equipment for blind divers

[АлександрД]

I have two friends, who blind and they are divers
Photos and story of one of them (under spoiler)

Spoiler: Visiting the sea king

Visiting the sea king
He slid over a light sandy bottom, like a ghost or an angel - too material for a ghost and too sinful for an angel to admit, but the flight-slip in clear water and really was ghostly noiseless. (c) Alexander Bushkov. "Piranha: The First Throw".

Not piranha, of course. Before a small toothy predator me oh how far. Let's start with what I do not strip by nature, again with vision is not as good as I would like, and my temper is moderate. In general, do not piranha. And the march warrant was not there, there were no completely secret fighters gliding behind me in the transparent twilight, there was no alarming rattle, there was not a deadly roundabout in the bay of El-Bakhlaka ... but on November 29, 2009, I will remember for the rest of my life.

Now it is absolutely necessary to name the immediate perpetrators of what happened to me. First of all, special thanks to Pavel Obiukh and the organization "Perspective". And also to their partners - the non-profit organization "Cellar". Many thanks to all those who were with me in the same group and a low bow to our instructors and assistants: Daria Portnova, Alexandra Zheglov, Kiril Yuvchenko, Igor, Elena Bezina, Mehdi and the guys who made it inaccessible to those who are on the wheelchair - affordable.

So, thanks to the invaluable efforts of many people, I, your humble servant, was on the edge of the Trud swimming pool, in order to undergo a trial, introductory immersion. It is difficult to describe what was done to me all the previous week before November 29. I do not know any kind of divers and there was nobody to ask. Therefore, some very simple and unpretentious memories and ideas based on once seen films, either about Cousteau, or someone else who dabbled with two cans behind his back, popped up and nested in his mind, died at eruption of an underwater volcano, fought with a shark, etc. Also, of course, there was a rush of something in the head from underwater pictures of KS. Mazur and the pen transferred to us. Bushkova ... All these corals, closed-type aqualungs, which do not give bubbles, moray eels, flocks of silver fish, the greedyly opened mouth of bathyal, which so loves to absorb the bodies of unsuccessful combat swimmers. I understood perfectly that all this is finite, it does not concern me and is unlikely to ever touch, but I literally took the time to wait. Literally tortured all friends and relatives, as well as the world network in search of information about diving. I slept and saw how I with the balloons, and in the mask ... To tell the truth, the equipment surprised me. Surprise was: the size and weight of the balloon, the type of waistcoat-compensator, the presence of rubber boots and especially a wet suit. A big and special thanks to the helper of our instructor Elena, who selflessly explained all the wisdom of equipment to blind children, i.e. me and Pavel Obiuh. Here I will note that it is really important for the blind to learn everything in more detail, you can tell to the intricacies: how, where, what is fastened to, how, what is attached, how much the ball weighs, how easy it is to lift, how it clings to the waistcoat: what belt , how strong a belt, how it lies, etc., what material the waistcoat has, what the rings are made of, what the inflator consists of, what is the weight and material of the lung apparatus, even how does the manometer look (where are the arrows, why is this hose in which port this hose is attached to). All this must be investigated and understood. In this sense, it should be noted that the blind person will not tell you about the color of the compensator, he will not be able to assess the transparency of the lens of the mask, but after a normal systematic investigation, he can memorize and accurately describe all the non-visual parameters of a particular equipment model (size, weight, distance from the fastening belt to the cylinder valve, where the corrugated hose, where not, how the ports are located on a certain regulator model and which one is high, and what is low pressure, where and which Velcro, where the rings on the waistcoat, etc.). Yes, of course, every other model will need to be studied again, but all its parameters and characteristics will be captured for long and long times. I once again emphasize my special thanks to Elena, who managed to make all the explanations for the equipment simply ideal, that is, that I personally received, perhaps, the most complete idea of what the rest of the group saw with their eyes.
... continue in the next message

My instructor-friend with him:

(next is autotranslation from "Equipment for blind divers" )
came the idea to make a depth gauge from a conventional syringe.

 

[АлександрД]

Spoiler: Visiting the sea king (part two)

To tell the truth, the hardest on the side was to wait for its turn. I will say without exaggeration, everything turned inside and turned: "I'll be in a suit now and I'll be at a depth of six meters ...". Delight and the strength of anticipation is simply impossible to describe. It is also impossible to overestimate the highest qualifications, professionalism and patience of our instructors. I dare to even assume that they do not quite know what exactly they did for me personally and for other children with disabilities who sank that day, for the whole community of disabled people in Russia and for society in general. The fact is that foreign experience in diving has long been a practice of immersing people with a variety of physical disorders, in our country, until now, such things have either not been practiced at all, or everything has been limited to single cases, such as the fact that a disabled person went to the Black Sea and persuaded the local instructor to let him dive. In this sense, a trial (survey) diving tour under the guidance of instructors certified in IAHD can be considered as a powerful start, as a breakthrough, as an amazing finding for Russian disabled people. It was very difficult without a habit to put oneself in a suit, small rubber boots were also unusual, but everything was already fastened, fixed, the mask on the face, the mouthpiece and the blessed water took me. In the water I meet an instructor, with whom we move to a small plastic platform, where we begin to perform some mandatory exercises. I very much hoped to quickly cope with the breath and coped quickly enough, but I realized that I was somewhat arrogant, because it turned out to be psychologically difficult for me to switch to breathing under water. It seems that you understand that there is air, that it is served easily, that you can breathe freely with your mouth, but to remove your head under water and breathe a dozen times was very difficult from the beginning, something inside of it was very resistant and alarmedly pounding. Having practiced breathing, they began to negotiate with the instructors about the signs, which we will communicate under water. Here again I will permit myself to recall the specifics of immersion of the blind. If ordinary divers can communicate under water signs, then a person with impaired vision or blind signs will not see these. This forces the companion to dive all the time to keep the handicapped person in sight by the hand and communicate with a set of specific movements and shakes. For example: the palm of the instructor with my palm goes up - float up, the instructor's palm with mine leaves down - we plunge, the instructor's palm leaves my left - turn left, the instructor's palm with mine goes to the right - we leave to the right, the shrug of my shoulder - are you okay? " (the answer is a short one-time shake of the instructor's palm - "yes, everything is OK!"), frequent repeated shaking hands of the instructor - "I have problems!" (it is obligatory to show with your hands what the problems are: balloon, mask, ears, etc.). In fact, a blind person with an instructor can communicate with ordinary (standard) signs, but such things, as I understand, are done by special arrangement. Having agreed on the signs, they tried to swim along the border, not at all deep, at the level of a step that seems to exist in all the basins. The situation is the simplest: I'm next to the side, touching the step with one hand, next to the other side is the instructor holding my hand. Checked the signs, I tried to swim faster and slower, prikovyk to the breath, I understood for myself the process of orientation in the water along the border. Walking around the bathtub, returned to the platform and decided that it was time to dive, of course, after having repeated the skill of blowing. Strange thing, I always believed that six meters, it's serious, but in fact - only three movements flippers and now I'm touching the bottom of the pool with my hand. In truth, for me it was a shock. The incomparable sensation from the understanding that I am currently at a depth of six meters, I myself breathe under water, from the fact that I can soar, I can not weigh anything, because I'm light, from that , that the element took me. Again and again check the signs, again and again I try to equalize my breathing so that it is even, deep and calm ... I understand that as I breathe, I can not breathe (I was too excited and blew bubbles like a steam locomotive - clouds of smoke). After some time, we float up and exchange impressions. I have impressions over the edge, it is impossible to express and describe it. The dive program continues. Standing on the platform, I master the skills assigned to each diver. The first is to pull the lung pod under the water and insert it correctly and start breathing. The second is the release of the mask from water. The first turns out quickly, with the second you have to suffer. For some reason it is very unpleasant to breathe out under the water.

Apparently because you really want to breathe, but you can not. The mask takes about five minutes, after which we again go to the bottom. And here it turns out that the instructor for me has a surprise. I do not even know if IAHD representatives taught him this, or it was an inspiration, a guess, but the idea was uniquely brilliant. After we float a couple of meters to the bottom, the instructor puts my hands on the interlacing seams. I myself, admittedly, thought about this, or something similar, but did not have time to discuss this with the instructor. The simplicity and originality of the idea is amazing, because the interlacing sutures are straight and easy to navigate through them. I'm already almost swimming, the instructor only touches my toes lightly. I show "ok" and I do not know how to show him a thousand and a thousand "ok" to express my delight. I myself need steam, too material for a ghost and too sinful for an angel. I'm free, I'm almost alone with water. After a while we climb the platform. I did not want to emerge, but I was waiting my turn for the next one.

What's next? And further, I'm afraid I got sick, got infected and got used to it. I catch myself on the fact that for a month now I can not think of anything else. I still want to visit the sea king! Perhaps someone will be surprised why they say blind sighted diving, especially considering that hearing under water loses its value by 50%, and tactile sensations, especially in the tropical seas, and even more, especially, touch there, anything seems generally unsafe. It's hard to explain ... Let's just say, to be able to dive for me (diving), it's like a person who does not have physical limitations to throw up his hands and understand that he can soar under the ceiling ... Understand and really swirl around the chandelier. This is a new degree of freedom for the blind, it is a new, higher, qualitatively different level of development, this is a new psychological situation that gives the opportunity to go beyond the usual world, the system of habitual things and relationships, perhaps this is also one of the optimal situations of self-satisfaction, self-realization, self-expression, and, of course, a certain kind of test, the release of adrenaline, a situation that allows you to feel the real taste of active life.

Petrov MA

so - thin - ok, we take an insulin syringe, compact, with a rubber piston - that's it.
pulled out the needle (it is not removable), sealed the edge, pulled the piston (it was without fixing in the extreme position), I stuck it back ... the first problem - the piston does not stay inside, the pressure is pushed out, so that it can easily fall out ...
tried to make a limiter from the native cap, which closes the rod during transportation - crooked, ugly.
The second problem is that the area of the piston is rather small, and the rubber sealing band is wide enough, and creates appreciable resistance when it is displaced relative to the syringe body. the piston moves with jerks when the external pressure changes ...

 

[АлександрД]

... so ... it is necessary to increase the ratio of the area of the piston to the area of its rubbing surface ... - we take a syringe of a larger volume.
(now I do not remember, but to mine it was 10 or 12 ml).

so:
principle of operation: the depth increases the pressure. It is considered that for every 10 meters of water the pressure increases by 1 atmosphere. (if you count the weight of water that presses on 1 sq. cm, it will be 1000 cubic centimeters of water, put one on top of another.) The weight of 1000 cm3 of water (this is one liter), usually is one kilogram. 10 meters high creates a pressure of 1 kg / cm2, and this is 1 atm.) It is also assumed that the pressure on the surface is usually the same as one atmosphere.
if we take a closed vessel with soft (or movable, as in our case) walls - then when immersed under water its volume will decrease, so that the pressure inside and outside would be the same.
The calculation is simple - at a depth of 10 m the pressure is 2 atm (one atmosphere on the surface, plus a column of water gives one additional atmosphere). so that inside the pressure is twice as large, it is necessary that the volume decreased by half.
if you take a closed cylinder with a movable piston and start immersing it under water, the water will begin to press the piston inward, compensating for the increase in pressure from the outside. The average piston position will correspond to the pressure inside it at 2 atm. - here is the first most simple mark.
the length from the closed edge of the cylinder to the piston can accurately show the pressure inside the cylinder - in fact the cylinder is constant in diameter, only here the scale then nonlinear leaves ...
but the ratio of atmospheric pressure to the external pressure of water - this is exactly what we need, if we take the length of the piston per unit.
we have:
P (atm) / P (at depth) = position of the piston (in fractions of a unit of the total volume)
the pressure on the coarse P (deep) = P (atm) + P (water column)
P (water column) = depth / 10 (see above explanation - every 10 meters of water give +1 atm.)
P (atm) = 1
put it all together:
position of the piston = 1 / (1 + depth / 10) = 10 / (10 + depth) is the basic formula for calculating the depth gauge.

if we have a syringe in which the marking by volume goes to the very extreme position of the piston, then it is easy to deduce a formula to what depth this or that volume of air inside will correspond.
V (max syringe) = Vmax

(# 1) V (current) = V (max.) * 10 / (10 + depth) is the formula for marking depths


0. take a disposable syringe with a volume of 10-20 ml.
required:
- not a plastic but a rubber piston (plastic moves very hard);
- it is highly desirable that, within the cylinder of the syringe, a belt defining the piston in the extreme extended position be closer to its edge, so that it can not be easily pulled out, and that it would be tactile to easily probe its outermost position.
- a removable needle - this is needed to "cock" the depth gauge
- it is desirable that the piston rod would be continuous, without cut-outs (so it will be more convenient then to put marks of depth)

1. pliers (or anything else) we pull out the metal needle tube from the plastic part that is put on the syringe.
2. With a lighter we melt the tip of the plastic part of the needle, so that it would be hermetically sealed.
3. We check the system - put it on the syringe with the piston pulled in, pull the piston out, create a vacuum inside, hold it for a long time, release the piston - if it's back to its original position - the system is sealed)
4. We take out the piston, we grease the cylinder of the syringe from the inside with the slippery lubricant (I used the standard silicone diver lubricant), we grease the piston itself, collect everything back, we drive the piston several times round-trip. if you walk easily - then what you need.
5. Begin the marking of the depths.

it is both strictly according to physical laws, and at the same time strictly individual.
the task is to find the mark of the next depth, cut out on the piston rod, exactly at the moment you reached the specified depth. if the mark is placed exactly on the position of the piston (this is the same strict physics), then it will not be possible to grope it (unless with the tip of a long nail) - the tip of the finger still has a rounded edge, and how not press it into the angle between the cylinder cut and the piston rod - do not feel anything. Accordingly, the label should be slightly displaced from the piston. Here it is strictly individual, as whom it is convenient. most likely this value should be approx. 1 mm.

and then determine for ourselves what depths are most important for reading the indications and using the formula (No. 1) for these depths, pushing the piston (the needle cap is better to remove, so that the piston does not run off to its original state), we cut out the plastic rod of the piston.
Cutouts are easiest to do with a clerical knife. The depth of the cut-out depends on the individual sensitivity of the fingers. usually 0.3 to 1 mm. shape and depth of cuts can be made different - for example, one notch - both edges under 60 degrees. to the stem, another cutout - one edge under 90 degrees, the other under 60, the third cutout - generally rectangular, etc.
combining the shape of the cuts, you can make different sensitivity marks for different depths.
well, between them - here is an approximate estimate.

that's all.

the procedure for working with the depth gauge is simple - before the dive, remove the needle cap, push the piston as far as possible, to the stopper, put the needle cap back in place, so that it would not fall off.
after diving - in reverse order.

readings in water - counted by the number of remaining cutouts on the piston rod, i.e. passed depth marks go inside.

as it turned out the idea with the syringe has already been implemented, but slightly differently
http://www.instructables.com/id/Diving-Depth-Gauge
made, went to the pool, dived, checked up to 6 meters - sort of like it works. gave it to Maxim.

 

[АлександрД]

Another my friend was a commercial diver, but later he lost eyes due to explosives blast unrerwater...
He had idea to have SPG, that he can use...
Once I found in one of the sales board old german scba with pin pressure gauge.
We make a deal with its owner to change normal SPG to this one.
I`d ordered from one fellow turner to change thread to the standard 7/16 for this pressure gauge.
Now my friend have this one:

I had descriprion of this SPG, but no one company was agree to produce it...
here is autotranslation of my idea:

the idea of such a gauge appeared after the seen piston regulator with a manometer for Ukraina-2.
a similar device existed also on old AVM devices (as they say). but there as far as I can remember - just a pin that jumped to 50 bar, that's all.
they also say that there is a similar device of the company Spirotechnika.
I hope to try to get it for possible copying.

in general, here is the idea of such a manometer:
the principle is extremely simple -
there is a cylindrical body inside which a piston is pushed from the side opposite to the measured pressure by a spring.
along the axis of the spring attached to the piston, is a pin extending outward from the housing.
the piston diameter and stiffness and length of the spring must be selected so that at zero pressure the pin must be inside the casing, and at a pressure of 350 atm - be maximally extended from the casing of the device.
A scale with pressure marks, in the form of dashes or pins, must be placed along the retractable pin.
label in 50 atm. It should be as noticeable as possible. this is the recommended minimum pressure to start the ascent.
At the opposite end of the dylindra there should be a lid with an outlet to the standard thread of the manometer, in order to be able to replace the usual manometer on the hose with a spring-pin.
the inner walls of the cylinder must be carefully polished.
on the piston and on the cylinder head there should be o-rings.
it also makes sense to install an O-ring seal at the exit point of the piston rod from the cylinder to prevent water from entering the cylinder to avoid corrosion.

This pressure gauge can be useful not only for blind divers, but also for those who dive in very cloudy waters or in unlit places - in case of lamp failure / mask loss / strong water cloudiness - there is always a possibility to calculate the pressure reading to the touch.
and this device can also be made quite compact.

Now I`m looking for voice assistant diving computer...

 

[Couv]

Fair dues to you sir and your instructor friend for assisting these adventurous souls. Kudos also for coming up with ingenious designs. Similar to your gauge, ScubaPro used to have a tank valve with a psi indicator pin built into the back of the valve.

For simple open water dives, after I've verified I've started with a good fill, I use a "Braille" method for most of the dive to check that I have over 1000 psi. The tension on the spool at pressures above 1000 psi make swiveling the gauge noticeably more resistant to turning.