DE3414094C2 - - Google Patents

Description

The invention relates to a plant for treatment of thermal injuries according to the preamble of Claim.

Such a system is from DE-AS 23 40 150 known. Devices of this type are used Treatment of burns, frostbite and after ver Burning trophic ulcers. You can also to improve the treatment of wounds soft tissue, for example as a result of a mechanical Injury, and trophic ulcers of various etyos logic can be used.

A system for treatment known from SU-PS 9 39 010 contains thermal injuries a radial serving as a fan fan for sucking the air out of the room and for conveying same for rinsing the injured part of the body Filter system that includes an air pre-filter and a bacterial filter comprises an electric heater, one as air line-designed device for conveying the aseptic Air out into an elastic inflatable sack guided treatment chamber and a sensor connected to the control unit of the heater for recording the temperature of the aseptic air.

The system known from SU-PS 9 39 010 enables flushing of the in the Treatment chamber housed injured body part the patient with a constant temperature air flow.

The target temperature of the air becomes with the target value adjuster one in the control unit of the heater arranged temperature controller set. The optimal one The temperature of the purge air is 30 to 32 ° C. This Value corresponds to the temperature of the body surface Sick and is considered a comfortable temperature.

The system known from DE-AS 23 40 150 is used for  postoperative treatment and can also accelerate treatment of burns and wounds softer Tissues are used. This system stabilizes the Air temperature on the given Level.

The insensitivity range of the temperature controller means that Difference between two temperature values at the installation point le of the sensor, namely between the temperature value at which the temperature controller turns on the heater, and the Temperature value at which the temperature controller the heater while the temperature setpoint remains the same adjuster switches off.

In other words, it can be said that insensitivity range of detuning between the temp temperature sensor measured temperature and the target temperature, at which the temperature controller responds and its output signal changes, is (yes-no).  

When using the known systems for rinsing an injured area with sterile air at con constant pressure and constant temperature get used to that of exposure to air at a stable temperature put body parts on this. After the treatment acts on the body mentioned divide the atmospheric air, its temperature inside of a sufficiently wide range fluctuates. This calls an irritation of the treated skin areas and leads to the "cancellation syndrome" known in medicine. The This circumstance reduces the generally high healing effect the familiar systems.

The invention has for its object a system for the treatment of thermal injuries with aseptic To create air at which the control unit looks like this is that they are treated with a stream of aseptic  Air of cyclically changing temperature of a certain maximum value in the initial period treatment to gradually decreasing values in the Course of treatment with simultaneous enlargement the cycle time enables.

This task is based on the generic type according to the invention by the characteristic features of the claim solved.

It is known from US-PS 26 75 455 for regulation the temperature of a hot plate between constant limits value to use a two-point controller. Furthermore, it is from the DE book: M. Reuter, control engineering for engineers, Braunschweig 1975, Friedr. Vieweg + Sohn publishing company mbH, pages 251 to 265, known that with a proportional Controlled system an increase in the insensitivity range (Hysteresis width) inevitably the period of oscillation, d. H. the Cycle time is increased. This leads to a downsizing of the setpoint in the range below half the value the maximum possible final value of the controlled variable an increase in the period of oscillation. The publication can therefore also be seen that the desired temperature course achieved with a proportional controlled system can be that the setpoint with the enlargement of the swan width is lowered such that the maximum value of the Temperature remains constant. Details of a suitable However, the circuit cannot be found in this document.

The plant for the treatment of ther mix injuries with sterile air a cyclical change in temperature in given Limits, namely:

In the initial period of treatment, the 48 hours from the start of treatment in the case of superficial fire sores, and in preparation for the car dermoplastic as well as during the first days after the car dermoplastic for deep burns, freezing and trophic ulcers, keeping the air temperature inside  Range from 30 to 32 ° C, then you expand evenly the temperature range while maintaining the maxi paint temperature value and decrease the minimum Temperature values on the sixth to eighth day up to 20 to 22 ° C, i.e. H. down to the ambient temperature, and keeps the air temperature in the reached Area. The cycle duration is even with the Extension of the temperature range enlarged.

When using the system according to the invention in be written operating condition becomes an effective cure thermal injuries and above a certain loading moment of action - a training of the injured body surface che by changing the temperature of the washing up Air reached. The mentioned temperature training of the traumatized Body surface accelerates their adaptation to fluctuation temperature of the ambient air and allows the "Withdrawal syndrome", which occurs when the be traded areas from the temperature-controlled treatment lungskammer using the known systems beo is excluded.

The executed according to the invention Facility for the treatment of thermal injuries possible effectively heals burns severity, frostbite and trophic ulcer ren, including in the final phase of treatment.

The plant for the treatment of ther mix injuries has an easy and for loading powered comfortable construction.

The invention based on the in the drawing shown embodiment explained. It shows

Fig. 1 shows schematically a plant for the treatment of thermal injuries and

Fig. 2 is a graphical representation of the temporal change in temperature of the germ-free purging air.

The system for treating thermal injuries with sterile air contains a blower 1 ( Fig. 1), which consists of a radial fan. The blower 1 serves to suck in the air, usually from the hospital room, the treatment room of the sanatorium, to convey the air via the elements arranged in technological order, described below, and to flush the injured part of the body with sterile air.

In the way of the air flow, a filter 2 for pre-cleaning the air from larger impurity particles is arranged in front of the blower 1 and a bacteria filter 3 is arranged behind the air blower 1 , which cleans the air of all aerosol impurities, including bacteria.

The bacterial filter 3 is followed by an electric heater 4 . The heater 4 is used to heat the Luftstro mes to the temperature required for the treatment of thermal injuries. The heater 4 has two limitations (requirements): low temperature of its working surface (not more than 70 to 90 ° C) and dust-free of the surface mentioned. These requirements are due to the need to preserve the properties of the original air as much as possible. The heater 4 is monitored by a control unit 5 . The temperature of the aseptic air is monitored by a temperature sensor 6 accommodated in the purge air flow.

To promote the germ-free and heated by the heater 4 , a device 7 for conveying the same in a loading treatment chamber 8 , in which the temperature sensor 6 be found, is provided.

It is most expedient to perform the device 7 for conveying the aseptic air in the form of a flexible line and the treatment chamber 8 in the form of an elastic, transparent bag inflatable by the abacterial air flow. The above-mentioned version corresponds best to the treatment goals, since it guides the treatment process comfortably both for the medical staff (visual control of the injured body area, palpation possibility, simple sealing of the sack on the injured part of the body, possibility of sterilization) as well as for the Sick (minimum mass of the sack, possibility of changing the position of the injured part of the body together with the sack, easy connection of the treatment chamber to the source of the bacterial air).

The control unit 5 monitors the function of the heater 4 with the aim of keeping the temperature of the aseptic air within the predetermined limits, which are determined differentially for each treatment stage. In addition, the control unit 5 has an element 5 a , which is conductively connected to the air blower 1 and intended to control the same.

The control unit 5 contains a two-point temperature controller 9 , which switches the heater 4 on or off, depending on how much the temperature measured by the temperature sensor 6 differs from the desired value. If the target temperature of the aseptic air is exceeded by a certain value, the controller 9 switches the heater 4 off and vice versa, if the temperature of the air flow falls below the target temperature by a certain value, the controller 9 switches the heater 4 on .

The two-point controller 9 can be of any type suitable for this purpose, provided that the output signal changes discretely.

To change the deviation of the temperature measured by the temperature sensor 6 from the target temperature, which is referred to as the insensitivity range, an insensitivity range controller 10 is used , which is connected to the comparison unit 11 of the temperature controller 9 .

The comparison unit 11 is used to compare the two signals that correspond to the actual temperature and the target temperature of the air flow. The signal corresponding to the actual temperature of the air flow reaches the comparison unit 11 from the temperature sensor 6 lying in the air flow. The signal corresponding to the setpoint temperature is generated in the temperature setpoint adjuster 12 connected to the comparison unit 11 .

Depending on the result of the comparison of the temperature signals mentioned, the comparison unit 11 generates the discrete output signal of the temperature controller 9 (yes - no).

For convenient operation, the insensitivity range controller 10 enables an asymmetrical change in the non-sensitivity range, namely a change in the lower limit thereof. In such a configuration of the controller 10 , the temperature determined by the setpoint adjuster 12 is exceeded by the actual temperature measured by the sensor 6 at the time when the heater 4 is switched off by the controller 9 . In contrast, the value of the reduction in the actual temperature measured by the sensor 6 changes compared to the target temperature specified by the setpoint adjuster 12 at the time when the heater 4 is switched on by the controller 9 as a function of the setting of the insensitivity range controller 10 .

The described design of the control unit 5 requires a cyclical change in the temperature of the air flow mentioned.

When the temperature setpoint (nominal temperature) is set on the setpoint adjuster 12 and the minimum value of the insensitivity range on the controller 10 , the actual temperature of the airflow is changed cyclically. The range of the temperature change compared to the setpoint is minimal in this case and is determined by the insensitivity range of the temperature controller 9 . The maximum air temperature exceeds that set on the setpoint generator 12 by the value of a certain part of the total insensitivity range, which is referred to as the upper interval. The minimum value of the air temperature differs from the setpoint by the value of the lower interval of the insensitivity range, which is the difference between the entire insensitivity range and the upper interval.

The described temperature behavior of the investment can act as temperature stabilization of the air current with at least achievable deviations from the nominal temperature.

In FIG. 2, the temperature variation of the germ-free air graphically described is (t temperature in ° C, cycle time τ in 24 hours) for the first two days of treatment shown. The value of the cycle time τ is determined in the specified operation by the requirements of the treatment and by the dynamic characteristics of the system for the treatment of thermal injuries, more precisely by the thermal inertia of the heater 4 , the flexible air line 7 , the sensor 6 ensures ge .

The transition to a new temperature cycle takes place by increasing the insensitivity range on the controller 10 with the position of the setpoint adjuster 12 unchanged.

The maximum actual temperature of the aseptic air remains unchanged. The minimum actual temperature of the air flow is reduced in proportion to the aforementioned increase in the insensitivity range. As a result, the range of the cyclical change in the temperature of the air flow in the direction of small temperature values is expanded. Simultaneously with the expansion of the range mentioned, the cycle time increases with constant values of the power of the heater 4 and the air flow from the blower 1 . According to Fig. 2 this is expressed by the following formula

τ ₂ < τ ₁ .

Mean here

τ ₁ the cycle time in the initial period of treatment,
τ ₂ the cycle time in the following periods of treatment.

For the plant for the treatment of thermal injuries with sterile air will Initial period of thermal injury treatment due to the optimal temperature of the air flow in the load rich from 30. . . 32 ° C marked. In this period are minimal deviations of the temperature from the nominal value and, accordingly, minimal insensitivity range of about 0.5 ° C is desirable. The end period of the Be action using the system training the injured body areas to normal Room temperature, the 20th . . 22 ° C is ahead. The Unemp range of sensitivity, the specified lowering of the lower Allows airflow temperature is approximately 10 ° C.

The change in the absolute cycle time of the temperature change of the aseptic air flow can be in the system for the treatment of thermal injuries by changing the throughput of the aseptic air in any way, for example with a throttle valve on the air line 7 or by changing the power of the heater 4 , also in any way, e.g. B. by subdevelopment of the heater 4 can be achieved.

The reduction in the performance of the heater 4 and the throughput of the aseptic air lead to an increase in the absolute cycle time. The above-described relative increase in the cycle time is maintained with the increase in the cyclical temperature change of the aseptic air flow.

The system for the treatment of thermal injuries with sterile air works as follows. In the initial period of the treatment, the temperature of the air flow is set in the range from 30 to 32 ° C. on the setpoint adjuster 12 with an insensitivity range of 0.5 ° C. on the controller 10 . As a result, in the initial period the temperature of the aseptic air flow is at a comfortable level and is maintained with the maximum accuracy that can be achieved for the specific system.

The initial period of treatment is:

• - For superficial burns, the first 48 hours the;
• - for deep burns, frostbite and trophic Ulcers are the time of preparation for autodermoplasty and the first 24 hours after autodermoplasty.

During the initial period, the Burn surface a thin crust (with superficial Burns), the autograft begins to take off grow (with deep burns).

After the initial period you start training the injured area by cyclically changing the temperature of the germ-free air that is flushing it. While maintaining the maximum air temperature (32 ° C on setpoint adjuster 12 ), the minimum temperature is gradually lowered by 1.5 to 2 ° C in 24 hours by increasing the insensitivity range that can be set on controller 10 . Here, in the course of every 24 hours, the temperature of the germ-free air stream rinsing the injured area is changed cyclically from the maximum value (which remains unchanged) to the minimum value determined by the insensitivity range set on the controller 10 .

With a size of the insensitivity range of 10 ° C, the minimum cyclically variable temperature for the sixth to eighth day is 20 to 22 ° C, which corresponds to the normal room temperature. The temperature cycle reached is retained in the course of further treatment. Fig. 2 illustrates the described change in the temperature of the aseptic air in temperature-time coordinates. As mentioned above, the cycle time increases as the lower temperature is lowered.

The recommended cycle time is 2 to 3 minutes in the initial period of treatment in the temperature range 30 to 32 ° C and 18 to 20 minutes in the end period of loading action in the temperature range 20 to 32 ° C.

The change methods of the absolute cycle time were the one described earlier.

The plant was clinically proven. The results of the treatment are as to be viewed positively. It became an essential min change in treatment time. At the out removal of the treated extremities from the treatment there was no shiver or itching, i. H. no "Aufhe exercise syndrome ". The possibility of a Temperature training of the injured area with the help of Plant according to the invention, the simple structure and be quem in operation is confirmed.

Claims (2)

Plant for the treatment of thermal injuries with aseptic air, in technological order

• - a blower ( 1 ) for sucking in the air and for flushing the injured body part with it,
  - a system of filters ( 2, 3 ) comprising a bacterial filter ( 3 ),
  - An electric heater ( 4 ) and
  - A control unit ( 5 ) connected to this
  • - A temperature controller ( 9 ) and
    - A temperature sensor ( 6 ) housed in a treatment chamber ( 8 ), and
• -a device ( 7 ) for conveying the aseptic air into the treatment chamber

contains, characterized in that

• - The temperature controller ( 9 ) in the control unit ( 5 ) is designed as a two-point controller and
  • - A to a comparison unit ( 11 ) of the temperature controller ( 9 ) connected insensitivity range controller ( 10 ) for cyclically changing the temperature between a maximum value and gradually decreasing the minimum values, the maximum value being the sum of the setpoint and the width of the insensitivity range on one connected to the comparison unit ( 11 )
  • - Temperature setpoint adjuster ( 12 ) and on the insensitivity range controller ( 10 ) is adjustable, and the minimum values can be selected by the insensitivity range controller ( 10 ) according to the treatment stages with simultaneous increase in the cycle time.