Incontinence Physics Calculation

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Worried Guy
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Date Joined Jul 2009
Total Posts : 3742
   Posted 11/12/2009 8:00 AM (GMT -6)   
Darn it all! It is OFFICIAL. I am a complete nerd!

"Hey drmartin,
My prostate was 56 grams, and I had restricted flow for at least 15 years before PCa. You know I'm an engineer and can measure anything. I tracked my volume, and "nozzle pressure" from the day the catheter came out and saw significant progress the first few weeks. But that leveled off and here I sit, leaking a constant 400 ml per day. I can probably figure out the size of the orifice leak. If I could just get my valve reaming tool up in there....
My Uro said I should wait until the 6 month point before deciding on a course of action. I will try to be patient. This issue is small when compared with the problems other brothers are carrying."


After I wrote that last post I could not resist. I just had to figure out the size of my bladder's leaking hole. If there is a hole or mismatch, all the kegels in the world won't fix it. So....

Given: 400 ml during waking hours, 4" H20 pressure
Approximations and assumptions: working fluid is water. Orifice is circular and relatively thin.
Determine: Diameter of circular orifice.

Results: I'll spare the method details but using Lee Company Hydraulic Flow Calculator I have determined my weep hole is 0.0036 inches in diameter or 0.091 mm (91 um) -about 1.5 times the diameter of a human hair.

I now have a way to track it! I will do that monthly. If the opening does not get smaller by Feb. I will schedule something.

Jeff
Maybe I need to drink a can of Radiator Stop Leak.
DX Age 56. First routine PSA test on April 8th: 17.8.
May PSA: 22.6, 3 weeks later: PSA: 23.2.
Biopsy 6/10/09: 7/12 scores positive, Gleason 6=3+3. Bone scan and C/T scan negative.
RP DaVinci -7/21/2009 @ Univ of Roch Medical Center
Left nerve gone, right partial spared.
Catheter removed - 7/31/2009 Pathology report received:
Gleason 3+4=7 Tumor size: 2.5 x 1.8 cm location: both lobes and apex. No Malignancy in Seminal Vesicle, vasa deferentia, lymph nodes 0/13
Extraprostatic extension present; Perineural invasion: present, extensive
Prostate mass 56 grams. Pathologic Stage: pT3aN0MX
Post Surgery Status:
Potency - 10/31 3 months, Still no activity, nada, zip
Incontinence - 8/20 4 full pads per day
. 9/7 3-4 full pads per day (I'm going to try cutting down on fluids. Bad idea. I know.)
9/17 2 months: Still 3 pads per day.
10/31 14 weeks: Still 3 pads per day. At this rate I'll be fine in 2012.
Post Surgery PSA - 9/3 6 weeks- 0.05, 10/13 3 months- 0.04 undetectable.


Worried Guy
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Date Joined Jul 2009
Total Posts : 3742
   Posted 11/12/2009 8:14 AM (GMT -6)   
Before any technical purist corrects me, I know the above is an approximation. I did not consider pipe flow and assumed the sphincter was a flat plate. Even with those assumptions I believe the numbers are pretty darn close. In general, Physics does not lie.

I just gained a little more respect for my sphincter. I'm going to call him Mr. Sphincter from now on.
Jeff

MrGimpy
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Date Joined Jul 2009
Total Posts : 504
   Posted 11/12/2009 8:26 AM (GMT -6)   
Good theory,

I like your thought process, get to the root cause of the problem

The key to success is enhancing flow not restricting it, blood flow that is

You may want to check your blood pressure as part of each test.

Any muscle requires adequate blood flow to operate efficiently and at its max capacity. A restriction caused by high blood pressure ( which is common) may be the cause

Coffee temporarily raises blood pressure, L-Arginine temporarily lowers it.

A test eating a 1/4 cup of walnuts 30 minutes prior to the controlled test, that will give you approx 2g of L-Arginine and in most cases will lower ones BP and increase blood flow

Who knows, it may be the nuts
Stats:
Age: 52
PSA (2008)=1.9
Biopsy on Jan 09, 2009
One (1) out of twelve (12) cores was positive, plus external nodule found
Gleason Score = 3+3
Surgery (Da Vinci, robotic prostatectomy): 4/7/09
Removed Catheter: 04/19/09
100% bladder control - Pad free 7/09
PSA 7/09 undetectable, under .0


Modelshipwright
Regular Member


Date Joined May 2009
Total Posts : 215
   Posted 11/12/2009 8:42 AM (GMT -6)   
Your slow leak reminds me of when I attempt to do toilet repairs. After carefully following the instructions for connecting all the bits and pieces, I always end up with a leak. After many hours of taking things apart and re-assembling them, the leaks still persist. At that point I call a plumber. There is no doubt that water can leak from the smallest orifice and my toilet repairs are here to prove it.

Regards,
Bill

Worried Guy
Veteran Member


Date Joined Jul 2009
Total Posts : 3742
   Posted 11/12/2009 9:00 AM (GMT -6)   
Mr Gimpy -- I like that experiment and it is something I can try with a little planning beforehand. If I want higher blood flow maybe running might stimulate things. I just need that sphincter to shift or contract a tiny bit. Come on Mr S. work with me here!

Modelshipwright - Clearly, you need to use a little more joint compound. Frankly I'm thinking of using some myself! Now where did I put that long syringe...

I have no right to worry about this yet. I know. But can you imagine at my 6 month check up, me telling my Uro that I measured and/or calculated leak rate, max flow, orifice size, pressure and discovered a 91 um pinhole leak when my sphincter is closed? He will think I am nuts - and I would agree. But data is data.
Does anyone know what a Urodynamic test outputs. Is it purely visual? Can it show something as small as 91 um?
Jeff

I looked up Urodynamic testing on the NIH site:
http://kidney.niddk.nih.gov/kudiseases/pubs/urodynamic/index.htm
I see that my testing is very similar and I am on the right track.
I keep track of weekly pad flow not hourly or daily so my results are pretty accurate.
To measure pressure, I use my calibrated test firing range in my back yard pea/pee gravel. A simple excel program calculates nozzle pressure from the distance the pee flies and height of the nozzle above ground. (The guys who came here for the Outing in September saw the markers - I won't say if anyone used it. )
I use a Mettler lab balance, accurate to 0.01 gram, to measure mass.

Oh, and if I have not said it enough already, Yes, my wife is a Saint! How else can she stand me for 34 years?
Jeff

Post Edited (Worried Guy) : 11/12/2009 8:47:28 AM (GMT-7)


LV-TX
Veteran Member


Date Joined Jul 2008
Total Posts : 966
   Posted 11/12/2009 9:11 AM (GMT -6)   
Well Jeff...this was way over my head...all the dynamics and such...

But for what it is worth, I still leaked at the 6 month mark and by the 8 month mark I was able to go without any pads and no longer leak. Regardless of the size of hole that was leaking...it fixed itself. Some times mother nature takes care of things without any intervention or invention on our part.

Good luck with all that...was interesting read though
You are beating back cancer, so hold your head up with dignity
 
Les
 
Age 58 at Diagnosis
Oct 2006 - PSA 2.6 - DRE Normal
May 2008 - PSA 4.6 - DRE Normal / TRUS normal
July 2008 - Biopsy 4 of 12 Positive 5 - 30% Involved Bilateral w/PNI - Gleason (3+3)6 Stage T1C
Robotic Surgery Sept 18, 2008
Pathology October 1, 2008 - Gleason 7 (3+4) Staged pT2c NO MX - Gland 50 cc
Seminal Vesicles and Lymph Nodes clear
Positive Margins Right Posterior Lobe
PSA 5 week Oct 2008 <.05
                   3 month Jan 2009 .06
                   6 month Apr 2009 .06
                   9 month Jul  2009 .08
                 12 month Oct 2009 .09 


reachout
Veteran Member


Date Joined May 2009
Total Posts : 739
   Posted 11/12/2009 9:22 AM (GMT -6)   
Interesting calculation. I wonder, though, how realistic is your assumption of a constant 4" H2O pressure? The bladder is muscular, right? And it contracts whenever it wants/needs to, so during those contraction periods, the pressure would increase quite a bit. Not sure what this does to your calculation, but would it decrese the size of the hole needed to leak the same amount of fluid over the same amount of time? Hard to imagine it woluld make it even smaller, but goes to show how tight that seal has to be.
Age 64 yrs
DX 5/2009
8 out of 12 cores positive
PSA 5.6
Gleason Score 3+4=7
Stage T2a
Da Vinci Surgery 08/07/2009
Upgrade Gleanson Score 4+3=7
Stage pT2c
Neg Margins and Nodes
Extracapsular extension noted but neg Extraprostatic Extention
Dry immediately
First PSA 11/3/09 <0.1


Worried Guy
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Date Joined Jul 2009
Total Posts : 3742
   Posted 11/12/2009 9:48 AM (GMT -6)   
Hey Reachout
I agree the pressure does change throughout the day. Flow varies with the square root of the pressure drop so if I go all the way to 10 inches, it would increase only 58%. In an earlier post I spoke about how I measured my pressure. In the first month I watched it improve from 2 inches H2O to 4" to 6" to finally 10" and that's where it has been ever since. I use 4"H2O (1 kPa, .14 PSI) as my average since it does go lower sometimes, and this is a square root function. It is amazing how tight that seal is. A hole much smaller than a pin hole is keeping Kimberly Clarke's Pension fund afloat. But I'm working on it.
Jeff

reachout
Veteran Member


Date Joined May 2009
Total Posts : 739
   Posted 11/12/2009 9:53 AM (GMT -6)   
Amazing calculations, Jeff, thanks. Let me know when you calculate the physics of ED :-) That's all fluid pressure vs leaky valves.
Age 64 yrs
DX 5/2009
8 out of 12 cores positive
PSA 5.6
Gleason Score 3+4=7
Stage T2a
Da Vinci Surgery 08/07/2009
Upgrade Gleanson Score 4+3=7
Stage pT2c
Neg Margins and Nodes
Extracapsular extension noted but neg Extraprostatic Extention
Dry immediately
First PSA 11/3/09 <0.1


Worried Guy
Veteran Member


Date Joined Jul 2009
Total Posts : 3742
   Posted 11/12/2009 10:25 AM (GMT -6)   
Don't think it hadn't crossed my mind. I figure size and firmness are a function of pressure differential. I already have a Magnehelic differential pressure gauge that I need to plumb into my VED. I have the Augusta pump which is too expensive to muck up. Need to buy a cheap one.
Right now, incontinence is more important to me. But once that is licked, watch out ED! I'm comin' after you!
(Yes, I was one of those kids who listened in Physics class. Do you think Mr Josephson would be happy or sad to see how his lessons are being used?)

Herophilus
Veteran Member


Date Joined Sep 2009
Total Posts : 664
   Posted 11/12/2009 10:31 AM (GMT -6)   

All I know is that your resistance is cubed with a square of velocity. I started this part of my recovery yesterday with prompt removal of the foley catheter at 06:30. Results to this point can be considered fairly normal as to what I have discovered from post on this site.

Good luck Jeff 6.02 x 10(23)

Hero

BTW thinking of a name change to "Hydros" or "Hydrus".

 


Age:  51
Overall Health: Excellent
PSA 08-31-2009  6.8
DRE 09-10-2009  Normal
BXY 08:30 on 09/24/2009 OUCH!
Gleason: 3+3 = 6
Cores 10 of 12 positive
75% of 1 core, 25% of 2, cores... all others 5-20% 
Surg: da Vinci November 2 2009 Wash U- Barnes Hospital
11/06/2009, Doing Excellent


Worried Guy
Veteran Member


Date Joined Jul 2009
Total Posts : 3742
   Posted 11/12/2009 10:44 AM (GMT -6)   
Hero,
I'm pretty sure Avogadro and Perrin listened in school, too. Smart boys they were.
Good luck today. May your static pressure increase faster than your retirement account.
Jeff

reachout
Veteran Member


Date Joined May 2009
Total Posts : 739
   Posted 11/12/2009 11:42 AM (GMT -6)   
Jeff, here is some data for future calculations. I have one of those VED pumps with a pressure gauge attached. I got it online from an adult shop, so I'm skeptical if the instructions are medically accurate.

The gauge measures in inches of mercury from -1 to -30. I assume anything even close to -14.7 is unatainable, since that's atmospheric pressure at sea level, meaning a perfect vaccum, right? The instructions that came with it say to pump to -10 but never exceed -12. No problem! It starts feeling very uncomfortable at around -5.

I looked at the instructions for pumps at medical sites and they say that 3-5 is about right. I find that even at -2 the blood starts flowing into the penis, and if I just have patience, within 5 minutes or so it's about as full as it's going to get, about the same as pre-surgery, so I keep it between -2 and -3, with an occasional pump to -5 just to see what happens. The pump has a quick release valve, and when I open it the penis goes flaccid very quickly, in about five seconds. Not as flaccid as before I pumped it, but I can tell that the bulk of the blood has leaked out. That's pretty darned fast, so that might tell you how much of a leakage there is in the veins.

What I don't understand is why it takes 5 minutes for the penis to become fully erect and about 5 seconds for it to drain back. Maybe it's just me, and when you start pumping you might get different results. In either case this is not good enough for intercourse, not even with those bands that come with it (when one of those snap while putting it on, ouch!). So I just use the VED to exercise blood flow in and out, you know, use or lose it.

Anyway, hope this data helps for your next science fair project :-)
Age 64 yrs
DX 5/2009
8 out of 12 cores positive
PSA 5.6
Gleason Score 3+4=7
Stage T2a
Da Vinci Surgery 08/07/2009
Upgrade Gleanson Score 4+3=7
Stage pT2c
Neg Margins and Nodes
Extracapsular extension noted but neg Extraprostatic Extention
Dry immediately
First PSA 11/3/09 <0.1


Worried Guy
Veteran Member


Date Joined Jul 2009
Total Posts : 3742
   Posted 11/12/2009 12:16 PM (GMT -6)   
Hey Reachout,
That is great data. I'll keep that -2 to -5 inches Hg in mind.
Atmospheric pressure varies with altitude and weather conditions but at sea level one standard atmosphere is 29.92 inches Hg, or 14.7 psi, or 101.3 kPa . Since your gauge is marked in inches of Hg we'll go with that. A reasonably good automotive hand vacuum pump can suck down to -24 inches before the seals start to leak.
That would be enough to pop your wiener like a Zweigel's pop-open hot dog.

Just like you, it takes me a few minutes before I fill up but only an instant to go down when I hit quick release.

I can think of a good evolutionary reason for this trait.
Way back, the guys that took a while to get it up, had more girlfriends since they paid more attention to the females.
When jealous mates returned, the fast retreat guys could run away without tripping over themselves, while the guys that took a while to go down were caught and killed.

Makes sense to me.
Jeff

Post Edited (Worried Guy) : 2/2/2015 7:25:22 PM (GMT-7)


English Alf
Veteran Member


Date Joined Oct 2009
Total Posts : 2218
   Posted 11/12/2009 2:06 PM (GMT -6)   
Hi Jeff.
 
Regarding what (extra) pressure may be casued by the muscles of the bladder.
 
When they x-rayed my bladder to check for leaks before they took out the catheter they had to get about 150cc of that fluid that x-rays can see into my bladder against the pressure. This was achieved using just gravity, and the bottle had to be raised on a stand until it was about three feet above my body. But like all bits of us I imagine that we have muscles of different strengths. So, did they do that to you, and can you remember the height difference required?
 
There are clearly other variables such as any additional variations in pressure on the bladder due to the contents of abdomen especailly gas in the rectum, plus your own orientation to the vertical and about the horizontal, plus the degree of restriction due to any kinking in the delivery pipe, to say nothing of the viscocity of the fluid invovled.
 
One possibility that springs to mind for obtaining extra data would be for you to sit in a pool at increasing depth until you establish pressure equilibrium, then you could work out what pressure your bladder is producing. The opposite effect of (atmospheric) pressure is clealry true on the pressure front as I read somewhere today about a couple (who were otherwise fully continent), who both wet themselves when going up to highish altitude in a cable car) 
 
It all keeps our minds occupied.
Alfred
 
 
 

Age at Dx 48         No Family history  of Prostate Cancer

Married 25 years, and I cannot thank my wife enough for her support.

April 2009: PSA 8.6  DRE: negative. Tumour in 2 out of 12 cores. Gleason 3+3.

RALP (nerve-sparing) at AVL-NKI Hospital Amsterdam on 29th July 2009. Stay 1 night.

Partial erections on 1st and 2nd Aug 2009, Catheter out on 6th Aug 2009. 

Dry at night, but wearing pads 24/7

Post-op Gleason 3+4. Tumour mainly in left near neck of bladder.

Left Seminal Vesicle invaded, (=T3b!)

no perineraul invasion, no vascular invasion. clear margins,

Erection 100% on 15th Aug 2009   Stopped wearing pads on 21st Sept 2009

Pre-op style intercourse on 24th Oct 2009 !! No use of tablets, jabs, VED etc.

 


MrGimpy
Veteran Member


Date Joined Jul 2009
Total Posts : 504
   Posted 11/12/2009 2:10 PM (GMT -6)   
They checked your urine level with an X-ray ?

Mine was different, they filled my bladder through the Cath and used an Ultrasound to see if it was leaking
Stats:
Age: 52
PSA (2008)=1.9
Biopsy on Jan 09, 2009
One (1) out of twelve (12) cores was positive, plus external nodule found
Gleason Score = 3+3
Surgery (Da Vinci, robotic prostatectomy): 4/7/09
Removed Catheter: 04/19/09
100% bladder control - Pad free 7/09
PSA 7/09 undetectable, under .0


reachout
Veteran Member


Date Joined May 2009
Total Posts : 739
   Posted 11/12/2009 2:33 PM (GMT -6)   
Jeff
Thanks for the info, I rechecked my pump gauge and you're right, it's inches Hg up to 30. I had my psi and inches Hg mixed up. So when I go to -5 it's in inches Hg, and there is another scale next to that which goes in fraction of Pa (ambient air pressure?). At around -5 or -6 it's about .2 Pa, so 20% times 14.7 psi would make it around 3 psi of negative pressure. As I said, I only go to at most half of that, so around 1 to 1.2 negative psi.

What you said about the evolutionary reason for quick deflation makes sense, and gave me a good laugh.
Age 64 yrs
DX 5/2009
8 out of 12 cores positive
PSA 5.6
Gleason Score 3+4=7
Stage T2a
Da Vinci Surgery 08/07/2009
Upgrade Gleanson Score 4+3=7
Stage pT2c
Neg Margins and Nodes
Extracapsular extension noted but neg Extraprostatic Extention
Dry immediately
First PSA 11/3/09 <0.1


Worried Guy
Veteran Member


Date Joined Jul 2009
Total Posts : 3742
   Posted 11/12/2009 2:42 PM (GMT -6)   
English Alf,
Yes I had a CT scan with contrast dye that was inserted into my catheter until I was about ready to explode. I was on my back with my hands up in the air holding the tubing and the bag was at that height. I just checked with a tape measure and see that it was at 26 inches off the floor. I then figured the bladder is half way up my body so was 5 inches off the floor. So, the Pressure differential was 21 inches of H2O. That positive pressure was enough to make my eyes water. On the other hand, I can fire out at 10 inches of water measured by trajectory. My tank capacity is 330 ml, 11 oz. I think with all this data, I've got a pretty good handle on the leaking orifice size. Now if only I can plug it with something. A 92 micron mineral deposit would be perfect. Or maybe a tiny clot or two. But nooo. I have to be one of those lucky guys with pee clearer than Manischewitz Cream White Concord.
Jeff

English Alf
Veteran Member


Date Joined Oct 2009
Total Posts : 2218
   Posted 11/13/2009 4:37 AM (GMT -6)   
Jeff
I assumed it was x-rays they were using to check whether there were any leaks, seeing there were radiation hazard warnings on the (thick) doors of the examination room, and when the doctor operated the machinery all the lights went out and she hid behind three inch thick glass walls while wearing a lead apron. She was also totally amazed that I felt no discomfort whatsoever during the procedure. I liked her; she was the first person to give me any good news during this whole business, in as much that she was the one that told me things were okay leakwise and the catheter could come out. It was the guy who took the catheter out an hour 30 minutes later that told me the less good news about my post op pathology that I have trouble liking. Any one else have trouble liking doctors that tell you bad less good news?



Good luck with stemming the flow.



Alfred

Worried Guy
Veteran Member


Date Joined Jul 2009
Total Posts : 3742
   Posted 11/13/2009 9:18 AM (GMT -6)   
Alfred,
When I was on the table and the dye was going in, they warned me that I would "have a coppery taste in my mouth and would feel like I was urinating. That is normal." Also I was surprised that my extended arms were the hangar for the tubing.
For 15 cents I can bend a coat hangar that will do that automatically. "Let me just screw it right into the machine right her... oops!"
Jeff ...Still waiting for 92 um plug.
DX Age 56. First routine PSA test on April 8th: 17.8.
May PSA: 22.6, 3 weeks later: PSA: 23.2.
Biopsy 6/10/09: 7/12 scores positive, Gleason 6=3+3. Bone scan and C/T scan negative.
RP DaVinci -7/21/2009 @ Univ of Roch Medical Center
Left nerve gone, right partial spared.
Catheter removed - 7/31/2009 Pathology report received:
Gleason 3+4=7 Tumor size: 2.5 x 1.8 cm location: both lobes and apex. No Malignancy in Seminal Vesicle, vasa deferentia, lymph nodes 0/13
Extraprostatic extension present; Perineural invasion: present, extensive
Prostate mass 56 grams. Pathologic Stage: pT3aN0MX
Post Surgery Status:
Potency - 10/31 3 months, Still no activity, nada, zip
Incontinence - 8/20 4 full pads per day
. 9/7 3-4 full pads per day (I'm going to try cutting down on fluids. Bad idea. I know.)
9/17 2 months: Still 3 pads per day.
10/31 14 weeks: Still 3 pads per day. At this rate I'll be fine in 2012.
Post Surgery PSA - 9/3 6 weeks- 0.05, 10/13 3 months- 0.04 undetectable.

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