System and method for leak testing a restricted access barrier system

Abstract

A system for leak testing a restricted access barrier system (RABS) with gloves includes a leak testing system capable of detecting presence of leak in a glove of the RABS. The system includes a coupling system configured to couple the leak testing system to the RABS to allow leak testing on the glove. The coupling system includes a headspace reducer that is configured to occupy a space when deployed to reduce a headspace within the glove.

Description

SYSTEM AND METHOD FOR LEAK TESTING A RESTRICTED ACCESS BARRTER SYSTEMTECHNICAL FIELD[0001 J This technology includes systems and methods for leak testing the glove portions of a restricted access barrier system (RABS).BACKGROUND

[0002] A restricted access barrier system (RABS) is an installation which is used in many industries, such as pharmaceutical, medical, chemical, material science, electrical engineering, etc., where a controlled atmosphere or sterile environment is needed. For example, within the pharmaceutical industry a RABS is used to maintain a sterile manufacturing environment for pharmaceutical products. A RABS has gloves that are used to manipulate components and products within the RABS system. Regulatory bodies require that such gloves be leak tested on a regular basis. Current leak testing is performed using a pressure decay approach. Such approaches may not be sensitive to critical leak sizes and may require a significant test time.SUMMARY

[0003] A system for leak testing a restricted access barrier system (RABS) with gloves includes a leak testing system capable of detecting presence of leak in a glove of the RABS. The system includes a coupling system configured to couple the leak testing system to the RABS to allow leak testing on the glove. The coupling system includes a headspace reducer that is configured to occupy a space when deployed to reduce a headspace within the glove.

[0004] Other elements of the system may include a pump and a connector configured to fit an opening of the glove. The connector includes an inflatable gasket and a first conduit for inflating the inflatable gasket using the pump, the headspace reducer, and a port configured to allow removable fluid connection with the leak testing system. The port is disposed between the inflatable gasket and the headspace reducer. The headspace reducer includes an inflatable balloon and the connector includes a second conduit for inflating the inflatable balloon using the pump. The coupling system is configured to inflate the inflatable balloon at a pre-determined pressurethat is greater than a first pre-determined target pressure of a pressure decay leak test performed by the leak testing system.

[0005] Other elements of the system may include that the coupling system includes a controller configured to operate and coordinate operations of the coupling system with operations of the leak testing system. The controller of the coupling system and a controller of the leak testing system are the same controller.

[0006] Other elements of the system may include that the leak testing system is configured to perform a vacuum decay leak test. The leak testing system is configured to perform a pressure decay leak test. The headspace reducer is configured to reduce the headspace by about 90%. The headspace reducer is a displacement core.

[0007] In another embodiment, a system for reducing a headspace inside a glove of a restricted access barrier system (RABS) when the glove is leak tested by a leak testing system includes a pump and a connector configured to fit an opening of the glove. The connector includes an inflatable gasket and a first conduit for inflating the inflatable gasket using the pump, a headspace reducer that is configured to occupy a space when deployed to reduce a headspace within the glove, and a port configured to allow removable fluid connection with the leak testing system.

[0008] Other elements of the system may include that the headspace reducer including an inflatable balloon and the connector including a second conduit for inflating the inflatable balloon using the pump. A controller is configured to regulate pressures for inflating the inflatable gasket and the inflatable balloon. The controller is configured to inflate the inflatable balloon at a predetermined pressure that is greater than a first pre-determined target pressure of a pressure decay leak test performed by the leak testing system. The headspace reducer includes a displacement core. The port is disposed between the inflatable gasket and the headspace reducer.

[0009] In another embodiment, a computer-implemented method of leak testing a glove of a restricted access barrier system (RABS) includes inflating an inflatable gasket to seal an opening of the glove. The method includes deploying a headspace reducer to reduce a headspace inside atest cavity inside the glove and performing leak testing to determine a presence of a leak in the glove.

[0010] Performing the leak testing may include pulling vacuum from the test cavity or pumping air into the test cavity until a pre-determined target pressure is reached and monitoring a pressure to determine the presence of the leak. The deploying the headspace reducer includes inflating an inflatable balloon at a pressure that is greater than a pre-determined target pressure used for performing the leak testing based on a pressure decay test.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a schematic showing an example restricted access barrier system (RABS).

[0012] FIG. 2 is a block diagram showing an example system for leak testing a RABS.

[0013] FIG. 3 is a schematic showing an example system for leak testing a RABS.

[0014] FIG. 4A is another schematic showing subsystems and components in an example system for leak testing a RABS.

[0015] FIG. 4B is another schematic showing subsystems and components in an example system for leak testing a RABS.

[0016] FIGS. 5A and 5B each shows a cross-sectional view of a coupling region between a RABS and a system for leak testing the RABS.

[0017] FIG. 6 shows an example method of using a system disclosed herein to leak test a RABS.DETAILED DESCRIPTION

[0018] FIG. 1 shows an example restricted access barrier system (RABS) 100. The RABS system may be any kind of glovebox or a sealed container that is designed to allow one to manipulate objects where a separate atmosphere is desired. For example, the RABS 100 is used to maintain a sterile manufacturing environment for pharmaceutical products. The RABS 100 includes gloves 102 arranged in a way that a user can place hands into the gloves 102 and performtasks inside the box without breaking containment. The RABS 100 may be configured to allow a user to work with hazardous substances or may be configured to allow manipulation of substances that must be contained within high purity inert atmosphere, such as argon or nitrogen. The RABS 100 may also be configured to allow manipulation of items in a vacuum chamber. Conventional leak testing on a RABS is performed using a pressure decay approach, which is not sensitive to critical leak sizes and requires significant testing time. The present disclosure is directed to systems and methods to overcome shortcomings of the conventional pressure decay approach on a RABS. In particular, the systems and methods disclosed herein are configured to significantly reduce the volume in a test space (e.g., headspace) of a RABS and thereby greatly increases the test sensitivity and shortens the test cycle.

[0019] FIG. 2 shows an example test system 200 for leak testing the RABS 100. The test system 200 includes a leak testing system 202 and a coupling system 204 configured to connect and allow the leak testing system 202 to perform leak tests on the RABS 100 with enhanced sensitivity and shortened test cycle (in comparison to conventional leak testing systems without the coupling system 204 disclosed herein).

[0020] The test system 200 includes a controller 206 configured to control and coordinate the operations of the various components of the leak testing system 202 and the coupling system 204 to perform leak testing on the RABS 100. The controller 206 may be a computer or may include any suitable processer(s), microprocessor s), transceiver(s), memory, a timer, analog-to- digital convertor(s) (ADC), programmable logic controller(s) (PLC), human machine interface(s) (HMI), etc. to enable its functions as disclosed and claimed. The controller 206 may further include any suitable user interface and / or display to allow output of the test results and allow a user to program or control the operation of the test system 200.

[0021] The leak tests may be performed based on vacuum decay leak testing or pressure decay leak testing. In one embodiment, the leak testing system 202 is configured to perform vacuum decay leak testing. In one embodiment, the leak testing system 202 is configured to perform pressure decay leak testing. In another embodiment, the leak testing system 202 is capable of performing both vacuum decay leak tests and pressure decay leak tests, and the leak testing system 202 is able to perform any one of the two types of leak tests on demand.

[0022] The leak testing system 202 may include components and systems that function in the same manner as a vacuum decay leak testing system or a pressure decay leak testing system. As shown in FIG. 3, the leak testing system 202 includes a pump 300, a conduit 302 in fluid connection between the pump and the coupling system 204, and a valve 304 to control airflow through the conduit 302. The leak testing system 202 may include includes any suitable pressure sensor(s) or sensing mechanism 306 to measure the pressure profde (e.g., pressure as a function of time) during a leak test performed by the leak testing system 202.

[0023] The controller 206 is communicatively and operatively connected to the pump 300, the valve 304, and the pressure sensor(s) or sensing mechanism 306 to perform leak tests (e.g., based on vacuum decay leak testing or pressure decay leak testing). In one embodiment, the pressure sensor(s) or sensing mechanism 306 includes a branch conduit 310 that branches out from the conduit 302 at a location between the valve 304 and the coupling system 204. The branch conduit 310 forms a closed loop 312 and disposed therein are a valve 314 and a transducer 316 (e.g., a differential transducer) whose output is received by an amplifier 318. In another embodiment, the pressure sensor(s) or sensing mechanism 306 may only include a pressure sensor disposed on the conduit 302 (e.g., without the branch conduit 310, the closed loop 312, and the components disposed thereon).

[0024] FIG. 4A shows an example coupling system 204 configured to couple the leak testing system 202 and the RABS 100 (e.g., a glovebox). The coupling system 204 may include a connector 400 configured to fit an opening 402 of the glove 102 of the RABS 100. Incorporated within the connector 400 are an inflatable gasket 406, a headspace reducer 407 including an inflatable hermetically sealed balloon 408 (hereinafter a “balloon”), a conduit 410 for inflating / deflating the inflatable gasket 406, a conduit 412 for inflating / deflating the balloon 408, and a port 414 configured to allow removable fluid connection with the conduit 302 of the leak testing system 202.

[0025] The coupling system 204 further includes a pump system 416 to regulate the pressures for inflating / deflating the inflatable gasket 406 and the balloon 408. The pump system 416 includes a pump 418 and a valve 420 and a sensor 422 disposed about the conduit 410 to regulate the pressure for inflating / deflating the inflatable gasket 406. The pump system 416includes a valve 424 and a sensor 426 disposed about the conduit 412 to regulate the pressure for inflating / deflating the balloon 408. The pump 418 may be connected to any suitable gas source, such as air, for inflating / deflating the inflatable gasket 406 and the balloon 408.

[0026] The coupling system 204 may include a controller 207 configured to operate the various components of the pump system 416. The controller 207 may be a computer or may include any suitable processer(s), microprocessor s), transceiver(s), memory, a timer, analog-to- digital convertor(s) (ADC), programmable logic controller(s) (PLC), human machine interface(s) (HMI), etc. to enable its functions as disclosed and claimed. The controller 207 may further include any suitable user interface and / or display to allow output of the operational conditions (e.g., pressure, time, etc.) and allow a user to program or control the operation of the coupling system 204. In one embodiment, the controller 207 and the controller 206 may be the same controller (e.g., the controller 206 is also configured to operate the coupling system 204). In another embodiment, the controllers 206 and 207 may be two separate controllers in communication with one another. In another embodiment, the controllers 206 and 207 may be two separate controllers and are not communication with one another.

[0027] FIG. 4B shows another example of the headspace reducer 407. Instead of the balloon 408 as shown in FIG. 4A, the headspace reducer 407 includes a displacement core 411 that is displaceable into the space 432 to reduce the headspace 434 in the glove 102. The displacement core 411 may be made of a rigid material or semi-rigid material (e.g., plastic, silicon, etc.). The displacement core 411 is hermetic such that no air, gas, or fluid is able to diffuse in and out of the displacement core 411. The displacement core 411 may be solid and hermetic. The displacement core 411 may be hollow and hermetic (e.g., the outer shell is hermetic and the inside is hollow or porous). The displacement core 411 is configured to maintain its shape when exposed to the leak testing pressure (e.g., a positive or negative pressure).

[0028] The connector 400 may be configured to loosely fit in the opening 402 of the glove 102. The connector 400 may generally have a disk shape with dimensions to loosely fit in the opening 402 of the glove 102 such that the headspace reducer 407 is at least partially positioned inside the glove 102. The inflatable gasket 406 forms a part of the circumferential edge of the connector 400 such that when the inflatable gasket 406 is inflated, the connector 400 is secured tothe glove 102 at the opening 402 in an airtight manner When the inflatable gasket 406 is not inflated or partially inflated, the connector 400 is only loosely fit in the opening 402 of the glove 102.

[0029] The connector 400 and the headspace reducer 407 (e.g., the balloon 408 or the displacement core 411) included therein may be positioned to fit the opening 402 of the glove 102 via any suitable manner or mechanism. For example, the connector 400 may be manually positioned to fit the opening of the glove 102. For example, the connector 400 may be positioned to fit the opening 402 of the glove 102 via a pneumatic system.

[0030] The headspace reducer 407 (e.g., the balloon 408 or the displacement core 411) has a shape and dimensions configured to fit within the glove 102 and substantially conform to an interior surface 430 of the glove 102 when deployed. The headspace reducer 407 is configured to conform to the interior surface 430 of the glove 102 to minimize a space 432 between the headspace reducer 407 and the interior surface 430 of the glove 102 while maintaining enough volume to provide breathability within the space 432. The purpose of the headspace reducer 407 is to reduce a headspace 434 inside the glove 102 (e.g., the larger the headspace reducer 407, the smaller the headspace 434). The headspace reducer 407 at a deployed configuration may reduce the headspace 434 by about 90 % (e.g., the headspace reducer 407 occupies about 90 % of the space 432), about 50 % - 99 %, about 60 % - 99 %, about 70 % - 99 %, about 80 % - 99 %, or about 90 % - 99%. In one embodiment, the headspace reducer 407is configured to only reduce the headspace 434 within the forearm portion of the glove 102 as shown in FIGS. 4A and 4B. In another embodiment, the headspace reducer 407has a shape substantially the same as the glove 102 (e.g., the headspace reducer 407is configured to also reduce the headspace 434 within the finger portion of the glove 102), only the size is smaller than the glove 102.

[0031] The port 414 is disposed between the inflatable gasket 406 and the headspace reducer 407such that the leak testing system 202 is able to apply pressure or draw vacuum from a test cavity 303 (e.g., the space 432 between the headspace reducer 407and the interior surface 430 of the glove 102). The port 414 may be any shapes and may be configured to allow removable fluid coupling to the conduit 302 via any suitable coupling mechanism.

[0032] FTG. 5 A is a cross-sectional view showing coupling between the connector 400 and the glove 102 (e.g., the opening 402 of the glove 102) according to one embodiment. The headspace reducer 407, the port 414, the inflatable gasket 406, and the opening 402 of the glove 102 may be arranged directly adjacent to one another in the illustrated order. The headspace reducer 407 is configured to fit within the glove 102. In the illustrated example, the port 414 has two opening. In another embodiment, the port 414 may have one opening or any suitable number of openings (e.g., three, four, etc.)

[0033] FIG. 5B is a cross-sectional view showing another embodiment where the port 414 is a circumferential tube to provide removable fluid coupling between the conduit 302 and the test cavity 303.

[0034] The test system 200 can test one glove 102 at a time, or test multiple gloves 102 at the same time, or even test multiple RABSs 100 at the same time. The setup described for testing one glove 102 can be scaled up to test multiple gloves 102 or multiple RABs at the same time.

[0035] FIG. 6 shows an example method 600 of performing a vacuum decay leak test or a pressure decay leak test using the test system 200. The method 600 may be executed via the controller 206 and / or the controller 207 (e.g., the controllers 206 and 207 may be the same controller or may be two separate controllers). The method 600 includes coupling the test system 200 to the RABS 100 (step 602). Step 602 includes attaching the coupling system 204 to the glove 102, such that the inflatable balloon 408 is inside the glove 102 and the inflatable gasket 406 is at the opening 402 of the glove 102.

[0036] Method 600 includes inflating the inflatable gasket 406 to seal the opening 402 of the glove 102 of the RABS 100 (step 604). Step 604 includes inflating the inflatable gasket 406 using the coupling system 416. Step 604 may include opening the valve 420, pumping air using the pump 418, regulating / monitoring the air pressure using the sensor 422, and closing the valve 420 once a pre-determined pressure (Pl) to inflate the inflatable gasket 406 is reached.

[0037] Method 600 includes deploying a headspace reducer 407 to reduce the headspace 434 in the test cavity 303 inside the glove 102 (step 606). Step 606 may include inflating the hermetically sealed balloon 408 to reduce the headspace 434 in the test cavity 303 inside the glove102. Step 606 includes inflating the balloon 408 using the coupling system 416. Step 606 may include opening the valve 424, pumping air using the pump 418, regulating / monitoring the air pressure using the sensor 426, and closing the valve 424 once a pre-determined pressure (P2) to inflate the balloon 408 is reached. Step 606 may include displacing the displacement core 411 to reduce the headspace 434 in the test cavity 303 inside the glove 102.

[0038] In step 604 and 606, air or any other suitable gas source (e.g., an inert gas) may be used to inflate the inflatable gasket 406 and the balloon 408.

[0039] In a vacuum decay application, after step 606, method 600 proceed to pulling vacuum out from the test cavity 303 (step 608) and monitoring the pressure to determine presence of leak in the glove 102 (step 610). Step 608 includes opening the valves 304 and 314 and turning on the pump 300 to apply a vacuum pressure to the test cavity 300.

[0040] Step 610 may include that once the pressure between the test cavity 303 and the leak testing system 202 is equalized, closing the valve 314, and monitoring the pressure corresponding to the pressure in the test cavity (e.g., the pressure measured by the pressure sensor or sensing mechanism 306) to determine the presence of a leak in the glove 102.

[0041] If the monitored pressure falls below a first pre-determine pressure (P3) within a first pre-determined time period (Tl), there is no leak in the glove 102. If the monitored pressure does not fall below the first pre-determined pressure (P3) within the first pre-determined time period (Tl), there is a leak in the glove 102. The test system 200 may be configured to determine a relative leak size of the leak based on the relative time and vacuum pressure. For example, the slower or the less steep decrease in the monitored vacuum pressure profile (e.g., monitored vacuum pressures as a function of time) indicate a relatively larger leak size. The test system 200 may be configured to compare the monitored pressure profile with a reference pressure profile (e.g., profile file of a leak-free glove) to determine whether there is a leak in the tested glove 102. The deviation from the reference pressure profile indicates presence of a leak. The relative degree of deviation from the reference vacuum pressure profile indicates a relative size of the leak (e.g., larger deviation indicates a larger leak and smaller deviation indicates a smaller leak).

[0042] The presence of the headspace reducer 407 (e g., the balloon 408 or the displacement core 411) occupies a significant portion of the space 432 within the glove 102 (the headspace 434 is significantly reduced) and makes the vacuum decay leak test more sensitive and faster (relatively to a test without the headspace reducer 407). The test system 200 is capable of detecting small leak size based on the vacuum decay leak testing disclosed herein (smaller leak size than conventional leak testing approach without the headspace reducer 407).

[0043] In a pressure decay application, after step 606, method 600 proceeds to pump air into the test cavity 303 until it reaches a first pre-determined target pressure (P4) (step 612) and monitoring the pressure to determine presence of leak in the glove 102 (step 614). Step 612 may include opening the valves 304 and 314 and turning on the pump 300 to apply an air pressure (or an inter gas pressure) to the test cavity 300 until a first pre-determined target pressure (P5) is reached. Once the first pre-determined target pressure (P5) is reached, the valves 304 and 314 are closed. The pump 300 may be connected to gas source(s) other than air, such as an inert gas, helium, or argon, to pump an inert gas into the test cavity 303 instead of air.

[0044] Step 614 includes that once the pressure between the test cavity 303 and the leak testing system 202 is equalized, opening the valve 314, and monitoring the pressure corresponding to the pressure in the test cavity 303 (e.g., the pressure measured by the pressure sensor or sensing mechanism 306) to determine the presence of a leak in the glove 102. If the monitored pressure falls below the first pre-determine pressure (P6) within a first pre-determined time period (T2), there is a leak in the glove 102. If the monitored pressure does not fall below the first predetermined pressure (P6) within the first pre-determined time period (T2), there is no leak in the glove 102.

[0045] The test system 200 may be configured to determine a relative leak size of the leak based on the relative time and vacuum pressure. For example, the slower or the less steep decrease in the monitored pressure profile (e.g., monitored pressures as a function of time) indicate a relatively smaller leak size. The test system 200 may be configured to compare the monitored pressure profile with a reference pressure profile (e.g., profile file of a leak-free glove) to determine whether there is a leak in the tested glove 102. The deviation from the reference pressure profile indicates presence of a leak. The relative degree of deviation from the reference pressure profileindicates a relative size of the leak (e g., larger deviation indicates a larger leak and smaller deviation indicates a smaller leak).

[0046] The presence of the headspace reducer 407 (e.g., the balloon 408 or the displacement core 411) occupies a significant portion of the space 432 within the glove 102 (the headspace 434 is reduced significantly) and makes the pressure decay leak test more sensitive and faster (relatively to a test without the headspace reducer 407). In step 606 of a pressure decay application, the pre-determined pressure (P2) of the balloon 408 is greater than the first predetermined target pressure (P4) of the pressure decay leak test such that the balloon 408 expands and occupies the majority of the space 432 within the glove 102, making the pressure decay leak test more sensitive and faster. The test system 200 is capable of detecting small leak size based on the pressure decay leak testing disclosed herein (smaller leak size than conventional leak testing approach without the headspace reducer 407).

[0047] This written description sets forth the best mode of practicing the claimed invention, and describes the invention so as to enable a person of ordinary skill in the art to make and use the invention, by presenting examples of the elements recited in the claims. The detailed descriptions of those examples do not impose limitations that are not recited in the claims.

Claims

CLAIMS1. A system for leak testing a restricted access barrier system (RABS) with gloves, the system comprising: a leak testing system capable of detecting presence of leak in a glove of the RABS; and a coupling system configured to couple the leak testing system to the RABS to allow leak testing on the glove, wherein the coupling system comprises a headspace reducer that is configured to occupy a space when deployed to reduce a headspace within the glove.

2. The system of claim 1, wherein the coupling system comprises: a pump; and a connector configured to fit an opening of the glove, the connector comprising: an inflatable gasket and a first conduit for inflating the inflatable gasket using the pump; the headspace reducer; and a port configured to allow removable fluid connection with the leak testing system.

3. The system of claim 2, wherein the port is disposed between the inflatable gasket and the headspace reducer.

4. The system of claim 2, wherein the headspace reducer comprises an inflatable balloon and the connector comprises a second conduit for inflating the inflatable balloon using the pump.5 The system of claim 4, wherein the coupling system is configured to inflate the inflatable balloon at a pre-determined pressure that is greater than a first pre-determined target pressure of a pressure decay leak test performed by the leak testing system.

6. The system of claim 1, wherein the coupling system comprises a controller configured to operate and coordinate operations of the coupling system with operations of the leak testing system.

7. The system of claim 6, the controller of the coupling system and a controller of the leak testing system are the same controller.

8. The system of claim 1, wherein the leak testing system is configured to perform a vacuum decay leak test.

9. The system of claim 1, wherein the leak testing system is configured to perform a pressure decay leak test.

10. The system of claim 1, wherein the headspace reducer is configured to reduce the headspace by about 90%.

11. The system of claim 1, wherein the headspace reducer is a displacement core.

12. A system for reducing a headspace inside a glove of a restricted access barrier system (RABS) when the glove is leak tested by a leak testing system, the system comprising: a pump; and a connector configured to fit an opening of the glove, the connector comprising: an inflatable gasket and a first conduit for inflating the inflatable gasket using the pump; a headspace reducer that is configured to occupy a space when deployed to reduce a headspace within the glove; and a port configured to allow removable fluid connection with the leak testing system.

13. The system of claim 12, wherein the headspace reducer comprises an inflatable balloon and the connector comprises a second conduit for inflating the inflatable balloon using the pump.

14. The system of claim 13, further comprising a controller configured to regulate pressures for inflating the inflatable gasket and the inflatable balloon.

15. The system of claim 14, wherein the controller is configured to inflate the inflatable balloon at a pre-determined pressure that is greater than a first pre-determined target pressure of a pressure decay leak test performed by the leak testing system.

16. The system of claim 12, wherein the headspace reducer comprises a displacement core.

17. The system of claim 12, wherein the port is disposed between the inflatable gasket and the headspace reducer.

18. A computer-implemented method of leak testing a glove of a restricted access barrier system (RABS), the method comprising: inflating an inflatable gasket to seal an opening of the glove; deploying a headspace reducer to reduce a headspace inside a test cavity inside the glove; and performing leak testing to determine a presence of a leak in the glove.

19. The computer-implemented method of claim 18, wherein performing the leak testing comprises: pulling vacuum from the test cavity or pumping air into the test cavity until a predetermined target pressure is reached; and monitoring a pressure to determine the presence of the leak.

20. The computer-implemented method of claim 18, wherein the deploying the headspace reducer comprises inflating an inflatable balloon at a pressure that is greater than a pre-determined target pressure used for performing the leak testing based on a pressure decay test.

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