Medical Design

Theunis Snyman

DESN 321 S002LouiSE ST PiErrE

PAKOoDLE

Pakoodle©

ProjEcT: PakooDLE

It is a device that primarily helps people living with cerebral palsy and other severe physical disabilities to more efficiently move through water in an recreational aquatic environment(the pool).

ThE coNcEPTIt has a water “slicing” effect to reduce drag and a “scoop” effect to increase propulsion. Precedence for this product can be seen in Nike swim gloves and other but can only be used on hands and feet. My aim is to be able to use this on the fore-arm and potentially the shin area, both spaces not yet been explored. The use of this product can effectively translate into the general market place to help beginners in the water without having to wear bulky inflatable devices as the product has buoyant properties.

ThE PSychoLogicaL aPProachIf the client is of diminished capacity and can utilize a product that can amplify their abilities, instead of highlighting their disabilities ,the sense of accomplishment created by increased propulsion will give them the motivation to incrementally increase their range of motion, but also foster confidence in their ability while in a vulnerable physical state. This will create a scenario where the client can once again compete in peer groups thereby empowering them

My Co-creator lives with Cerebral Palsy. He is by definition a hemiplegic. This means that he has reduced or limited use of part of his body as a result of brain damage at birth.

He loves going to the swimming pool at Stan Stronge on Tuesdays and loves encouragement.

uSEr ProfiLESwimming in the supine position can be very tedious and slow and I want to explore the idea of adding surface to increase propulsion

ProbLEM SPacECreate device that would enhance ability as opposed to highlight disability.

oPPorTuNiTy

Pakoodle©

Visual Design brief

Research and develop an upper extremity propulsion aid to augment or increase range of motion and propulsion for co-creator struggling with reduced strength in arms and uneven centre of buoyancy.

objEcTiVE

Positive propulsion in desired directionLightweightMinimum upward dragIntuitive installationHydro dynamic

MuST haVES

NicE To haVESAttractive to user(non therapeutic or prosthesis form.Pink /purple color schemeUniversal fit for other clients.

Design intention

augMENT or iNcrEaSE raNgE of MoTioN

Device will reduce the negative drag and increase positive propulsion and encourage the client to increase range of motion.

rETraiNiNg braiNPaTTErNS

Designing to facilitate the Body and brain to memorize new motion and buoyancy adjustment. It means that repetitive positive thought and positive activity can rewire your brain and strengthen brain areas that stimulate positive feelings.

ProDucE PSychoLogicaL EffEcTS

Confidence is instilled by a sense of accomplishment and encourages self motivation. The act of moving faster and more efficient in the water might motivate the client to work harder and with new enthusiasm and create a new sense of a competitive environment

coMPETE iN SociaLENViroNMENT

Swimming facilitates freedom of movement due to reduction in gravity, thus makes client feel like they have a competitive edge and new sense of acomplishment

Problem Space

Hemiplegic Cerebral Palsy clients can sometimes only utilize the “backstroke” swimming style to move around in the pool and this was the area identified to attempt an increase in productivity in the pool sessions.

Limited range of motion makes this exercise arduous and monotonous. The opportunity here is utilize the 80- 95 degree range of motion that exist and to systematically increase this range by self motivation.

Precedents

Hand gloves are very effective for able bodied people and even to some people living with disability, but does not accommodate for clients who have flexion in the hand and cannot fit into the general space of the glove or device

The hand glove only utilizes the space or surface of the hand and not the entirety of the arm’s surface available. In this project I aim to take ownership of the whole available surface to maximise gain.

Looking at current “normal” products and therapeutic aids and changing the visual language from therapeutic into adaptive technology that is “Sporty and fun”

TargET auDiENcE oPPorTuNiTy ViSuaL LaNguagE

but...

Unfortunately in most cases these commercial consumer products does not fit our intended user because of basic body dimensions and limitations to muscular structure. Flexibility and range of motion creates much of this discrepancy. People living with cerebral palsy have a high percentage of flexion issues in the rest and hand.

These hand paddles are designed to help strong swimmers train and gain a competitive edge by adding resistance and therefore increasing endurance and strength.

research and Development of ideas

ThiNkiNg ProcESS

What moves water ?

What moves in water ?

What moves the best in water ?Why

What Else worksPaddlesPropellersTurbinesScoopsFriction

FishBoatsBirdsAmphibiansMammalsWaterPlantsCrustaceans

Fish has the best hydrodynamic shape in nature

The shape of the leading edge of the fish has evolved to move water around it very efficiently. Fish are free of surface turbulence so in other words they move through water with maximum efficiency.

The random-looking bumps on the humpback whale’s flippers have just inspired a breakthrough in aerodynamic design that seems likely to dramatically increase the efficiency and performance of wind turbines, fans, flippers and even wings and airfoils.

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ideation Sketches

concept

DoWNWarD STrokE ToWarD boDy

uPWarD STrokE ToWarD ShouLDEr

Scoop to increase propulsion

Flow Direction Flow Direction

Leading Edge shaped to reduce drag on the upstroke to conserveenergy for client

Trying to understand the measurements?

The sex-specific constant correction values in the Corrected MUAMA formulae are derived from empirical studies.The MUAMA formula assumes that the upper arm has a circular cross-section, with a uniform subcutaneous fatlayer and negligible bone content. This is, of course, not the case in reality. The correction factors are attempts todiscount the contribution of the humerus. By comparing MUAMA values against computed tomography, studies byHeymsfield et al. found that, at the maximum circumference of the triceps, the contribution of bone to the totalcross-sectional area was 18% in men and 17% in women, which were 10 cm² and 6.5 cm² respectively.[3]Even the Corrected MUAMA formulae are not valid for people who are obese or for older people.[4] They tend tooverestmate muscle area for obese people.[8] The results of the formulae can contain small but significant errors inthe cases of young people, and errors of up to 41.5% for older people.[9] Moreover, the size of the humerus is notin fact equal in all individuals.[7] It also varies with nutritional status.[3]The formulae for the derived measures are based upon an assumption that the arm is cylindrical in shape, and arethus based upon the simple geometry of a cylinder. The arm is not in fact an ideal cylinder. However, theassumptions of the formulae yield results that are close enough to actual reality that the measurements are reliableand accurate when averaged over groups of people.[

I quickly came to realize that I would not be able to use any kind of anthropomorphic data that exists currently as there are no consistencies in the bone structure or muscle mass in clients living with cerebral palsy primarily because of muscular atrophy.

Prototype 1.

This was by far the most interesting form prototype and was responded well to, but proved to be almost an impediment in the pool because of the way it caused excess drag on the upstroke.

I started hacking it to pieces to get to a workable model that could do the job but in compromising the structure of the original prototype my experiment failed and ruined the prototype.

I added holes on the lower arm space and added a flap that would respond to the water and create downward drag. This meant to work as a valve system that would let water through on the uptake and scoop the water on the down stroke.

Mechanism and material exploration.

Some of my next exploration moved form soft form to semi rigid in the medium of HD foam and Insulation sculpting foam to see what it could do.

Inspired by feedback I received during a group critique I started playing with live hinges in fabric. This live hinge unfortunately was unsuccessful for two reasons.

A.) The foam I used to create this scoop under the arm wanted to come to the surface and therefore became awkward to operate. This does not necessarily mean that the principle could not work, only that I chose to change direction in my strategy. I’m sure with a few more iterations in prototyping connecting soft and hard form there is a likelihood of success.

B.) the mechanism of the arm did not want secure the device and kept wanting to slip because of the forests of the water pushing against it. This could also be solved by some creative

Prototype 2

My first real success came from this testing of the prototype in the pool. Assisting myself with a flotation device under my hips I positioned myself in a supine position and mimicked my co-creators swimming movements. The way I could tell it was working was the uneven line in which I was moving, pulling to the one side more dramatically than the other.

Using a form sculpted piece of high density foam and my generically made straps this exercise proved quite insightful. My next challenge was to confirm the reduction in drag in my next iteration.

Notice the cool capture of my device and arm parting the water below. Not only was this a fun by product of this experiment, but also a confirmation of the volume of water I was displacing with my prototype.

This is the probably the biggest stumble block in this project. The question is how to create a biomorphic product that will also create the structure to actual do what is expected of it. Materials, technology, lack of know-how and just pure crazy ideas is what kept me from getting the right form at this point.

My next steps was to change materials and see whether I can draw a solution from a different medium.

Morphology Take 1

Creating these organic forms from foam proved to be quite challenging and my 3-D modeling class with Keith Chapland in second year provided me with the necessary tools to be able to control the form. The problem with the form and material is that it’s both bulky and hard to replicate due to its density.

Morphology Take 2

My next stab at this proved much more successful. I created a form in sculpting clay and froze it. I then vacuum formed the shape and was then able to cast it

Casting multiples and building up a form with clay and the supporting structure and was able to make a rough cast of the form I was aiming for.

After casting this in plaster I could then go and sand it to my own specification. I then use this form as my template for vacuum forming this beautiful organic shape.

Morphology Take 3This kind of morphological shape is what is driving this project. Unfortunately the shape does not support the needed structure and I had to get creative with laying in some ribbing into the form. Visually this was very distracting to some of my reviewers and I chose to set this form aside and work on the form that has proven successful.

I should note that I believe this form combined with a proper substructure would achieve the goals as I set it out at the beginning of the project and it is organic, biomorphic form I am aiming for. More prototyping is needed in order to resolve this.

Morphology Take 4

This template was created by creating two profiles, manufacturing multiples, and combining them in an array. The pieces were stuck together with double-sided tape and proved to be a quick method to create a mechanistic solid form that I was able to vacuum form.

At this point I was able to create multiples in a very short period of time giving me the flexibility to experiment with its attachment mechanisms. In another effort to reduce drag, I chose to integrate straps to the form by simply cutting holes away from the leading edge to stick the straps through.

3d Printing

finding the compromise between mechanistic and biomorphic

caD Modelling

Pakoodle©

PAKOoDLE

WhaT iS ThE PakooDLE

This project is the development of an aquatic propulsion assistive device. This is a device that would be used by clients living with severe physical disabilities, in this case ,cerebral Palsy. It simply attempts to increase movement in the pool.

ThE DESigN briEf

Create a more efficient propulsion device for clients living with a diminished capacity in one or both of their arms. The outcome must be positive propulsion and the client must have fun.

Why?

Current hand paddles and devices are made to fit people with “normal” anatomy and this project rethinks the underutilized space between the wrist and the elbow as valuable surface area.

hoW DoES iT Work?

This technology is based around bio-mimicry and wants to mimic the leading edge of the steering fin to the Humpack whale. The bumpy side reduces drag on the upstroke and increases drag on the downstroke with the PAKOODLE

co crEaTor

Lives with variants of cerebral Palsy and has dimimished used of one or either arms and hands. They use the aquatic recreational facilities at Stan Stronge Pool with several of the Recreational Therapist working for Coastal health.

incrEAsED rAngE Of mOtiOn

BOOst cOnfiDEncE

trAin nEw nEurAL

nEtwOrKscOmPEtE in PEEr grOuPs

Device will reduce the negative drag and increase positive propulsion and encourage the client to increase range of motion.

Confidence is instilled by a sense of accomplishment and encourages self motivation. The act of moving faster and more efficient in the water might motivate the client to work harder and with new enthusiasm and create a new sense of a competitive environment .

Body and brain will memorize new motion and buoyancy adjustment. It means that repetitive new motions and emotional activity can rewire your brain and strengthen brain areas that stimulate various receptors

Swimming facilitates freedom of movement due to reduction in gravity, thus makes client feel like they have a competitive edge and new sense of self appreciation.

PAKOoDLE

PAKOoDLE

PiNch ProTEcTorS

iNTEgraTED STraPS

coMforT PaDS

hyDroDyNaMic

LighTWEighT

MoVEMENT STuDy

coNcEPT DiagraM

Quick rELEaSE buckLE