Review of simulation model for education of point-of-care ultrasound using easy-to-make tools

Table 1 Ingredients and classification of simulator according to surrounding materials used in simulators

Surrounding materials	Ref.	Brand of main materials (A)	Ingredients for echogenicity (B)	Other ingredients (C)	Ratio or amount (A: B: C)	Target simulator
Gelatin based	Lo et al[18]	Jell-O gelatin cherry flavor (Kraft Foods, Northfield, IL, United States )	Sugar-free Metamucil (P and G, Cincinnati, OH, USA) brand psyllium hydrophilic mucilloid fiber	NA	12:4 tablespoons in 1 L water	Soft tissue abscess
	Wilson et al[53]
	Chao et al[23]	Unflavored gelatin powder, not mentioned brand name	sugar-free psyllium fiber (Metamucil Sugar Free; P and G)	NA	40 g: 20 g in 250 mL water	Soft tissue abscess, central vein access, foreign body
	Seguin and Tessaro[29]	Beef gelatin powder, not mentioned brand name	Orange colored psyllium fiber (Metamucil sugar free; P and G)	NA	90 mL: 60 mL in 500 mL water	Intubation
	Merali et al[13]
	Do and Lee[28]	Gelatin, not mentioned brand name	Agar, no mentioned brand name	NA	20 g:1 g in 60 mL water	Lung, A-lines, B-lines, pleural effusion
	Zerth et al[26]	Plain gelatin, not mentioned brand name	NA	Green and red food coloring, surgical iodine solution	16 oz (473 mL): several drop of coloring agent + 120 mL iodine in 4 quarts (3785 mL) water	Pericardial effusion
	Cuévas Gonzales[25]	Unflavored gelatin, not mentioned brand name	NA	70% ethanol	100 g: 30 mL in 500 mL water	Eye (normal, foreign body, ONS, dislocation of lens, vitreous hemorrhage, retinal detachment)
	Murphy et al[15]	Unflavored gelatin, not mentioned brand name	sugar-free psyllium powder (e.g., Metamucil Sugar Free Dietary Fiber Supplement; P and G)	NA	Not mentioned gelatin amount, one tablespoon Metamucil in 250 mL water	ONS
	Soucy et al[27]	Sugar-free gelatin, not mentioned brand name	Metamucil (P and G)		20 g: 10 g (1 tablespoon) in 250 mL water	Skull fracture
	Amato et al[24]	Unflavored gelatin, not mentioned brand name	NA	NA		Vascular access
	Cheruparambath et al[22]	Plain gelatin, not mentioned brand name	Coarsely ground finger millet (Eleusine coracana) flour	NA	15 g: 20 g in 1.2 L water	Vascular access
	Chao et al[23]	Unflavored gelatin, not mentioned brand name	Sugar-free psyllium fiber (Metamucil Sugar Free; P and G)	NA	40 g: 20 g in 250 mL water	Vascular access
	Rathbun et al[39]	unflavored Knox gelatin (Kraft Foods)	Sugar-free psyllium hydrophilic mucilloid fiber (sugar-free Metamucil; P and G)	NA	4 envelopes of Knox gelatin add 1 tablespoon of Metamucil (2 cups a of cold water)	Nerve block
Agar based	Earle et al[32]	Agar, not mentioned brand name		Flour (1 teaspoon) Red dye ethanol	38 g: 750 mL water (for 5% model) Compare 4 different concentrations (10%, 7.5%, 5%, 2.5% by weight)	Vascular access
	Nikitichev et al[33]	Agar (A7002; Sigma-Aldrich, St Louis, MO, United States)	NA	NA	5.5% by weight	Vascular access
Ballistics gel based	Morrow et al[35]	10% ballistic gelatin (Clear Ballistics LLC, Fort Smith, AR, United States)	Not required. Main material provided the sonographic appearance similar to human tissue	Clear gel dye if needed	NA	Soft tissue abscess
	Seguin and Tessaro[29]	ballistic medical gelatin #3 (Clear Ballistics)	psyllium fiber (Metamucil sugar free; P and G),	ballistic gelatin dye (Clear Ballistics)	250 mL: 5 mL: 45 mL	Intubation
	Young and Kuntz[38]	Ballistics gel, plastic Halloween skeleton thorax, plastic, manikin dress-form torso	NA	flesh-colored dye	NA	Pericardial effusion
	Morrow and Broder[34]	10% ballistic gelatin (Clear Ballistics LLC)	NA	NA	NA	Vascular access
	Amini et al[36]	Clear ballistic gel, not mentioned brand name	NA	NA	NA	Vascular access
Gel and wax based	Campo Dell’orto et al[20]	Gel wax (mixed store, 74532 Ilshofen)	Gel (Sonosid 1 L, Asid Bonz GmbH, 71083 Herrenberg, PZN 5362311)	Silicon skin/Thera-Band (Schmidt Sports PHYSIO TAPE, 42699 Solingen, Art.Nr. 111202)	NA	Pericardial effusion
	Daly et al[37]	Gel wax, flour, plastic artificial rib cage (axial skeleton)	NA	Silicon skin/Thera-Band (Schmidt Sports PHYSIO TAPE, 42699 Solingen, Art.Nr. 111202)	One gallon (4546 mL) gel wax + three tablespoons of flour	Pericardial effusion

NA: Not applicable; ONS: Optic nerve sheath.

Table 2 Method and time to produce of simulator according to surrounding materials used in simulators

Surrounding materials	Ref.	Heating	Refrigeration	Time to produce	Target simulator	Material for target simulator
Gelatin based	Lo et al[18]	Required	At least 4 h to firm	at least 5 h	Soft tissue abscess	Ultrasound gel
	Wilson et al[53]
	Chao et al[23]	Required	NA	NA	Soft tissue abscess, central vein access, foreign body	Pipette bulbs with water, latex rubber tube, NA
	Seguin and Tessaro[29]	Required	Required, overnight at 4°C	NA	Intubation. Trachea, esophagus	Holes, the block that came out when making the hole
	Merali et al[13]
	Do and Lee[28]	NA	NA	NA	Lung, A-lines, B-lines, pleural effusion	Dressing material (Medifoam®, Mundipharma, South Korea), balloon with water
	Zerth et al[26]	Required	Required for at least 2 h	NA	Pericardial effusion	Balloon with red food coloring water
	Cuévas Gonzales[25]	Required	Required for 2 h	NA	Eye (normal, foreign body, ONS, dislocation of lens, vitreous hemorrhage, retinal detachment)	Printing was required using aluminum paper mold on gelatin
	Murphy et al[15]	Required	Required	At least 30 min	ONS	Ping-pong ball, Vinyl tube + a stylet of 18-guage needle with metal tip
	Soucy et al[27]	Required	Required	NA	Skull fracture	Coconut
	Amato et al[24]	Required	Required	NA	Vascular access	Removed plastic tube
	Cheruparambath et al[22]	Required	Required	NA	Vascular access	Plastic tube
	Chao et al[23]	Required	Required	NA	Vascular access	Latex rubber tube
	Rathbun et al[39]	Required	Required	Approximately 2–3 h	Nerve block	Hot dog and straw
Agar based	Earle et al[32]	Required	Cooling at room temperature	NA	Vascular access	Penrose drain or long latex balloon
	Nikitichev et al[33]	Required	Cooling at room temperature	NA	Vascular access	Removed rod
Ballistics gel based	Morrow et al[35]	Required	Cooling at room temperature	Various time according to heating methods	Soft tissue abscess	Water
	Seguin and Tessaro[29]	Required	Cooling at room temperature	At least 1 h	Intubation	Marker embedded in surrounding materials
	Young and Kuntz[38]	Required	Cooling at room temperature, ice underneath the plastic manikin torso	NA	Pericardial effusion	Ping-pong ball in 250 cc normal saline bag
	Morrow and Broder[34]	Required	Cooling at room temperature	Less than 1 h	Vascular access	Latex tube
	Amini et al[36]	Required	Cooling at room temperature	NA	Vascular access	Removed plumbing tube
Gel and wax based	Campo Dell’orto et al[20]	Required	Not required	1 h	Pericardial effusion	Celluloid table tennis ball with red colored water in balloon
	Daly et al[37]	Required	Cooling at room temperature for 1 h	NA	Pericardial effusion	Ping-pong ball in 250 cc normal saline bag

NA: Not applicable; ONS: Optic nerve sheath.

Table 3 Special features of surrounding materials used in simulators

Surrounding materials	Available	Cost	Time	Durability and resusable	Infection	Coloring	Reality of the image	Reality of resistance	Need for additives
Gelatin based	Easy	More cheaper	Need more time (usually need refrigeration)	Weak	Relatively vulnerable	Easy	Very good	Relatively unrealistic	Often needed
			Approximately 2–3 h and can take up to 5 h
Agar based	Easy	Cheap	Relatively less time	Good	Relatively vulnerable	Easy	Good	Relatively unrealistic	Rarely needed
Ballistics gel based	Not difficult	Relatively expensive	Short preparation time (about 1 h)	Excellent	Resistant	Not difficult	NA	Great realism	Usually not required