygen to the tissues and of helping in the disposal of carbon dioxide and protons formed by tissue metabolism. Thus, it has a much simpler structure than most human cells, being essentially composed of a membrane surrounding a solution of hemoglobin (this protein forms about 95% of the intracellular protein of the red cell). There are no... 

Medication Transportation System. If the brain, the spinal cord, and the nerves make up the body s communication system, then the heart, blood vessels, and blood are the body s transportation system. Blood carries oxygen and nutrients to the organs and then returns the wastes for disposal. Medications use this same internal highway system to travel throughout the body. 

The Bohr effect is closely related to the major roles that hemoglobin plays in disposing of the C02 produced in tissues, and in controlling the blood pH. While oxygen is being delivered to the tissues in the venous blood, the C02 is being removed from the tissues (fig. 5.5). The C02 that diffuses into the erythrocytes is rapidly converted into carbonic acid, which in turn dissociates into H+ and HC03. The protons produced by this dissociation would lower the pH and reverse the dissociation if it were not for the buffer-... 

In recent years newly invented detection devices have enabled scientists to investigate the minute quantities of materials that are involved in our metabolic processes. The super oxide anion (Op is one of the enemies of the cells of our bodies. It is generated as a by-product of respiration with oxygen and is also made by specially activated white blood cells. In normal healthy people the body has its own way of disposing of these ions using of an enzyme called super oxide... 

Either the CO2 formation is followed potemiometrically (243) or the O2 consumption is measured amperometrically at an oxygen electrode (245). In the first method, the enzyme is physically immobilized with a dialysis membrane. The response is linear in the range 5-300 pg/mL of salicylate. The second technique uses chemically immobilized enzyme (GA -F BSA) attached to a pig intestine mounted on the tip of the O 2 electrode. Samples containing from 10 pM to 2 mM salicylate were analyzed. An elegant microelectrode (244) has the enzyme and the cofactor immobilized in the electrode matrix (carbon paste) and the catechol formation is monitored at -F 300 mV versus Ag/AgCl. The electrode consists of a disposable strip, allowing measurements to be made on a drop of blood within 1 min. 

A fluorosensor for monitoring blood gases and pH in an extracorporal loop is commercially available [125]. Arterial or venous oxygen and carbon dioxide pressure, pH, and temperature can be determined continuously during cardiopulmonary bypass surgery. The system consists of a microprocessor-based instrument, bifurcated fiber-optic cables, and a disposable sensor head with fluorescent spots sensitive to the respective analytes. 

Frequent measurement of blood gases, that is, oxygen partial pressure (PO2), carbon dioxide partial pressure (PCO2), and pH, is essential to clinical diagnosis and management of respiratory and metabolic problems in the operating room and the ICU. Considerable effort has been devoted over the last two decades to developing disposable extracorporeal and in particular intravascular fiber optic sensors that can be used to provide continuous information on the acid-base status of a patient. 

FIGURE 20.9 Hemodialysis exchangers are disposable units similar to membrane oxygenators in construction, (a) Note the simple design of the device as shown in the upper portion of the figure (Artificial Organs Division, Travenol Laboratories, Inc., Deerfield, Illinois). (6) Close-up view of hollow fibers used to separate the patient s blood from the dialysate fluid. Toxins in the blood diffuse through the fiber walls to the dialysate fluid. 

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