Biomedical Instrumentation

Archive for the ‘Therapy Equipments’ Category

High Frequency Heat Therapy: Physical stimulus commonly employed in the practice of physiotherapy is in the form of heat, either by simple heat radiation or by the application of high frequency energy obtained from special generators. The use of high frequency energy in thermotherapy has the advantage of considerable penetration as compared with simple heat application. Thus, with high frequency energy, deeper lying tissues can be provided heat. High frequency therapy is based on the fact that the dipole molecules of the body are normally placed randomly. Under the influence of an electric field, they rotate according to the polarity of their charge in the direction of the field lines.

The positively charged end of the dipole then orients itself to the minus pole and negatively charged end to the plus pole. Since the polarity of the electric field alternates, a micro-heating effect results from the continuous re-alignment of the molecules. High frequency energy for heating is obtained by various ways. It may be from the short-wave therapy unit making use of either the condenser field or the inductor field method. Microwave and ultrasonic waves are also used for heating purposes in special cases.

Microwave Diathermy: Microwave diathermy consists in irradiating the tissues of the patient’s body with very short wireless waves having frequency in the micro wave region. Microwaves are a form of electromagnetic radiation with a frequency range of 300-30000MHz and wavelengths varying from 10mm to 1mm. In the electromagnetic spectrum, microwaves lie between short waves and infrared waves. The heating effect is produced by the absorption of the microwaves in the region of the body under treatment. Microwave diathermy provides one of the most valuable sources of therapeutic heat available to the physician.

However, in many conditions, though the therapeutic effects of microwave diathermy are similar to short-wave diathermy, yet in others, better results are obtained by using microwave. The technique of application of microwave diathermy is very simple. Unlike the short-wave diathermy where pads are used to bring in the patient as a part of the circuit, the microwaves are transmitted from an emitter, and are directed towards the portion of the body to be treated.

Intermittent treatment with a mechanical device like the artificial kidney will reduce the accumulation of waste products and water and thus the blood concentrations of the toxic substances are returned to normal levels. By effectively removing these materials from the blood, the dialyzer temporarily replaces the function of the natural kidney is a dialyzing unit which operates outside the patient’s own body. It receives the patient’s blood from the cannulated artery via plastic tubing. The return of the dialyzed blood is by another plastic tube to an appropriate vein.

The artificial kidney is thus simply a membrane separation device that serves as a mass exchanger during clinical use. It is unable to perform any of the synthetic or metabolic functions of the normal kidney and, therefore, cannot correct abnormalities that result from the loss of these functions. The only use of the artificial kidney in replacing renal function, therefore, is the transfer of noxious substances from the blood to the dial sate, so that they might be eliminated from the body. The dialyzer is the part in the artificial kidney system in which the treatment actually takes place and where the blood is freed from the waste products.

It is the meeting point of two circuits, one in which the blood circulates and the other in which dialysis fluid flows. Dialyzer, in routine clinical use, may be classified according to three basic design considerations: coil, parallel plate and hollow fiber type. Each type of dialyzer has certain optimum operating requirements. The rate of clearance of substances such as urea, creatinine, etc. from the blood during passage through an artificial kidney is dependent upon the rate of the blood flow.

As the flow rate falls, there is a disproportionate fall in clearance. At high flow rates, there is little advantage in further augmentation of the blood flow. The rate and pattern of the dialysate flow also influence overall performance in respect of clearance of waste products. Almost all commercial dialyzers use cellulosic type membranes, the most common being Cuprohon. My dear friends! I am sure this article will enhance your knowledge regarding the artificial kidney.

Pharmacotherapy: It is the use of medications to foster relief from mental illness such as depression. Antidepressant medications are place into four categories: selection serotonin reuptake inhibitors, tri-cyclic antidepressants, a typical antidepressants, and monoamine oxidize inhibitors. Antidepressant medications are usually considered, in conjunction with psychotherapy, when there is a moderate-to-serve form of depression. Selective serotonin reuptake inhibitors are the most commonly prescribed antidepressant medications currently on the market. They are better tolerated, have less dramatic side effects, and are safer in overdose than older medications. The most commonly prescribed SSRIs include Prozac, Paxil, and Zoloft. Monoamine oxidize inhibitors are generally no longer considered for used due to their dangerous side effects and difficulty of administration.

Electroconvulsive therapy: It is the use of electrically induced repetitive firings of the neurons in the central nervous system in order to bring about improvements in depression. It is usually not a first line of treatment. Electroconvulsive therapy is recommended when the depressive symptoms are severe; when there are psychotic features due to depression , as a rapid response to strong suicidal potential, during a physical condition; or when there is intolerable suffering. It may also be used when alternative therapies are riskier, such as tolerable side effects to medications, or when antidepressant medications prove to be unhelpful.

Light therapy: It is used to treat a depressive condition known as seasonal affective disorder. Seasonal affective disorder involves a pattern of Major Depressive Episodes at specific times of the year, most commonly in fall or winter. Light therapy is controlled exposure to specific levels of light in order to create relief from an evident seasonal pattern of depression. It involves lamps with specific light frequencies designed to treat the condition effectively. It is important to monitor for signs of a deteriorating condition throughout the treatment, suggesting the need for hospitalization. Signs may include a high potential for suicide, severe psychotic features, inability to eat or sleep for long periods or posing a threat to others. My dear friends! I am sure this article will enhance your knowledge regarding pharmacotherapy, electroconvulsive therapy and light therapy.

Dear friends! When a patient is incapable of adequate by natural process, mechanical assistance must be provided so that sufficient oxygen is delivered to the organs and tissues of the body and excessive levels of carbon-di-oxide or not permitted to accumulate. The procedure and instrumentation involved in providing mechanical assistance in respiration and in supplying hypoxic patients with higher-than-normal concentration of oxygen or therapeutic gases or medications constitute a field known as respiratory therapy. Until the past few years this field was known as inhalation therapy, but since it covers much more than inhalation, the more encompassing term is preferred. Instruments for respiratory therapy include such devices as inhalators, ventilators, respirators, resuscitators, positive-pressure breathing apparatus, humidifiers, and nebulizers. Many of these instruments, however, have overlapping functions, and the name used for a particular device may vary among manufactures.

Inhalators: The term inhalator generally indicates a device use to supply oxygen is some other therapeutic gas to a patient who is able to breathe spontaneously without assistance. As a rule, inhalators are used when concentration of oxygen higher than that of air is required. The inhalators consist of a source of therapeutic gas, equipment for reducing the pressure and controlling the flow of gas, and a device for administrating the gas. Devices for administrating oxygen to the patients include nasal cannulae and catheters, face masks that covers the nose and the mouth, and, in certain settings, such as pediatrics, oxygen tents. The oxygen concentration presented to the patient is controlled by adjusting the flow of gas into the mask.

Ventilators: The term ventilators and respirators are used interchangeably to describe equipment that may be employed continuously or inter mitten to improve ventilations of lungs and to supply humidity or aerosol medications to the pulmonary tree. Most ventilators in clinical settings use positive pressure during inhalation to inflate lungs with various gases or mixtures of gases. Expiration is usually passive, although under certain conditions pressures may be applied during the expiratory phase as well, in order to improve arterial oxygen tension only under rare circumstances is negative airway pressure utilized during expiration. My dear friends! I am sure this article will enhance your knowledge regarding respiratory therapy and hope, it is very useful.