CA1293169C - Pump arrangement and monitoring apparatus for use in pleura drainage - Google Patents
Pump arrangement and monitoring apparatus for use in pleura drainageInfo
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- CA1293169C CA1293169C CA000537570A CA537570A CA1293169C CA 1293169 C CA1293169 C CA 1293169C CA 000537570 A CA000537570 A CA 000537570A CA 537570 A CA537570 A CA 537570A CA 1293169 C CA1293169 C CA 1293169C
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- subpressure
- pump
- value
- chamber
- patient
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Abstract
CANADIAN PATENT APPLICATION OF
OF
CONNY ERLINGSSON
FOR
PUMP ARRANGEMENT AND MONITORING
APPARATUS FOR USE IN PLEURA DRAINAGE
Abstract of the Disclosure A pump arrangement for use in pleura drainage to establish a predetermined subpressure in a patient's pleural cavity comprises a means to connect the arrange-ment to a drainage tube attached to the patient and extending into the patient's pleural cavity. The arrange-ment further comprises a subpressure chamber and a pump which is connected with the subpressure chamber to main-tain a subpressure therein. A first means is adapted to sense the subpressure in the subpressure chamber, to activate the pump in order to increase the subpressure in the subpressure chamber when the sensed subpressure falls below a given first value which is higher than the value of said predetermined subpressure, and to inactivate the pump when the sensed subpressure reaches a given second value which is higher than said first value. A second means is adapted to sense the subpressure in the drainage tube, to provide a connection between the subpressure chamber and the drainage tube when the sensed subpressure in the drainage tube falls below said predetermined subpressure, and to interrupt said connection when the sensed subpressure in the drain-age tube reaches the value of said predetermined sub-pressure. An apparatus for monitoring the patient s state comprises an indicator having an impulse generator and an actuator for acuation thereof during the intervals when the pump arrangement is in operation. The indicator is adapted to indicate the time during which the inter-mittently operating pump arrangment is in operation, and comprises a display means for displaying a value which is dependent on the said time.
OF
CONNY ERLINGSSON
FOR
PUMP ARRANGEMENT AND MONITORING
APPARATUS FOR USE IN PLEURA DRAINAGE
Abstract of the Disclosure A pump arrangement for use in pleura drainage to establish a predetermined subpressure in a patient's pleural cavity comprises a means to connect the arrange-ment to a drainage tube attached to the patient and extending into the patient's pleural cavity. The arrange-ment further comprises a subpressure chamber and a pump which is connected with the subpressure chamber to main-tain a subpressure therein. A first means is adapted to sense the subpressure in the subpressure chamber, to activate the pump in order to increase the subpressure in the subpressure chamber when the sensed subpressure falls below a given first value which is higher than the value of said predetermined subpressure, and to inactivate the pump when the sensed subpressure reaches a given second value which is higher than said first value. A second means is adapted to sense the subpressure in the drainage tube, to provide a connection between the subpressure chamber and the drainage tube when the sensed subpressure in the drainage tube falls below said predetermined subpressure, and to interrupt said connection when the sensed subpressure in the drain-age tube reaches the value of said predetermined sub-pressure. An apparatus for monitoring the patient s state comprises an indicator having an impulse generator and an actuator for acuation thereof during the intervals when the pump arrangement is in operation. The indicator is adapted to indicate the time during which the inter-mittently operating pump arrangment is in operation, and comprises a display means for displaying a value which is dependent on the said time.
Description
~ ~3~ig The present invention relates to a pump arrangement for use in pleura drainage to establish a predetermined subpressure in a patient s pleural cavity, said pump arrangement being connectible to a drainage tube attached to the patient and extending into the patient s pleural cavity.
The present invention also relates to an apparatus for monitoring the state of a patient who has a punctur-ed pleura for which he is treated by pleura drainage, the punctured pleura being kept expanded in that a sub-pressure is maintained in the patient's pleural cavity by means of an intermittently operating pump arrangement.
Pleura drainage means treating a patient with a punctured pleura by artificially maintaining in the pleural cavity a subpressure to keep the damaged pleura expanded, and in such treatment use is made of a pump arrangement which is connected to a drainage tube attached to the patient and extending into the pleural cavity.
Known pump arrangements for this purpose are designed such that a pump included therein must operate continu-ously without interruption in order to maintain a pre-determined subpressure in the pleural cavity. This causes considerable wear of the pump motor, and known pump arrangements therefore require extensive maintenance and have a comparatively short life. The sound of a continuously working pump motor may also disturb the patient.
One object of the present invention is to provide 11.293~
a pump arrangement for use in pleura drainage which is designed such that its pump can operate intermittently so as to reduce both the wear of the pump motor and the noise level.
According to the invention, this is achieved with an arrangement of the above-mentioned type which is characterised by a subpressure chamber; a pump connected to said subpressure chamber to maintain a subpressure therein; a first means adapted to sense the subpressure in said subpressure chamber, to activate -the pump in order to increase the subpressure in sai.d subpressure chamber when the sensed subpressure falls below a given first value which is higher than the value of said predetermined subpressure, and to inactivate the pump when the sensed subpressure reaches a given second value which is higher than said first value; and a second means adapted to sense the subpressure in the drainage tube, to provide a connection between said subpressure chamber and said drainage tube in order to increase the subpressure in the drainage tube when the sensed subpressure in the drainage tube falls below the pre-determined subpressure, and to interrupt said connection when the sensed subpressure in the drainage tube reaches the value of said predetermined subpressure.
When the subpressure in the pleural cavity, and thus in the drainage tube, falls below the desired sub-pressure, i.e. the said predetermined subpressure, the second means provides a connection between the subpressure ~3~
chamber and the drainage tube. Since the subpressure in the subpressure chamber is higher than the subpressure in the drainage tube, the latter will be increased without necessitating activation of the pump. The pump is acti-vated only when the subpressure in the subpressure chamber has fallen to a lower limit value (the said first value) and then is again inactivated when the subpressure in the subpressure chamber reaches an upper limit value (the said second value). Thus, the pump need not work continuously but may work intermittently to maintain a sufficient subpressure in the subpressure chamber.
It will be appreciated that the pump need not even be activated each time the subpressure in the drainage tube must be increased. In this manner, the wear of the pump motor and the noise level are efficiently re-duced.
The pump arrangement according to the present in-vention preferably is adapted to establish a subpressure of 10-20 cm water gauge in the patient s pleural cavity, said first means preferably being set such that the said first value amounts to about 40 cm water gauge and the said second value to about 65 cm water gauge.
Said first means preferably is a pressostat, and said second means preferably is a vacuum regulator.
For pleura drainage, use is made of so-called bubble bottles, i.e. containers filled with liquid and connected to the drainage tube, for monitoring the state of the patient, i.e. the healing of the damaged pleura. As 3~
long as the pleura has not healed, an airflow through the punctured pleura is obtained. This airflow which is dependent on the healing and decreases as healing progresses, creates bubbles in the bubble bottles. By visual monitoring of the bubbling intensity, the state of the patient is estimated. When the formation of bub-bles has ceased, the damaged pleura is considered to be healed, and the treatment may be discontinued. In the terminal phase of the healing, bubbles are formed at long intervals. Since, for practical reasons, the bubble bottles cannot be watched continuously, the for-mation of further bubbles can easliy be overlooked in the terminal phase and lead one to believe that the puncture has healed. However, one is aware of this risk and, as a precaution, the treatment therefore is con-tinued for still some time after the formation of bub-bles is believed to have ceased. As a rule, this makes the time of treatment longer than necessary. Because of the insufficient monitoring as described above, the time of treatment in each separate case is unnecessarily extended by approximately two days.
Therefore, another object of the present invention is to provide a monitoring apparatus which, when used together with an intermittently operating pump arrangement, provides for such precise and safe monitoring of the patient s state that the time of treatment can be con-siderably shortened, without jeopardising the patient s health.
3~
According to the invention, this is achieved with a monitoring apparatus of the type mentioned by way of introduction, which is characterised by an indicator adapted to indicate the time during which the intermit-tently operating pump arrangement is in operation, and comprising a display means for displaying a value which is dependent on the said time.
In a preferred embodiment, the indicator comprises an impulse generator and an actuator for activating the impulse generator during the intervals when the pump arrangement is in operation, the display means being a eounter for counting the impulses provided by the impulse generator so as to display a eounted value whieh is substantially proportional to the operational time of the pump arrangement.
The impulse generator preferably eomprises an oseil-lator eircuit and a frequeney dividing eireuit eonnected to the output thereof and adapted to provide an impulse to the counter eaeh time it has reeeived a predetermined number of impulses from the oseillator cireuit.
The oseillator eireuit preferably is adapted to provide impulses with a frequeney of about 100 ke/s, while the frequeney dividing eireuit divides this fre-queney by 2 The actuator is, in a preferred embodiment, a pres-sostat whieh is adapted, when sensing a predetermined first subpressure, to eonneet an activating signal both to the pump arrangement and to the impulse generator.
3~ig I'he inventlon will now be descrlbed in greater detail below, reference being had to the accompanying drawings in which Fig. 1 is a schematic view of a pump arrangement and a monitoring apparatus connected thereto, and Fig. 2 is a detailed view of the monitoring apparatus.
The pump arrangement shown in the drawing is in-tended for pleura drainage to establish a predetermined subpressure in a patient s pleural cavity and has a connection means 1 by which it may be connected to a drainage tube S attached to the patient and extending into the patient s pleural cavity.
The pump arrangement comprises a subpressure cham-ber 2. An airtight pump 3 which in a preferred embodiment is a pump sold by Venture Tekniska AB, Sweden, under the name of Vakuumpump 5010, is tightly connected to the subpressure chamber 2 in order to maintain a sub-pressure therein. A pressostat 4 which in a preferred embodiment is a pressostat designated IP 32 6NN and manufactured by Herga Electric Limited, England, is adapted to sense the subpressure in t}le subpressure chamber 2. The pressostat 4 is electrically connected via a line Ll to the motor M of the pump 3. When the pressostat 4 senses a subpressure which is lower than a given lower limit value which is higher than the value of said predetermined subpressure to be established in the patient s pleural cavity, it starts the motor M of the pump 3 in order to increase the subpressure ~3~69 in the subpressure chamber 2. When the subpressure in the subpressure chamber 2 reaches an upper limit value, the pressostat 4 stops the motor M of the pump 3. In a preferred embodiment, the pressostat 4 is chosen and set such that the lower and upper limit values amount, respectively, to about 40 and about 65 cm water gauge.
Via a regulator 5 which in a preferred embodiment is a vacuum regulator of the mark PURITAN, designated "Thoracic Suction Regulator", the subpressure chamber 2 is connected via a conduit 6 to the connection means 1 for further connection with the drainage tube S. The regulator 5 is adapted to sense the subpressure in the conduit 6, which, when the pump arrangement is connected to the drainage tube S, is substantially the same as the subpressure in the drainage tube and in the patient s pleural cavity. When the subpressure in the pleural cavity falls below the desired subpressure, i.e. the said predetermined subpressure which preferably is 10-20 cm water gauge, the regulator 5 provides a connection between the subpressure chamber 2 and the pleural cavity via the conduit 6 and the drainage tube S in order to increase the subpressure in the pleural cavity. When the desired subpressure has been attained, the regulator 5 interrupts this connection. As long as the subpressure in the subpressure chamber 2 is higher than the lower limit value, the subpressure in the pleural cavity can be increased without necessitating activation of the pump 3.
~i!93~
Two pressostats 7 and 8 which in a preferred em-bodiment each are a pressostat designated IP 32 6753 F
and manufactured by Herga Electric Limited, England, are connected to the conduit 6 to sense the subpressure therein. The pressostat 7 is adapted to activa-te a first alarm device (not shown) when the subpressure in the conduit 6 and thus in the drainage tube S and the pa-tient s pleural cavity reaches a lower value, and the pressostat 8 is adapted to activate a second alarm device (not shown) when this subpressure reaches an upper value.
The pressostats 7 and 8 preferably are chosen and set such that the lower and upper values are, respectively, 5 and 35 cm water gauge.
The pressostat 8 is electrically connected, in a manner not shown in detail, to the motor M of the pump 3 such that the motor is stopped or, optionally, cannot be started if the pressostat 8 senses a subpressure which is higher than the upper value. This provides for additional safety in case such a functional defect should arise in the regulator 5 that the regulator main-tains a connection between the subpressure chamber 2 and the conduit 6, although the subpressure therein is higher than desired.
A pressure gauge 9 is connected to the conduit 6 to enable reading of the subpressure therein.
The monitoring apparatus comprises an indicator which in Fig. 1 is generally designated 10. The indicator 10 is adapted to indicate the time during which the .. 9 ~L2~3~
intermittently operating pump arrangement described above is in operation, i.e. the time during which the motor M of the pump 3 operates.
The indicator 10 comprises an impulse generator 11 and a display means 12 connected to the output thereof.
An actuator which in Fig. 2 is a switch Sl, is adapted to activate the impulse generator 11 during the intervals when the motor M of the pump 3 operates. The switch Sl and the switch, i.e. the pressostat 4, which activates the motor M are therefore perEerably one and the same switch. When the motor M is started by the pressostat 4 (Sl), the impulse generator 11 thus is also activated.
One contact of the switch Sl is connected to a 12 V voltage source, and its other contact is connected via a line Ll to the motor M and, via a line ~2, to the impulse generator 11. When the pressostat 4 senses a subpressure in the subpressure chamber 2 which is lower than a given lower limit value, the switch Sl switches on and activates both the motor M and the im-pulse generator 11. When the pressostat 4 senses that the subpressure in the subpressure chamber 2 reaches an upper limit value, the switch Sl switches off, whereby the motor M is stopped and the impulse generator 11 is inactivated. The impulse generator 11 thus provides impulses during the time when the motor M is in operation, said impulses being received by the display means 12.
In the preferred embodiment, the display means 12 comprises a counter which counts the impulses provided ~29~
by the impulse generator 11 and displays the attained counted value which thus is proportional to the time during which the impulse generator 1] has been in opera-tion, i.e. the time during which the motor M has been in operation.
While measuring known airflow volumes in the pump arrangement, the monitoring apparatus is calibrated preferably in such manner that -the displayed counted value indicates the airflow volume in a suitable unit of volume. When the pump arrangment and the monitoring apparatus are used for treating a patient by pleura drainage, the airflow through the patient s punctured pleura can thus be determined in a simple and reliable manner by reading the counter 12, and in this way the patient s state is monitored and judged. Continuous observation as is required for the bubble bottles de-scribed above, is of course not necessary in this case.
A diode Dl is connected across the motor M so as to eliminate voltage peaks when the motor is switched on and off.
The impulse generator 11 comprises a first integrated circuit IC 1 (CMOS 4093 B) and a second integrated circuit IC 2 (CMOS 4020 B).
The first integrated circuit IC 1 is connected as an oscillator circuit comprising a first inverter 13 t a second inverter 14 and an oscillator 15. One input (pin No. 6) of the first inverter is connected via a protective resistor Rl (3.3 kQ) to the line L2, and its other input (pin No. 5) ls also connected to the line L2 via a potentiometer R2 (200 kQ~ and the protective resistor Rl. The other input (pin No. 5) is connected to earth via a capacitor Cl (0.15 ~F). The output (pin No. 4) of the Eirst inverter 13 is connected to the inputs (pins Nos. 8 and 9) of the second inverter 14.
The output (pin No. 10) of the second inverter 14 is connected to one input (pin No. 1) of the oscillator 15.
The other input (pin No. 2) of the oscillator 15 is connected on the one hand to earth via a capacitor C2 (0.01 ~F) and, on the other hand, to the output (pin No. 3) of the oscillator 15 via a potentiometer R3 (60 k~) for setting the frequency. Pin No. 7 of the first integ-rated circuit IC 1 is connected to earth, and its pin No. 14 is connected to a 12 V voltage source.
The second integrated circuit IC 2 is connected as a frequency dividing circuit, its pin No. 8 being connected to earth and its pins Nos. 11 and 16 to a 12 V voltage source. The input (pin No. 10) of the fre-quency dividing circuit is connected to the output of the oscillator circuit, i.e. the output (pin No. 3) of the oscillator 15, and its output (pin No. 3) is connected to the base contact of a transistor Tl (2N2222A).
The emitter of the transistor Tl is connected to earth, and its collector is connected to the counter 12.
To make the monitoring apparatus operate with high accuracy, the oscillator circuit preferably is set to provide impulses with a frequency as high as about 100 , ~3~9 kc/s. The frequency dividing circuit preferably is adapted to divide this frequency by 214 (=16,384). The frequency dividing circuit thus provides an impulse to the counter 12 for every 16,384th impulse that it receives from the oscillator circuit. Between two successive activating periods of the oscillator circuit, the frequency dividing circuit is not "zeroised" but transmits the number of impulses that have been received after providing the last impulse to the counter during an activating period of the oscillator circuit, to the ne~t activating period of the oscillator circuit.
The RC circuit at the second input (pin No. 5) of the first inverter 13, which consists of the potentio-meter R2 and the capacitor Cl provides a delay of the starting time for the signal activating the oscillator 15, i.e. the signal at the output (pin No. 10) of the second inverter 14, in relation to the starting time for the signal which activates the motor M. This delay is used to compensate for the fact that the motor M does not develop its full power, on which the above-mentioned calibration is based, during the entlre period of opera-tion. At the beginning of each period of operation, a certain amount of time passes from the moment when the motor M receiv s a starting signal until it has developed its full power, and a certain amount of time passes from the moment when the starting signal switches off until the motor has come to a complete standstill.
The RC circuit compensates for this variation in power during the period of operation.
..
The present invention also relates to an apparatus for monitoring the state of a patient who has a punctur-ed pleura for which he is treated by pleura drainage, the punctured pleura being kept expanded in that a sub-pressure is maintained in the patient's pleural cavity by means of an intermittently operating pump arrangement.
Pleura drainage means treating a patient with a punctured pleura by artificially maintaining in the pleural cavity a subpressure to keep the damaged pleura expanded, and in such treatment use is made of a pump arrangement which is connected to a drainage tube attached to the patient and extending into the pleural cavity.
Known pump arrangements for this purpose are designed such that a pump included therein must operate continu-ously without interruption in order to maintain a pre-determined subpressure in the pleural cavity. This causes considerable wear of the pump motor, and known pump arrangements therefore require extensive maintenance and have a comparatively short life. The sound of a continuously working pump motor may also disturb the patient.
One object of the present invention is to provide 11.293~
a pump arrangement for use in pleura drainage which is designed such that its pump can operate intermittently so as to reduce both the wear of the pump motor and the noise level.
According to the invention, this is achieved with an arrangement of the above-mentioned type which is characterised by a subpressure chamber; a pump connected to said subpressure chamber to maintain a subpressure therein; a first means adapted to sense the subpressure in said subpressure chamber, to activate -the pump in order to increase the subpressure in sai.d subpressure chamber when the sensed subpressure falls below a given first value which is higher than the value of said predetermined subpressure, and to inactivate the pump when the sensed subpressure reaches a given second value which is higher than said first value; and a second means adapted to sense the subpressure in the drainage tube, to provide a connection between said subpressure chamber and said drainage tube in order to increase the subpressure in the drainage tube when the sensed subpressure in the drainage tube falls below the pre-determined subpressure, and to interrupt said connection when the sensed subpressure in the drainage tube reaches the value of said predetermined subpressure.
When the subpressure in the pleural cavity, and thus in the drainage tube, falls below the desired sub-pressure, i.e. the said predetermined subpressure, the second means provides a connection between the subpressure ~3~
chamber and the drainage tube. Since the subpressure in the subpressure chamber is higher than the subpressure in the drainage tube, the latter will be increased without necessitating activation of the pump. The pump is acti-vated only when the subpressure in the subpressure chamber has fallen to a lower limit value (the said first value) and then is again inactivated when the subpressure in the subpressure chamber reaches an upper limit value (the said second value). Thus, the pump need not work continuously but may work intermittently to maintain a sufficient subpressure in the subpressure chamber.
It will be appreciated that the pump need not even be activated each time the subpressure in the drainage tube must be increased. In this manner, the wear of the pump motor and the noise level are efficiently re-duced.
The pump arrangement according to the present in-vention preferably is adapted to establish a subpressure of 10-20 cm water gauge in the patient s pleural cavity, said first means preferably being set such that the said first value amounts to about 40 cm water gauge and the said second value to about 65 cm water gauge.
Said first means preferably is a pressostat, and said second means preferably is a vacuum regulator.
For pleura drainage, use is made of so-called bubble bottles, i.e. containers filled with liquid and connected to the drainage tube, for monitoring the state of the patient, i.e. the healing of the damaged pleura. As 3~
long as the pleura has not healed, an airflow through the punctured pleura is obtained. This airflow which is dependent on the healing and decreases as healing progresses, creates bubbles in the bubble bottles. By visual monitoring of the bubbling intensity, the state of the patient is estimated. When the formation of bub-bles has ceased, the damaged pleura is considered to be healed, and the treatment may be discontinued. In the terminal phase of the healing, bubbles are formed at long intervals. Since, for practical reasons, the bubble bottles cannot be watched continuously, the for-mation of further bubbles can easliy be overlooked in the terminal phase and lead one to believe that the puncture has healed. However, one is aware of this risk and, as a precaution, the treatment therefore is con-tinued for still some time after the formation of bub-bles is believed to have ceased. As a rule, this makes the time of treatment longer than necessary. Because of the insufficient monitoring as described above, the time of treatment in each separate case is unnecessarily extended by approximately two days.
Therefore, another object of the present invention is to provide a monitoring apparatus which, when used together with an intermittently operating pump arrangement, provides for such precise and safe monitoring of the patient s state that the time of treatment can be con-siderably shortened, without jeopardising the patient s health.
3~
According to the invention, this is achieved with a monitoring apparatus of the type mentioned by way of introduction, which is characterised by an indicator adapted to indicate the time during which the intermit-tently operating pump arrangement is in operation, and comprising a display means for displaying a value which is dependent on the said time.
In a preferred embodiment, the indicator comprises an impulse generator and an actuator for activating the impulse generator during the intervals when the pump arrangement is in operation, the display means being a eounter for counting the impulses provided by the impulse generator so as to display a eounted value whieh is substantially proportional to the operational time of the pump arrangement.
The impulse generator preferably eomprises an oseil-lator eircuit and a frequeney dividing eireuit eonnected to the output thereof and adapted to provide an impulse to the counter eaeh time it has reeeived a predetermined number of impulses from the oseillator cireuit.
The oseillator eireuit preferably is adapted to provide impulses with a frequeney of about 100 ke/s, while the frequeney dividing eireuit divides this fre-queney by 2 The actuator is, in a preferred embodiment, a pres-sostat whieh is adapted, when sensing a predetermined first subpressure, to eonneet an activating signal both to the pump arrangement and to the impulse generator.
3~ig I'he inventlon will now be descrlbed in greater detail below, reference being had to the accompanying drawings in which Fig. 1 is a schematic view of a pump arrangement and a monitoring apparatus connected thereto, and Fig. 2 is a detailed view of the monitoring apparatus.
The pump arrangement shown in the drawing is in-tended for pleura drainage to establish a predetermined subpressure in a patient s pleural cavity and has a connection means 1 by which it may be connected to a drainage tube S attached to the patient and extending into the patient s pleural cavity.
The pump arrangement comprises a subpressure cham-ber 2. An airtight pump 3 which in a preferred embodiment is a pump sold by Venture Tekniska AB, Sweden, under the name of Vakuumpump 5010, is tightly connected to the subpressure chamber 2 in order to maintain a sub-pressure therein. A pressostat 4 which in a preferred embodiment is a pressostat designated IP 32 6NN and manufactured by Herga Electric Limited, England, is adapted to sense the subpressure in t}le subpressure chamber 2. The pressostat 4 is electrically connected via a line Ll to the motor M of the pump 3. When the pressostat 4 senses a subpressure which is lower than a given lower limit value which is higher than the value of said predetermined subpressure to be established in the patient s pleural cavity, it starts the motor M of the pump 3 in order to increase the subpressure ~3~69 in the subpressure chamber 2. When the subpressure in the subpressure chamber 2 reaches an upper limit value, the pressostat 4 stops the motor M of the pump 3. In a preferred embodiment, the pressostat 4 is chosen and set such that the lower and upper limit values amount, respectively, to about 40 and about 65 cm water gauge.
Via a regulator 5 which in a preferred embodiment is a vacuum regulator of the mark PURITAN, designated "Thoracic Suction Regulator", the subpressure chamber 2 is connected via a conduit 6 to the connection means 1 for further connection with the drainage tube S. The regulator 5 is adapted to sense the subpressure in the conduit 6, which, when the pump arrangement is connected to the drainage tube S, is substantially the same as the subpressure in the drainage tube and in the patient s pleural cavity. When the subpressure in the pleural cavity falls below the desired subpressure, i.e. the said predetermined subpressure which preferably is 10-20 cm water gauge, the regulator 5 provides a connection between the subpressure chamber 2 and the pleural cavity via the conduit 6 and the drainage tube S in order to increase the subpressure in the pleural cavity. When the desired subpressure has been attained, the regulator 5 interrupts this connection. As long as the subpressure in the subpressure chamber 2 is higher than the lower limit value, the subpressure in the pleural cavity can be increased without necessitating activation of the pump 3.
~i!93~
Two pressostats 7 and 8 which in a preferred em-bodiment each are a pressostat designated IP 32 6753 F
and manufactured by Herga Electric Limited, England, are connected to the conduit 6 to sense the subpressure therein. The pressostat 7 is adapted to activa-te a first alarm device (not shown) when the subpressure in the conduit 6 and thus in the drainage tube S and the pa-tient s pleural cavity reaches a lower value, and the pressostat 8 is adapted to activate a second alarm device (not shown) when this subpressure reaches an upper value.
The pressostats 7 and 8 preferably are chosen and set such that the lower and upper values are, respectively, 5 and 35 cm water gauge.
The pressostat 8 is electrically connected, in a manner not shown in detail, to the motor M of the pump 3 such that the motor is stopped or, optionally, cannot be started if the pressostat 8 senses a subpressure which is higher than the upper value. This provides for additional safety in case such a functional defect should arise in the regulator 5 that the regulator main-tains a connection between the subpressure chamber 2 and the conduit 6, although the subpressure therein is higher than desired.
A pressure gauge 9 is connected to the conduit 6 to enable reading of the subpressure therein.
The monitoring apparatus comprises an indicator which in Fig. 1 is generally designated 10. The indicator 10 is adapted to indicate the time during which the .. 9 ~L2~3~
intermittently operating pump arrangement described above is in operation, i.e. the time during which the motor M of the pump 3 operates.
The indicator 10 comprises an impulse generator 11 and a display means 12 connected to the output thereof.
An actuator which in Fig. 2 is a switch Sl, is adapted to activate the impulse generator 11 during the intervals when the motor M of the pump 3 operates. The switch Sl and the switch, i.e. the pressostat 4, which activates the motor M are therefore perEerably one and the same switch. When the motor M is started by the pressostat 4 (Sl), the impulse generator 11 thus is also activated.
One contact of the switch Sl is connected to a 12 V voltage source, and its other contact is connected via a line Ll to the motor M and, via a line ~2, to the impulse generator 11. When the pressostat 4 senses a subpressure in the subpressure chamber 2 which is lower than a given lower limit value, the switch Sl switches on and activates both the motor M and the im-pulse generator 11. When the pressostat 4 senses that the subpressure in the subpressure chamber 2 reaches an upper limit value, the switch Sl switches off, whereby the motor M is stopped and the impulse generator 11 is inactivated. The impulse generator 11 thus provides impulses during the time when the motor M is in operation, said impulses being received by the display means 12.
In the preferred embodiment, the display means 12 comprises a counter which counts the impulses provided ~29~
by the impulse generator 11 and displays the attained counted value which thus is proportional to the time during which the impulse generator 1] has been in opera-tion, i.e. the time during which the motor M has been in operation.
While measuring known airflow volumes in the pump arrangement, the monitoring apparatus is calibrated preferably in such manner that -the displayed counted value indicates the airflow volume in a suitable unit of volume. When the pump arrangment and the monitoring apparatus are used for treating a patient by pleura drainage, the airflow through the patient s punctured pleura can thus be determined in a simple and reliable manner by reading the counter 12, and in this way the patient s state is monitored and judged. Continuous observation as is required for the bubble bottles de-scribed above, is of course not necessary in this case.
A diode Dl is connected across the motor M so as to eliminate voltage peaks when the motor is switched on and off.
The impulse generator 11 comprises a first integrated circuit IC 1 (CMOS 4093 B) and a second integrated circuit IC 2 (CMOS 4020 B).
The first integrated circuit IC 1 is connected as an oscillator circuit comprising a first inverter 13 t a second inverter 14 and an oscillator 15. One input (pin No. 6) of the first inverter is connected via a protective resistor Rl (3.3 kQ) to the line L2, and its other input (pin No. 5) ls also connected to the line L2 via a potentiometer R2 (200 kQ~ and the protective resistor Rl. The other input (pin No. 5) is connected to earth via a capacitor Cl (0.15 ~F). The output (pin No. 4) of the Eirst inverter 13 is connected to the inputs (pins Nos. 8 and 9) of the second inverter 14.
The output (pin No. 10) of the second inverter 14 is connected to one input (pin No. 1) of the oscillator 15.
The other input (pin No. 2) of the oscillator 15 is connected on the one hand to earth via a capacitor C2 (0.01 ~F) and, on the other hand, to the output (pin No. 3) of the oscillator 15 via a potentiometer R3 (60 k~) for setting the frequency. Pin No. 7 of the first integ-rated circuit IC 1 is connected to earth, and its pin No. 14 is connected to a 12 V voltage source.
The second integrated circuit IC 2 is connected as a frequency dividing circuit, its pin No. 8 being connected to earth and its pins Nos. 11 and 16 to a 12 V voltage source. The input (pin No. 10) of the fre-quency dividing circuit is connected to the output of the oscillator circuit, i.e. the output (pin No. 3) of the oscillator 15, and its output (pin No. 3) is connected to the base contact of a transistor Tl (2N2222A).
The emitter of the transistor Tl is connected to earth, and its collector is connected to the counter 12.
To make the monitoring apparatus operate with high accuracy, the oscillator circuit preferably is set to provide impulses with a frequency as high as about 100 , ~3~9 kc/s. The frequency dividing circuit preferably is adapted to divide this frequency by 214 (=16,384). The frequency dividing circuit thus provides an impulse to the counter 12 for every 16,384th impulse that it receives from the oscillator circuit. Between two successive activating periods of the oscillator circuit, the frequency dividing circuit is not "zeroised" but transmits the number of impulses that have been received after providing the last impulse to the counter during an activating period of the oscillator circuit, to the ne~t activating period of the oscillator circuit.
The RC circuit at the second input (pin No. 5) of the first inverter 13, which consists of the potentio-meter R2 and the capacitor Cl provides a delay of the starting time for the signal activating the oscillator 15, i.e. the signal at the output (pin No. 10) of the second inverter 14, in relation to the starting time for the signal which activates the motor M. This delay is used to compensate for the fact that the motor M does not develop its full power, on which the above-mentioned calibration is based, during the entlre period of opera-tion. At the beginning of each period of operation, a certain amount of time passes from the moment when the motor M receiv s a starting signal until it has developed its full power, and a certain amount of time passes from the moment when the starting signal switches off until the motor has come to a complete standstill.
The RC circuit compensates for this variation in power during the period of operation.
..
Claims (5)
1. A pump arrangement for use in pleura drainage to establish a predetermined subpressure in a patient's pleural cavity, said pump arrangement being connectible to a drainage tube attached to the patient and extending into the patient s pleural cavity, c h a r a c t e r -i s e d by a subpressure chamber, a pump connected to said subpressure chamber to maintain a subpressure therein, a first means adapted to sense the subpressure in said subpressure chamber, to activate the pump in order to increase the subpressure in said subpressure chamber when the sensed subpressure falls below a given first value which is higher than the value of said pre-determined subpressure, and to inactivate the pump when the sensed subpressure reaches a given second value which is higher than said first value, and a second means adapted to sense the subpressure in said drainage tube, to provide a connection between said subpressure chamber and said drainage tube in order to increase the subpressure in said drainage tube when the sensed subpressure in said drainage tube falls below said pre-determined subpressure, and to interrupt said connection when said sensed subpressure in said drainage tube reaches the value of said predetermined subpressure.
2. A pump arrangement as claimed in claim 1, c h a r -a c t e r i s e d in that it establishes a subpressure of 10-20 cm water gauge in the patient s pleural cavity.
3. A pump arrangement as claimed in claim 2, c h a r -a c t e r i s e d in that said first means is set such that said first value amounts to about 40 cm water gauge and said second value to about 65 cm water gauge.
4. A pump arrangement as claimed in any one of claims 1-3, c h a r a c t e r i s e d in that said first means is a pressostat.
5. A pump arrangement as claimed in any one of claims 1-3, c h a r a c t e r i s e d in that said second means is a subpressure regulator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000537570A CA1293169C (en) | 1987-05-21 | 1987-05-21 | Pump arrangement and monitoring apparatus for use in pleura drainage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000537570A CA1293169C (en) | 1987-05-21 | 1987-05-21 | Pump arrangement and monitoring apparatus for use in pleura drainage |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1293169C true CA1293169C (en) | 1991-12-17 |
Family
ID=4135712
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000537570A Expired - Fee Related CA1293169C (en) | 1987-05-21 | 1987-05-21 | Pump arrangement and monitoring apparatus for use in pleura drainage |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1293169C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10646629B2 (en) | 2013-10-11 | 2020-05-12 | Rocket Medical Plc | Pleural manometry catheter |
-
1987
- 1987-05-21 CA CA000537570A patent/CA1293169C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10646629B2 (en) | 2013-10-11 | 2020-05-12 | Rocket Medical Plc | Pleural manometry catheter |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |