Originally Posted by marinera
I would like to put here my 2 cents again, if you guys don’t mind.
Wow! This is more than 2 cents.
Originally Posted by marinera
I think things are becoming confusing because we have adopted a too much abstract point of view. If we are speaking about physics phenomena, we have to start by what we can observe. Let’s suppose an average penis is 6” length (NBP) x 5” girth. If we clamp so tight that 3” inch of the penis is practically “void”, we are raising the pressure at roughly double of when starting. So, if pressure in erect penis is 3 HG, clamping up to half length raise the pressure to about 6 HG.
I’ve never clamped, so I’ll leave comments regarding “voids” to those that do. However, I find it hard to believe that you can crank down a clamp that hard on a peak erection without causing severe damage.
I think you’re underestimating pressure increases in the erect penis. As mentioned before, compliance plays a role. As the penis gets very firm, it begins to act like a rigid pipe. The pressure increase with small increases in volume (say when you push blood away from a clamp) will not be linear; it will cause an extremely rapid increase (exponential). Clamping half the length, will cause more than twice the pressure, far more.
Originally Posted by marinera
Let’s see what happens with a pump: raising pressure to 6 HG will lead to same injury? Do a try, you’ll find the answer is “Not”.So: analogous levels of pressure aren’t affecting in the same way the tunica when pumping as it happens when clamping. This is a fact.
This is likely. The mechanical force is different.
Originally Posted by marinera
Is theoretically possible raising pressure in the pump so much that same degree of stress on the tunica is obtained? Theoretically, yes. But let’s see what happens with lower numbers.
A clamp (so tight that volume under of the penis gripped is zero) wide 1 inch should cause a raise in the pressure inside tunica of roughly 1/6 higher. A practical experiment will tell us that 1) the expansion obtained is near (or above) dangerous levels; 2) the penis is rock-hard.
Translating that pressure to pumping, it would be a 3.5 Hg; this is a level of pressure not dangerous at all. This confirm what we have observed above.What would be a level of pressure so high that tears or break of tunica would happen by pumping? I don’t think that even at 12 HG of pressure this could happens – let’s relate to what ttt just said about his experiment with pump. But what would happens (for most of us) using a 12 HG pressure when pumping? Easily, “fluff” penis, temporary ED, loss of sensitivity etc..
So: using a pump, the pressure is deforming other penile tissue’s than tunica more than it happens by clamping. It means: pressure is affecting (and deforming) tunica more when clamping than when pumping. It means again that, for our goals, pressure is more profitably used when clamping than when pumping. In the first case, tunica resistance is the limit; in the second, not.
The explanation of this fact could be that others tissue than tunica (and/or limph build-up) are, to use a metaphoric term , absorbing the pressure.
I agree with you here. I think that translating pressures is difficult because the true pressures in clamping are not assessable. Clamping to 102% as ttt describes will cause pressure to jump quite high (because of the low compliance). If at peak you’re 200-300 mmHg, the clamp may even double (or more) the pressure.
Even if you could match pressures with pumping, I agree, you’d be hard press to believe that you could cause tunica damage before your penis would first fill up with fluid (edema).
Originally Posted by marinera
I want to add an attempt of a more formal description of what I mean. This is in blue color, so those not interested in details can miss it- it is not essential, and could be confusing.
All of you have also to remember that I’m not a phisicist, and this is just a try for a “second level” reading, if you get what I mean.Pressure (P) is what we want to use for deforming the tunica.
Pressure should act on volume (V) of tunica.
Changes in volume are (dV).
Deforming effect is D.
While the absolute value of D should be P/dV, if we want a relative measure, or index, we have to relate dV to starting V.
So: D= P/(dV/V).
If penis was only made of tunica, higher levels of P should lead to higher D values in a linear way.
But if penis was made of, in example, three different tissues, the higher pressure level could be not so linear; i.e., I suppose (a physicist or engineer should chime in) this:P = (P1+P2+P3)/3=(D *dV1/V1 + D *dV2/V2 + D *dV3/V3)/3.
Otherwise said, when clamping P is pressure hitting tunica entirely. When pumping, P is the median pounded value of those P(n) values- this is what we read on the pump-gauge.
Moreover, the maximum level of P that can be obtained is correlated to the mini-max of that these P(n) we want : the lower value of each max P(n) value.
This mini-max P(n) is, itself, dependent to the maximal D value we want on each tissue : the lower value of each max D(n) value.
Others things related to penis anatomy, observed by our thread-MEDS, can of course concur as well in limiting the maximum value of P that can be obtained, or the effectiveness of P on tunica deformation.
I know we’re lose 99.9% of the readers of this thread by discussing this further, so I’ll just add a few comments to help you refine your explanation:
Deforming effect (D) is descriptive (qualitative) and not numerical (quantitative). Also because deforming effect is, say stretching of the tunica (which is very tight already), it’s hard to imagine its response will be linear.
The penis is complex because of its unique construction and connective tissue arrangement. All this said, if you consider all the erection chambers as one, there really is only one important fluid compartment in the penis.
A tissues volume varies. The tunica for example has little fluid volume. So its volume is ignorable. The same is true for the skin and the tissue between it and the tunica. Unless you accumulate a significant amount of edema, this is also negligible.
You’re saying that each tissue (of the three you propose) represents a fraction of the total volume change ; dV/V. This is not necessary because the penis, for our purposes is a single compartment. The volume changes in the erection chambers dwarf any changes in fluid in other tissues. This would definitely be true if the change in volume you are considering for the erectile chambers is from flaccid.
Because of the compliance of the tunica at peak erection, this change in (dV) for a given pressure change may be almost immeasurable, in my mind.
Is the deformation directly related to pressure or is the pressure response a result of the poor ability to deform? Or both? That will be hard to quantify.
This is interesting. Did you derive this yourself or adapt it from somewhere else? You will need to refine it.