DD218732A3 - OXYGEN MEASURING AND WARNING DEVICE - Google Patents

Abstract

THE INVENTION CONCERNS AN OXYGEN MEASURING AND WARNING DEVICE WHICH MAY BE USED IN ANESTHESIA AND INTENSIVE MONITORING, ESPECIALLY IN CONNECTION WITH NARCOSIS AND VENTILATION DEVICES OR OTHER FACILITIES WITH CONTROLLED AIR FLOW GAS. THE APPLIANCE SHALL SPECIFICALLY DISTINGUISH NORMAL EXPENDITURES OF ALARM EXPENSES WHICH ARE DIFFERENT FROM THE EXCEEDANCE OR REDUCTION IN THE LIMITATION OF THE LIMITATION OF THE LIMITATION. WITHOUT ADDITIONAL SWITCHING ELEMENTS, THE SIGNALING SYSTEM USES A MEASURING CABLE SYSTEM THAT ENTAILS INTERRUPTED OR INTERRUPTED INTERCONNECTIONS THROUGH A SENSUAL COMMUNICATION.

Description

Oxygen measuring and warning device. '.

Field of application of the invention:

The invention relates to an oxygen measuring and warning device that can be used in anesthesia and intensive care, especially in anesthesia and ventilators or other devices with controlled breathing gas throughput and continuously measures the total oxygen concentration digitally or allows a digital parameter measurement of the breathing gas. This oxygen measuring and warning device, connected either to the respiratory piping system of a patient or directly to the ambient atmosphere, is provided with two independently adjustable limit switches which indicate the limit values for the required oxygen concentration visual and audible alarm signal triggered ·;

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Characteristic of the known technical solutions:

An oxygen measuring and warning device intended for the medical field is known in which the oxygen diffuses out of the surrounding gas mixture through the plastic membrane of a sensor into the interior of its double measuring cell, thereby causing an electrochemical reaction on its electrodes is (Oxyc.om loo D brochure 6191.11 /. Drägerwerk AG, DE). , When equality of these two Meßströme a display and the two Meßströme not equal, malfunction, signaled «The measuring system is so signal-linked with the optical-acoustic warning device that falls below the manual adjustable limit size on, acoustic warning and disturbed .Punktion a visual warning. ,. · ·. , .. '"

Pernerhin an oxygen warning device is known in which the ^arrival: show 'by application of "the principle of measurement Polarograph" takes place, · namely here with a sensor that includes a designed as a disposable cell electrode (OXYGEN MONITOR - mono 2 / Roche! Bio-Electronics, US) The optical limit alarm is indicated by a flashing black triangle in the numeric display.

According to the same measuring principle, the display works with another oxygen warning device, which warns when it exceeds or falls below the adjustable limits (oxygen monitor QM-15 / Bechman Instruments Prance, PR). To signal the limit value violations, conventional warning lamps are used in this warning device.

Finally, an oxygen measuring and warning device has become known which measures the total oxygen density within an incubator for premature babies, newborns, an oxygen tent or other anesthesia ventilatory units and which is capable of detecting gas leaks in the oxygen supply and to warn (Oxygen Monitor OMD - loo / Aika Medical Corp., JP). Again, a polarogisphic sensor

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used for measuring the oxygen density, which is displayed digitally by means of liquid crystal (LCD). Upper limit and lower limit of the oxygen density are separated ·., Adjustable and leaving the border area is warned both optically by digital display and acoustically by discontinuously audible tones. ~. Although this and the other digitally indicating oxygen measuring and warning devices ensure accurate oxygen measurements, the optical signaling of limit violations is either negligible or has not been optimally solved with additional effort and thus far.

Object of the invention:. ''

The aim of the invention is the elimination of the indicated disadvantages and the avoidance of a complex circuit structure. Their purpose is particularly to provide an optimal warning in economic and ergonomic respects while maintaining the existing circuit elements and the digital numeric display or symbol display in addition to a flawless oxygen measurement. In addition, the optical alarm signaling should be bright and at a relatively long distance still perceptible.

Explanation of the essence of the invention:

The object of the invention is to develop an oxygen measuring and warning device which clearly distinguishes the normal conditions (no limit violation) from the alarm conditions (limit value violation) by either making visible only the measured oxygen concentration on the display panel or in addition to this its entire size is flashing. It is further desired to distinguish the leaving the set limit range depending on its overrun or undershoot distinguishable. ''.

According to the invention, the object is achieved by a signal timing system and a circuit linkage in such a way that the two,., The upper limit and the grenzetergrenz '· isolated.aufstellbaren limit value transmitters two parallel oxygen concentration via an analog / digital converter and measuring the limit violation Signaling circuits are connected downstream via a first and a second basic circuit, which on the one hand emit a digital signal in the BGD-Kcde via key switches and via a display circuit upstream of the display unit, and enable a 7-segment coding for controlling the display panels via a decoder and on the other hand, cause a switching or blocking effect during a border violation »

According to the invention, it can be assumed that the first limit value transmitter is connected to the one key switch and to a comparator intended for the upper limit value and the second limit value value is connected to the other key switch and to a comparator determined for the lower limit value, and that the second key switch via the first key switch and the two comparators a the. · Oxygen partial pressure proportional voltage is supplied from an oxygen converter via a measuring amplifier. ·

In a further embodiment of the invention, the circuit produced via the two key switches has two signal connections which are led to the display panel with a sign indication and are interconnected with the interposition of a diode, and this circuit has a further signal combination.

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• test to the analog / digital converter, which is connected on the one hand to the decoder and via this with the display panel and on the other hand, for time-division-multiplexed control with these via the responsible transistors. The invention over. the two Kompara'tpren produced. Circuit has two logic signals signal-linked to the comparators

Basic circuits, one of which contains a connected by two comparators NAND gate, the first via a multivibrator with the decoder and directly with the. Sign display panel and secondly with a NASJDi gate

an acoustic signal generator is connected and the other basic circuit in the direct access of the lower limit ^ comparator to the transistor which engages in the sign display tableau leading signal links of the first basic circuit of the second switching "circle and in the first circuit "

Conveniently, the acoustic signal transmitter can be temporarily blocked. This is made possible by the fact that the NAND gate of the signal generator on the input side with a. ' Timer and via this with a button "Alarm reset" and. Output side connected to a multivibrator and above this with a warning horn.

The digital numeric display is preferably designed so that an additional display of the first digit can be done after the comma. This is made possible by a key "cal", which is in the signal link to the rear digital input. the display panel is connected between these and the upstream transistor.

By supplying a reference voltage U- to the limit value transmitter, a. Operating voltage U-g to the connected to the Digiteingängen the display panels transistors and to the digit sign input and a corresponding circuit connection to ground a reliable function profile according to the embodiment s at game produced. , ..

Embodiment:

In the following a preferred embodiment of the invention is explained in more detail with reference to the accompanying drawings. This illustrates the logical connection of the oxygen measuring and warning device according to the invention with integrated circuits,

where an oxygen converter 1 and two. 2.3 limit are upstream. With these are on the one hand Meßver- stronger 4 and on the other hand two comparators 5.6 connected, which in turn are two t signal switches knobs t. ; The two comparators 5.6 are connected to a NAND gate 9 of a basic circuit in connection, which are still associated with a multivibrator 15 and a signal generator with a button "alarm reset" lo, a multivibrator 11, one of this and the NAND gate. 9 wired second NAND gate. 13 and a further multivibrator 16 and a Warnhüpe 18-r Another basic circuit is made by means of a transistor 24 which is connected on the one hand to the output of the comparator 6, on the other hand to the output of the multivibrator 15 and a sign display panel 19 of a display unit Basic circuits are part of a second circuit.

The two mentioned key switches 7,8 allow the output of dual functions. To. For this purpose, one output of the key switch 7 is connected to one input of the key switch 8, while its other output has a signal connection to the sign display panel 19. At the key switch. 8, on the other hand, the one output to an analog-to-digital converter 14 and the other output once via a diode 12 to the sign display tableau led signal combination of the key switch 7 and the other via a further signal link to the sign display panel 19.

The analog circuit associated with the first circuit, which is composed of a 3-digit analog-to-digital converter circuit known in the art as C 52o D, is provided with its outputs to and via the decoder 17 Display panels 19, 2o and connected to transistors 21 to 23, which in turn .eine

Establish connection to the digital inputs of the display panels 19, 2o. The transistor: 23 is still a key "cal" 25 'downstream, so' so that a 3-digit ~ display area is created.

In this invention connected oxygen measuring and warning device of the oxygen converter 1 provides an electrical voltage which is proportional to the partial pressure of oxygen. , This is amplified with the measuring amplifier 4, which consists of an operational amplifier stage, to a unit level of 1 volt DC and via the key switches 7, 8 (non-latching) placed on the input of the analog / digital converter 14 »At the same time carried by the sense amplifier 4 an adjustment to the oxygen converter 1 (calibration).

The analog-to-digital converter 14 converts the analog output signal of the measuring amplifier 4 into a digital signal in the BCD code, which is subsequently converted into a 7-segment coding by the integrated circuit of the decoder -17 known by the designation D 147 C. This 7-segment coding drives the display panels 19, 2o and shows the oxygen concentration in. In addition, the analog / digital converter 14 performs a time-multiplexed activation of the display panels 19, 20 via the transistors 21 to 23 "".

The upper limit (maximum) and the lower limit (minimum) are adjustable in the range from 2o to 99 vol.%. For this purpose, by means of the limit switches 2, 3 continuously comparison voltages in the 3ereich set from o, 2 to 1 volt and switched to their associated comparators and optionally with actuation of the key switch 7 and * of Tastenschalters'8 to the input of the analog / digital converter 14. Depending on the operation of the corresponding key switch 7, 8, the set upper or lower limit value then appears on the display unit. With the Freigebe this key switch 7, 8 is immediately the re-display of the measured value.

The operation of the corresponding key switch 7, 8 also has the consequence that the display of the upper limit value is signaled with the sign "plus" and the lower limit value with the sign "minus ^11. This is possible by the dual function of the two key switches 7, 8 in that, at the upper limit, all connections pass through the diode 12, and at the lower limit only one connection to ground is established.

The comparators 5, 6 are preferably realized by means of known operational amplifier circuits. In this case, the, measured value in the comparator 5 to the inverting input., At the comparator 6 placed on the non-inverting input of the respective operational amplifier circuit, .so that after the connection of the two, other inputs with the associated reference voltages, a so-called Pensterdiskriminator arises. As long as the measured value is within the range of the set limit values, both comparators 5, 6 are at aus level on the output side, the measured value exceeds or falls below the set reference voltages of the upper or lower limit value, the corresponding comparator tilts and leads on the output side Level. About the one basic logic circuit or the JJAiFD gate 9 and the NAND gate 13 takes place 'Ansteue.- tion of the astable multivibrators 15, 16 and for flashing frequency, the multivibrator 15 and for acoustic' signal to the multivibrator 16. This both multivibrators 15, 16, the aug each a gate of the well-known TTL circuit DHo D and jeeinem trigger circuit A 3o2 consist begin to cancel their blocking - Aμsgelöst by Η level at their inputs - to clock, so that. in the rhythm of the clock frequency output side L / H level (square wave voltage) abut. About the connection of the multivibrator 15 with the He11-dark control of the decoder 17, an alarm condition is initiated and there is a in

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2 Hz rhythm flashing display of the measured value. At the same time, the sign display panel 19 is driven so that e.g. in case of violation of the upper limit all on. For the sign of the sign by the multivibrator 15 are rhythmically switched to ground, whereby a flashing display of the sign "plus" is reached, while violation of the lower limit by L level at the output of the comparator 6, the transistor 24 is blocked, which finally leads to the rhythmic illumination of the symbol "minus".

During a limit violation, the multivibrator can be blocked for 6o seconds. This blocking is achieved by the preferably consisting of a known trigger circuit A 3o2 and a well-known TTL NAND gate timer 11 by pressing the button "Alarm reset" Io an L level at its output. This in turn has the consequence that for the time of 6o seconds the warning horn 18, so the acoustic signal is switched off, however, the limit violation is still optically signaled by the flashing of the display including signs. , '

As stated earlier, by pressing the "cal" key 25, an additional indication of the first digit behind the decimal point can be made, which is necessary for precise calibration of the measuring amplifier 4 and oxygen converter 1.

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Claims (4)

Claim of the invention:      , '' 1..Oxygen measuring and warning device, with two independently-adjustable limiters and a digital numeric display, which are interconnected via circuits, characterized in that the two, the upper limit and the lower limit separately adjustable limit switches (2,3) two parallel the oxygen concentration via an analog / digital converter (14) measuring'and the limit violation via a first and a second basic circuit (with 5 »6). signaling circuits are connected downstream, via the key switch (7,8) and via one of the display unit (19,2o) upstream transistor circuit ('21 to 24). on the one hand deliver a digital signal in the BCD code'and via a decoder (17) a 7-segment coding for An' 'control of the display panels (19,2o) allow and on the other hand a. Gating or blocking effect during ··. a "limit violation" effect 2. oxygen measuring and warning device according to item 1, characterized in that the first limit sensor (2) to the - Key switch (7) and to one for the upper limit: value / determined comparator (5) and the second limit (3) to the key switch (8) and to a specified for the ¹ lower limit comparator (6) connected; sen and that the second key switch (8) via the first key switch (7) and the two. · Comparators (5> 6) supplied to the oxygen partial pressure.proprtionale · voltage from an oxygen converter (1) via a measuring amplifier (4) is ·  ''. ι 3 * Oxygen MeS- and warning device kach point 1 and 2, characterized in that the circuit produced via the two key switches (7,8) two to the display panel (19) and with the interposition of a diode (12) - 11 - has interconnected signal connections and has a further signal connection to the analog / digital wall transducer (14) which is connected to the decoder (17) via the latter and to the display panels (19, 20) on the one hand and via the transistors (21 to 23) « 4. Oxygen measuring and warning device according to item 1 to 3 », characterized in that: the circuit produced via the two comparators (5, 6) has two logic base circuits which are signal-linked to the comparator (5, 6) and whose one basic circuit is one of connected to two comparators (.5,6) connected NANG gate (9), firstly via a multivibrator with the decoder (17) and directly to the display panel (19) and second with a -NAND gate (13) of an acoustic signal transmitter is connected and the other basic circuit in the direct access of the lower limit comparator (6) to the transistor (24) leading to the sign display panel (19) leading signal links' the first basic circuit of the second circuit and in the first circuit engages. .. 5 * Oxygen measuring and warning device according to item 4, characterized in that the NAND gate (13) of the signal transmitter   on the output side with the timer (11) and via this with a button "Alarm reset" (lo) and on the output side to a   Multivibrator (16) and is connected via this with a warning horn (18). , 6. Oxygen measuring and warning device according to item 1 to 4, characterized in that a key "cal" (25) in the signal connection to the rear bigiteingang the display panel (2o) between these and the transistor (23) is connected. 1 page drawings