What do I need to consider when selecting a DIY manikin?

A brief summary of some relevant scientific findings

Tuesday, 29.11.2022

Reading time 5 mins

The learning goals should influence manikin selection

The level of the learner, as well as the intended learning outcomes influence the criteria by which a DIY manikin should be selected. For example, if the goal is to achieve learning (and transfer) of correct compression recoil, it may be advisable to select a stiffer manikin that retains its ability to recoil over numerous practice repetitions. With a toilet paper roll trainer, full recoil is no longer possible after several compressions – the rolls “fatigue” (1). In this case, a manikin with realistic stiffness and the ability to recoil to the same position for many repetitions (e.g., a PET bottle model) may be important. If compression depth and recoil is not a goal, a simpler and softer tool such as a toilet paper trainer may be fine. 

Another question is whether the learnt skills should include ventilation, or whether the goal is compression-only CPR. Most studies that tested DIY models focused on compression-only CPR – the reason being that most deaths due to cardiac arrest occur outside the water and do not involve airway or breathing problems. Two exceptions for this rule are children, who usually arrest due to choking (and thus require rescue breaths along with compressions) and drowning victims who also arrest due to lack of oxygen in the brain. CPR with rescue breaths has a very high success rate in these two groups, which is why ventilation skill is a useful skill.

 

A further factor to consider when selecting a DIY manikin is the need for feedback. From motor learning research, we know that feedback given at the right time may be beneficial for learning and retention of skills (2,3). However, some findings in CPR skill learning contradict this idea. For example, a study by Sá-Couto (14) found that a group that trained on a traditional manikin with added feedback improved their performance to the same extent as a control group that trained on the same manikin without added feedback. Some authors would argue that constant feedback may lead to a reliance on it and may therefore have some negative effects on learning (4). Advanced manikins  provide feedback via sound or an LED light. But even simple ways to obtain knowledge of results, e.g., hearing the clicking of a jar lid, may benefit the learning process, as indicated by the positive results of Ohle’s research (1,5).

Individual factors that influence manikin selection

Other factors that may influence how the ideal DIY manikin should look, be built and function include age, strength, ability, education level, and income. A traditional manikin requires 35.5kg of force to compress to the required depth of 5-6cm (12). A child may struggle to produce this much force, but they may learn adequate CPR skills when practicing on a smaller, softer apparatus. When training school children, the question becomes relevant “do they really need to be able to compress 5-6 cm?” After one of our reality checks with a primary school, kids reported finding it more motivating to compress the DIY manikin compared to a Mini Anne model, because they were more successful at it.

How realistic does the manikin have to look?

realistic manikin
Manikins for emergency services training are becoming more and more realistic. 

In First Aid training, fidelity (i.e., “trueness”) of a simulation or practice scenario may be an important factor in predicting learning. The highest performance at a learned task can be achieved when important factors (so-called constraints) in the learning context are similar to those in performance context (6). Tanaka et al. (2017)’s work in Japan showed that participants preferred the traditional manikin as it was more life-like, and they felt better prepared, which shows that subjective factors may play a great role. Recent first aid and CPR simulation literature overall supports this claim and makes some arguments for high-fidelity manikins (7,8). 

 

However, more recent literature  points out that psychological factors during practice may be more relevant than physical attributes (9). The learner’s mental state, and environmental characteristics of the learning context should be as reflective of the performance context as possible. It is important to create realistic, stressful scenarios, but this may not require a lot of high-tech equipment (10). For example, practicing with a realistic manikin, involving the processes that cause scruples such as removing clothing or touching a stranger’s body, may be useful to increase willingness to act.

 

Women are less likely to receive CPR from strangers (11). This may be linked to scruples around touching or exposing someone’s body. However, even the most realistic hi-fi manikins are usually male, white, and featureless. In addition to provide female and different-sized and coloured manikins, one might also think about including the requirement of having to remove a bra, shirt, chest hair (for AED) etc.

IMG_20220813_091203

From our reality checks we learned that children required some visual similarity in order to be able to draw parallels between a simulation and real life. The children that practiced on a toilet roll and towel manikin reported that they struggled to see it as a human torso. The manikin was too abstract for them. A suggestion from practitioners was to add a head (e.g. balloon, carboard cut-out, hoodie) or to let the kids attach nipples (e.g., made of cardboard) on the towel to make the manikin look more realistic.

What materials to use?

Environmental sustainability remains a big concern for the DIY idea. In order for the idea to be adaptable in different contexts, a selection of different solutions, with different resources needs to be provided. For example, for a low-income region it may be a priority to use cheap materials, however, this may mean that waste products are used, such as plastic / PET bottles etc., which cannot be repurposed. Similarly, using t-shirts or more expensive products will lead to waste if these cannot be re-purposed. Some ingredients may vary between regions, for example a toilet paper roll does not have a strong cardboard core in all countries. In general, the ideal manikin model depends on location, socio-economic status of learners, and their motivation towards sustainability. Having a wide range of options and providing information about the environmental impact of the different materials, may be two ways to enable people to make environmentally sustainable choices.

References:

  1. Ohle R, Moskalyk M, Boissonneault E, Bilgasem A, Tissot E, McIsaac S. Is a homemade cardiopulmonary resuscitation (CPR) trainer non-inferior to a commercially available CPR mannequin in teaching high-quality CPR? A non-inferiority randomized control trial. Resusc Plus. 2021;6(February 2021):100134.
  2. Magill RA. The influence of augmented feedback on skill learning depends on characteristics of the skill and the learner. Quest. 1994;46(3):314–27.
  3. Salmoni AW, Schmidt RA, Walter CB. Knowledge of results and motor learning: a review and critical reappraisal. Psychol Bull. 1984;95(3):355–86.
  4. Schmidt RA, Wulf G. Continuous Concurrent Feedback Degrades Skill Learning: Implications for Training and Simulation. Hum Factors. 1997;39(4):509–25.
  5. Ohle R, Moskalyk M, Boissonneault E, Simmons K, McIsaac S. A homemade CPR trainer can enable real time practice during online hands only CPR training. Resuscitation. 2021;158(PG-71-72):71–2.
  6. Renshaw I, Chow JY, Davids K, Hammond J. A constraints-led perspective to understanding skill acquisition and game play: A basis for integration of motor learning theory and physical education praxis? Phys Educ Sport Pedagog. 2010;15(2):117–37.
  7. Cheng A, Lockey A, Bhanji F, Lin Y, EA H, Lang E. The use of high-fidelity manikins for advanced life support training–A systematic review and meta-analysis. Resuscitation. 2015;93(PG-142-9):142–9.
  8. Nimbalkar A, Patel D, Kungwani A, Phatak A, Vasa R, Nimbalkar S. Randomized control trial of high fidelity vs low fidelity simulation for training undergraduate students in neonatal resuscitation. 2015;8(PG-636):636.
  9. Beaubien JM, Baker DP. The use of simulation for training teamwork skills in health care: How low can you go? Qual Saf Heal Care. 2004;13(SUPPL. 1):51–6.
  10. Bredmose PP, Habig K, Davies G, Grier G, Lockey DJ. Scenario based outdoor simulation in pre-hospital trauma care using a simple mannequin model. Scand J TRAUMA Resusc Emerg Med. 2010;18(PG-).
  11. Blewer AL, McGovern SK, Schmicker RH, May S, Morrison LJ, Aufderheide TP, et al. Gender Disparities Among Adult Recipients of Bystander Cardiopulmonary Resuscitation in the Public. Vol. 11, Circulation. Cardiovascular quality and outcomes. 2018. p. e004710.
  12. Wanner GK, Osborne A, Greene CH. Brief compression-only cardiopulmonary resuscitation training video and simulation with homemade mannequin improves CPR skills. BMC Emerg Med. 2016;16(1):4–9.

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