Additive Manufacturing Principles and Applications - MEC454

Additive Manufacturing – principles and applications MEC454 Week 3 – Medical applications of AM Candice Majewski (she/her) [email protected]  Why the big fuss about medical applications? Growing sector: Ageing population Increasing survival rates for major diseases...

Additive Manufacturing – principles and applications MEC454 Week 3 – Medical applications of AM Candice Majewski (she/her) [email protected]  Why the big fuss about medical applications? Growing sector: Ageing population Increasing survival rates for major diseases Cost constraints (especially for NHS) Patient expectations High value (not just financially…) Thanks to Professor Richard Bibb (Loughborough University) for providing much of the background information in this talk 2  All of this means we need new innovations Products New process chains In terms of medical devices, AM has the potential to influence both of these areas Customised devices Mass-produced devices Focus in this session is on customised devices 3  Customised devices, e.g.: Maxillofacial prostheses Dentures Dental aligners Custom orthoses Artificial limbs Burns splints Etc. Often as simple as wanting it to fit correctly 4  Customised devices to assist with surgeries, e.g.: Texas Children’s Hospita Drill guides Surgical planning models Texas Children’s Hospital 5  Or perhaps we want a customised implant itself, but... Often an AM device will cost substantially more to manufacture than a more traditional device… So why bother looking at it? 6  Sometimes it’s the general benefits of AM, e.g. Geometric complexity Fit to individual (we’re all shaped & sized differently!) Weight saving Fluid flow Cellular growth All of these could improve function of the device, but at higher cost … But, we often need to look further In other words, consider the whole process chain… 7  Traditional methods for producing customised devices: Often hand-made Labour-intensive Skill-dependent Slow Can be inaccurate Often involve one or more trips to a specialist May need adjustments/replacements if fit is incorrect Can involve physical contact… 8  Consider a burn mask Used for severe facial burns, to aid healing & prevent scar tissue formation Often worn more or less continuously in between reconstruction sessions http://www.hangerclinic.com/ 9  Traditional method of construction Apply plaster to the patient’s face to make a mould Plastic mask produced from this mould Very effective method, but… Can be painful Patients can become extremely anxious during the procedure 10  Traditional method of construction Hopefully you’re starting to see the benefits (including psychological) of a non-contact method of producing these masks… Various companies using non-contact scanning, combined with AM, to make moulds for these masks in a more user-friendly way Greater financial cost, weighed against patient benefit? http://www.hangerclinic.com/ 11  Another example – prosthetic leg 12  Traditional method of production Produce Manual Produce Fitting and physical mould finishing of socket from alignment of of remaining mould mould socket limb 13  So what’s wrong with this? Mould-making – needs to be performed in a load-bearing situation Can be painful (especially soon after injury) What if the patient moves? Wasteful – e.g. use of sacrificial mould Lots of manual steps in the process – finishing, fitting, alignment etc. May require new prosthetic after time passes E.g. changes in remaining limb shape, increased levels of activity, or general deterioration of the prosthetic (Process needs to repeat multiple times) 14  What if we scanned the remaining limb and used this data to 3D Print the socket? And what if the 3D Printed version was more expensive than a more traditional socket? Here’s where we need to start thinking about the whole process chain, and the effect on our stakeholders 15  So, who are our stakeholders? (In other words, who do we need to think about when making our decisions?) Spend a couple of minutes talking with the people near to you – who are the main stakeholders in this example? 16  So, who are our stakeholders? Patients Carers/family Medical Staff The NHS (think through how the considerations might be different in different countries) Others (employers, colleagues, Government, anyone else?) 17  If we look at the whole treatment process, rather than just the cost of device manufacture, we can start to see the potential benefits In each case, we need to consider the effects on each stakeholder. For purposes of today let’s focus on: Patient Medical staff NHS 18  Where to start? Look to remove stages of the process chain, e.g.: Minimise number of consultations (streamlining) Localised scanning and manufacture, with remote prosthetist input? (remove physical transport) Reduce manual labour Faster, improved quality & accuracy Reduces need for adjustments Ideally, we will benefit as many interested parties as possible in one go 19  Minimising consultations - who does this benefit? Patient Less travel to/from appointments Minimise time away from work Reduces stress associated with frequent visits Medical staff Can see higher numbers of patients NHS Reduction in number of missed appointments These cost over £700million per year!!! 20  Localised scanning and manufacture Patient Minimising travel (e.g. not travelling to visit specialist) Potential benefits from familiarity with local GP Medical staff (especially prosthetist) Focus on the specialist parts of the job NHS Lower transport costs (patient and product) Shortening of waiting lists 21  Reduced manual labour (need for re-adjustments) Patient Quicker treatment Less painful (both at treatment stage and during normal use of the product)) NHS/Medical staff Many of the same benefits from before Less wastage through removing the initial moulding process, replacements/adjustments Possibility of using scan data to ‘track’ progress? 22  An example to finish with – maxillofacial prostheses Based on the PhD/research of Dr Dominic Eggbeer (Cardiff Metropolitan University) You can download his PhD thesis if you’re interested - https://www.dominiceggbeer.com/downloads 23  Maxillofacial prostheses Every device is unique (location, geometry, colour, etc.) Increasingly important to produce an ‘exact match’ How can we use digital technologies to add value? Consider who is involved at each stage Let’s look at a tooling route (most similar to traditional) Dominic Eggbeer PhD thesis 24 Stage of process People involved Costs Patient consultation Patient, surgeon, Patient travel & prosthetist, nurse, accommodation, clinic time & receptionist staff salaries Impression taking Patient, prosthetist Patient travel & accommodation, staff salary, laboratory time, materials Design and Prosthetist, patient for Laboratory time, staff salary, manufacture of fitting of pattern materials, patient travel & pattern accommodation Production of mould Prosthetist Laboratory time, staff salary, from pattern materials Production of final Prosthetist, patient Laboratory time, staff salary, prosthetic (including materials, patient travel & colour-matching, accommodation fitting) 25  So where can we actually have an effect? Certain aspects must always be carried out: E.g. initial consultation must always take place Some areas where we can eliminate/replace steps of the process This example will focus on a tooling route, but think about what difference it might make if we were using AM to make the final product? What would be the advantages? What are the limitations? What improvements might we need to the AM process itself? 26 Stage of process Opportunities Potential to add value? Patient consultation Scan patient at See and scan patients in consultation batches Impression taking Eliminate patient visit Faster & more comfortable for (already has a 3D scan) patient, no travel, time off work, accommodation etc. Design and manufacture Remove/improve stages Schedule work in optimum of pattern (e.g. 3D CAD & AM to order (patient not required), produce pattern) reduced overheads Production of mould Remains the same Remains the same from pattern Production of final Remains the same Remains the same prosthetic (including colour-matching, fitting) 27  Summary Hopefully you can now see that the cost of manufacturing the device is often only a small fraction of the overall process cost. Think about: Whole treatment process What are the real costs of the current process? Who are the potential beneficiaries, and how can we provide benefits to everyone involved? Are there current bottlenecks that we can reduce? Where can we add value? (e.g. reducing patient visits, more accurate devices etc.) Consider this for other applications… 28  Any questions? 29 Additive Manufacturing – principles and applications MEC454 Week 3 – Polymer and other non-metal processes Candice Majewski (she/her) [email protected]  Today’s session: Focus on polymer AM processes. A very quick run-through of the basics – spend some of your independent learning time reading more about these processes. Links to some online videos included throughout. Some extra slides at the end of this presentation relating to ‘other’ materials. Please take a quick look at these processes, and ask if you would like more information about them and can’t find it!. 2 Material Extrusion 3  Fused Deposition Modelling Molten plastic extruded through a heated nozzle to create cross- section Chamber may be heated to just below melt temperature of the plastic Support structures for overhanging geometries http://www.custompartnet.com 4  Advantages Office friendly – raw materials not hazardous, although there is potential for fumes and particulates to be released during processing (but can be loud/hot!) Some companies (e.g. Materialise) make use of this for heating their facility Several available (often low cost) materials, some of which compare with traditional materials Coloured materials (often only one at a time) Range of systems available (size, speed, cost etc.) Soluble supports 5  Limitations Slow production of parts with large cross-sections Mechanical properties, particularly in z direction Surface finish can be poor Support structures can be difficult to remove Often only single colour at a time 6  A video! https://www.youtube.com/watch?v=yKHMmKqdI68 7  Personal systems Often defined as costing