0031 Adamgel: An economical, easily prepared, versatile, selfrepairing and recyclable tissue analogue for procedural simulation training

Abstract

BackgroundTeaching invasive techniques via simulation requires using phantoms. These teaching aids can be expensive, due in part to the cost of silicone material used. A progression of developments necessitated by lack of resources resulted in the creation of ADAMgel (Aqueous Dietary fibre Antifreeze Mix gel), a material that shows great promise for use in simulation phantoms.MethodologyWhile developing gelatine based ultrasound phantoms we accidentally discovered that the contrast medium routinely used with this medium the last 20 years (Ispagula husk – a dietary fibre laxative and food thickener) had some interesting properties. It transpired that if prepared at higher temperatures than employed in use as laxative at higher concentrations than used in food processing a gel formed which passed all the criteria for the perfect US medium.1,2 Searching for a suitable preservative among common substances found around the house we discovered preparation, if including antifreeze, is possible at a temperature higher than 100°C. This creates a stronger medium either by changing the already known temperature induced gel structure changes, or by liberating gel fractions known to have higher melting points.3 When using mono ethylene glycol (the commonest antifreeze) it forms a stable elastic polymer even without water.ResultsADAMgel can be prepared using ordinary kitchen utensils for <£2/kilo. It can be cast, folded, hot or cold pressed, layered, cut, moulded and made into thin films or strands. It is self-adherent and a model can be built incrementally incorporating other structures. It is selfrepairing and does not form needle tracts visible under ultrasound up to 18FG dilation. Diathermy or harmonic scalpel can both be used on it. In formal and informal feedback from anaesthetists and surgeons nobody has encountered a more realistic human tissue analogue.ConclusionADAMgel could make realistic phantoms for high fidelity simulation training more readily available.ReferencesBarnes L, Willers J, Hariharan S, Uncles D. Gauging the gel in Fybogel. Anaesthesia 2014;69:33Sultan S, Shorten G, Iohom G. Simulators for training in ultrasound guided procedures. Med Ultrasound 2013;5(2):125–131Farahnaky A, Askari H, Majzoobi M, Mesbahi G. The impact of concentration, temperature and pH on dynamic rheology of psyllium gels. J Food Eng 2010;100:294–301

Development of a Low-Cost, High-Fidelity, Reusable Model to Simulate Clamshell Thoracotomy

“…The soft tissues were simulated using Aqueous Dietary fibre Antifreeze Mix gel (ADAMgel), a recyclable, highly realistic and low cost tissue analogue that is easily made using standard kitchen facilities. 14 Two layers of ADAMgel of differing thickness backed with muslin cotton formed the subcutaneous tissue, while the superficial skin was a simulated using an ADAMgel/gellan mixture on a muslin backing (Figure 2). These layers were self-adherent, forming a single sheet, and this was clipped to the chest model using ‘bulldog’ clips.

Figure 2.The layers of the model’s soft tissue covering.

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“…Across both testing sessions, following use of the model, trainees were asked questions assessing its quality as a teaching tool. Cumulatively, between both testing sessions, responses were mainly from specialty registrars (14), with some from consultants (3), and a single response from a senior house officer and a medical student. Of the 19 responses, 17 (89.47%) agreed (Likert 4/5 and 5/ 5) the model was a reasonable substitute for practice, 19 (100%) agreed the model made a good training aid for inexperienced trainees, and 19 (100%) agreed other trainees should use the model before being involved in the procedure in practice (Table 1).…”

Paracentesis Model for Junior Doctors

“…A simple, cost‐effective simulation model, ANDREUS (ascites needle drainage replicator employing ultrasound), has been designed to overcome this. ANDREUS has been constructed using ADAMgel (aqueous dietary fiber antifreeze mix gel) as a soft tissue simulant to enable trainees to practice the technique under ultrasound guidance in a safe educational setting and thus be verified as competent before undertaking the procedure on patients …”