The panel mount connectors were water-proofed using rubber o-rings and silicone rubber sealant
Tried inflating balloons using negative pressure – no success because the balloons were too resistant; after stretching out the balloons several times still very little response
Replaced with plastic bags wrapped around and ziptied to tubing – no success because there were still some leaks in connectors and the between the bags and the tubes they were attached to
Resealed some panel mounts at the leaks and replaced plastic bags around tubings – negative pressure works! But not as much as it should (removing 800 mL water resulted in about 100 mL lung inflation)
the lid was collapsing slightly inward resulting in lack of response from the negative pressure
the pump takes long time to warm up before it can be run at above half max flow rate
tubing wears out heavily in the pump; plastic bags are tied around tubing weirdly and do not fully allow air flow
Resealed some panel mount connectors and placed plastic bags beneath the lids in order and replaced some tubes that were not properly attached – better response, but still minimal response (400 mL pulled out resulted in under 100 mL lung inflation); in addition bags around tube in left chamber seem to be properly sealed on, no response right chamber
Performance Video can be seen here: http://goo.gl/cv7YQ
Filled the chambers more fully with water in order to eliminate air compression in chamber and calibrated the pump as per instruction manual- no success PUMP IS BROKEN????
Pump is not working
Pump will be returned and new one delivered by 3:00 pm tomorrow (May 26, 2011); Return Authorization #: 531 444; and new Reference Number: 6369247-90
drilled holes in new smaller (rat-lung sized) chambers for panel-mount connectors
Placed panel mount connector through a cut hole in a zip-lock bag (to be used as mock lung) and sealed with rubber O-ring and silicone sealant - Success; tested with water and no water leaks; sealing panel mount in bag works even better than in the rigid container
Attached zip-lock bags on the insides of both containers to serve as mock lungs and on the outside of one container in order to see progress. There do not appear to be any leaks. Also, new L/S-36 Norprene tubing placed in pump. Pump run at 2900 mL/min for 5 seconds running about 480 mL per cycle.- works smoothly, no leaks anywhere; however, appears to only be partially responding (not full 480 mL)
Performance video can be seen here: http://goo.gl/FgaHO
Pump makes louder than expected noise when running with both pump heads, especially while running counterclockwise (will call Cole Parmer tomorrow)
Called Cole Parmer as did Prof. Lima; tried to wear in tubing- no help; Dr. Lima is waiting to hear back from Jim at Cole Parmer to see what can be done
Starting to look more into sensors: want all sensors to be compatible with a data acquisition system and to be read by one computer, cannot be anything intrusive.
Will compile list of materials (sensors and others) needed.
Pump still makes loud noise (see notes from June 6 & June 13)
Called Cole Parmer about pump noise - unsure whether noise is a result of pump head problem or pump drive problem; for now CP will be sending new backs for the pump heads as that may be the cause of noise.
Attempted to run pump with bags with food coloring to see if system would work -NO SUCCESS, waste bag leaks into 'clean' side; pos pressure could not fight gravity to push fluid out of 'lung'
Testes one-way valves manually - let liquid flow freely the correct way and the incorrect way, just slower going the incorrect way.
Tried full process again, but with pump on same level as reservoirs (so it does not have to fight gravity) - still pulls in from both sides, however w/o gravity helping now it is barely pulling the liquid (pulling about 1.2 L from the chamber results in a .15 L response; when putting fluid back into chamber it forces the lid off
Note: Be sure reservoirs are empty of air or else the neg pressure will pull in air instead of fluid
Pump still makes loud noise- waiting for confirmation from CP that new back plates will be sent
One-way valves do not appear to work
Without gravity, negative pressure works very poorly; with gravity forcing fluid out of 'lung' cannot fight the gravity
Replacing water into lung chamber forces the chamber lid open- even though the 'lung' is also emptying: maybe lung is not emptying enough and replacing fluid creates higher pressure in chamber
Filled the chamber with water and held upside down and container lid did not open and fully maintained seal - whatever problem we had yesterday with the opening container therefore appears to be related to the bag and bag shape popping it open
Reran everything with the 'lung' made smaller to avoid lid popping off - no success
Cole Parmer is looking into problem with One-way valves (Dan ext 5221)
Chambers are leaking again - need to be resealed
Waiting to hear on one-way valves
Same problems with operation as June 29
Confirmed that new pump head will be sent and we will have it by this Thursday and we do NOT need to return the current one(RA#: 533 371; Order#: 6369247-00)
attempted to eliminate tube connections while testing neg. pressure - no success; still takes in much less fluid then it should be (about 10%)
attempted to hold down lid with hands while water was placed back into chamber- no success; while water is returned to the chamber the pressure still forces the lid off before it forces the media out of 'lung'- could be because of weird bag shape- the fluid stays in pockets before it will be forced out
tried evacuating the lung with the lung starting full- appears to work better (about 20% of expected response)
waiting to hear back from Carl in the factory tomorrow about one-way valves
still need to reseal chambers (silicone sealant does leave traces in the water)
still need to get pos and neg pressure working properly
Contacted Cole Parmer again about One-way valves; spoke to Peg (ext 5115) and spoke to Carl at the factory- says he's waiting for a reply and package from the plant in maryland and will get back to me today or tomorrow by noon
Carl from Bel-art called back and said that all check valves in stock currently have the same problem and they are investigating where in the factory line the defect occurred. He will replace our 6 defective valves with Belart Model # 197130002, a similar product.
Received new pump head from CP - works with no noise when there are no tubes in, and with some, but much less noise, with tubes in
Repeated July 5 experiment; started with lung full of fluid and evacuating the lung by placing water in the sealed chamber; however, today first filled chamber 1 completely to get rid of air and then pulled water from it then replaced that water - Partial success; the increased pressure still forces the lid open, even while using some hand pressure to seal; but we did have 40% of the expected response! Replacing 500mL into the chamber forced 200 mL out of lung
Repeated above experiment with lid taped down in addition to holding it down - More success; we now had a 300 mL response to the 500mL water being placed into chamber (60% success); however, the 'lung' was still not responding to the increased pressure quickly enough and the pressure therefore forced the chamber and severely damages the waterproofing around panel mounts (however, when water just sits in there with no additional pressure it does not leak heavily)
Attempted to measure the reverse again- NO success; only pulling in about 30 mL into the lung when 500 mL of water is pulled
This time with the aid of gravity: pulled out 200 mL of water from chamber and 100 mL of fluid was passed into lung
After testing pump itself: Attempted to pull 200 mL through each pump head and only received under 175 mL through each pump head - Pump MUST be calibrated! All results from today should therefore be altered to reflect that (i.e. the most recent 'lung evacuation' test was in fact about 70% successful; and filling the lung was about 55% successful)
Waiting for confirmation that replacement check valves were sent
Need to find stronger method of sealing panel mount connectors that will not respond to pressure as much
Need to find better method of sealing chamber lid - taping it down heavily and untaping each time is annoying and tape-wasting
Need to figure out method of properly filling and emptying lung
Received replacement check valves from BelArt - did not receive the product number discussed on the phone, but these ones do appear to work
Ran system again as well - chamber is cracked in a few locations from the constant pressure; and pump is incredibly noisy now
Resealed chamber around the cracked area and will wait to dry to test again
Ran full system again for longer time - the one way valves are NOT working (I e-mail Carl from BelArt and will call him tomorrow); the lid still pops off the chamber while emptying the lung; the new sealing on the chamber held; and we got about a 200mL from pulling 800 mL - it appears that as a result of the longer tubing and the many connections we lose some efficiency
Contacted Cole Parmer about pump noise - waiting to hear back from Evangelica: says she can definitely send a new pump head, but we might have to send in Drive for repair rather than being replaced, I asked her to see if they can send us a new one so we don't waste time
Need to contact BelArt for new, working check valves
Need to call Cole Parmer back if she does not call me back for the pump noise problem
Need to find better method of sealing chamber lid - taping it down heavily and untaping each time is annoying and tape-wasting
Need to figure out method of properly filling and emptying lung (will try tomorrow to set up with same connections, but shorter tubing)
Carl responded to my e-mail saying that the valves sent were made and tested separately from the defective batch and they were sent because unlike the other offered replacement, these ones are autoclave-able; he will look into the problem and get back to me
Evangelica's supervisor Tiffany called me back about pump noise - they would have to take it in for repair and we would be without it for at least 4 weeks, attempted to explain that that was unacceptable and she hung up on me - will contact again tomorrow and see what can be done
see July 12, 2011
Called and left message for Tiffany about pump - she said we can send the pump in as a return and they would evaluate the pump's condition and refund value of the pump (she claims that if there is no additional damage to the pump we would get a full refund)
Called and left Carl a message about check valves - waiting
Calibrated pump - now gives more accurate reading of what is being pumped; however it's max is only about 70% of what it should be, inefficiency is possibly related to the other pump problems
shortened all tubing on the trachea side so that fluid has less to travel and in addition on the way out of the lung waste arrives at the waste reservoir as quickly as possible so that when process is reversed there is less waste sitting in the tubing that gets pulled back into lung
Ran full process again with shorter tubing - negative pressure pulled in about 40% of what it should, no improvement
Took video and a picture of flaws with check valves and e-mailed to Carl - he responded that he is still working on a solution and will get back to me
Continued to look into different sensor options - very few meet all of our requirements (stay updated on our Sensors page).
Carl from BelArt e-mailed me saying that his engineering team has not yet found a solution and we should look into other manufacturers.
Picked up a glasslock container from the container store - main body is a sturdy glass, lid locks down on all 4 sides, and lid is plastic but does not seem to be too bendable/likely to cave-in
Laser cut plastic piece to place on top of new chamber lid in order to add support
Laser cut holes in the plastic piece and the chamber lid to be used for the panel mount connectors
Epoxied crack in lid and epoxied lid to plastic piece
Contacted Qosina for check valves for our size and needs - they will be sending a sample of Qosina Part #: 91030, the only model that will fit our set up
Contacted Smart Products about check valves - they sell in minimum packages of 25 at $8 a piece. Smart Products Series 300 check valves - We will want #306 barbed connections on both sides using Ultem as the body material and Viton as the O-ring material, as they can both handle autoclave temperatures.
See Tubes and Valves.
Left a message for Tiffany at Cole Parmer to call back to arrange for pump return, re-order, and request refund for BelArt check valves.
Called Joe Ross (IR guy) - his office got our package, but he is not in until Friday to look at the tubing.
Waiting to hear back from CP on pump and check valves
(Lab cleaning)
Re-epoxied plastic piece and the lid, and epoxied panel mount connectors in place
Contacted CP about pump return - will receive e-mail with free UPS label for free pump return
CP sent out a new pump drive with free express shipping and charged us $1,676 (a 20% discount on standard price)
Tiffany at CP said she would look into our troubles with BelArt in the hopes of issuing a refund for defective check valves
Joe Ross said our tubing had too thick of a wall to work with IR sensors; contacted him back asking if 1/16” wall thickness would work from CP (http://www.coleparmer.com/catalog/product_view.asp?sku=0641112&pfx=EW)
Waiting to hear back from CP on check valves
Received new pump; need to send back old pump
Joe Ross said that the other tubing info I sent him would also not work and he recommends not using IR for our process.
Tiffany was not in today to check on check valve refund.
Filled our new chamber with water to check for leaks - there IS a leak somewhere, but cannot tell from where it is coming.
With plastic sheet covering it leaks a little less; re-epoxied the crack in lid and the center panel mount.
Tested new pump - STILL makes loud noises using both pump heads individually!! In addition, for tubing calibration pumped 270mL out of 320mL (out of box only 84.375% efficient; I need at least 92% efficiency for this pump to be useful)!!
Drafted new drawing with exact plans for sensors, etc.; also Bill of Goods updated further.
Waiting to hear back from CP on check valves
Need to deal with pump noise and inefficiency
Leaking chamber
Met with Prof. Lima - see Minutes page
Continued to update the Bill of Goods
Received sample of Qosina check valves (model 91030)
Tested valves by attaching short tubes to both ends and pouring water through either end - no water flowed through in the reverse direction (Success); in the correct direction water only flowed if there was at least 2 inches in the tube, less than that the disk remained in place and blocked correct flow as well - this matches specifications of 1.72” Water cracking pressure - full success with use.
Tested check valves with each one connected to different color water and facing different directions - only one color flowed, success.
Since the check valves do limit even correct flow, ran the system to measure how much actually flowed through; set the pump to pump 320 mL through (note: 320 mL pumps a reality of about 270 mL) - about 250 mL was received on the other side (this means about 93% efficiency with check valves in process; maybe we can recalibrate pump and process based on that)
Gave Maria the old pump to ship (Tracking #: 1Z 773 57W 90 9384 9299)
Research solenoid valves (power needed for operation, tube connection, response time, fluid & air)
Deal with pump problem
check on check valve refund from CP
Finalize check valve decision AND DO probe decision as per e-mails to Prof. Lima
Draw sketch on computer
Met with Daniel and learned basics of using Arduino to control pump
Researched solenoid valves
Did most of the planning sketch in AutoCad
Deal with pump problem
check on check valve refund from CP
Finalize check valve decision AND DO probe decision as per e-mails to Prof. Lima
Finish sketch on computer
Met with Prof. Lima - see Minutes page
Contacted Tiffany at CP to inquire about check valve refund, current pump return status, and returning our current pump - waiting for her to return call
Finished/updated Bill of Goods
Finished sketch of current plans
Purchased silicone sealant and resealed chamber lid - leaks much less through the lid, but still leaks from the sides
With plastic beneath lid and the new silicone seal, much less leaking
Need to hear back from Tiffany at CP about check valves, current pump return status, and future pump return
See if we can eliminate leaking even more from the lid
Updated wiki page and Bill of Goods
Spoke with Tiffany from CP - she is still investigating check valve issue (just sent her an e-mail with my communication with Carl Sisco from Bel-Art); returned pump has not yet been processed (was received yesterday); she is trying to get in touch with Masterflex in order to further resolve our issue
Need to hear back from Tiffany at CP about check valves, current pump return status, and future pump return
Redo panel mounts in new lid
Played with Arduino
Bought new chamber
started to attempt to try to remove panel mounts from the old chamber
Tiffany at Cole Parmer issued a full refund of $42.00 for the check valves
Need to hear back from Tiffany at CP about check valves, current pump return status, and future pump return
Redo panel mounts in new lid
Destroyed old container to harvest panel mounts
Laser cut new lid and plastic for panel mounts
Tiffany at Cole Parmer issued a full refund of $2,095.00 for the original pump
Still waiting to hear about the pump we currently have
More Arduino playing - struggling to use PWM to analog converter properly (have PWM connected to the RC circuit and then to both an led and the Arduino analog input - results are not accurate when the led is connected as well, but when led is removed then the output matches the input)
Learned how to use relay switches
Cleaned out old panel mounts from the epoxy
Packed up lab to move to Columbia and brought all equipment up
Used silicone sealant to seal panel mounts connectors through chamber lid and plastic support piece
Contacted Tiffany at CP by both phone and e-mail about our current pump and still waiting for response.
Discussed our issue with Tiffany at Cole Parmer several times - they will take our pump drive, 2 pump heads, mounting hardware, computer software, and computer cable back for a full refund (and has waived any restocking fee) - RA #: 535058, Return Tracking #: 1Z 773 57W 90 9248 3113; however, at this time she will not take the tubing back (she will ask her supervisor and get back to me)
[For these returned items we should receive $2,926.00; purchasing the currently planned new pump and accessories will cost $3,902.00]
Discussed with Prof. Lima that we will spend the extra $1,000 on a replacement pump for the pump we will be returning
Met with Dr. Buchetta and Dr. Singh and Saw the artificial lung machine connected to all pumps and tanks in use on patient
Intend to meet with perfusionist Jimmy Beck next week in order to discuss what sensors are available for us to use
Began programming arduino to control our pump and to read any sensors that we may have attached to the arduino
In the small glass-lock containers that we now use there is no room for the 2 sides of panel mount connectors attached to the 'lung' - instead siliconed a short length of tubing directly into the bag
Connected Arduino to relay switches and set up as planned to be used to control pump start/stop and pump CW/CCW - see main page, Pump Control
Played around more with Arduino and its capabilities, working on sending data to an excel file
Met with perfusionist Linda to gather available sensors - she e-mailed Steve Turner to find what we can get
Met with Dr. Bachetta and discussed where we are now.
Collected some different chambers to try out in order to replace the ones we currently have - our new chamber is fully water tight.
Spoke with Tiffany from CP - we still need to discuss tubing return; she has shipped out what we need for our next pump and will overnight that to us.
Received new pump, set up
Contacted CP about the plastic piece on the pump head shafts – it is a boot to eliminate noise, they will be sending us an additional one for free to arrive on Monday (these plastic boots may also wear out and would need to replaced)
CP also e-mailed me a data sheet about Norprene tubing lifespan
Connected wires, breadboard, and arduino to the back of the pump – currently connected using tape (CP sells a $110 cable to make the connection more secure; Cooper EE lab does not have the pin to solder connection for this setup, Glen says it is a non-standard military connection, and obtaining the proper size may be difficult and expensive)
The connections and everything work to control the pump on our 10 second cycle – see picture and video under pump control section on main page
Tested pump flow rates:
With the pump set to 50% we should have a flow rate of 4 LPM in each pump head;
Therefore, on our 4 second run we should have 533.33 mL from the 2 pump heads –
with the pump head occlusions on the lowest setting we got about 490 mL,
with the occlusions set to an intermediate setting we got exactly 500 mL,
with the occlusions set to the highest setting we again got 490 mL
NOW Running the pump for 10 seconds should give us 1,333.33 mL –
with the pump head occlusions set to the intermediate level we received 1,400 mL
TEST NOTES: the measurements were taken during normal pump operation, meaning that the 20 inches of tubing through the pump were NOT primed
The tubing used was not our Norprene tubing, but it was the I/P 73 Silicone tubing (Norprene may give lower flow rates
The 4 and 10 seconds were timed and controlled by the arduino and depended fully on its internal timing abilities
CONCLUSION: Actual flow rate will vary; we will need to fully calibrate it depending on how long we will actually run it for. In addition, when actually in use between 2 chambers the tubes will possibly never be full of air, but will have fluid in it the entire time.
Silicone sealed the ‘lung’ bag to the lid of chamber, and siliconed tubes to the inside of the chamber lid to reach the bottom of chamber
We need a better solution to connect wires to the back of the pump, everything right now appears to be expensive
The relay switches frequently pop out of the breadboard while in use (which means pump stops running) – can either tape those down or maybe ditch the breadboard and solder everything together
We need to properly connect tubing to our chamber lid securely.
Received extra I/P tang boots for the pump heads
Worked more on Arduino coding and understanding methods of converting Arduino data to .txt or .xlx
Using a program called GoBetwino we can write anything from the Arduino Serial port to a .txt or a .csv – however, while the .csv is open in excel the program will not continue to write, which means we can log, but not monitor live with this; in addition, still need to figure out how to put data in different columns
Added power/kill switch to the entire pump system in order to ensure that the pump would start going in the correct direction when ready.
The relay switches and all wires do appear to stay in place properly as long as they are not abused too much.
Silicone sealed more tubes into the and out of the chamber we will use – should be ready for full use now
Set up the system with all tubes and connectors using the 'lung' in the newest chamber - NO success; leaks in several tubes and the chamber lid; could see 'lung' expand and contract, but was barely pulling in the correct amount of fluid and the reservoirs were filling with air
Resealed all the tube connections and reran full system - NO success; the tube seals appeared to hold, but the chamber lid was continuously leaking water; waste reservoir bag was also found to be full of air, signifying leaks in the system
Ran the system using the glass-lock chamber - NO success; pressure forced the lid up (even with hard plastic piece on top) and water spilled through the lid
Used less water in the chamber to start with (so that there would be less pressure and less liquid to leak out) - NO success; pressure destroyed one of the panel mount seals and water sprayed out.
Showed our current setup to Dr. Bacchetta - he said he will see what he can do about a proper chamber, pump for pulmonary side, and will order more panel mount connectors and check valves
None of our chambers will withstand the pressure - will look into other chamber options while waiting to hear from Dr. Bacchetta on what he can offer.
Need to send Dr. Bacchetta list of supplies needed that Linda will not be providing (check valves and panel mount connectors)
Laser cut new lid for the chamber to hopefully hold better, and to hold panel mount connectors neatly
Used binder clips to hold lid down
Ran pump - NO success; lid and binder clips did not hold pressure; water sprayed everywhere
Cut holes in chamber lip to hold wire in an attempt to hold down lid better - NO success; chamber still leaks
We all met (Elli and Igor with Dr. Bacchetta and with Dr. Lima)and discussed where we are (see Minutes page) - currently we plan on producing our own chamber.
Discussed the current set up of what he have working and how it works
Discussed additional problems for us to deal with:
(Discussion, project plans, and some project happenings between Sept. 26 and Oct. 31 have been recorded on the Minutes page.)
Moved all equipment back from Columbia today/ stole equipment through a door not monitored by Columbia security.
Sinisa finished the walls and floor of both chambers (completely together, sealed, and watertight) and will finish lid, clamps, panel mounts when we bring them to him
Received toggle clamps today - all appear to be there and in proper condition (we received 13 instead of 12 yay)
1) Started with 'lung' empty and chamber full of water (NO air)
2) Pumped water out of chamber and watched as red water entered the lung from the reservoir
3) Pumped water back into chamber and watched lung empty
The lung's inflation and compression can be seen pretty easily and amount of fluid emptied from the chamber closely matched the fluid emptied from the reservoir as a result, and vice versa.
WE pulled about 3/4 of a liter and we saw about 700 mL of fluid pulled into the 'trachea'
The problems and the lack of 100% efficiency were the result of several air leaks from the panel mount connectors since we were still using old ones and they were not put in properly by Sinisa.
Attempted to fix some chamber leaks using tape
still had air problem, solved mostly by air bleed system described on homepage
improve the arduino to be able to control the changing pump speeds depending on direction
Testing Flow Sensor (Omega - FLR1012):
Based on very coarse measurements we pumped through at 2.3333 LPM: 1400mL in seconds (measured through a volumetric flask thing and a manually pressed stopwatch) with the pump set at 32%, which should have given 2.56 LPM. Our sensor gave 2.39 V, the equivalent of 2.39 LPM (accurate to flow rate till the tenths place- and all based on coarse measurements).
Using same method we now pumped 1.2444 LPM: 1400mL in 67.5 seconds with the pump set at 20%, which should have given 1.6 LPM. Our sensor gave 1.47 V. This is much higher than expected.
Repeated previous with same results.
We pumped at 3.574 LPM: 1400mL in 23.5 seconds at 50% pump speed. We got sensor reading of 3.5 V = 3.5 LPM.
Now we pumped .760LPM: 1400mL in 110.5 seconds with pump set at 10%. We get sensor reading of .8 V = .8 LPM (N.B. with this trial the ssensor reading was less consistent and fluctuated between .78 and .83).
2.456 LPM: 1400mL in 34.2 seconds gave 2.49V = 2.49 LPM.
NOTE: Even while pump is off sensor is giving reading of .01 V.
Powering Sensors:
We want to power the Pressure Sensor at ~28V and the Flow Sensor at ~12V. To accomplish this we have the power supply set at 28.2V with 4 10M-Ohm resistors between the - and +. The voltage across 3 resistors is then 12V.