Equipment for artificial life support and monitoring of human vital functions
Equipment to support life - designed to support the work of the patient. At the stage of basic life support actions are performed to restore vital functions of the body - the heart and respiration, as apparatus for artificial life support includes medical ventilators (IVL apparatus), heart-lung machines, dialysis machines and others.
ABOUT THE ORGANIZATION intensive care
Need help in emergency can occur in any environment. The life of the victim in this case will depend on whether the person providing aid has methods resuscitation (external cardiac massage and artificial respiration). Of course, full resuscitation may conduct a medical professional.
Found that the human body continues to live after respiratory arrest and cardiac activity. Indeed, with stops supply of oxygen to the cells as a precondition for the existence of a living organism. Different tissues respond differently to the lack of blood supply to them and oxygen, and their death is not in the same time. Therefore, restoration of blood circulation and breathing through a set of measures called resuscitation may lead a patient with a terminal condition.
Terminal condition can be caused by various reasons: shock, myocardial infarction, high blood loss, airway obstruction or asphyxia, electrical, drowning, falling asleep underground, etc.
In a terminal state distinguish 3 phases or stages:
?span style='font:7.0pt "Times New Roman"'> pre-agony condition;
?span style='font:7.0pt "Times New Roman"'> agony;
?span style='font:7.0pt "Times New Roman"'> clinical death.
In the state of consciousness of the patient pre-agony still remains, but it confused. Blood pressure drops to zero, the pulse accelerated sharply and becomes threadlike, shallow breathing, shortness, skin pale
During the agony of blood pressure and heart rate are not defined, eye reflexes (corneal , pupil reaction to light ) disappear , breathing character gets swallowed air.
Clinical death - short transitional stage between life and death, duration of 3-6 minutes. Breathing and heart function available, pupils expanded, cold skin, no reflexes. During this short period, it is still possible to restore vital functions by resuscitation. In later periods , irrevocable changes in tissue and clinical death becomes biological, true .
After returning the body from a state of clinical death initially reduced cardiac performance, respiration, and later self only later, when gone dramatic changes in metabolism and acid-base status may recover brain function.
The period of recovery of brain function longest. Even after short-term hypoxia and death experience (less than a minute) consciousness may be absent for a long time.
Organizing special cabinet in the clinic, pharmacy, any medical point where you need to be reanimation set is a very important.
Fig.1. Bag-laying. ?Fig. 2.?Resuscitation kit.
Reanimation should be equipped with everything you need for intensive care as well as for operations such as tracheotomy, catheterization of veins, arteries and the heart, direct cardiac massage, etc.
Fig.3. Equipment reanimobile.
Modern ambulances are equipped:
1. doctor's chair with back and headrest;
2. two-position automatic safety belt;
3. outpatient table with electro-hydraulic principle of action;
4. stretcher with a possible function of transporting the patient from the accident site to the bed;
5. defibrillator - Series professional defibrillators, monitors with:
?span style='font:7.0pt "Times New Roman"'> biphasic rectangular pulse with the innovative technology of current stabilization (CCD),
?span style='font:7.0pt "Times New Roman"'> High contrast LCD monitor
?span style='font:7.0pt "Times New Roman"'> ?-channel ECG
?span style='font:7.0pt "Times New Roman"'> mode of cardioversion (synchronized with ECG)
?span style='font:7.0pt "Times New Roman"'> automatic ECG analysis,
?span style='font:7.0pt "Times New Roman"'> defibrillation in manual and automatic modes,
?span style='font:7.0pt "Times New Roman"'> integrated pulse oximeter,
?span style='font:7.0pt "Times New Roman"'> transthoracic pacemaker,
?span style='font:7.0pt "Times New Roman"'> reusable adult / child electrodes for defibrillation ("irons")
?span style='font:7.0pt "Times New Roman"'> built-in thermal printer,
?span style='font:7.0pt "Times New Roman"'> automated storage media memory card (ECG, duration of resuscitation, defibrillation episodes, audio);
6. apparatus for maintaining the patient's vital for cars intensive care in an emergency;
7. apparatus for oxygen
inhalation, oxygen tanks;
8. artificial lung device;
9. mount for 2 infusion bottles;
10. power socket for connecting an incubator for babies;
2. power equipment from AC (230V) electric vehicle and the onboard battery.
APPARATUS FOR ARTIFICIAL LIFE OF RIGHTS
Artificial ventilation ?AV ?(Controlled mechanical ventilation - CMV) - method by which the restored and maintained impaired lung function - ventilation and gas exchange.
The essence of mechanical ventilation (respirator) is compulsory introduction of air into the lungs. It is used in cases of respiratory arrest, and the presence of incorrect or almost imperceptible breath. Artificial ventilation is designed to solve problems that normally perform the respiratory muscles. This task includes ensuring oxygenation and ventilation (removal of carbon dioxide) lung patient. With a beating heart effective CPR quickly improves patient. Skin acquire natural color, there is a pulse, blood pressure begins to manifest.
The most effective artificial respiration or mechanical ventilation, spending by special apparatus for artificial respiration. In the absence of such an artificial ventilation device transmitting means "mouth to mouth". In the light of the victim gets about 1.5 liters of air equal to the volume of one deep breath.
Indications for mechanical ventilation
Ventilator shown in all cases where there is acute respiratory failure leading to hypoxemia and (or) hypercapnia and respiratory acidosis. Analysis of arterial blood gas composition - the most accurate method of assessing lung function, but, unfortunately, not always possible, especially in emergency situations. In these cases the indications for mechanical ventilation are the clinical signs of acute respiratory disorders: severe shortness of breath, accompanied by cyanosis (bluish skin and mucous membranes caused by high levels of reduced hemoglobin), sharp tachypnea (temporary cessation of breathing movements) or bradipnoye (abnormal decrease in respiratory rate that grow with reduced excitability of the respiratory center) attended the auxiliary respiratory muscles of the chest and abdominal wall in breathing, abnormal breathing rhythms. Transfer patient required mechanical ventilation with respiratory failure, accompanied by disturbances, with coma, earthy color of the skin, increased sweating, or change the size of the pupils.
Thus, artificial respiration is carried out:
?in all cases of severe shock, hemodynamic instability, progressive pulmonary edema and respiratory failure caused by bronchopulmonary infection;
?In case of traumatic brain injury with signs of respiratory and / or consciousness (through the need for treatment of cerebral edema by hyperventilation and sufficient oxygen supply);
?In case of severe trauma of the chest and lungs, leading to respiratory failure and hypoxia;
?In the case of drug overdose and poisoning sedatives (immediately, because even a slight hypoxia and hypoventilation worse prognosis);
?after failure of conservative therapy ODN-induced asthmatic status or exacerbation of COPD.
There are two main types of ventilation: ventilation with negative pressure and positive pressure ventilation.
The first ventilator copying mechanism for human breathing. They work on the principle of negative pressure ventilation. ?/span>
Ventilation with negative pressure conducted an external effect on the wall of the chest cavity (thorax or diaphragm).
Mechanical ventilation devices outside of work on gravity or pneumatic principle.
By gravitational include "bed, swinging" (patient laid on his back on the bed, which is reeling regarding its transverse horizontal axis. Headboard When lowering the content of their abdominal mass pressing on the diaphragm, making breathing is active. When lifting bed diaphragm drops, ensuring the flow of air to the lungs).
By air include:
- Devices of the "iron lung." Shell respirator grabs the trunk below the neck and under the shell created negative pressure gives rise to pressure gradients and gas-flow the upper airways in the lungs. Inspiration is by creating vacuum around the chest cell and exhalation is passive.
- Devices with cuirass. Implementation of mechanical ventilation by creating a cyclical changes in air pressure around the chest and upper abdomen of the patient. Their work is the same as the "iron lung", but the ventilation effect is smaller.
- Devices with pneumatic breast girdles. MV made by creating a cyclical changes in air pressure in the zones that are put on the chest or upper abdomen of the patient. Ventilation is active exhalation (air injection at the waist) and passive inhalation (sucking air from the belt).
Fig. 1. ?/span>Artificial ventilation with negative pressure. The device "Iron Lung".
This mode makes it difficult to access the patient's body and unacceptable during surgery. Currently not used.
One more way to ensure gas exchange - electrical stimulation of respiration, which is used infrequently (principle of action is to control ventilation by periodic stimulation of the diaphragmatic nerve or diaphragm electrical pulses).
Ventilation with positive pressure may be invasive or noninvasive.
Mechanical ventilation with endotracheal intubation called invasive methods.
? ?img width=167 height=212 src="12_Equipment%20for%20artificial%20life%20support%20and%20monitoring%20of%20human.files/image007.jpg" alt=iv-patient.jpg>
à ? ?/span>b ? c
Fig. 2.? Patients with:
nasotracheal (?, orotracheal (b) intubation and with tracheostomy (c).
Noninvasive methods of ventilation.
In the late 80-ies of XX century for prolonged ventilation proposed a new method of respiratory support - noninvasive or auxiliary ventilation via nasal and facial masks (NSHVL).
Fig. 3. Patient on ventilation through a mask
To fully understand the methods noninvasive positive pressure ventilation is necessary to consider the process of breathing.
During spontaneous inspiratory respiratory muscle contraction reduces intrathoracic pressure and making it a below atmospheric pressure and the air enters the lungs. The volume of gas that enters the lungs with each breath, determined by negative airway pressure and depends on the strength of respiratory muscles and lung compliance and chest. During spontaneous expiratory airway pressure is weakly positive. Thus, in spontaneous breathing (independent) respiration occurs at a negative pressure, and breathing - with positive airway pressure. So-called middle intrathoracic pressure during spontaneous breathing, designed largest area above and below the zero line atmospheric pressure during the entire respiratory cycle will be equal to zero.
Any mechanical breath can be described based on the answers to three questions: how it begins, and how is over. Begin inhaling called triheruvannyam. Triheruvannya the pressure - this is the beginning of mechanical breaths with decreasing airway pressure below the level called trigger sensitivity. Triheruvannya downstream by the appearance of signs of breathing circuit air flow generated by the respiratory effort of the patient. The third type triheruvannya - on time. In this case, the mask begins to breath without mechanical respiratory patient attempts - after a doctor prescribed period of time elapsed since the last previous breath.
Positive pressure ventilation method can be divided into two main types:
?ventilation with intermittent positive pressure (VPPD; intermittent positive pressure ventilation - IPPV English authors), in active and passive exhalation breath,
?ventilation with intermittent positive-negative pressure (VPPOD; intermittent positive-negative pressure ventilation - IPNPV, NEEP english s), in the active inhalation and exhalation active.
Ventilation with intermittent positive pressure has two varieties:
a) ventilation with intermittent positive-pressure zero (Zero end-expiratory pressure - ZEEP English authors), in which passive exhalation occurs freely and without delay, and the patient's lungs during exhalation fall to the size of the functional residual capacity,
b) ventilation with intermittent positive - positive pressure (Positive end-expiratory pressure - PEEvY English authors), in which passive resistance through the trachea (or back pressure) the patient's lungs during exhalation is not caca to functional residual capacity. Thus there are constant in sign, but different from the pressure at the end of inhalation and exhalation.
The most widely used methods of mechanical ventilation in which the respirator through the airways patient injected gas mixture with a given volume or set pressure. In the airways and lungs creates a positive pressure. After inhalation of artificial feed gas mixture into the lungs stop breathing and there, during which the pressure decreases. These methods are called mechanical ventilation with intermittent positive pressure (Intermittent positive divssure ventilation - IPPV). When mechanical ventilation with intermittent positive pressure mean intrathoracic pressure is positive, since both phases of the respiratory cycle - inhale and exhale - performed with positive pressure.
Despite the widespread application of HF ventilation, they are mainly used as auxiliary methods during respiratory therapy. As an independent view of HF ventilation to support gas exchange is irrelevant. Direct application of this technique sessions lasting 40 minutes can be recommended for all patients who performed more than 24 hours of mechanical ventilation. The combination of HF ventilation with conventional mechanical ventilation - ventilation intermittent RF - is a promising method of maintaining adequate gas exchange and prevention of pulmonary complications in the postoperative period. The method consists in the fact that the mode of mechanical ventilation RF input pause to allow reduction of airway pressure to the required value. These pauses correspond to the expiratory phase with traditional mechanical ventilation. Pauses are created by turning off the electromagnetic transducer apparatus HF ALV 2-3 of 6-10 times per minute under the control of gases in the blood.
Considered to be high-frequency ventilation with a frequency of more than 60 respiratory cycles per minute. This value is chosen so that the specified frequency switching phases of respiratory cycle is the basic property of HF ventilation - continuous positive pressure ( CPAP ) in the airways. Naturally, limit the frequency on which this property appears quite broad and depend on the conditions of lung elasticity and chest, speed and method of respiratory gas injection and other reasons. However, in most cases it is at a frequency of 60 respiratory cycles per minute in the respiratory tract of the patient creates a PPT.
Classification of respirators
Single and universally accepted classification of devices currently no ventilation. Usually it involves the distribution of a group of a number of characteristic features: the type of energy used during the fan mode switching phases of the respiratory cycle, on the basis of the alarm system and more. On the other hand, the ventilator divided by appointment (stationary traffic), the design (mobile, transported, portable), by way of motion mechanism (centralized source of compressed gas, internal or external compressor, bottle, etc.) and so on.
The basis of the proposed classification ventilator - a place and purpose of use. Depending on all respirators can be divided into several classes:
1. apparatus for respiratory support at home and hospice (nonreanimation model), as well as transport respirators;
2. sets the standard for respiratory support in non-intensive care units (base model);
3. apparatus for respiratory support in patients with severe respiratory distress in non-intensive care (models with advanced features);
4. apparatus for respiratory support in respiratory centers and specialized units resuscitation in patients with extreme severity of respiratory distress, usually in combination with other manifestations of multiple organ failure (higher models);
respiratory equipment for special purposes - devices for high-frequency ventilation, devices for supplying nitrous oxide, helium-oxygen mixture extracorporeal oxygenation and elimination of carbon dioxide.
Let us consider the technical features of different groups of respirators.
No resuscitation and transport model
The features of these respirators are:
?Only need one source of compressed gas - oxygen. Air is sucked from the environment or through a system of low pressure - blower ;
?simplified preparation of oxygen- air mixture. As a result, the oxygen content are approximate and no possibility of fine adjustment of its concentration ;
?low weight and ease of administration;
?lack of a positive airway pressure - PEEP. If this opportunity is then carried out using a mechanical valve petal inhalation - exhalation. The device does not allow the valve to maintain high accuracy produced by PEEP. In a long-term mechanical ventilation valve can stick the petals together by moisture exhaled breath and stop function adequately . Having petal valve does not allow to include in the circuit respirator active moisturizer. Should be excluded , even short-term use because of the risk of active humidifier exhalation valve obstruction with the development of hypoxia and hypercapnia. The only way to ensure hydration respiratory gas - use filter - heat exchanger;
?Minimum ventilation modes and alarms. Number of alarm mode is limited. One reason is the lack of restrictions on the flow sensor in the knee exhalation respirator that does not allow to measure the compliance of flow and volume of air entering the lungs doctor prescribed values. Typically, the group is described respirators only pressure sensor in the respiratory circuit. Said sensor provides control only over the required parameters : excess pressure in the airways.
?The use of two systems of compressed gas - oxygen and compressed air. These two systems compressed gas required to ensure accurate mixing of oxygen- air mixture in specified proportions ;
?Availability of additional control concentrations of inhaled oxygen. Monitoring can be carried out mechanically by plate valve or a special oxygen sensor ;
?Availability exhalation valve , located on the distal respirator with respect to the patient. In the basic model passive exhalation valve as it opens to patients exhaled air and closes at the end of exhalation. Its device allows very precise dosage amount PEEP. The design of the valve provides for a use heat exchanger so , if necessary, and active airway humidification using the built in humidifier circuit breathing ;
?Availability of pressure sensors and flow. Using two types of sensors can provide the required audible and visual alarm when discrepancies respirator settings and actual parameters of ventilation the patient;
?the possibility of mechanical ventilation on two main algorithms - Assist Control and SIMV. Mandatory breaths in each of these algorithms are provided as a mode of ventilation volume (Volume Control), and the pressure ventilation (Pressure Control). Assisted breaths using the algorithm SIMV modes supported in Pressure Support or CPAP . It is possible apnoynoyi ventilation, in mechanical ventilation in the absence of mandatory or assisted breaths during a certain period of time ;
?the ability to create pauses inhalation and exhalation. Pauses are created to assess inspiratory plateau pressure and internal PEEP (auto- REER);
?ensuring synchronization attempts respiratory patients and ventilator work through triggers on the flow and the pressure. In the basic model the response trigger is usually 300 -400 ms.
Models with advanced features
In addition to the options presented in the basic models, optional apparatus of this group should be:
?Enhanced patient attempts to synchronize breathing with a respirator work . Response time attempt to trigger the respiratory patient should not exceed 100 - 150 ms. With this value of response time patient does not respond to delay filing inspiration. In some models so short a time are realized by using two sensors: Flow - inhale and exhale . In other modern respirators trigger downstream functions without a base flow;
?graphical representation of curves , flow and pressure in the airways ;
?ability to change the speed and flow profile during ventilation in the pressure mode . Regulation of these parameters is required to improve the convergence of the respiratory pattern of the patient and of the respirator ;
?active exhalation valve . Its opening and closing are regulated separately from the microprocessor respirator inspiratory valve . This allows ventilation with two levels of airway pressure (such as BIPAP);
?Dual mode ventilation - PRVC and perhaps , VAPS;
?Automatic measurement of respirator airway resistance , dynamic compliance , and the ability to determine the activity of the respiratory pattern of the patient.
Models of higher level
Respirator higher must be equipped with large specialized ICU . However, due to their high cost of units higher in the respiratory park should not exceed 20 to 30% . The use of this technique is only justified when the extreme severity of respiratory disorders , as well as damage to other systems , such as coupled traumatic brain injury and severe abdominal compartment syndrome.
By respirators upper class , except those opportunities that have models with advanced features impose the following requirements:
?ability to maintain spontaneous respiration of the patient in any phase of the respiratory cycle in any mode of ventilation (so-called virtual Pressure Support);
?ability to change the expiration criteria using Pressure Support;
?opportunity multi- monitor lung mechanics using tracheal and esophageal sensors;
?the presence of one or more integrated applications to determine the static pressure -volume curve , recruitment of lung automatically determine the optimal parameters of ventilation and weaning the patient from the respirator .
The main part of the ventilator
Ventilator consists of the following components (figure. 4):
?source of medical gases;
?mixing oxygen and air;
?device for moistening and cleansing the respiratory mixture;
?Breathing circuit with inhalation and exhalation valves;
?sensors control the flow and pressure.
The main problem that solves the respirator, are as follows: respirator should be mixed in specified proportions of air and oxygen, cleanse and moisten them, then apply under positive pressure in the airways of the patient according to the specified algorithm. This unit ventilator shall monitor the safety of all products manufactured by him actions.
?/span>. Ventilator circuit with an active humidifier and flow sensors;
b. Figure ventilator with filter- heat exchanger and pressure sensors;
c. Ventilator circuit combined with distal flap inhalation-exhalation (transport model).
Figure. 4. Figure ventilator. 1, 2 - cleaning filters; 3 - oxygen sensor; 4 - inspiratory valve; 5 - additional flow sensor; 6 - active moisturizer; 7 - knee inspiratory breathing circuit; 8 - Y-connection of the respiratory circuit of the endotracheal tube; 9 - knee expiratory breathing circuit; 10 - breathe clean air filter; 11- main flow sensor; 12 - exhalation valve; 13 - heat exchanger filter; 14 - proximal pressure sensor; 15 - distal pressure transducer; 16 - manifold nebulizer; 17 - combining distal inspiratory-expiratory valve.
In modern respirators control center consists of one or more microprocessors.
The task control center are:
1) supervision of sensors and flow volume;
2) Control valves for coordinated work of timely filing and cessation of oxygen-air mixture;
3) responding to rejection of certain parameters of a given ventilation systems.
Sources of medical gases
To create a breathing mixture of two sources need medical gases : oxygen and air. Oxygen for mechanical ventilation in intensive care units , usually comes with a centralized hospital oxygen plant . In the centralized supply of oxygen can be provided with two ways: directly from gas cylinders installed next to the respirator , and the oxygen concentrator. Installing an oxygen cylinder in intensive care is dangerous because of the possibility of his fall and subsequent explosion. The use of an oxygen concentrator that extracts oxygen from surrounding air , economically disadvantageous. In this context, hubs are used only for mechanical ventilation and oxygen therapy at home, at a low flow of oxygen.
In simple models respirator air supplied to the patient to create an oxygen- air mixture , " sucked " from the environment. Modern devices use mechanical ventilation of the compressed air. Compressed air can come from three sources: the central hospital compressor respirator compressor and turbine ventilator . If in the intensive care unit for at least 6 respirators most economically using a centralized supply of compressed air. To ensure patient safety compressed air will flow centrally and compressor respirator be in standby mode . Failures of the centralized supply , compressed air flow is achieved compressor respirator (figure. 5)
Figure. 5. The best way to supply the intensive care unit. 1 - oxygen hose from the central oxygen plant, 2 - hose compressed air from the main compressor 3 - compressed air hose from the compressor to the blender respirator ventilator, 4 - panel wiring centralized gas, 5 - Compressor respirator.
If a centralized system the compressed air in the hospital is not available, then we have to use a respirator compressor or turbine. Prolonged use of ventilator compressor is disadvantageous because it is designed mainly for emergency and must include, as a rule, less life than turbine. At the same time, the turbine can not be used during mechanical ventilation in neonates, as has excessive inertia. This feature does not allow the turbine to create high air flow needed for patients in this category. In addition, a large turbine inertia reduces the possibility of respirators (this applies to the creation of sensitive methods are on a respirator respiratory efforts of the patient).
The advantage of the turbine respirators is their lower weight compared to the compressor. This turbine apparatus suitable for internal or Interhospital transporting a patient with severe respiratory disorders as undesirable and dangerous reduce the quality of respiratory support. Turbulent air flow generated by the turbine, adequate mixing medical gases as in their low and high pressure. In this regard turbine respirators can switch from work at high pressure oxygen at low pressure mode.
Precise mixing of oxygen-air mixture produced a special device - mixer (blender). Control accuracy of the blender and creates a concentration of oxygen in the inhaled gas is carried out in two ways: mechanically through plate valve or using a special oxygen sensor. When inconsistencies given concentration of oxygen in the inhaled gas and its actual content respirator delivers audible and visual alarms.
The principle of plate valve is as follows. The valve provides uniform pressure compressed air and oxygen, which guarantees compliance with doctor prescribed oxygen concentration. Excess pressure on one another back plate valve, and a beep sounds, indicating that the lack of guaranteed accuracy of oxygen (Fig. 6).
Fig. 6. The principle of washer valve. A - By doing the same pressure gases - plate is parallel to the flow, b - different pressure By doing gases - plate overlapping stream.
An oxygen sensor analyzes the content of oxygen in the breathing mixture after mixing blender. The principle of the sensor is based on the change in its physical and chemical properties depending on the concentration of oxygen. This sensor is located at the outlet of the respirator breathing mixture, which allows for more precise control of the oxygen content before entering it to the patient than using washer valve.
Devices for humidification and purification of respiratory gas
Air mixture coming from the ventilator, it is necessary to warm and humidify. Otherwise, these measures result in damage to the lungs even after short-term mechanical ventilation. To clear the respiratory gas inlet mask is placed special filters that also provide protection and respirator and the patient from accidentally hitting the impurities (oil, etc.) from the mains.
For Near Y-shaped connection can be located an additional filter that has two purposes. First - clean inhaled air and exhale patients. The second - delay exhale patient warm water vapor, allowing the filter to perform functions of heat exchanger (Fig. 7).
Fig. 7. Filter exchanger by heat
Instead of filtering heat exchanger and humidification mixture inhaled can be active humidifier (see Fig. 4 , a). It breathing mixture before entering the patient's lungs is passed through a layer of water (bubbling method), warmed and saturated with water vapor. Another option is to go through dampening respiratory gas through a special chamber in which the evaporation of water. To maintain the high intensity of the process , the area is usually increased evaporation due to the location in the cell porous fabric, similar to a school blotting paper. An even greater degree of hydration provides sprayer ( nebulizer ) that allows spray airway of the patient as medicines. Note that the simultaneous use of nebulizers and filter - heat exchanger inappropriate because the share of liquid spray nebulizer and cause wet filter that removes it down.
Under the current requirements for safety, for the prevention of infection of medical staff and other patients exhaled breath patients must disinfect. This additional filter is placed closer to the ventilator, knee expiratory breathing circuit. This arrangement Filter prevents its rapid contamination of sputum and wet (see Fig. 1.1, b). Some models have a unique opportunity respirators heat flow sensor, located near the respirator at the end of exhalation line . Heat sensor can solve two problems: to prevent excessive accumulation of moisture on it and disinfect the air that the patient breathes.
Inhalation and exhalation valves
Proceeds oxygen- air mixture is regulated work of inhalation and exhalation valves . In simple models of respirators function of these valves are combined constructively in a single device , which is located on the machine next to the endotracheal tube and petal is a mechanical valve ( see Fig. 4c ). Valve is nereversiynym and allows for air movement : the inhalation into the lungs of the patient , and on the exhale - the environment. The device allows the valve to regulate the amount of approximately PEEP ( positive end expiratory pressure in the distal airways in the absence of mechanically generated pressure).
As the valve is in close proximity to the endotracheal tube , when you try to prolonged mechanical ventilation petals valve may stick to each other under the influence of moisture exhaled breath and stop function adequately . The presence petal exhalation valve can not include in the circuit respirator active moisturizer, so in this case using filter heat exchanger.
In more complex models of inhalation and exhalation valves are separated and located off the respirator . Work actively inhale valve regulated respirator microprocessor , exhalation valve and often passive because it opens the air exhaled by the patient, and closes at the end of exhalation. The device exhalation valve allows very precise dosage amount PEEP. Valve design provides both use heat exchanger and active airway humidification using the built in humidifier breathing circuit .
Most modern variant is the presence of active valves and inhale and exhale. In this case, open and close the exhalation valve respirator microprocessor regulated separately from the inhalation valve , thus preserving the possibility of spontaneous breathing patients during mechanical ventilation.
Series C- REER includes seven valves, each of which generates a single, unchanging value REER (REER , positive end expiration pressure, the pressure at the end of a long exhalation, PDKV). Each value REER corresponds to a certain color, uniform labeling of other manufacturers. Transparent casing and internal components of the valve coloring can observe his work and to monitor respiration.
Sensors control the flow and pressure
The main task flow sensor - Analysis of expiration. The sensor measures the amount of flow, then the microprocessor respirator integrates the rate and calculates the volume of patients exhale air. This amount must match the amount set by the doctor on the panel respirator and entered into the patient's lungs air.
The main purpose of the pressure sensor - control the same parameter in the airway of the patient barotraumas and to prevent leakage of air.
Using two types of sensors provides the necessary sound and light alarm when a respirator settings discrepancies and actual parameters of patient ventilation . Sensors provide a respirator information necessary for the operation of audio and visual alarms.
Major alarms are as follows:
?limiting the airway pressure (Rmax)
?Control the maximum frequency of respiratory movements (fmax)
?Control the minimum value of the respiratory volume (VT min)
Due to the information received by the mask of flow and pressure sensors, the device responds to patient breathing attempt . This reaction is called triggering as a device that provides feedback - trigger. Trigger (born trigger) means the trigger.
There are two types of triggers - for flow and pressure. Trigger on the flow responds to changes in air flow in the respiratory circuit, trigger the pressure - the pressure changes in the airways of the patient when trying to take a breath .
In addition to these two characteristics of the trigger , there is another , equally important - a reaction attempted respiratory patient. A number of ventilator fast response is realized by means of two flow sensors - for inspiration and expiration (Fig. 9).
Fig. 9. Improving tryheruvannya using two flow sensors. and - the patient is not breathing: inhale flow is flow at expiration, b - patient makes breath: flow by inhalation to exhalation flow more. 1 - flow sensor in the knee inspiratory breathing circuit, 2 - flow sensor in the knee expiratory breathing circuit.
A circuit is fed respirator constant weak, base, flow 3 - 5 l / min, which passes by the patient. Performance gauges compared respirator. If the sensor registers exhale the same thread as the sensor for breath, the respiratory understands that there is no breathing attempts. If the patient attempts to inhale, some of the basic flow enters the respiratory tract. On exhalation flow sensor registers reduce the base flow, which is a signal for tryheruvannya and supply of mechanical inspiration.
Some modern respirators streaming trigger functions without the base flow. Respirator just preparing fresh gas flow and the appearance of trying to inhale takes it in the airways. For the operation of the described system must be met high technical demands on the sensitivity of the trigger.
Fig. 10. A functional block diagram of a ventilator with automatic control without using biological information.
There are many different sets of mechanical ventilation with the implementation of such a system of " Enhstrem - Eric " (Sweden ), " Draeger -Eve " ( Germany), "System" (Spain) , the phone company for children " fol " (UK ) and others. Consider the generalized functional diagram of mechanical ventilation (Fig. 10) in order to demonstrate the capabilities and tasks performed in the apparatus of this type. The scheme refers to the ventilator with a constant flow generator and shows the main features of automatic control systems.
Breath control , getting through the signal generator comparative information set and actual values of minute ventilation , measured on line exhalation valve supported by inhaling the same gas flow on inspiration to set minute ventilation did not differ from the measured , regardless of the load on the measurement apparatus and leakage connect the device to the patient . Specified ( generator curve shape speed ) signal is compared with the actual form of speed, measured in the line of inspiration, is transmitted through inhalation controller that receives the information about the position of the actuator valve inhalation , causing the regulator valve controls the inspiratory breath so that ensured given the shape of the curve rate of injection. Regulator exhalation, inhalation similarly regulator controls the exhalation valve , receiving for his work about the value of minute ventilation , the pressure required from the generator end expiratory PTKV , actual pressure value and temporal characteristics of expiration.
Information from the flow transducer, pressure, concentration of pCO2 and O2 enters the monitor system that produces signals to the alarm system if the settings have gone beyond the established values, transmits this information to the storage device and a means of displaying information.
Features Microprocessor control is not limited to this scheme. Urgent task is to study the adequacy of the technical capabilities required ventilator use in a particular application area.
Fig. 11. Modern devices ventilator
Apparatus "artificial kidney"
Fig.1. Modern apparatus "artificial kidney"
Hemodialysis - a mechanical cleansing the blood of waste salts and fluids necessary for patients whose kidneys are healthy enough to do the job . Hemodialysis is the most common method for the treatment of severe renal insufficiency. This procedure will help the patient to lead an active life, despite the disruption of the kidney.
Hemodialysis is usually assigned when kidney patient can perform only 10-15% of their work. Hemodialysis takes of renal function - it controls blood pressure patient and maintains the normal balance of electrolytes in the body fluids . It also helps maintain a healthy acid- alkaline balance.
Hemodialysis is carried out using the apparatus "artificial kidney", whose main task is to clean the blood from various toxic substances , including metabolic products. The volume of blood outside the body remains constant.
The method is based on the principle of diffusion and convection substances with low and medium molecular weight through a semipermeable membrane , which allows you to remove toxic substances from the blood and metabolic products. The need for dialysis occurs in severe kidney disease, or if you receive a large amount of blood toxins.
Apparatus " artificial kidney " consists of the following components : a device for giving blood, a device for preparing and filing dialysis solution, monitor dialyzer . The most important function of the dialyzer. It contains a semi-permeable membrane based on cellulose or synthetic polymers. The membrane has an area of 0.2 to 2 m ², thickness 8, 11, 15 or 30 mm, pore diameter from 0.5 to 5 nm. It divides the inner space into two parts dialyzer (for blood and solution), each of which has its own entrance and exit. Blood is taken from vessels of the patient enters the dialyzer and is located on one side of the membrane, on the other side is a solution that is similar to electrolyte composition of the blood.
Fig. 2. Scheme of the membrane dialyzer
By diffusion in the direction of lower concentration through a membrane removes substances with small molecular weight (electrolytes, urea, creatinine, uric acid, etc.). By ultrafiltration removes excess water and substances with high molecular weight (up to 30000). Purified blood returns to the vascular patient.
Prosedure of hemodialysis
Before the procedure, an artificial kidney machine washed, sterilized, with attached canister concentrate salts dialyzer attached to the patient, the system is administered heparin to prevent clotting. To the patient device can join veno-venous or arteriovenous way. If necessary, reusable patient implanted external arteriovenous shunt. With screen monitor and regulate the chemical composition, pH, blood pressure in the office and more. Patient safety provide special devices to protect it from air embolism, excessive ultrafiltration bacterial contamination. Duration of hemodialysis 5 - 6 hours.
Fig. 4. The principle of the Hemodialisis
Structurally apparatus "artificial kidney" consists of two main blocks-block hydraulics and power processor. Hydraulic unit performs the following tasks:
1. Prepares dializuyuchu fluid from concentrate and purified water by mixing one part concentrate and 34 parts water.
2. Held cooked dialysis aeration of liquids to prevent ingress of small air bubbles in the dialyzer.
3. Dializuyuchu heated fluid to the desired temperature. Typically, this temperature is close to the temperature of the human body and is set in the range of 35.0 to 41.0 degrees Celsius.
4. Provides supply dialysis solution in the dialyzer at speeds ranging from 300 to 1000 ml per minute. The default rate is 500 ml per minute.
5. Held by ultrafiltration, ie the displacement of low blood connections (water, urea) by creating a pressure difference in the dialyzer (between blood and fluid dializuyuchoyu that are on opposite sides of the membrane). This pressure is called transmembralnym (TMP).
6. Provides intake of dialyzer fluid dialysis with ultrafiltrate.
7. Where necessary, provide bypass dialysis dialyzer fluid by the so-called system BYPASS.
8. Conducts internal disinfection device before and after hemodialysis.
As part of the unit is the hydraulic conductivity and temperature sensors, sensor TMP detector leakage of blood from the dialyzer and specific sensors for each specific model of device "artificial kidney" that monitor the system hydraulics and its constituent pumps and pumps.
There are two basic types of devices "artificial kidney". The first type include sets of ram dialysis passage of fluid through the dialyzer. In devices of this group dialysis solution flow is performed by two pumps, one of which faces the dialyzer and the other after the dialyzer.
By applying to a regulated pump pressure is maintained constant stream dialysis solution and formed a negative pressure in the dialyzer. This pressure is directly related to the magnitude transmembralnoho pressure (TMP) and TMP is therefore controlled variable. In turn, TMP affects the amount of ultrafiltration and controls the amount derived from the patient's blood fluid. This principle of construction of hydraulic machines "artificial kidney" there is a very long time. The main advantage of this technical solution design simplicity, the main drawback, the presence of uncontrolled ultrafiltration. The problem is that to ensure the safety of dialysis at zero ultrafiltration (often used in children and in certain types of acute poisoning in adults) need to provide negative pressure TMP. However, the dialyzer will skip certain amount of ultrafiltrate that will not be taken into account. On the other hand a zero pressure TMP in the dialyzer is unacceptable, because the latter will reverse the process of filtering dialysis solution to the blood. At that hemodialysis would be considered dangerous to the patient. Despite these deficiencies, sets of ram dialysis passage of fluid through the dialyzers are widely used in medical practice.
The second group of devices "artificial kidney" are devices with a closed loop dialysis fluid , which flow through the dialyzers is formed by the so -called equalizer. Because the flow of fluid through dialysis dialyzers runs in a closed circuit , it is possible to carry out hemodialysis with ultrafiltration zero for any values of TMP under the terms of patient safety . This is due to the fact that inverse filtering from an enclosed volume possible. On the other hand , the need for ultrafiltration is able to pump from an enclosed volume of fluid required for a conventional pump. The volume of a pump movement can be calibrated and usually is 1 milliliter. Thus, in contrast to the first group of devices where TMP is the main factor , which is calculated by ultrafiltration, in the apparatus of the second group ( closed- loop ) ultrafiltration volume formed directly by the number of movements ultrafiltration pump . This control volume ultrafiltration called Volumetric and provides more accurate parameters hemodialysis.
Apparatus " artificial kidney", based on a closed loop is now become the most widely produced and leading manufacturers hemodialsis equipment. ?/span>
If the construction of the hydraulic apparatus "artificial kidney" are fundamentally different , the processor block all similar devices and performs the following tasks:
1. Provides apparatus "artificial kidney" modes of preparation for dialysis, hemodialysis various options and mode of disinfection apparatus after dialysis.
2. Control of arterial, venous and transmembralnym (TMP) pressure.
3. Control of fluid conductivity dialysis solution.
4. Control heat and maintain a constant temperature dialysis solution.
5. Control of the cooking dialysis solution.
6. Calculation program for dialysis input parameter of time and volume
ultrafiltatsii and maintaining control of the design during dialysis.
7. Control of the aeration fluid in hydraulic system.
8. Control of detector leakage of blood from the dialyzer.
9. Control Detector getting air into the blood in extracorporal circuit.
10. Circulates blood through the extracorporal circuit through dialyzers.
11. Provides heparin in blood during hemodialysis.
12. Provides input data required dialysis and the ability to adjust the data in the process of dialysis.
13. Monitors all controlled parameters of output key data on the screen.
14. Electronic, light and sound alarm system included in the output of any of the monitored parameters specified limits or faults in the device and in some cases automatically terminates dialysis.
One means of improving the reliability of hemodialysis, is the availability of modern devices "artificial kidney" battery pack. It allows you to turn the patient's blood during emergency power outages and thus avoid blood loss, and allows staff to remember all the settings and return to continue dialysis after the removal of the accident.
An essential component of the apparatus "artificial kidney" is an electronic weighing system, without which it is impossible to conduct precise monitoring of the change in body weight of the patient during hemodialysis.
Ventricular fibrillation - the most common cause of sudden cardiac arrest in adults. Initial resuscitation (cardiac massage and artificial respiration) in these patients can not translate fibrillation to normal rhythm. Only the timely (early) defibrillation is the only chance to restore hemodynamic effective heart rate and save a patient with cardiac arrest from certain death. Timely defibrillation - is defibrillation, which is carried out in the first 5 minutes after the onset of cardiac catastrophe. With each minute of delay the chances of survival drop by 10-15%. After 7-10 minutes after the occurrence of atrial fibrillation patients return to life is almost impossible.
When electrical defibrillation through the patient's body by two spaced electrodes on the chest passed a short (0,01 seconds) electrical discharge of high voltage (7000 V), causing momentary depolarization of the maximum number of cardiomyocytes, which allows arrest existing cardiac arrhythmias and gives possibility of driver restore normal heart rhythm course excitement.
Possible causes of inefficiency defibrillation:
− Erroneous imposition of electrodes;
− Grease the electrodes is absent or very low (high resistance of the skin);
− Electrodes sufficiently tightly to the chest;
− Very low energy defibrillation;
− Lack of myocardial oxygen saturation.
To carry out this manipulation of the special device - electric defibrillator, a variant of which is shown in Figure 1. Correct positioning of the electrodes on the chest is shown in Figure 2.
Fig.1. Defibrillator FID-02 UOMZ
Fig.2.?Location of electrodes on the chest
Block diagram of the defibrillator
Fig. 3. - Block diagram of the apparatus
Power the unit on AC 220 V, 50 Hz power supply provided 220 - 18 , and in the absence of the network - from the onboard battery, a charge which takes place on the network through the power supply 220 V , 18 V and battery charger . Transducer (10-20 ) B - 5 , +15 , -15 V generates the necessary voltage to the machine . The unit charge high voltage (VV) capacitor is fed directly from the power supply 220 V , 18 V and provides a controlled explosive charge controller capacitor. Controller using capacitor energy explosives , pulse shaper via BB latches submits bipolar electrodes pulse with defined parameters and amplitude of the first half-wave selected on the electrode - the dispenser. Display provides information on the power supply, the battery when powered by battery , the battery charging status and performance of the machine.
Electric circuit defibrillator
Fig. 4. A simplified circuit diagram defibrillator.
Description of the electrical circuit defibrillator. After turning on the defibrillator high voltage switch S charges the capacitor C (capacitance of a capacitor depends on the amount of electricity injected into the patient, and the duration of the pulse defibrillation). The charged capacitor is disconnected from the power source and through the inductor is connected to the defibrillator electrodes. Capacitor discharge occurs only after pressing the button S1 and S2, located on the electrodes so that the doctor can just push them in a position where it does not touch your hands or metal electrodes or the patient's body. Inductance L in terms of discharge rounds off the top of the pulse and increases the length of its front (it is believed that defibrillation is critical in the first half-wave, the effect of subsequent "negative" current (curve 2 Fig. 5) still not fully elucidated).
Fig. 5.?Defibrillator discharge curve
Short pulses of high-used for defibrillation, is produced by the accumulation capacitor discharge.
Charging process obeys the formula:
The voltage of the charged capacitor is given by:
The energy defibrillation ?in the absence of losses in an electric circuit, electrodes, etc. can be determined from the expression:
Defibrillator discharge process obeys the formula:
During discharge only a small part of the energy affects the heart due to the presence of different levels of resistance (impedance) of the chest. The value of energy required during defibrillation (defibrillation threshold) increases with time after cardiac arrest. For resuscitation of adults used empirically chosen level of 200 joules for the first two categories and 360 J for the following. Discharges DC must be applied at the correct formulation of the electrodes and good contact with the skin. The polarity of the electrodes is not crucial , since in their correct positions " breast " and " tip " on the screen projected defibrillator correct orientation of the complex. Electrode that is applied to the breast , placed on top of the right half of the chest under the collarbone . Electrode affixed to the top of the heart is located slightly lateral point of the normal projection of the apical impulse , but not for breast cancer in women . If unsuccessful, may apply other provisions of the electrodes , for example, at the top and the back surface of the chest.
Over recent years, semi-and automatic defibrillators. In conjunction with the patient, such devices are able to self-assess heart rate and perform the required level.
Some also allow you to evaluate the resistance of the chest in order to select the required amperage discharge. The latest generation of defibrillators using two-and three-phase waveform energy for successful defibrillation at lower energy force.
Appearance defibrillator DKY - H - Aksyon 08-X
1 - button is charging network
2 - Button inclusion defibrillator
3 - The power of the network
4 - LED battery
5 - A cell in which the AC power cord is placed and the wires from the " iron "
6 - Sync Button category
7 - The button changes the voltage scan film
8 - Button transfer mode in ECG defibrillator / monitor and switch leads
9 - Stop Button ECG
10 - Two buttons switch pulse energy (more - less)
11 - Reset button battery
12 - Film ECG ( Thermoprinters )
13 - Connector for ECG - cables (using synchronization and button 6)
14 - The LCD
15 - Iron the breasts, and upon it
16 - Button Shoot
17 - Button starting ECG thermal printer (12)
18 - Iron on top, also with buttons :
19 - Shoot
20 - Set of charge
Fig. 6. Defibrillator
In the past 10 years, more widespread use of automatic receiving (external) defibrillator (AED, AND). These devices allow us not only to determine the need for defibrillation and discharge power, but usually also provided the voice instructions for carrying out the entire cycle of cardiopulmonary resuscitation. They are set in the most crowded and visited places as defibrillation efficacy falls sharply after 7 minutes after the occurrence of ineffective circulation. The standard method using AND as follows: find a person in an unconscious state and calling an ambulance , skin, breast stacked disposable electrodes (you can not even spend time checking pulse and pupils ). On average a quarter of a minute of the unit ( if there are indications in the category ) offers push a button and make defibrillation or (where no indications ) begin chest compressions / CPR and includes a timer. Rhythm analysis is performed again after discharge or after the standard time allotted for CPR. This cycle continues until the arrival of medical teams . When restoring a heart defibrillator continues to operate in a follow-up.
Fig. 7.?Portable automatic external defibrillator
Daily monitoring of blood pressure, cardiac activity and blood oxygen saturation
Blood pressure monitoring. Traditionally made when examining patients single measurement of blood pressure (BP) do not always reflect the true value of it, do not give an idea of the daily trend. This approach is not possible diagnosis of hypertension, the selection of antihypertensive agents, assess their effectiveness (especially after a single application) and the ratio of treatment.
In a fairly significant number of patients with a visit to the doctor, a frequently in clinical practice, with single measurements revealed high numbers of blood pressure, sometimes by 20-40 mmHg higher than when measured at home. Sometimes it is mistakenly interpreted as a hypertension, but more frequently - as "white coat effect". Outpatient ambulatory blood pressure monitoring (DMAT) in a normal human life helps to eliminate this effect, improve the quality of diagnosis and define the need and treatment strategy.
Additionally, DMAT helps identify false-negative cases when the disposable blood pressure measurements obtained normal values and are considered as normotensive patients , although in reality are hypertensive , ie at -monitoring them throughout the day are more high numbers of pressure.
In current approaches to the treatment of hypertension (GB) should be selected drugs that are capable of maintaining an adequate level of blood pressure for 24 hours. Thus the importance of DMAT as a method of assessing the quality of antihypertensive therapy can not be overemphasized .
Blood pressure monitoring during the day and more can be used not only for diagnosis and monitoring the effectiveness of treatment of arterial hypertension (AH), but also to study the effect on the blood pressure of various stress, diet, alcohol intake, smoking, physical activity, concomitant drug therapy, etc. etc.
DMAT - the only non-invasive method of examination, which allows:
- Obtain information on the rate and blood pressure fluctuations during the day, during wakefulness and sleep;
- Identify patients with nocturnal hypertension, which increased the risk of organ damage;
- Assess the adequacy of BP reduction between doses of regular doses of the drug;
- Control the absence of excessive blood pressure lowering at peak drug action or lack of decline before the next intake, especially for zastosuvanni prolonhovanyh antihypertensive drugs targeted at single dose per day;
- Identify patients with low or high BP variability (insufficient or excessive decrease it at night) and decide on the recruitment of anti-hypertensive drug, taking into account its effect on blood pressure values not only in the daytime, but at night.
Types of monitors pressure
To achieve the objectives of the doctor and the correct evaluation of DMAT necessary knowledge of the principles and operation of devices used for pressure-monitoring.
The work of all ambulatory pressure meters based on the identification of restoration of blood flow through the artery after perezhymu and subsequent discharge pressure cuff. As used in some monitors principle of measuring the pressure in the injection of air into the cuff gives inflated results as to overcome the elastic artery wall by clamping it necessary to create excess pressure that exceeds the pressure in the vessel, particularly for its hardening.
To determine the restoration of blood flow through the vessel may apply different methods: volumetric or elektropletizmohrafiya, fotopletizmohrafiya (sensors operating in passing or reflected light and react to the appearance of oxyhemoglobin), ultrasonic blood flow detector capacitance transducers pulse sensors that record the clearance of isotopes etc.
Not all of these techniques are applicable in the design nosym devices for blood pressure monitoring. Impedance of the system, for example, where the restoration of blood flow through the arteries is controlled by reohrafichnym not been used in ambulatory practice not only because of the complexity of the operation, but not because of the small dimensions of the devices.
Ultrasonic sensors are based on the Doppler effect, also were used in systems of ambulatory blood pressure monitoring via low immunity and difficulties with blood flow sensor positioned over the artery.
The first serial ambulatory pressure monitors used acoustic measurement method is based on the detection of Korotkoff tones with special microphones embedded in the cuff. Overlay Cuff require precise placement of the microphone artery and maintaining its position in all dimensions, it is difficult to provide during the day.
This method, although it became the largest distribution and is considered the benchmark does not always satisfy the users due to lack of precision measuring diastolic pressure (ADT) where errors can reach 10-20%. Also, still not fully elucidated the mechanism of the origin of Korotkoff tones and the dependence of their amplitude and frequency characteristics, as well as the onset and disappearance of the elastic properties of the arteries.
Fig.1.? Monitor blood pressure
Fig. 2 The principle of connecting the monitor to the blood pressure of the patient
Monitors, built on the principle of acoustic measurements are not adequately protected from external noise and interference , resulting in friction sleeve located in her microphone against clothing , etc. So were produced combined with simultaneous recording of the ECG , which provided immunity that attaches to the microprocessor pressure values only colors that coincide with the R wave electrocardiosignal and the remaining acoustic phenomena are regarded as artifacts.
Disadvantages pressure monitor with acoustic measurement principle not limited . Built- in cuff sensors are sensitive to mechanical damage, often fail because of the broken crystal piezoceramic or wire failure .
More suitable for use in ambulatory monitor system was recognized oscillometric method. Oscillatory systems, such as monitor AVRM -02 by " Meditech " (Hungary) , were quite widespread , as they practically insensitive to noise , can quickly and easily apply the cuff , without worrying about the accuracy of positioning. An important advantage of oscillator method is to determine the average pressure ( ATsr ) , details of which are necessary for the understanding of the course of development of different forms hipertoniy , depending on the definition of blood pressure from external factors and therapeutic interventions . These monitors are suitable for monitoring blood pressure in patients with weak pulse, deaf Korotkov tones or low blood pressure.
In devices based on the oscillator method, there systolic dimension (ATC) and average (ATsr) blood pressure. For PBX accepted value of pressure in the cuff at the time the first pulsations during decompression, and in ATsr - pressure corresponding to the appearance of oscillations of maximum amplitude . Diastolic pressure (ADT) based on an automatic analysis of the amplitude and shape pulsations of air in the cuff on algorithms that are usually kept secret Firms developers.
Monitors other designs ATsr often calculated automatically by adding 1/3 of the pulse pressure to the diastolic.
Recently, there have monitors with pulse-dynamic way of determining blood pressure. For example, the monitors' Dinapuls "American company" PulseMetric ", instead of using the amplitude of the so-called" similar "or outline a way to assess where in the analysis of each oscillation of air in the cuff is made construction, a patented method of pulse wave in the arteries and it is measured by ATS and ADT, and ATsr automatically calculated by adding up to 1/3 systolic 2/3 diastolic.
Displays on the computer screen reconstructed for each individual reduction pulse wave analysis allows the detection of irregular shape (arytmychni) reduction, which helps in assessing accuracy.
By themselves, the value of ATS and ADT defined by any indirect method is not numeric pressure inside the artery. It's more pressure, you want to create a cuff to stop blood flow and pulse wave propagation along the artery or the changing nature plays with her colors. These values are pressure though with true respect in direct proportion , yet are much higher and are purely local and conditional value at the place of the imposition of the cuff , the patient and the type of equipment used . However, ignore these figures should not be, because they may be relevant to the characteristics of the vascular system and blood circulation in general. At the same time , the value ATsr absolute and not dependent on the arterial wall , soft tissue and covered limbs and properties cuff .
Ostsyllometrychni blood pressure monitoring system is also not without drawbacks. If their application is mandatory security at the time of measurement estate limbs, which cuff. Therefore, some firms, including firm "Schiller" (Switzerland), producing oscillating pressure monitors in which to improve noise immunity uses a combination of acoustic and oscillometric methods.
Apparently, the development of blood pressure monitors appropriate to use a combination ostsyllyatornoho and electrocardiography or, in extreme cases, acoustic and electrocardiography, but best of all three methods, as is done in combination monitors " Kardiotehnika -4000 -AD " company " INKART " (St. Petersburg ), for monitoring blood pressure and ECG. It should be noted that the use of monitors, blood pressure, ECG which only serves to control the accuracy of the allocation ripple or ringing Korotkov , cost is not entirely justified, because it requires the purchase of one-time ECG electrodes , which increases the cost of the study. But, due to greater noise immunity, blood pressure through them can be carried out during exercise .
In modern ambulatory blood pressure monitor pumping air into the cuff is automatic to a certain, predetermined value. If this value is significantly higher than the systolic blood pressure or does not reach it, then repeated measurements automatically adjusts the pressure generated in the cuff.
The measurements are usually performed for a given program during decompression that occurs on different algorithms. Some monitors rate of discharge pressure in the cuff is uneven - first pressure dropped slowly, and after determining PBX - faster, in other uniform rate - 2-3 mmHg pulse to punch in the third it is automatically adjusted depending on the pressure and heart rate , which is better because of the constant uniform tightening procedure drop blood pressure , especially in the rare pulse and cause discomfort to the patient. Increasing the speed of decompression can lead to errors in the measurements , more noticeable when bradycardia.
Accuracy pressure monitors are not usually controlled by the user , as guaranteed by the manufacturers of compliance with international requirements and standards. Patient safety is ensured by monitors software or mechanical means to automatically turn off the power of the compressor and dump the cuff pressure in excess of the maximum value of pressure or time compression limbs controlled by built-in real time clock. In addition, the monitors can be equipped with the manual emergency shutdown of the compressor and pressure relief .
Holter-monitoring - a method to evaluate the patient's cardiac function in terms of the traditional way of life.
As a result of physician cardiologist can watch the reaction of the heart to physical and emotional stress, to determine possible myocardial ischemia as heart during sleep and during the day. Also, the method allows to determine the cause of syncope and presyncope. Research conducted in the outpatient mode, so the patient is free to go about their everyday business. This technique is highly informative and completely safe for the patient.
Fig.3 Holter monitor and event recorder ECG Merlin
Fig. 4. The principle of connecting to the body of a cholera patient
Monitor blood pressure and electrocardiosignal designed for simultaneous monitoring changes in blood pressure and heart.
Fig. 5.?Monitor blood pressure and electrocardiosignal day.
Fig. 6.?Monitor blood pressure and electrocardiosignal day SDM23
The main components of the monitor are:
?compression Cuff AT the shoulders
Fig. 7. One of the possible schemes of arrangement of electrodes on the patient's chest
Fig. 8. Fixing the electronic unit monitor blood pressure and ECG
a) on the cuff, b) at the waist of the patient
Circadian blood pressure monitor ABPM-05
Daily Monitor blood pressure and ECG Holter Card (X) Plore
Circadian blood pressure monitor AVRM 04
Pulse Oximeter - Medical diagnostic device for measuring the oxygen saturation in capillary blood. There are many pathologies involving hypoxia (lack of oxygen in the blood). In such cases, the need to constantly monitor the saturation.
Fig. 9. Pulse Oximeter.
In pulse oximeter has two LEDs that emit red and infrared light, and photodetector (photodetector) that it takes light. The changes in the ratio of absorption of red and infrared light receiver during systole and diastole, pulse oximeter determines the content of oxygenated hemoglobin in arterial blood, as infrared light absorbs oxygenated hemoglobin and red light - deoksyhenovannyy hemoglobin.
Fig. 10.?The principle of the pulse oximeter
Fig. 11. Block diagram of pulse oximeters
Saturation, pulse oximeter designate certain characters - SpO2. If saturation measured by laboratory (invasive) by (so-called true saturation), it denoted symbols - SaO2. Normal values of saturation (SpO2) - 95-98%.
Whatever the correct figure numbers saturation can be compared with the partial pressure of oxygen in the blood (PaO2).
?span style='font:7.0pt "Times New Roman"'> ?Since saturation (SpO2) 95-98% answers - 80-100 mm Hg. century. (PaO2).
?span style='font:7.0pt "Times New Roman"'> ?carbonation (SpO2) of 90% corresponds to - 60 mmHg (PaO2).
?span style='font:7.0pt "Times New Roman"'> ?carbonation (SpO2) of 75% corresponds to - 40 mmHg (PaO2).
Monitoring equipment for obstetrics and gynecology
Incubators the newborns
Incubators the newborns especially designed to create conditions newborns with extremely low body weight ranging from 500 g. The incubator is able to automatically maintain a stable temperature inside the incubator to maintain the temperature at a given level of the child's body and automatically maintain the humidity level inside the incubator without infecting with the child, even if prolonged nursing. Incubator at work exclude all factors adverse effect on the child while nursing.
Infant incubators with air temperature control and humidity system provides automatic control of oxygen supply. The system has a feedback device, such as an oximeter. Oxygen regulator is designed as a solenoid valve, input is connected to a source of fresh oxygen, and out - of incubator.
Fig. 1. Incubator for Intensive Care PC-305
Emergency care is a complex open-type incubators for newborns. Infrared lamp automatically maintains a stable body temperature regardless of the child's environment. This system keeps the most severe children, who often need to manipulate. The system has an effective infrared heater that measures the temperature of the child 40 times in 1 second with an accuracy of 0.01 deg C and heat capacity changes. The system allows its use even as an operating table for surgery in infants. To stabilize body temperature need only specify the desired body temperature and observe the current temperature and alarms.
Fig. 2. Intensive care unit MULTISYSTEM 2051
Fetal (embryonic) CTG fetal monitor registration
Electronic fetal heart monitoring is commonly used for tracking how well the baby is doing within the contracting uterus and for detecting signs of fetal distress.
External fetal heart monitoring is performed by attaching external transducers to the mother's abdomen with elastic straps (see diagram). The transducers use Doppler ultrasound to detect fetal heart motion, and the information is sent to the fetal heart monitor which calculates and records the fetal heart rate on a continuous strip of paper. More modern fetal heart monitors have incorporated microprocessors and mathematical procedures to improve the fetal heart rate signal and the accuracy of the recording.
During fetal monitoring, a nurse will evaluate the strip for continuity and adequacy for interpretation, identify the baseline fetal heart rate and presence of variability, determine whether there are accelerations or decelerations from the baseline, identify patterns of uterine contraction, and correlate accelerations and decelerations with the uterine contractions. This will allow the nurse to determine whether the fetal heart rate recording is reassuring, nonreassuring, or ominous. A plan can then be developed for the situation to help deliver the baby in the best possible manner.
Fig. 3. Fetal Monitor CTG registration fruit.
PRINCIPLES OF RECEIPT OF MONITORING
Pulsed Doppler directed system works with sensors 1.5 and 2.0 MHz. The sensor is fully internally shielded to minimize high-frequency emissions and interference ultrasound.
Fig. 4. The results of monitoring.
Fig. 5. Measurement of uterine contraction.
For the convenience of the patient and ensure the accuracy of measuring the strength of uterine contraction using lightweight, flat protective ring tokodynamometr Cmita such as straps and buckles, as well as for the ultrasonic sensor.
To register, fetal movements using low-frequency component of the Doppler ultrasound signal using ultrasound transducer 1.5 MHz. Graphic curve is low frequency Doppler signals (which reflect the speed of less than 4 cm / s).
Fig. 6. Aktohrama.
Apparatus for artificial respiration BEAR CUB 750psv focused on the use of infants with birth weight ranging from 300-400 grams. It has 14 possible modes of ventilation, allowing the unit to adapt to any condition of the newborn with respiratory disorders with minimal consequences of artificial ventilation. The device is supplied fully automatic humidifier that maintains heating and humidifying respiratory gas to the desired physiological level. A special sensor measures the tidal volume connector directly to the patient, allowing exactly 0.1 mL of shahom maintain standards of ventilation. In addition, the device allows to adapt to the child's spontaneous breathing, while the machine takes your breath synchronized with the patient's breathing efforts.
Fig. 7. Apparatus for artificial respiration BEAR CUB 750psv