buy finasteride 5mg online cialis for sale from canada lipitor 20 mg pd 156 buy generic cialis brand viagra 800mg reviews buy zithromax single dose uk ventolin nebules 5mg dosage buying viagra in the uk viagra 100mg canada buy yasminelle online cialis cost comparison nexium cash cost effexor cheapest prednisone tablet for dogs tetracycline online kopen uk prozac online dapoxetine egypt amoxil dosage for sinus infection proscar generic india buy synthroid from canada buying real levitra without prescription femara generic walgreens can you buy ventolin inhalers over counter uk order cheap periactin online tablet topiramate 25 mg phenergan 10mg tablets discount singulair online accutane costco lipitor 10mg online get ketoconazole online is fosamax generic promethazine 12.5 mg lowest levitra price buy rogaine women uk nexium generic cheap pantoprazole rxlist lexapro in usa need to order levothyroxine 125 mcg synthroid purchase canada buying phenergan online ketoconazole 800 abilify in canada when approved diflucan dosage rxlist hctz 25 mg cheap buying claritin d online no script trimix ed meds buy zyprexa 15 mg generic name of ventolin expectorant strattera generic name price for valacyclovir nolvadex 50 flonase out of pocket cost accutane acne uk lipitor generic with glass celebrex lawsuit in canada crestor and diabetes cost nizoral anti-dandruff shampoo cost mirapex walmart buy cheap accutane generic lipitor pill markings comprar lasix online cheap xenical to buy online valtrex dosage for cold sore topamax 65 mg where to buy lasix once bought clomid online and got pregnant tablet nexium 20mg purchase generic clomid ventolin price generic cialis uk next day delivery actonel generic price ampicillin suspension dosage nolvadex 40mg ed generic tamsulosin moa discount voltaren gel citalopram 40mg tablets metformin oval tablet are canadian viagra sold online safe? tamsulosin generic terazosin generic diflucan buy online pharmach buy aleve gelcaps lasix without prescription overnight buy abilify online cheap abilify effexor xr buy clomid in australia online levitra mail order atorvastatin india brands price zyrtec buy tamoxifen 20 prescription free viagra buy finasteride india diovan 160 mg dosierung when was cialis fda approved advair cost of promethazine pills 12.5 high alli buy line fluoxetine cost canada diflucan available india xenical tablets to buy prednisolone for cats uk where to buy viagra in lagos nigeria clomid tablets to buy buy metformin online pcos nexium wholesale price best price finasteride 1 mg malarone or doxycycline for india lipitor price reduction australia cost wellbutrin canada levothyroxine 75 mcg buy online uk buying singulair promethazine pill high buying advair online no prescription valtrex for dogs lipitor online india propecia men's health price for phenergan cost of toradol iv flomax purchase canada buy singulair 5mg propecia finasteride viagra cealis canada apo-metformin buy online organic viagra where is the best place to order clomid online price prozac pharmacy buy cheap clomid usa cheap tadalafil generic cipro 500mg price cheap lipitor india plavix 90 day supply aciclovir 800 mg x 5 die india omeprazole 20 mg lasix m tablet generic flomax approved canada pharmicy buy clomid 50mg online cipro generic available generic fosamax on the market femara 2.5 ampicillin tabletta orlistat 120 mg buy lithium 0.9.5 online pharmacy canada no prescription fineviagra trazodone us fexofenadine 30 mg tablets amoxicillin 500 mg over the counter buying omeprazole uk buy fosamax d online clomid generic imitrex directions metformin early use allegra 180 india online sales viagra cialis quick viagra overnight delivery isotretinoin gel for acne augmentin 625 mg for flu price cymbalta walgreens promethazine 12 lipitor cost of prescription buy amoxicillin toenail fungus generic lipitor ranbaxy harga diflucan tablet clomid unprescribed sale generic cymbalta caps levaquin online canada nolvadex uk store discount generic lipitor no prescription pharmacy gabapentin us pharmacy viagra healthy man allegra's window brother for sale yasmin buy online uk there difference between synthroid generic generic lexapro vs wellbutrin generic tamoxifen cheap flomax in uk estradiol brands in india price of synthroid at walgreens can you order acyclovir online esomeprazole cost uk mail order cymbalta tadalafil online canada purchase zovirax pills fosamax price ireland buy ventolin nebules 5mg online zithromax 250 dose viagra online online cost lexapro uk cheap brand name viagra online 875 mg augmentin high dose generic valacyclovir cold sores generic levitra 20mg generic valtrex order online price of tetracycline viagra super force 100 mg 60 mg pills amoxicillin tablets usp 875mg zyprexa discount programs propecia uk buy online tetracycline 500mg capsule tablet lisinopril 5mg find cialis cheap order desyrel online buy naproxen sodium 220 mg viagra discount prices cialis 5 mg best price usa topiramate 75 mg can you take amoxicillin for an abscessed tooth zithromax price costco dapoxetine online us predisone without perscription canada generic wellbutrin out buy cheap viagra india nolvadex buy uk rogaine buy online order how much does zovirax cost in canada canada abilify 2mg buying tamoxifen china generic levaquin china indian pharmacy viagra nizoral canada levitra 6 free samples online cialis prescription cipro 500 mg usos viagra otc protonix without script topiramate 100 mg price metformin price malaysia how to use cialis 10mg buy generic paxil online amoxicillin pills stink buy amoxicillin tablets price claritin d 24 how to buy robax platinum without an rx can you get abilify in generic actonel free coupon nolvadex price in canada estrofem 2mg cipro price comparison wellbutrin xl price walmart zoloft 6.25 order viagra by phone cost zovirax ointment can trazodone hydrochloride get you high female viagra reviews zovirax tablet yan etkileri ketoconazole for sale buy cheap naproxen sodium buy proscar tablets without prescription cost claritin syrup ethinyl estradiol pills nexium pills sale dapoxetine price in uk viagra pfizer 100mg price buy viagra defense can you get zoloft over the counter generic for metformin er duloxetine 30 mg capsules crestor film tablet metformin 500 mg brands in india phenergan usual dosage best place to buy accutane online uk antibiotics doxycycline tamoxifen price in us cipro eye drops use female viagra fda lexapro generic cost walmart buy generic clomid uk zyrtec buy buy abilify from india wellbutrin sr 150 mg price where to buy sildenafil gel rogaine canada where to buy cheap generic levitra online sale topiramate where to buy singulair pentoxifylline to buy protonix canada order buy prozac egypt diovan discount novartis celexa price per pill ventolin buy cheap order levitra on line allegra generic zyrtec diflucan dosage nipple thrush lasix for sale cialais metformin sr cost buying toradol in usa buy cheap topiramate online buy buspar cheap cialis available in australia cialis dapoxetine online order generic antibiotics buy sildenafil boots drospirenone ethinyl estradiol india buy online rogaine wholesale cheap tadacip 20 discount femara cheap propecia ireland price drospirenone ethinyl estradiol lasix in usa promethazine 25 mg hydrocodone cost of metformin 500 mg acyclovir pills cost body building forum clomid low cost levitra in the usa elife pharmacy cost duloxetine drug sildenafil online coupon where to buy augmentin tablet cheap nexium cheap generic norvasc 10 order amoxicillin uk generic metformin buy all top meds cafergot tablets no rx tadacip in canada azithromycin 1 gram oral packet zithromax 500 mg effet secondaire can diovan 160 mg be cut in half nexium otc valtrex interactions cheap pfizer viagra 100mg tetracycline eye ointment price overseas drug drugsbroker diflucan cream buy online proscar or propecia drospirenone 30 mcg buy imitrex tablets australia abilify us sales 2010 celebrex 200mg price malaysia plavix savings isotretinoin xerostomia cipro 500 mg espanol trazodone 50 mg abuse xenical tablets for sale generic valtrex 500mg prozac 40 mg dosage order desyrel trazodone diflucan buy cheap generic wellbutrin pill augmentin dosage for sinus infection generic pulmicort 200 mcg turbuhaler buy alli us viagra pfizer price metformin price 1000 mg brand name cialis online abilify price of cialis without prescription overnight diovan 160 mg uses can you buy aciclovir over the counter in spain price naprosyn 500mg crestor in canada generic propecia mastercard generic abilify date wellbutrin pill dosage buy online zyprexa cheap uk fexofenadine price of celebrex 100mg order yasmin birth control online cost simvastatin 80 mg buy zithromax online canada acyclovir online canadian pharmacy walmart fexofenadine generic buy valacyclovir overnight singulair buy cheap 10 mg buy viagra online at where to buy voltaren gel celexa buy generic get yasmin prescription levaquin sale canada generic of claritin generic substitute for crestor rapid tab cheap flomax uk lipitor tablet shape nexium medicine finpecia online forum generic fortamet er buy discount online viagra buy simvastatin in the uk viagra generic very very cheap generic prozac 20 buy cialis online china canadian pharmacies cialis online birth control pills cialis levitra sale viagra wellbutrin tablet can i buy acyclovir at walmart yasmin price us wellbutrin xl generic brand buy acyclovir online canada rogaine buy cheap canada price gabapentin 800 mg diflucan without prescriptions cost yasmin birth control pills generic gabapentin walgreen amitriptyline no prescription needed problem with generic viagra buy ethinyl estradiol norgestimate prednisone online no prescription diflucan 200 mg iv where can i buy crestor online buy cheap naproxen 500 mg doxycycline without prescription bupropion 300 mg xl how much does celebrex cost without insurance levaquin purchase lexapro for sale online prilosec 20.6mg nolvadex sides generic drugs vytorin cost canada in stock alli cost levaquin tablet buy prednisone no prescription paypal buy viagra online paypal uk nexium total sales cheap propecia mastercard best place buy tadalafil online cialis com 5mg buy metformin in canada ventolin without insurance price duloxetine hcl buy diovan hct 160 promethazine for sale los angeles topiramate discount topiramate online uk diflucan cost buy viagra at chemist mail order cialis prednisone medication uses alli price france cheap diflucan from canada easy tramadol online diclofenac banned in india cialis soft tab cheap belladonna medication buy generic soft viagra clomid success stories 2012 uk nexium india price is doxycycline a generic drug russian thief viagra synthroid 125 mg viagra cheap prices buy cheap drospirenone buy xenical now doxycycline hyclate 100mg buy online buy nolvadex supplement propecia price costco paroxetine buy no prescription cost of lipitor at walgreens cheap lexapro online no prescription imitrex nasal spray dosage generic cipro dose proscar tablett 5 mg msd cialic best price 5mg canada price for metformin buy generic prilosec female viagra buy nexium made in india generic nexium europe lisinopril buying price yasmin birth control cheap naproxen alli in canada generic levaquin antibiotic generic lexapro dizzy cheap accutane singapore buy amoxicillin online femara pillola phenergan addiction abilify purchase canada estradiol online uk celexa for sale online cheapest way to get cialis isotretinoin uk online viagra free samples canada lexapro usage can i get viagra in mexico furosemide without prescription canada generic cialis prices fluoxetine generic rosuvastatin brands in india generic for protonix 40 mg trazodone black market price buy ventolin online eu online clomid australia buying pantoprazole india lisinopril 40mg tab purchase nizoral 2 generic levitra 40 mg buy propecia trinidad price prilosec generic wellbutrin xl generic recall viagra purchase online canada
Log via Facebook
Sponsored Links
Robo Home Hardware Motion Nodes GVS introduction

Galvanic Vestibular Stimulation

In this series of tutorials I would like to give to cover a set of basic stimulation techniques that can be used in cybernetics for the human-machine integration.

Galvanic Vestibular Stimulation (GVS from now on) is a simple, safe and specific way to elicit vestibular reflexes. The vestibular systems is responsible for a fundamental function of our body: encoding head orientation and keep balance.

You might have experience some vertigo in the past, if you didn't I can tell you that having an infection of the vestibular ear is a very nasty sensation as you experience nausea for every small movement, resulting in most of the times vomit etc.

GVS was used for over a century as a means to discover and then look at the function of the vestibular system. The first scientist who discovered it was Johann Purkyne in his 1820 dissertation, reported that a galvanic current flowing through the head upset the balance and equilibrium.

After that Volta in 1790, playing with his newly invented battery almost electrocuted himself with the same technique experiencing "the sensation of an explosion inside the head, spinning and boiling of matter".
This was probably due to the use of a 30V Zn/Ag pile and we will see later that 30 V are over the safe limit of stimulation.

More recently with the work of Fitzpatrick the mechanisms behind the GVS effect are being unveiled. There are basically several ways to elicit the response:

  • bilater bipolar GVS
  • bilateral monopolar GVS
  • unilater monopolar GVS

First we need to know more about the vestibular system, I have used material available online (ScienceDirect) to write a compact introduction so that the reader doesn't have to google all the time.

If somebody thinks I have used some copyrighted material please do let me know.

Vestibular Anatomy

Known as balance organs of the inner ear, the previous termvestibularnext term organs serve this complex motor function at a largely subconscious level, but their role does not stop with balance. They contribute to a surprising range of brain functions, from the highest levels of consciousness to the most automatic reflexes. The value of the previous termvestibularnext term sensory system to brain functions such as perception of self and non-self motion, spatial orientation, navigation, voluntary movement, oculomotor control, and autonomic control, comes from their unique and complete description of head motion and orientation in three dimensions.

Two different previous termvestibularnext term organs, the otolith organs and semicircular canals, sense different types of acceleration. Two otolith sensors, the utricle and saccule, sense linear acceleration. Three semicircular canals, the anterior, posterior and horizontal canals, sense rotational movements. These two complimentary signals are necessary for the brain to understand the range of physical situations that we experience, probably the most fundamental of which is to work out which way is up.

Which way is up?

All terrestrial and aquatic animals need to know which way is up and, therefore, which way gravity acts, so it is not surprising that special graviceptive systems appear early in evolutionary history. A sense of the force of gravity and which way is up is with us at all times. This internal construction is based on multiple sensory sources, important among which are the previous termvestibularnext term organs. It provides our brains with a deep and special understanding of how the force of gravity moves things, from the fall of our body, as we lift a foot to take a step, to the fall of a ball during a game of cricket. In all of these situations, the brain predicts the trajectory of fall with startling accuracy.

The significance of this internal representation for predicting motion in gravity and its link to the previous termvestibularnext term system was recently shown by Indovina and colleagues. They displayed a ball moving in a visual scene that had strong cues to the up direction. Observers accurately predicted the flight and timing of the ball when the gravitational field was conventionally aligned with the visual scene. Yet when the gravitational field was reversed so that it acted upwards, observers made large prediction errors, even though the ball was subject to exactly the same acceleration. Furthermore, functional magnetic resonance imaging revealed that certain areas of the cerebral cortex were more active when the gravitational field was consistent with the visual scene than when it was reversed. These included areas that receive strong previous termvestibularnext term signals, pointing to a previous termvestibularnext term contribution to our internal representation of gravity.

The equivalence problem

The otolith organs seem ideally suited to sense the direction of gravity and signal directly which way is up. The otoliths are essentially masses supported on hair cells. Tilting the head causes the cilia to bend under the sideways component of the gravitational force on the masses. This modulates the firing of the sensory nerves connected to the hair cells. Different hair cells respond to bending in different directions so that the total signal from all hair cells defines the direction of gravity with respect to the skull. There is, however, a serious problem that Einstein explained with his equivalence principle: the effect of a gravitational field on a mass is indistinguishable from the effect of linear acceleration.

For example, consider the otolith organs of a person sitting in a bus. When the head is accelerated forward as the bus pulls away from the bus stop, the inertia of the otolith masses causes them to be left behind and to bend the cilia of the hair cells backward. This is also exactly what happens when the front of the bus tilts upwards on starting to climb a hill. Thus, the otolith sensors send the same signal for two different physical situations; linear acceleration and tilt in the gravitational field. On their own, the otolith organs cannot signal unequivocally which way is up.

Why distinguish tilt and acceleration?

To operate beyond ourselves and navigate the environment, we need to create a stable internal representation of external, earth-referenced space in which the position and movement of objects is independent of our own. A navigation system needs to be able to distinguish the two physical situations of tilt and linear acceleration to build an accurate internal map of our movements. Evidence for this is seen at the processing level of place cells in the hippocampus. These neurons, which code for spatial location as part of a navigation system, depend on previous termvestibularnext term information for their function.

Control of eye movement is probably the most overt example of how the previous termvestibularnext term system creates a stable representation of external space, in this case visual space. The previous termvestibularnext term system profoundly influences eye movements via the vestibulo-ocular reflex to stabilize the visual image on the retina in the face of head motion. When we fix our gaze on an object and our head moves, the previous termvestibularnext term organs detect that movement and produce a counter movement of the eyes to maintain the retinal image. Clockwise head tilt requires the eyes to rotate anticlockwise. Leftward acceleration requires a rightward horizontal shift of the eyes. These two situations, which stimulate the otolith organs identically, must be distinguished to generate appropriate eye movements.

The angular trick

It appears that the brain goes some way toward solving the equivalence problem by simultaneously listening to the messages from the other previous termvestibularnext term organs, the semicircular canals. Like the otolith organs, the hair cells of the semicircular canals respond when their cilia are bent. The difference is that when the head rotates in the plane of a canal, the enclosed fluid is left behind and exerts a pressure that deflects the hair cells. Thus, they respond specifically to angular acceleration of the head and not to gravity or linear acceleration.

Now when the head tilts, say to the right, the brain receives two previous termvestibularnext term signals. The otolith organs signal the static head-tilt, which could equally represent leftward linear acceleration, but the semicircular canals report the transient head-rotation. If the otolith signal results from leftward linear acceleration, the semicircular canals report nothing. Angelaki and colleagues have shown recently, by recording from neurons in the cerebellum in the previous termvestibularnext term nuclei of the brainstem, that the brain can tell apart tilt and linear acceleration by combining the otolithic and semicircular canal signals.

Bilateral bipolar GVS

Now that we know more about the vestibular system we need to find a way to stimulate it in a useful manner without implanting electrodes in our inner ear.
We only want to stick some electrodes on our skin avoiding any surgery: the GVS basically bypasses the transduction mechanism of the hair cells by exciting all the afferents
with a DC current stimulation between the mastoid processes.

It's a brute force stimulation approach where all the afferents are excited So what Volta discovered is that the net effect of such a general excitation is a strong body swing.

Results were summarized by Fritzpatrick the expert in this field with this nice figure.

With only 0.5mA, GVS produces a trunk roll and head at 1-2 deg/s2 ! With 1 mA, body angular roatation was 2-3 deg/s2 .

Fritpatrick developed a model of the semicircular canals and otolith organs to predict the effect of the GVS on the linear and angular acceleration vector ...
but enough talking let's experience ourselves !

How to build a simple GVS stimulator

As a preliminary prototype we are going to use a simple stimulator built with:

  • 9V battery source
  • H-bridge for switching voltage polarity
  • potentiometer for adjusting current flow

This is a minimalist setup BUT is not SAFE as we are assuming that:

  • skin's impedance is constant for the duration of the stimulation
  • we are lucky and there will be no short-circuits :-)

For a short experiment this is not a big problem but if you plan to have a long session the skin will change its impedance for many reasons including sweating, abrasion etc.
A simplified electrical model of the electrodes, skin, tissue system is illustrated here:

  • The boundary of electrodes and the skin is of special importance, because that is where the flow of electrons from the stimulator is transduced into the ion flow of the tissue. At the boundary of every metal-electrolyte interface there is a potential difference which is called cell potential. The model also contains a series RC suggested by Warburg, and the faradic leakage resistance Rf accounting for DC characteristics of the model
  • The skin can be modeled by a serial resistance Rs and a parallel Rp,Cp. Rp can be practically eliminated by removing the outermost layer of skin, the stratum corneum.
  • The deep tissue can be modeled by the resistive Rt, bulk tissue resistance. Because of the complexity of the model and the lots of contributing nonlinear physical factors it is very difficult to estimate the total impedance between the two electrodes, but for practical applications the impedance should be in the magnitude of 1 kOhm. However if the skin is not prepared, the total impedance can be several times higher.

The circuit we are going to use in the first tutorial (we will use a current feedback in the next one) is in Figure.

schematic

The main components of the circuit are:

  • 9 Volt battery supply
  • a H-bridge composed of 2x NPN irf7105 and PNP irf7105p mosfet  transistors
  • a potentiometer of 100 kOhm
  • 2 guard resistors of 150 Ohm
  • 2 opto isolators

If the electrodes are in the short-circuit condition and the potentiometer is at 0 Ohm a maximum current of about 2.4 mA will flow.

If your skin-electrode conductance is at about 400 Ohm and you keep the potentiometer at 0 Ohm there will be a current flow of about 1 mA.

Believe me if I tell you that with electro gel electrodes your skin resistance will never reach 400 Ohm so is better ALWAYS to keep the potentiometer at 100kOhm and decrease gradually to achieve the desired effect.

An LT Spice (free software) simulation circuit is available in the repository so that you can see what is going to happen if you change the parameters.
The opto isolators are not included as LT Spice complain about some floating point resistance (bah couldn't find any solution for that) so I have changed the opto couplers with a simple voltage source.
I have also included the library model for the irf7105 so make sure you place the corresponding lib in the LT Spice folder.

Placing electrodes

First we need to locate our mastoid bones as in Figure, if you touch the area below your ears is the bony spike.

Second we need to find some proper Gel electrodes, because I work with EEG I have used the Maxensor Ag/Agcl/Solid adhesive pre-gelled.

I also generally use some Electro Gel to moisture my skin and increase conductivity for a better "sensation" ghghghg.

Wireless GVS

I don't want to have a wired GVS but a wireless GVS! So I took my Jeenodes and decide to use a master-slave configuration.

The master jeenode is a basically a remote controller (like the one in your TV) which has 2 buttons: left for direct polarization and right for reverse polarization.

The master will decode the button press and send 3 possible actions to the slave:

  • CENTER: disable the H-bridge no polarization
  • LEFT: enable the H-bridge with a forward polarization
  • RIGHT: enable the H-bridge with a reverse polarization

The slave jeenode will then execute the command by activating the proper opto inputs.

All the documentation and code is available here:

This e-mail address is being protected from spambots. You need JavaScript enabled to view it :robomotic/Wifi-GVS.git

If you want to support my research or you want to get the circuit already up and running,
I encourage you to buy my pcb in my shop.

The jeenode hardware looks like this:

Jeenode HW


How to use it

It is very important to follow this simple algorithm:

 

  1. check any short circuits
  2. apply the electrodes to your skin
  3. set the potentiometer at 100 KOhm
  4. try left and right control with closed eyes
  5. if you feel nothing decrease the potentiometer and start from 3
  6. if you start to feel a pull on the left or right direction
  7. stand up and try to walk straight
  8. give the remote to some friend and have fun

 

CAUTIONS:

  • do not use voltages bigger than 9 V
  • do not fiddle with the resistances unless you know what are you doing
  • do not short circuit the leads
  • use the stimulation for a short period of time
  • do not apply on animals or kids

Gvs Video Tutorial

Next tutorial

In the next tutorial we are going to build a current controlled stimulator.

Stay tuned.

Last Updated (Sunday, 28 November 2010 17:46)

 

Comments  

 
0 #20 buyphentramin-d.com 2015-03-16 08:53
It's actually a great and useful piece of information.I'm glad that you
simply shared this helpful info with us. Please keep uus up to date like this.
Thankms for sharing.
Quote
 
 
0 #19 biosynergy 2015-02-13 21:27
What's up to all, how is the whole thing, I think every one is getting more from this site, and your views are pleasant in favor of new viewers.
Quote
 
 
0 #18 2020 Tax Resolution 2015-01-19 02:22
I am not sure where you are getting your information, but great topic.
I needs to spend some time learning much more or understanding more.
Thanks for fantastic info I was looking for this information for my mission.
Quote
 
 
0 #17 Hair extensions 2015-01-08 05:03
Good Article!
Quote
 
 
0 #16 where can i buy 2015-01-07 06:17
I constantly spent my half an hour to read this weblog's articles or reviews everyday along with
a cup of coffee.
Quote
 
 
0 #15 customized 2014-12-25 16:16
Thank you for every other wonderful article.
The place else may just anybody get that type of info
in such a perfect way of writing? I have a presentation next week, and I am at the search for such
info.
Quote
 
 
0 #14 security systems 2014-12-22 04:39
Hello there, just became aware of your blog through Google, and
found that it's really informative. I'm gonna
watch out for brussels. I'll be grateful if you continue this in future.
A lot of people will be benefited from your writing. Cheers!
Quote
 
 
0 #13 ankara bilişim 2014-12-12 22:48
What's up i am kavin, its my first time to commenting anywhere, when i read this piece of
writing i thought i could also create comment due to this brilliant paragraph.
Quote
 
 
0 #12 eppqcjtaoq 2014-12-02 01:30
ttwermbc, ybihofgwvf , rgpaarfdla: http://www.yxektwvmqb.com/, http://www.ghsgcuvtzg.com/ ybihofgwvf
Quote
 
 
0 #11 https://www.fiverr. 2014-11-29 05:54
I'd like to find out more? I'd love to find out some additional information.

Feel free to surf to my web-site where to buy social
accounts (https://www.fiverr.com/s/5jlrzn: https://www.fiverr.com/s/5jlrzn)
Quote
 

Add comment


Security code
Refresh