Dublin Institute of Technology Department of Mechanical Engineering

Innovating the CPR Mask

Year DT710-4

Module title Team Design Project

Lecturer Name Graham Gavin, Claire Brougham,

Ken Keating

Students Names Sean Stack,

Morven Gannon,

Andrew O’Shaughnessy,

Safwan Alhadeedy

Student Number C12564907

C12760661

C08669252

D15123213

i

Abstract The purpose of this report is to improve the design and the performance of the standard CPR

(Cardiopulmonary Resuscitation) pocket mask. This is a team design project that is to be

completed as part of a team with four members. This report has been carried out as part of the

Medical Device Innovation program (DT710-4) in the Dublin Institute of Technology.

The aim of this project if to improve the quality of air in a CPR mask from 16% oxygen to

the standard atmospheric quantity of 21% oxygen.

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Declaration

I hereby certify that this material, which I now submit for assessment on the programme of

study leading to the award of Bachelor of Science (Medical Device Innovation), is entirely

my own work and has not been submitted for assessment for any academic purpose other

than in partial fulfilment for that stated above.

Signed:

1. ............................................

2. ............................................

3. ............................................

4. ............................................

Date...............................................

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Table of Contents

Abstract ....................................................................................................................................... i

Declaration ................................................................................................................................. ii

Table of Contents ..................................................................................................................... iii

Table of Figures ......................................................................................................................... v

Table of Tables .......................................................................................................................... v

1.0 Introduction .......................................................................................................................... 1

1.1 The Statement of Intent .................................................................................................... 2

2.0 Literature Review................................................................................................................. 3

2.1 For Who and where is CPR used? ................................................................................... 3

2.2 How is CPR carried out?.................................................................................................. 3

2.3 An Existing Product ......................................................................................................... 3

2.3.1 The CPR Bag Valve .................................................................................................. 4

2.4 How will this benefit CPR? ............................................................................................. 5

2.5 Material Properties ........................................................................................................... 6

2.5.2 Silicone ..................................................................................................................... 6

2.5.1 PVC ........................................................................................................................... 6

2.5.3 Thermoplastics .......................................................................................................... 6

2.6 Market Research .............................................................................................................. 7

2.6.1 Defining the Market: ................................................................................................. 7

2.6.2 CPR Providers Market Analysis ............................................................................... 8

2.6.2.1 Interviews ........................................................................................................... 8

2.6.2.2 Research ............................................................................................................. 8

2.6.2.3 The Questionnaire .............................................................................................. 8

2.6.2.4 Conclusions ........................................................................................................ 9

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3.0 Product Design Specifications ........................................................................................... 10

4.0 Concept Design .................................................................................................................. 12

4.1 Concept 1 “Bag Incorporating Attachment Device” ..................................................... 12

4.2 Concept 2 “Balloon Incorporating Attachment”............................................................ 13

4.3 Concept 3 “Diaphragm Incorporating Attachment Device” .......................................... 14

5.0 Calculations ........................................................................................................................ 15

6.0 Final Design ....................................................................................................................... 16

7.0 Discussions and Conclusions ............................................................................................. 18

7.1 Marketing Plan ............................................................................................................... 18

7.1.2 Phase 1: Partial Market Entry or Full Market Exit ................................................. 18

7.1.3 Phase 2: Full Market Entry ..................................................................................... 18

7.2 AmbiValve “Ambient Air Attachment” ........................................................................ 19

7.3 Materials & Manufacturing............................................................................................ 19

7.4 Possible Changes ........................................................................................................... 20

References ................................................................................................................................ 21

Appendixes-A .......................................................................................................................... 22

Appendixes-B .......................................................................................................................... 27

Appendixes-C .......................................................................................................................... 34

Appendixes-D .......................................................................................................................... 42

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Table of Figures Figure 1: The Bag Concept. ..................................................................................................... 12

Figure 2: The Balloon Incorporating Intraoral Device ............................................................ 13

Figure 3: The Diaphragm Incorporating Attachment Device .................................................. 14

Figure 4: The Pugh design process model adapted and employed for the three selected

concepts.................................................................................................................................... 16

Figure 5: AmbiValve Ambien Air Attachment w/ Intraoral Mask .......................................... 19

Table of Tables Table 1: Results for dimensions of the device. ........................................................................ 15

Table 2: 2 Tiered design refinement matrix ............................................................................. 17

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1.0 Introduction The clients brief stated that there were a number of faults with the standard CPR mask along

with several unlisted faults.

In this report the key focal point of the project is to improve the quality of air being supplied

to the patient undergoing manual CPR with a first responder. By carrying out this

improvement it will inadvertently create a further barrier which will act as a seal between the

patient and operator to prevent the spread of contact pathogens.

Currently 1 in 12 patients that suffer a cardiac arrest and need CPR outside of the hospital

setting will survive. This low survival rate is due to the issue around the quality of the CPR

given to the patient i.e. with the strong chest compressions and quality of air. It has been

noted in reports that approximately 460,000 patients die in America each year from improper

use of CPR [1]. This can be due to people carrying out CPR incorrectly or by Emergency

Services personnel being unable to perform proper chest compression while in the back of the

ambulance [1].

At present, atmospheric air contains 21% Oxygen (O2) and 0.039% Carbon Dioxide (CO2)

[2]. On the other hand when a person exhales and breaths out these percentages change to

just 16% O2 and 4% CO2 [3]. This rise in CO2 is 100 times larger than what the human body

is used to. Therefore during the CPR process, whether the person is carrying out the process

using “mouth to mouth” or using a standard CPR mask, the air quality being delivered to the

patient is insufficient [4].

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1.1 The Statement of Intent

The aim of this project is to improve the quality of air being supplied to a patient undergoing

Cardiopulmonary Resuscitation (CPR). The quality of air being delivered can be improved by

supplying ambient air to the patient by using an add-on device that can be fitted onto a

regular CPR mask. This must be a purely manually operated system that is controlled by the

operator’s breath. By achieving this aim it will ensure that the new device will benefit the

patient and improve the CPR process and increase the survival rate.

This will be done by increasing the Oxygen levels from 16%-21% and decreasing the Carbon

Dioxide levels from 4%-0.04%. By creating an ambient air environment for the patient it will

also create a barrier between the operator and patient which will prevent the spread of

pathogens in either direction. This is particularly beneficial for immunocompromised

patients.

The final design must not only improve the air quality but it must also not slow the process

down. This means that the product itself should not need any excessive training.

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2.0 Literature Review 2.1 For Who and where is CPR used?

The proposed CPR device will focus on a bystander and first responder in the event of

cardiac arrest in various scenarios, namely heart attacks, strokes, drowning or sudden adult

death syndrome. The device will cater for all age groups and will not be hindered by facial

deformities or facial hair due to the intraoral construction.

The proposed device will be used following cardiac arrest in everyday situations primarily.

Further use in ambulances will be facilitated by the device to provide an influx in oxygen

levels for the patient.

Furthermore, in situations where the oxygen levels are low (factory conditions, high altitude

conditions) the device will facilitate release of oxygen stores through material or mechanical

means.

2.2 How is CPR carried out?

In this section the topic of discussion is based on how CPR is carried out. CPR is extremely

important and if it is not carried out immediately or in the correct manner it can be

detrimental to a patient’s survival.

CPR is carried out using two stages. The first and most important part of carrying out CPR is

the chest compressions. Chest compressions are imperative and any prolonged pause can

result in the death of the patient. Chest compressions are carried out by pushing down on the

chest in a strategic position to force the heart to start beating. When this process is carried out

it causes the blood to flow around the body and keep the brain oxygenated.

The second step carrying out is delivering the rescue breaths. Between 500- 600mL of air

should be exhaled out of the rescuers lungs and into the patient. This quantity of air should

cause a rise in the patient’s chest as their lungs begin to fill up with the exhaled air [5].

The ratio of chest compressions to rescue breaths is 30 compressions to 2 rescue breaths i.e. a

ratio of 30:2 [6]

2.3 An Existing Product

A similar product that works on the same principle of supplying ambient air to the patient as

well as creating a seal from pathogens is the CPR Bag Valve. The CPR Bag Valve is most

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commonly used in the professional environment due to a high level of training needed to

operate it correctly without causing damage to the patient [7].

2.3.1 The CPR Bag Valve

A product that has the similar goal of reducing the C02 levels and increasing the oxygen

levels in the CPR mask is the CPR bag valve [7].

The CPR Bag valve has many key attributes such as:

It supplies ambient air to the patient. The bag has a one way valve that allows the

operator to compress the bag. By compressing the bag it forces air into the CPR mask

and thus into the patients mouth. When the operator releases the bag it expands and

creates a vacuum that in turn draws the ambient air into the bag and the cycle

continues again. This aspect is a major selling point of the product as it ensures that

the patient is supplied with the correct levels of Oxygen and Carbon Dioxide [7].

By removing the physical aspect of the operator having to exhale his/her breath into

the patient’s body it removes the possibility of transmitting an infection or disease

that the operator may have present in their system. By ensuring a supply of ambient

air it reduces the chances of cross contamination to the patient through the operator’s

breath [7].

The operator uses his/her hands to compress the Bag Valve. This means that the

operator can monitor the situation more efficiently to assess the current state of the

patient. This means that as the operator is utilising the bag valve they can also monitor

the patient to ensure that the process is working by confirming that the patient’s chest

rises when the bag is being compressed. This will let the operator know that and

adequate amount of air is being delivered to the patients lungs [7].

By having the operator in a better position it also means that they can monitor the

patient to ensure that they have not regurgitated during the process. If the operator did

not notice that the patient regurgitated it would create serious problems for the patient

and it could result in a fatality [7].

However there can also be a number of drawbacks associated with the Bag Valve CPR mask:

The lungs operate by flexing the Diaphragm in the body which in turn creates a small

vacuum in the lungs. This is what allows a person to draw in a sufficient amount of

air to breath. During CPR the operator changes this process by forcing air into the

lungs by compressing the Bag Valve [7].

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During the CPR process the operator may force air into the lungs at too high of a

pressure. By doing this the air is not only forced into the lungs but it also travels

through the oesophagus and into the stomach of the patient. This fault can result in

gastric inflammation which causes the patient to regurgitate which can be a hazard

during CPR [7].

Excess pressure can also lead to the stomach rupturing inside the patient causing a

fatality due to the stomach acids leaking out into the body [7].

2.4 How will this benefit CPR?

Two sets of pigs were compared and the effect of ventilation on acid-base

conditions and the result from cardiac arrest in a pig model of CPR was shown,

one group didn’t receive ventilation throughout the first 10 minutes of CPR and

the other one did, the study indicated that ventilation through the 10 minutes of

CPR after 6 minutes of untreated ventricular fibrillation was accompanied with

a considerably greater rate of ROSC compared with the set that didn’t receive

ventilation. The nonventilated set had considerably larger arterial and mixed

venous hypoxia and hypercarbic acidosis. These results propose that ventilation

is a vital element of CPR for the treatment of cardiac arrest and that hypoxia

and hypercarbia unfavorably affect resuscitation [8], both hypercarbia and

hypoxia individually had an opposing effect on resuscitation from cardiac arrest

[9]. Coronary perfusion pressure is identified to be one of the greatest factors of

effective resuscitation from cardiac arrest [10]. Studies using an isolated heart

model revealed that hypercarbia and hypoxia intensely reduce myocardial force

of contraction [11]. Other studies of the effects of P02, Pco2 and pH on the

success of defibrillation have stated that animals with greater hypoxia or

hypercarbic acidosis needed the uppermost dose of electrical energy for

defibrillation and failed resuscitation more often [12].

One study presented that ventilation with air throughout 6 mins of CPR caused

a return of spontaneous circulation in 10 of 12 animals compared with only 5 of

12 animals ventilated with exhaled gas (p<.04). Mixed-venous and Arterial Po2

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were considerably higher and Pco2 was considerably lower in the air ventilated

group. [13]

We can conclude from the previous studies that reducing carbon dioxide and

increasing oxygen to the ambient air percentages rather than the normal

exhalation can improve the CPR success rate.

2.5 Material Properties

In this section the topics of discussion are the materials that are most commonly used in a

CPR mask. By studying the material properties that make up the CPR mask it will give the

reader a better understanding of how the CPR mask operates and why these materials were

chosen (See Appendixes-A for full research on the materials and manufacturing of CPR

Masks).

2.5.2 Silicone

Silicone is ideal for use in a medical device as its formation is physiologically inert, making it

suitable across the three grades of medical device classification.

2.5.1 PVC

PVC is a polymer with a crystal clear appearance formulated for injection moulding and

extrusion. Its heat stability characteristics make it ideal for connectors, drip chambers and

medical catheters. [2]

2.5.3 Thermoplastics

Two thermoplastics polymers that are currently used in the manufacturing of CPR masks are

Polyethylene (PE) and Polypropylene (PP) due to their various material properties that make

them suitable for the purpose of this product [14].

A material classified as a thermoplastic polymers is a material that incorporates toughness,

resistance to chemical attack and recyclability. Thermoplastic polymers are an easy material

to mould and are relatively low in cost due to their wide availability and high demand.

Polyethylene (PE) is an inert material that is extremely resistant to acid wear and low in cost.

Polyethylene is also a very easy material to manufacture and mould, which can also be

manufactured in different colours [15].

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Polypropylene (PP) is a very similar material to PE as it contains the same material properties

such as it is resistant to acid wear. On the other hand PP is flammable but flame retardants

will ensure that the material is slow to burn in the event of a fire. To ensure that the PP has

stability “stabilizers” can be added to the material to increase the stability and can hold its

form correctly during operation [15].

All of these properties that are incorporated in the two thermoplastic materials (PE and PP)

are essential to the operation of the CPR mask and how it operates.

1. The materials resistance to acidic wear is imperative because it is not uncommon for

the patient undergoing CPR to regurgitate. As the patient regurgitates the fluid that is

excreted from their system contains acidic properties that is used in the breakdown of

food in the digestive system. If this resistance to acidic wear were not incorporated in

the material it could lead to premature failure of the material and a fatality with the

patient could be the end result [6].

2. As said previously thermoplastics in general are a very tough material. Toughness in a

material is its ability to withstand fracture [16]. The product itself is very flexible and

has a high elastic limit which means it will return back to its original shape. To create

an efficient seal on the patients face the operator has to push down and slightly

manipulate the CPR mask to get a correct seal prior to administering the rescue

breaths [5].

2.6 Market Research

2.6.1 Defining the Market:

It was determined early on in discussions, using SWOT analysis and initial market sector

analysis, that it would be more pragmatic to investigate CPR course providers within Ireland

than to investigate manufacturers of present CPR barrier device solutions for market

information (see Appendixes-B for full Market Research and Standrards). This would refine

our findings by:

Eliminating confusing product promotion details

Confine the research to the 271 course providers within Ireland

Course providers having a greater grasp on the human element

Course providers having a practical view of current equipment in use and could

point out any conflicts of use (i.e. defibrillator and possible fluids)

Highlighting any blind spots in either the design or regulatory needs

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This would also offer a platform to introduce our product to the market sector.

2.6.2 CPR Providers Market Analysis

2.6.2.1 Interviews

Two emailed questionnaires where developed to target the CPR course providers. They were

sent to a limited number and made personal (distinguishable from junk mail) to try and

ensure an honest response, and designed not to be intrusive, leading or time consuming for

the responder:

2.6.2.2 Research

The first questionnaire email was sent to 18 course providers. Of which, there were 6

responses all with full answers (some in great detail). It was then decided that the questions

asked could be more direct in nature, so the questions where refined keeping these responses

in mind and amended to suit the current product specification.

The second questionnaire email was sent to 25 course providers, of which there were 7

responses. All of these responses where extensively detailed and used in modifying the

product specification.

2.6.2.3 The Questionnaire

The questions asked were:

1. How high would you rate CPR givers concerns over contact pathogens during mouth to

mouth resuscitation? - where 1 = low and 10 = high

An average response of 8

2. How would you rate the ease of use of present CPR masks? - where 1 = low and 10 = high

An average response of 6.5

3. What are your reservations regarding the use of a CPR bag valve mask by first aiders?

All mentioned over application risks and lack of training

4. Are you aware of the difference in air quality between ambient air and exhaled breaths?

All answered yes

5. What level of difference does air quality make in the outcome of a CPR event? - where 1 =

low and 10 = high

An average response of 8

6. Do you think first aiders (excluding healthcare professionals) would commitment to a device

that put a greater distance between them and the CPR recipient?

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83.33% said yes

7. Do you think first aiders (excluding healthcare professionals) would commitment to a device

that delivers a higher quality of air?

83.33% said yes

8. If these problems were overcome, would you be prepared to amend your course content to

accommodate alternative methodology?

83.33% said yes

16.67% said it depended on complexity of device usage

9. What extra cost would your clients be willing to incur for solutions to these problems?

33.33% said very little

16.67% said not sure

33.33% said €5.00

16.67% said €10.00

2.6.2.4 Conclusions

This process benefitted the analysis by:

Giving us contact to the market sector and a potential client base

Defining the problem in practical user friendly terms

Finding out if our solution is a requirement within the market sector

Informing us of new developments within the sector (especially with regards

to new ILCOR guidelines which have been mentioned several times). Further

research will be directed towards ILCOR COSTR (International Liaison

Committee on Resuscitation) guidelines published on Friday 16th October

2015.

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3.0 Product Design Specifications At the beginning of any design project, it is imperative that the designer creates a product

specification list. A product specification list is essentially a “wish list” that the designer has

created from their research. This list would incorporate all the key aspects of the design to

ensure the product would meet all of its goals.

In this design project the key aims to accomplish are:

1. Increase the oxygen levels in the mask from 16% to 21%. At present the current

ambient percentage of oxygen in the air is 21%, while the air being supplied to a

patient undergoing CPR is 16% as it is exhaled from the operator into the patient’s

lungs.

2. Reduce the Carbon Dioxide levels from 4% to 0.04% (ambient level). As the operator

exhales their breath into the patient it causes an increase in Carbon dioxide of 100

times the normal value for humans on earth. Carbon Dioxide is a poisonous gas to

humans, this increase in the CO2 levels are extremely negative in the hope of survival

for the patient.

3. The product should act as a barrier to prevent the possibility of passing a disease

between the patient and operator. The current CPR mask allows for direct contact

between the patient and the operator through the air being transferred. By creating a

product that supplies ambient air to the patient through a design that used the breath

of the operator, it should create a barrier that prevents cross contamination between

the operator and patient.

4. It should fit directly onto a CPR mask i.e. a connecting device. By creating a

component that attaches onto the standard CPR mask it will be sold as a separate item

that increases the survival rate of the patient.

5. It should function using the operator’s breath and it should be strictly mechanical. No

electronic parts should be required.

6. Quick and easy to use. This means that the finished product should not hinder or slow

down the CPR process. If the finished product were to hinder the process it would

have extremely negative ramifications. The product should also be easy to use and

would not need extensive training beyond the standard level for first responders at an

emergency scene.

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7. Attempt to adhere to ISO 10993-Should be strictly manufactured using biomaterials.

Failing to use biomaterials could be catastrophic to the finished product. Biomaterials

must be used to ensure that the materials do not irritate or cause damage to the

person’s skin.

8. Attempt to adhere to ISO 10651-4 2002 specifications:

a. Connection Ports

b. Operational Requirements

c. Ventilator Requirements

d. Storage and Operation Conditions

e. Marking Information and Instruction

ISO 10651 is the standard for CPR masks and how they operate.

9. Adhering to the recently released ILCOR 2015 Guidelines to satisfy the market

requirements (CPR course providers). ILCOR are the regulatory body for all CPR

trainers in Ireland. They have a strict procedure format for how CPR should be

administered.

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4.0 Concept Design Three concept designs were chosen to further study and analyse as possible products. The

form will incorporate dimensions to achieve an optimum volume of air for the patient to fully

gain the effects of the ambient air. Appendixes-C incorporates all of the conceptual designs

that were designed for this report.

4.1 Concept 1 “Bag Incorporating Attachment Device”

Figure 1: The Bag Concept.

This concept utilises the principle of air pressures to obtain ambient air from the external

environment and delivering them to the patient (see Figure 1). The Bag incorporating concept

essentially uses a bag to draw in ambient air (at 21% Oxygen and 0.04% Carbon Dioxide

concentration) into the device hollow, which can then be delivered to the patient through

rescue breaths. The device utilises a lightweight internal bag which will inflate and deflate

that will provide the rescue breaths through the device. Ambient air will be drawn into the

bag, through the one way valve, when the operator inhale’s. The pressure from the exhale

cycle of their breath will then force the bag to compress and deliver the ambient air to the

patient.

Pros

16% to 21% oxygen increase is achieved.

Intuitive use would require little if any training.

Cons

The operator needs to exhale to create the vacuum within the device to draw air in

prior to exhaling, which creates the pressure to force the air out of the device and into

the patient. This can lead to complications and the device will be no longer intuitive.

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Bag will need to be of a material that will change shape under pressure delivered from

breaths, this may be expensive to manufacture.

Use of internal bag may lead to instances of failure in the mechanical operation of the

device.

Additional time needed to attach device before CPR commencement.

4.2 Concept 2 “Balloon Incorporating Attachment”

Figure 2: The Balloon Incorporating Intraoral Device

This concept utilises the principle of air pressures to obtain ambient air from the external

environment and delivering them to the patient (see Figure 2). The concept achieves this by

incorporating a balloon which, as it is inflated/deflated creates a pressure change inside the

device. This pressure change will draw ambient air in that can be delivered to the attached

CPR device. The concept itself will take the form of an attachment which can be combined

with both intra-oral masks and pocket mask valves for ease of use.

Pros

Ambient air delivery is achieved.

Little additional training required, use remains the same.

Less mechanical moving parts which leads to a lower risk of failure.

Operator only needs to exhale into the device for it to operate.

Cons

Additional time needed to attach device before CPR commencement.

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4.3 Concept 3 “Diaphragm Incorporating Attachment Device”

Figure 3: The Diaphragm Incorporating Attachment Device

The Diaphragm Incorporating Attachment Device using the same mechanical principle as

Concept 1 and 2, draws in ambient air through changes in air pressure within the device (see

Figure 3). This concept however replaces the balloon feature with a mechanical diaphragm

which is operated through the users rescue breaths. Due to the spiral spring, the diaphragm

naturally draws the ambient air into the device. As the user exhales, the pressure from this,

forces the diaphragm component down, delivering the ambient air to the patient. The

diaphragm is also contained within a plastic casing, to retain its shape and the ambient air.

Once the operator stops exhaling into the device the spring will return to its natural position

and draw the ambient air back into the system and ready for its next cycle.

Pros

16% to 21% oxygen increase is achieved.

Attachment does not add bulk to the overall operation of the device.

Little additional training required, use remains the same.

Operator only needs to exhale into the device for it to operate.

Cons

Additional time needed to attach device before CPR commencement.

Use of semi-complex internal mechanism may lead to device failing.

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5.0 Calculations In this section we shall discuss the calculations of the dimensions and the volume of the

AmbiValve. The criteria which our choice of dimensions is based on to deliver the right

amount of volume.

The tidal volume will restrict the volume of the cylinder to 500 ml

𝑣 = 𝑡𝑖𝑑𝑎𝑙 𝑣𝑜𝑙𝑢𝑚𝑒 ≅ 500 𝑚𝑙

And for calculating the radius of the cylinder

𝑃1 ∗ 𝑉1 ∗ 𝑅1 = 𝑃2 ∗ 𝑉2 ∗ 𝑅2

𝑃1 ∶ 𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑖𝑛 𝑡ℎ𝑒 𝑡𝑟𝑎𝑐ℎ𝑒𝑎 𝑃2 ∶ 𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑖𝑛 𝑡ℎ𝑒 𝑎𝑚𝑏. 𝑣𝑎𝑙𝑣𝑒

𝑉1 ∶ 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 𝑖𝑛 𝑡ℎ𝑒 𝑡𝑟𝑎𝑐ℎ𝑒𝑎 𝑉2 ∶ 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 𝑖𝑛 𝑡ℎ𝑒 𝑎𝑚𝑏. 𝑣𝑎𝑙𝑣𝑒

𝑅1 ∶ 𝑅𝑎𝑑𝑖𝑢𝑠 𝑜𝑓 𝑡ℎ𝑒 𝑡𝑟𝑎𝑐ℎ𝑒𝑎 𝑅2 ∶ 𝑅𝑎𝑑𝑖𝑢𝑠 𝑜𝑓 𝑡ℎ𝑒 𝑎𝑚𝑏. 𝑣𝑎𝑙𝑣𝑒

Due to the too many unknowns in the equation it makes it quite difficult to generate a

solution or in other words we can have too many solutions to pick from. However, if we want

to deliver the tidal volume which is 500 ml as shown in the equation above the optimum

design would be the one with the radius of the trachea (1 to 1.25 cm) but that would result in

a height of a 159 cm in length which wouldn’t serve our purpose. For this very reason the

most suitable method of determining the dimensions of the AmbiValve is through the design.

In other words the dimensions of the device are design driven.

The table below (see Table 1) shows a range of possible solutions for the delivery of the tidal

volume by calculating the height for every given radius using the following equation:

ℎ =500

𝜋. 𝑟2

The choice of parameters is driven by design, the most realistic model will have a radius of 3

cm to 3.4 cm, since it is desired to keep the radius at it a minimum.

Table 1: Results for dimensions of the device (see Appendixes-D for the full table).

Radius(cm) Height(cm) Volume Cubic cm(ml)

1 159.1549 500

3 17.6839 500

3.2 15.5425 500

3.4 13.7677 500

6.4 3.8856 500

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6.0 Final Design Using the linear elements of ‘Pugh’s Total Design’ model to control the design process and

reach a higher product specification, we ran each of the three principle concepts through the

mode as shown in Figure 4.

We omitted the ‘Sell’ phase and replaced the ‘Manufacture’ phase with a ‘Prototyping’ phase

to fit the brief:

Figure 4: The Pugh design process model adapted and employed for the three selected concepts

The initial product specification was defined by the marketing analysis (completed at this

stage), the requirements of regulatory bodies (valve dimension etc.) and the function of the

product as defined by the team.

This was done in conjunction with a weighted scoring criteria as seen in Table 2, we used the

second tier of selection to re-write the product specification where required.

The first tier required all specifications to be met to move onto the second tier.

For example, product specification 6 regarding ease of use was re-worded when looking at

the response time factors and mechanical robustness of the device in the tier 2 selection and

discussing the concept images number 1 and 3.

The second tier has a greater emphasis on qualitative variables in order to assist product

specification development and to refine the perception of the product.

Prototyping

Derived from specifications in the detailed design

Detailed Design

Derived from the Concept DesignAmmended for problems encountered within the

prototyping process

Concept Design

Derived from the Product SpecificaitonsAmmended for problems encountered within the

Detailed Design

Product SpecificationDerived from the product and market research

informationAmmended for problems encountered within the

Concept Design

Market

Information gathered from all product and market research

17

Table 2: 2 Tiered design refinement matrix

Tier 1 Selection Criterion (Yes or No) – Defined by the Product Specification

Concepts: Con 1 Con 2 Con 3

Increased O2 Y Y Y

Lower CO2 Y Y Y

Create a Barrier Y Y Y

Fitting on existing CPR masks Y Y Y

Operator Breath Y Y Y

Efficiency Y Y Y

Biomaterial - ISO10993 Compliant Y Y Y

CPR Device - ISO 10651 Compliant Y Y Y

CPR Course Provider Regulatory Body - ILCOR 2015 Y Y Y

Intuitive and Simple to use Y Y Y

Tier 2 Selection Criterion (1 = low/5 = high)–Defines the Product Specification and the Detailed Design

Key Aspects: Weight Given Con 1 Con 2 Con 3

Elegance 0.2 2 4 3

Added Value to service provided 0.8 4 4 4

Robustness 0.8 1 4 2

Aesthetic 0.2 2 3 2

Affordability 0.5 1 3 2

Resources Available 0.7 1 5 1

Response Time Factors 0.7 3 4 2

Safety 0.9 1 4 4

Calculated Weighted Totals: 9 19.2 12.5

Moving from a concept design to a detailed design went against concept 2 both in the

weighted score and in trying to design a reliable, affordable and returnable diaphragm.

18

7.0 Discussions and Conclusions 7.1 Marketing Plan

For a product within the medical market sector, the first phase is to provide free units to the

first point of reference for CPR in the general public, who are the instructors of CPR in

Ireland. This would promote an adoption, awareness and an identity of the product and

ensure a better share of the public market.

It would also act as a test market to further refine the product and an opportunity to

investigate other opportunities. Although this would incur great cost at first, it would provide

a solid foundation for long term sales.

7.1.2 Phase 1: Partial Market Entry or Full Market Exit

Batch manufacture 300+ AmbiValve units.

Contact all CPR course providers in Ireland (271 course providers in 2015) informing them

that they will receive an AmbiValve unit via the mail. It will incorporate instructions for use

and documentation detailing the benefits of the product with emphasis on the air quality

delivered.

After a 2 month period we will contact the CPR course provider with a detailed questionnaire

to further refine the product and assess the market.

The results of which will determine if:

a. We leave the market.

b. We stay in the market.

c. We stay in the market and further develop and improve the product.

We repeat the process after 4 months, and then 6 months.

The potential cost of the product will be assed at each 2 month stage.

7.1.3 Phase 2: Full Market Entry

If we have decided to stay in the market after 6 months, and depending on the scale of market

response, we will approach the top 40 manufacturers of First Aid kits in Europe that would

include a CPR mask (scaled to the relevant ISO standard) and negotiate the inclusion of our

product along with their CPR mask units.

All manufacturing will be lean and to a larger batch scale.

The final cost of the unit will be addressed at this stage.

19

7.2 AmbiValve “Ambient Air Attachment”

Figure 5: AmbiValve Ambien Air Attachment w/ Intraoral Mask

The chosen concept, the AmbiValve, utilises the principle of air pressures to deliver ambient

air from the external environment to the patient, thus increasing the Oxygen concentration

from 16% to 21% whilst decreasing Carbon Dioxide levels also.

The attachment achieves this by incorporating a balloon component which can deflate to

draw in ambient air, and force this air out through the valve into the attached CPR mask. One

way valves are fitted both at the ambient air inlet, and the tapered outlet, to create the

pressure differences that create the increase in pressure and the vacuum, for this device to

operate.

The final product takes the form of a CPR mask attachment and is designed to fit any ISO

10651 – 4 (2002 Specification) standard valve, using a tapered outlet, creating an interference

fit. Markings on the top and bottom of the device will be applied to indicate the correct

orientation for first time users.

7.3 Materials & Manufacturing

The attachment, along with its internal components, will be made from different grades and

formulations of the polymer PVC. PVC was chosen for its crystal clear appearance, ideal for

determination of the internal balloons successful operation, and ability to be manufactured

both by extrusion, and injection moulding methods, the latter being used in the manufacturing

of the AmbiValve. The internal balloon is also to be made from PVC, formulated and

manufactured in the same way as IV bags to achieve appropriate shape and required

20

characteristics. All materials follow ISO 10993 standards for Biomaterials being used in a

Grade I medical device.

7.4 Possible Changes

Although the design of the AmbiValve has been a success and all of the criteria of the

product specification has been met, the design itself still has room for improvement.

1. In the event of the patients airway being blocked there is no pressure relief valve. This

is a vital component to have on the device. In the event of the patients airway being

blocked the air being supplied can be forced down the wrong path into the stomach

leading to gastric inflammation.

2. A CPR mask in the professional setting could be used quite regularly. To avoid this

product being disposed of after each use, the balloon mechanism should be designed

that it can be easily replaceable.

The AmbiValve’s concept design as shown in this report has been a success. The main aim of

the design was to improve the patient’s chances of survival by supplying ambient air instead

of poor quality recycled air. By utilising the one-way valves it allows the design to do this

similar to that of the Bag Valve which was discussed previously in the report. The major

advantages the AmbiValve has over the Bag Valve on the market is that the pressure being

applied to the patients lungs is significantly lowered thus preventing any further accidents

such as gastric inflammation.

The other major advantage is that the AmbiValve is designed to deliver 500 ml of ambient air

which is the correct tidal volume needed to see a visible chest rise in the patient. This is a

major advantage as it ensures that the patient is being supplied with the correct quantity of

quality ambient air.

21

References

[1] S. Jeffery, “PARAMEDIC: No Advantage for Mechanical vs Manual CPR,” Medscape,

2016 November 2014. [Online]. Available:

http://www.medscape.com/viewarticle/835008#vp_1. [Accessed 08 October 2015].

[2] P. Shakhashir, “GASES OF THE AIR,” Scifun, November 2007. [Online]. Available:

http://scifun.chem.wisc.edu/chemweek/pdf/airgas.pdf. [Accessed 08 October 2015].

[3] M. O'Callaghan, Biology Plus, The Educational Company of Ireland, 2013.

[4] D. P. Keseg, “The Merits of Mechanical CPR,” JEMS, 29 August 2012. [Online].

Available: http://www.jems.com/articles/2012/08/merits-mechanical-cpr.html.

[Accessed 08 October 2015].

[5] P. J. K. R. O. T. V. John M. Field, “The Textbook of Emergency Cardiovascular Care

and CPR,” in The Textbook of Emergency Cardiovascular Care and CPR, Philidelphia,

Lippincott Williams and Wilkns, 2009, p. 180.

[6] C. Robert A. Berg, R. Hemphill, B. S. Abella, T. P. Aufderheide, D. M. Cave, M. F.

Hazinski, E. B. Lerner, T. D. Rea, M. R. Sayre and R. A. Swor, “Part 5: Adult Basic Life

Support,” American Hearts Association, 2010. [Online]. Available:

http://circ.ahajournals.org/content/122/18_suppl_3/S685.full#sec-1. [Accessed 08

October 2015].

[7] M. a. M. L. M. Ann M. Weiss, “Focus On - Bag-Valve Mask Ventilation,” ACEP News,

01 September 2008. [Online]. Available: http://www.acep.org/Clinical---Practice-

Management/Focus-On---Bag-Valve-Mask-Ventilation/. [Accessed 06 November 2015].

[8] B. L. F. R. W. V. R. W. M. R. O. D. Idris AH1, “Pubmed,” Department of Surgery,

(Division of Emergency Medicine), University of Florida College of Medicine,

Gainesville 32610-0392., 12 1990. [Online]. Available:

http://www.ncbi.nlm.nih.gov/pubmed/7994855.

22

[9] W. V. B. L. B. M. O. D. Idris AH, “Pubmed,” 1995. [Online]. Available:

http://www.ncbi.nlm.nih.gov/pubmed/7634893.

[10] M. G. R. E. G. M. A. T. F. M. N. R. Paradis NA, “Pubmed,” Feb 1990. [Online].

Available: http://www.ncbi.nlm.nih.gov/pubmed/2386557#.

[11] B. R. G. H. Weisfeldt ML, “Pubmed,” 1975. [Online]. Available:

http://www.ncbi.nlm.nih.gov/pubmed/1832.

[12] M. G. B.-J. P. L. W. M. N. B. M. J. F. M. N. A. MD M von Planta, crit care, Feb 1992.

[Online]. Available: http://www.annemergmed.com/article/S0196-

0644%2805%2980471-8/abstract.

[13] I. AH, “Pubmed,” Crit Care Med, 28 Nov 2000. [Online]. Available:

http://www.ncbi.nlm.nih.gov/pubmed/11098945.

[14] Dongguan City Risen Medical Products Co., Ltd, “Promotional Mouth to Mouth CPR

Mask for First Aid,” Dongguan City Risen Medical Products Co., Ltd, 01 Novemeber

2015. [Online]. Available: http://risenmedical.en.made-in-

china.com/product/RKOJsmzGgqhr/China-Promotional-Mouth-to-Mouth-CPR-Mask-

for-First-Aid.html. [Accessed 06 November 2015].

[15] CES Edupack 2015, “CES Edupack 2015,” Granta Design Limited, Cambridge, 2015.

[16] W. H. J. S. W. A. W. N. R. Dietmar Gross, Engineering Mechanics 1, Dordrecht:

Springer, 2013.

[17] Continence Product Advisor, “Indwelling Catheters,” Continence Product Advisor,

[Online]. Available:

http://www.continenceproductadvisor.org/products/catheters/indwellingcatheters.

[Accessed 02 10 2015].

Appendixes-A Current Device Specifications

23

Manufacturing:

The selection of the materials in the manufacturing of a CPR pocket masks lies in its

biocompatibility as well as the ease of which this material can be manufactured to create the

required shape, regardless of its complicated structure (e.g hollow air filled structure). Indeed

the fore mentioned structure is the most complicated part along with the one way valve,

primarily made from PC + Silicone Rubber. The manufacturing methods used in the creation

of the hollow structure is explained below:

Hollow-Air Filled Structure:

The manufacturing method is outlined in the United States Patent1 No: 8,852,480 B2

“Method For Manufacturing Hollow Structure For Breathing Mask”. The patent references a

manufacturing method that “…includes producing an open hollow structure of a first

material, positioning the open hollow structure on a tool adapted to hold the open hollow

structure, filling the open hollow structure with a filler medium, and closing the filled open

hollow structure with a second material ”. This method produces the hollow on existing

Pocket CPR Masks. The hollow itself can have a varying wall thickness2, with a thicker

second material closing off the vacuum and also being in contact with the patients face.

Mask:

The most important aspect of a “pocket” CPR mask is its portability combined with its ability

to actually function properly. These functions come from both its material selection and

manufacturing selection. The material must be flexible, transparent, form-retaining and most

likely a plastic such as PVC, Polystyrene or Polyurethane. The resilience of the material also

needs to be such as that it can be flexed into a hollow for its intended purpose and then

24

returned to its collapsed shape to aid in portability. Resilience is explained as “….the

property of returning to the original shape after distortion within elastic limits." Hackk's

Chemical Dictionary Fourth Edition p. 578, column 23.

Valve:

Commonly made of PVC, the valve used in the construction of these masks is a “multi-stage

mouth-to-mouth resuscitation valve in combination with a first valve to allow exhaled breath

from a mouth of an operator to pass through the first valve to the mouth of a victim”4. The

second valve assumes the role of ensuring exhaled air from the victim does not reach the

operator.

Materials:

The project doesn’t require a complete overhaul of the material selection, but the re-design of

an existing product to solve problems. I have not identified any issues using the existing

materials at this stage so have decided a brief overview is adequate:

Polyvinyl Chloride:

“Crystal clear, with high melt flow and excellent heat stability characteristics for

connectors, drip chambers and accessories to medical bags and catheters. Formulated

for injection moulding or extrusion”.

Silicone:

“Resistant to ultra-violet light, ozone and weathering”

“Silicone rubber is physiologically inert, thus making it the preferred choice of the

medical, pharmaceutical and food processing industries”.

1 patent available in Dropbox

2 a thinner degree wall thickness could perhaps solve bearded patient problem.

3 patent included in Dropbox folder

4 patent available in Dropbox folder

CPR Facts and Statistics

25

• About 75 percent to 80 percent of all out-of-hospital cardiac arrests happen at home, so

being trained to perform cardiopulmonary resuscitation (CPR) can mean the difference

between life and death for a loved one.

• Effective bystander CPR, provided immediately after cardiac arrest, can double a victim’s

chance of survival.

• CPR helps maintain vital blood flow to the heart and brain and increases the amount of time

that an electric shock from a defibrillator can be effective.

• Approximately 95 percent of sudden cardiac arrest victims die before reaching the hospital.

• Death from sudden cardiac arrest is not inevitable. If more people knew CPR, more lives

could be saved.

• Brain death starts to occur four to six minutes after someone experiences cardiac arrest if no

CPR and defibrillation occurs during that time.

• If bystander CPR is not provided, a sudden cardiac arrest victim’s chances of survival fall 7

percent to 10 percent for every minute of delay until defibrillation. Few attempts at

resuscitation are successful if CPR and defibrillation are not provided within minutes of

collapse.

• Coronary heart disease accounts for about 550,000 of the 927,000 adults who die as a result

of cardiovascular disease.

• Approximately 335,000 of all annual adult coronary heart disease deaths in the U.S. are due

to sudden cardiac arrest, suffered outside the hospital setting and in hospital emergency

departments. About 900 Americans die every day due to sudden cardiac arrest.

• Sudden cardiac arrest is most often caused by an abnormal heart rhythm called ventricular

fibrillation (VF). Cardiac arrest can also occur after the onset of a heart attack or as a result of

electrocution or near-drowning.

• When sudden cardiac arrest occurs, the victim collapses, becomes unresponsive to gentle

shaking, stops normal breathing and after two rescue breaths, still isn’t breathing normally,

coughing or moving.

Experts say CPR is a lifesaver, and with good reason. Each year, more than 350,000 people in

the United States — one every 90 seconds — experience cardiac arrest. The vast majority of

26

these do not occur at a hospital, and those who receive CPR from a bystander are up to three

times more likely to survive than someone who doesn’t receive such assistance.

Additional Problem Identification

“The air a person normally breathes contains approximately 21 percent oxygen. The

concentration of oxygen delivered to a victim through rescue breathing is 16 percent,

therefore the oxygenation levels supplied by a pocket CPR mask is insufficient.”

“When administering CPR the patient may experience vomiting or other discharge from

the mouth. In this case, CPR must be stopped to administer suction, and as a consequence

the patient does not receive adequate oxygenation. Additional readjusting of the mask in

this instance will also hinder recovery.”

*how will this work with an in mouth piece?

This problem is also significant in CPR recovery but is only mentioned in passing in most

documentation. Statistics are obviously hard to come by on how often an occurrence this is

but I feel it could be important to look at and allow for a bit of creativity in how it is

approached with regards to material use. There are materials that shrink when wet/moist,

could be useful in this case?

The detection of the resumption of breathing in a patient is not always evident when

bystander CPR is performed, resulting in additional CPR being performed that may cause

unnecessary trauma (chest bruising, fractures of the ribs etc.) This problem is in

conjunction with the problem in actually detecting that oxygen levels have returned to the

patient.

The pocket mask is made transparent for to make the identification of oxygenation status in

patients. However, even with this, a bystander performing CPR without adequate training

will make no sense of the indicators (blue lips, the actual sound of breathing etc.). A way of

counteracting this would be to introduce elements that act as indicators of factors such as

oxygenation (material that indicates oxygen levels), C02 release (again by indicator).

Shape of the mask creating an appropriate seal that does not need constant readjustment

Conceptual Research

27

Idea:

“Utilizing a One-Way Permeable Membrane to recover oxygen from the ambient air, storing

it, and then delivering it to the patient through CPR recovering breathing”

Explanation:

Inflatable tube material that will increase in volume through inhaling through a one-way

permeable membrane. Inhale to increase the volume from the ambient air; the one-way

membrane will prevent leaking of said air back to the external air. Exhaling during CPR

method using intraoral device will then force the increased ambient air into the patient. This

in turn will increase oxygen intake from 16% to 21%.

Backup research:

One-way oxygen permeable membranes are used in the construction of certain type of “rigid

gas permeable” contact lenses. The materials used are various but the principle of the

material permeability is the same when applied to the idea.

Oxygen Absorbing Crystals

Idea:

“The use of so called “Aquaman Crystal”, which can steal oxygen from the air and store it to

be used later, could be used in the construction of the CPR device to deliver an increased

oxygen dose to the patient”

Explanation:

The use of oxygen absorbing material in the construction of the facemask or intraoral device

could allow for storage of oxygen to be used in situations where the ambient air is not

sufficient to be drawn in for use. The material, albeit in its infancy, has been tested and

described as a technical synthetic “hemoglobin”.

Backup research:

Oxygen Chemisorption/Desorption in a Reversible Single-Crystal-To-Single-Crystal

Transformation

McKenzie, Christine; Sundberg, Jonas; Cameron, Lisa; Southon, Peter D.; Kepert, Cameron

J. Published in: Chemical Science

Appendixes-B

28

Relevant ISO 10651 Points:

4.3 Face mask connectors

If provided with the resuscitator, face masks shall have either a 22 mm female connector or a 15 mm male connector which shall mate with

the corresponding connectors specified in EN 1281-1.

4.7 Oxygen tube connector and pressure gauge connector

The oxygen tube connector, if provided, shall comply with EN 13544-2:2000. The pressure gauge connector (if provided) shall not be

compatible with tubing fitting the oxygen tube connector.

5.2 R) Dismantling and reassembly

A resuscitator intended to be dismantled by the user, e.g. for cleaning, etc. should be designed so as to minimize the risk of incorrect

reassembly when all parts are mated. The manufacturer shall recommend a functional test of operation to be carried out after reassembly

6.1 R) Supplementary oxygen and delivered oxygen concentration

When tested by the method described in A.4.6 in accordance with the requirements of its classification (see 6.7.1)

a resuscitator shall provide a minimum delivered oxygen concentration of at least 35 % (V/V) when connected to an oxygen source supplying not more than 15 l/min and, in addition, shall be capable of providing an oxygen concentration of at least 85 % (V/V) (see note).

The manufacturer shall state the range of delivered oxygen concentrations at representative flows, i.e. 2 l/min, 4 l/min, 6 l/min, 8 l/min, etc.

6.2 R) Expiratory resistance

In the absence of positive end-expiratory pressure devices, and when tested by the method described in A.4.7, the pressure generated at the

patient connection port shall not exceed 0,5 kPa (_ 5 cmH20). (See also 10.2 c) 8)).

6.3 R) Inspiratory resistance

When tested by the method described in A.4.8, the pressure at the patient connection port shall not exceed 0,5 Kpa (_ 5 cmH20) below

atmospheric pressure. (See also 10.2 c) 8)).

6.4 R) Patient valve malfunction

When tested by the method described in A.4.9, an inadvertent positive expiratory pressure greater than 0, 6 Kpa

(_ 6 cmH2O) shall not be created at an added input flow of up to 30 l/min when this flow is added in accordance with the manufac turer’s

instructions.

6.5 R) Patient valve leakage - Forward leakage. If forward leakage is a design feature, it shall be so stated in the instruction manual.

6.6 R) Resuscitator dead space and rebreathing. When tested by the method described in A.4.10, the resuscitator dead space shall not

exceed 5 ml + 10 % of the minimal delivered volume specified for the classification of the resuscitator. Excessive rebreathing should not occur during spontaneous breathing.

6.7.1 R) Minimum delivered volume (Vdel) When tested as described in A.4.11 using the compliance, resistance, frequency and I:E ratio

given in Table 1, the minimum delivered volume shall be as given in Table 1.

6.7.2.1 For resuscitators designated for use with a body mass less than 10 kg, a pressure-limiting system shall be provided so that the airway

pressure does not exceed 4, 5 Kpa (_ 45 cmH20) under the test conditions described in A.4.12. However, it shall be possible to generate an

airway pressure of at least 3 Kpa (_ 30 cm H2O).

NOTE: An override mechanism can be provided.

6.7.2.2 If a pressure-limiting system is provided for a resuscitator designated for use with patients of over 10 kg body mass, the pressure at

which it operates shall be stated in the instruction manual [see 10.2 c)9)]. Any pressure-limiting device provided that limits pressure to below 6 Kpa (_ 60 cmH20) shall be equipped with an override mechanism. If provided with a locking mechanism, pressure override

mechanisms shall be so designed that the operating mode, i.e. on or off, is readily apparent to the user by obvious control position, flag, etc.

7.2 R) Operating conditions

When tested by the method described in A.4.13, the resuscitator shall comply with clause 6 throughout the range of relative humidity from

15 % r.h. to 95 % r.h either:

- throughout the temperature range from - 18 °C to + 50 °C ; or

- If a specific operating range is given (see 9.2 and 10) throughout the temperature range declared by the manufacturer.

9 Marking

9.1 General

Marking of resuscitators, or parts if applicable, packages, inserts and information to be supplied by the manufacturer shall comply with EN

1041.

9.3 Indication of pressure-limiting system setting

If the resuscitator is supplied with a pressure-limiting system set at one fixed pressure, the nominal pressure setting

at which the system is activated shall be marked on the resuscitator.

10 Information to be provided by the manufacturer in operating and maintenance instructions

10.1 General

29

The manufacturer shall provide instructions for use and maintenance. The size and shape of these instructions for

use should be such that they can be enclosed with or attached to the resuscitator container.

10.2 Contents

In addition of EN 1041 the instructions for use and maintenance shall include the following information, where

applicable :

a) a warning to the effect that incorrect operation of the resuscitator can be hazardous ;

b) instructions on how to make the resuscitator operational in all intended modes of operation ;

c) a specification detailing the following information for the resuscitator and its recommended accessories if

applicable :

A.4.7 Expiratory resistance

For resuscitators suitable for use with patients with a body mass of up to 10 kg, connect the patient connection port

to an air source and introduce air at a flow of 5 l/min. Record the pressure generated at the patient connection port.

For all other resuscitators, connect the patient connection port to the air source and introduce air at a flow of

50 l/min. Record the pressure generated at the patient connection port.

For resuscitators suitable for use with patients with a body mass of up to 10 kg, connect the patient connection port

to a vacuum source producing an air flow of 5 l/min. Record the pressure generated at the patient connection port.

For all other resuscitators, connect the patient connection port to a vacuum source producing an air flow of

50 l/min. Record the pressure generated at the patient connection port.

A.4.10.1 Principle

Ventilation by the resuscitator of a “bag-in-bottle” reservoir with 100 % (V/V) oxygen as tracer gas. Calculation of

the total deadspace of the resuscitator from the volume of ventilation and the oxygen concentration of the inspired

gas captured inside the bag.

The standard goes on to detail testing procedures:

Relevant ILCOR 2015:

Nothing has changed since the ILCOR guidelines published in 2010 regarding pulmonary resuscitation, but these passages are

relevant to our product. This is the document that every CPR training professional refers to for regulatory and procedural

guidelines throughout the world (governing bodies are: CoSTR ERC - Europe, CoSTR AHA – U.S.A and JRC – Asia)

Page 89:

Rescue Breaths:

In non-paralysed, gasping pigs with unprotected, unobstructed airways, continuous-chest-compression CPR without artificial ventilation

resulted in improved outcome.140Gasping may be present early after the onset of cardiac arrest in about one third of humans, thus facilitating

gas exchange.48During CPR in intubated humans, however, the median tidal volume per chest compression was only about 40 mL,

insufficient for adequate ventilation.141In witnessed cardiac arrest with ventricular fibrillation, immediate continuous chest compressions

tripled survival.142Accordingly, continuous chest compressions may be most beneficial in the early, ‘electric’ and ‘circulatory’ phases of

CPR, while additional ventilation becomes more important in the later, ‘metabolic’ phase.39During CPR, systemic blood flow, and thus

blood flow to the lungs, is substantially reduced, so lower tidal volumes and respiratory rates than normal can maintain effective

oxygenation andventilation.143–146When the airway is unprotected, a tidal volume of 1 L produces significantly more gastric inflation than a

tidal volume of 500 mL.147Inflation durations of 1 s are feasible without causing excessive gastric

insufflation.148Inadvertenthyperventilation during CPR may occur frequently, especially when using manual bag-valve-mask ventilation in a

protected airway. While this increased intrathoracic pressure149and peak airway pressure, 150a carefully controlled animal experiment

revealed no adverse effects.151From the available evidence we suggest that during adult CPR tidal volumes of approximately 500–600 mL

(6–7 mL kg−1) are delivered. Practically, this is the volume required to cause the chest to rise visibly.152CPR providers should aim for an

inflation duration of about 1 s, with enough volume to make the victim’s chest rise, but avoid rapid or forceful breaths. The maximum

interruption in chest compression to give two breaths should not exceed10 s.153These recommendations apply to all forms of ventilation

during CPR when the airway is unprotected, including mouth-to-mouth and bag-mask ventilation, with and without supplementary oxygen.

Page 92:

30

Disease transmission:

The risk of disease transmission during training and actual CPR performance is extremely low.255–257Wearing gloves during CPR is

reasonable, but CPR should not be delayed or withheld if gloves are not available.

Barrier devices for use with rescue breaths:

Three studies showed that barrier devices decrease transmission of bacteria during rescue breathing in controlled

laboratorysettings.258,259No studies were identified which examined the safety, effectiveness or feasibility of using barrier devices (such as a

face shield or face mask) to prevent victim contact when per-forming CPR. Nevertheless if the victim is known to have a serious infection

(e.g. HIV, tuberculosis, hepatitis B or SARS) a barrier device recommended. If a barrier device is used, care should be taken to avoid

unnecessary interruptions in CPR. Manikin studies indicate that the quality of CPR is superior when a pocket mask is used compared to a

bag-valve mask or simple face shield.260–262Foreign

CPR Course Trainers Interview 1:

Questions:

Would you prioritise finding a defibrillator unit over administrating chest compressions?

In what instance would you not administer mouth to mouth resuscitation and why?

Are you aware of the difference in air quality between ambient and exhaled air?

Would you be prepared to amend your course content to address this issue?

What is the biggest problem addressing mouth to mouth resuscitation?

Dear ....

I am a student at DIT Bolton Street completing a course in Medical Device Innovation.

I'm conducting market analysis for a course project aimed at improving devices used in the mouth to mouth resuscitation

process.

It would be of great help to us if you could answer the following 5 questions.

Your response does not need to be detailed but I do need to use the answers by next Monday.....

Would you prioritize finding a defibrillator unit over administrating chest compressions?

In what instance would you not administer mouth to mouth resuscitation and why?

Are you aware of the difference in air quality between ambient and exhaled air?

Would you be prepared to amend your course content to address this issue?

What is the biggest problem addressing mouth to mouth resuscitation?

Your help would be greatly appreciated

Many thanks

Morven Gannon

Initial Risk Assessment for the Problem Definition Phase:

Risks & Failures Identified and Solutions Offered:

Risk I.D Number Potential Risk/Failure Solution

31

1 Failure to achieve the time allotted for the

entire project

Clearly achieve all the set objectives required for the

course content within the set time

2 Individually returning personally assigned

tasks behind schedule

Ensure that all participants are up to date and have

clearly defined, achievable objectives set each week

3 Unable to attain the correct resources Make realistic material or technological demands in the

design process

4 Failure to id/quantify the customers’ needs

or priorities

Make a detailed analysis of the market sector with

specific attention paid to the end user

5 Poor project planning and scheduling Ensure that all individually assigned tasks are relevant,

realistic and in line with the expectations of the module

6 Product will not work or is of poor quality Deliver a basic tried and tested assembly system utilising

available components

7 User safety concerns and customer

acceptance problems

Detailed analysis of market and end user requirements

8 Inability in design to fulfil regulatory

criteria

Consistently refer to the relevant regulatory bodies

(FDA/ISO)

9 Competitive market sector and high risk of

obsolesce

Extensive analysis of the existing client base with

reference to potential shortfalls in the market

10 Production requirements are too excessive Keep an eye on materials, production systems and costs

in the design process

11 Environmental impact failures Include a factor of fatigue/failure testing sequence in the

product testing stage

12 Other teams on the module delivering the

same idea

Keep quiet while in the development stage

Risks Calculations:

To ask: Should a RPN be introduced or will this basic risk calculation be enough?

Risk = (RP) x (RM)

Where:

RP = Probability of the risk occurring with a natural range of 0% - 100% (0.00 to 1.00)

RM = Magnitude of the risk occurring, where 0% means there is no impact on the project and 100% assures project failure (0.00 – 1.00)

The following table is only the opinion of team member Morven Gannon.

Risk I.D Probability of Risk Occurring Magnitude of Impact on Project (RM) Quantitative Value of RISK (RP

32

Number (RP) x RM)

1 0.3 0.8 0.24

2 0.4 0.6 0.24

3 0.1 0.4 0.04

4 0.4 0.6 0.24

5 0.4 0.4 0.16

6 0.5 0.8 0.40

7 0.2 0.3 0.06

8 0.5 0.5 0.25

9 0.4 0.2 0.08

10 0.2 0.6 0.12

11 0.3 0.5 0.15

12 0.5 0.3 0.15

The top 5 prioritised risks:

Risk 6: Product will not work or is of poor quality

Risk 8: Inability in design to fulfil regulatory criteria

Joint third:

Risk 1: Failure to achieve the time allotted for the entire project

Risk 2: Individually returning personally assigned tasks behind schedule

Risk 4: Failure to id/quantify the customers’ needs or priorities

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STRENGTHS

OPPERTUNITIES

WEAKNESSES

THREATS

3 successful DIT engineering students and 1 international engineer specialising in medical devices

A strong reservoir of experience to draw on within the module and at DIT

A well considered problem with enough space in the market to bring innovation to

Enough time to allot each facet of the project in extensive detail

Potential to be adopted by other facets of emergency response, not just a first aid kit user

Add to the whole field of assisted breathing technology

The market seems to have hit a ceiling in product development

The other teams on the module coming up with the same idea

Loss of intellectual property Undiscovered regulatory restrictions

No clear strategic direction Inexperience in medical device

product development and design No educated understanding of

regulatory procedure as of yet Untested team dynamic Potentially conflicting information

from advisory bodies

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Appendixes-C Concept Generation

Concept Ideation

Concept 1 “Oxygen Absorbing Attachment”

Explanation

This concept revolves around the newly formulated material, which essentially “absorbs”

oxygen from the air, releasing it later under certain stimulus (heat, electricity, movement).

The material itself comes in a crystalline form at present but further research in the area

means its applications could be widespread, especially in the rescue mask and deep sea

diving areas.

The concept mask and attachment uses this material to achieve optimum oxygen delivery in a

patient who has suffered cardiac arrest. The mask itself is made of a porous silicone with the

ability to allow oxygen through its membrane. The attachment has the “oxygen absorbing”

material encased in a similar membrane allowing delivery of the stored oxygen into the

hollow between mask and patient. The material releases its stored oxygen when the rescuer

applied pressure and heat with the hands to the mask attachment. The mask is then used

normally by applying rescue breaths.

Pros

16% to 21% oxygen increase is achieved.

Attachement does not add bulk to the overall operation of the device.

No additional training required, use remains the same

Cons

“Oxygen absorbing” material still in its infancy stage of implementation.

Cost of this material would likely push the product into an unafforable range.

Sterilisation for multiple uses would cause an issue.

Concept 2 “Two Way Oxygen Delivery Mask”

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Explanation

This concept also boarders on the conceptual side, also utilizing the “oxygen absorbing

material” mentioned in Concept 1. The mask itself is formed by both an over the nose CPR

pocket mask, combined with an intra oral mask. The idea behind this concept is that air will

be directed both through the mouth, and through the nose, the latter being delivered oxygen

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through the “oxygen absorbing” material, activated once again by the rescuers hand position.

Normal rescue breaths are initiated through the intra oral mask also.

Pros

16% to 21% oxygen increase is achieved.

Oxygen delivery through two airways may aid faster recovery.

Cons

“Oxygen absorbing” material still in its infancy stage of implementation.

Cost of this material would likely push the product into an unafforable range.

Although shape is familiar, in pressure situations, mask may not be intuitive to use.

Use of material in a cold environment may render additional mask useless.

Concept 3 “Intra Oral Accordion”

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Explanation

The accordion concept essentially uses a “pump” mechanic to draw in ambient air (at 21%

oxygen concentration) into the device hollow, which can then be delivered to the patient

through rescue breaths. The device utilizes a porous silicone which allows oxygen to pass

through when the rescuer performs an inhale breath. Once an exhale is applied, the internal

cylinder pushes down, along with compressing the silicone accordion shape, and delivers the

higher concentration of oxygen.

Pros

16% to 21% oxygen increase is achieved.

Intuitive “pump-like” use would require little if any training.

Cons

Uses materials which may price the device out of competing in the market.

Use of porous silicone may lead to instances of failure in the mechanical operation of

the device.

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Additional Concept Ideation

39

40

41

Additional Final Design Iterations

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Appendixes-D Radius(cm) Height(cm) Volume Cubic

cm(ml)

1 159.1549 500

1.2 110.5243 500

1.4 81.2015 500

1.6 62.1699 500

1.8 49.1219 500

2 39.7887 500

2.2 32.8833 500

2.4 27.6311 500

2.6 23.5436 500

2.8 20.3004 500

3 17.6839 500

3.2 15.5425 500

3.4 13.7677 500

3.6 12.2805 500

3.8 11.0218 500

4 9.9472 500

4.2 9.0224 500

4.4 8.2208 500

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4.6 7.5215 500

4.8 6.9078 500

5 6.3662 500

5.2 5.8859 500

5.4 5.458 500

5.6 5.0751 500

5.8 4.7311 500

6 4.421 500

6.2 4.1403 500

6.4 3.8856 500