Don’t we all love homemade food? Nothing like all kinds of yummy stuff in the fridge!!! But wait a minute? Fake bones in Jell-O? Cords and tubes sticking out of bologna roll? 5 boxes of dark blue gelatin? Modelling balloon wrapped in chicken breast and clingy plastic? And what is that zip-locked goo??? None looks quite that edible, but the concept is brilliant IMHO! Just as brilliant and amazing as bedside ultrasonography itself.
Ladies and gentlemen, we are talking about revolutionary homemade models for ultrasound education. Who on earth needs the expensive simulators?! Let alone affording them… I’m telling you – the magic you can whip up with some gelatin and related ingredients is pretty exciting. To be honest, I don’t think there is enough evidence that high-fidelity (meaning pricey) phantoms perform any better when it comes to transfer of simulation-learned skills into clinical practice. If surgeons can learn laparoscopy on boxes, we can surely teach some basic ultrasound techniques on homemade goodies! Combine that with harmless „experiments” on real people, and your students scan like pros in no time. Get to work folks! A lot of „cooking” and teaching to do! Don’t forget we are aiming at „ultrasound first” for any possible imaging needs, because it’s „safe, effective and affordable”.
I did some digging around the net and I came up with quite a few gelatinous or meaty inspirations for your ultrasound sim lab needs. Let me show you what’s out there! Please refer to the individual links for detailed recipes and tips. All the links should be open access – please let me know if you have any trouble getting to a particular phantom.
No scanning without ultrasound gel! While some may use water, lotion (your transducer won’t like it though) or even spit (imagine the looks) :-), I’d recommend getting the recipe from Dr. Boughton’s blog. It’s edible (unless you add EDTA for bacteriostatic properties) and environmentally friendly. Super easy to make!
Ingredients/equipment: kitchen utensils, guar gum, salt, water, (EDTA)
Some people like it on their sandwich (weirdos, right?), while Drs. Wells and Goldstein turned bologna (polony) meat into a training model for ultrasound-guided procedures. Perfect for vascular access and nerve blocks. It can be constructed in less than 5 minutes. Make sure you get the finely minced roll (0.5 kg works best), so it’s not too echogenic. Pork worked best for them, but it might differ locally. Phantom is great and gives you a „hands-on” feel – it’s important to achieve that probe/needle dexterity prior to attempting any procedures on real patients. Now it’s been made even easier: „just fill with water and block off with a plastic cork” 😉 says @docmikewells.
Ingredients/equipment: 0.5 kg bologna roll, hand drill with a 12-mm bit, IV infusion set, bag of saline, red dye, kitchen cutting board, drape, cork, thin wire, 600-mm woven nylon shoelace, tape
Yet another variation for vascular access training in case you are a vegan or vegetarian and the smell of bologna meat makes you particularly uncomfortable. Check out Dr. Kendall’s model! I’ve tried adding some dark food dye to make the Penrose drains invisible. It worked like a charm.
Ingredients/equipment: water, unflavored gelatin, sugar-free Metamucil, latex tubes and cord to tie them off (Penrose drains – 0.5 in. for neck/femoral, 0.25 in. for brachial vessels), rectangular Pyrex glass cake pan (17 × 27 × 5 cm), non-stick spray
When I thought I’ve seen it all, Dr. Rippey sent me a link to his vascular phantom lecture. Wow – less than 5 minutes and your vascular chicken devollaie is ready to use. Seems like a great model for group training sessions as it lasts for any 20 to 50 uses.
Ingredients/equipment: water, red dye, chicken breast, modelling balloons in two different widths and clingy plastic wrap
This ocular model is just ingenious, isn’t it? You can use it to practice normal ocular exam, ocular FB, elevated ICP with increased optic nerve sheath diameter (ONSD), lens luxation, vitreous hemorrhage or even retinal detachment. How cool is that!!! Critical Ultrasound Journal is an open access source – so please refer to Dr. Gonzales’ article for all the details on pretty easy assembly. Beware – you might get addicted to the journal for other ultrasound references.
Ingredients/equipment: unflavored gelatin, 70% ethanol, plastic microwave-safe bowl, measuring cup, aluminum paper, skin lubricant (oil), aluminum rod (1 mm thick, 1.5 cm wide and 40 cm long) – you can use a Zimmer splint and just rip off the foam, spoon, electric hand mixer and a mixing bowl
In case you desperately wanted to eyeball a different ocular phantom, good news is: Dr. Lewiss’ team has something for ya! You’d never guess what they used to mould their models! Anyone seen the colorful plastic balls filled with candy in a vending machine at the supermarket entrance? Yep – the very ones! Looks like they do the trick! And if you add a fluid filled latex glove underneath the posterior portion of the model, you can simulate a retrobulbar hematoma.
Ingredients/equipment: 250 mL of water, 3 packets of unflavored gelatin, 1 tablespoon of psyllium powder, round plastic mold, size 15 scalpel, ECG sticker with metal snap for lead attachment, 18-gauge needle, Elmer?s Glue or casting plaster, balloon or latex glove
Got some spare ribs? Chicken breast? Wait!!!! Don’t throw them on the grill – I am not that hungry! I just want to build a thoracic phantom. I found this mind blowing recipe in Dr. Rippey’s thoracic cookbook. Maestro – he must have built hundreds of models. Anyways, with this relatively inexpensive and easy to assembly phantom (+/- modifications) you can practice identifying a variety of chest pathologies such as pleural effusion or empyema (just add a teaspoon of Metamucil), pneumothorax, lung point and interstitial edema. You can even „fake” a normal ventilating lung. I’d never think it’s so easy to simulate lung ultrasound with a sponge! Damp one for normal lung and wet one for interstitial edema. Want to practice thoracentesis? You got it! Just keep in mind that you’d need to replace the fluid bags after every 10 attempts or 30-45 minutes of poking it with the needle. Have a few spare ones ready, and switch as needed.
Ingredients/equipment (effusion/thoracentesis): plastic bucket, pork rib / loin, resealable, slide-locking plastic bags, synthetic, fine-holed sponge, water, psyllium husk (Metamucil), strong adhesive tape, absorbent sheet and kidney dish
Ingredients/equipment (normal lung/pneumothorax/pulmonary edema): shallow tray (2-3cm deep), water, chicken breast or pork ribs, fine-holed synthetic sponge
Here a quick mention of a very simple hand model to explain the lung sliding concept. Dr. Shokoohi suggests using your own palms! While scanning your own hand palm in transverse, you ask a second person to place their fingers on the dorsum of your hand sliding the skin back and forth. Concept applicable in B-mode (+/- color Doppler) and M-mode to show „lung” sliding or its absence and „lung point”.
Since we are in the chest, let’s talk ultrasound-guided pericardiocentesis. One of the most exciting procedures, short of ED thoracotomy. We all know that blind attempts have a very high failure and complication rates. Thanks to ultrasound use, you can be a cardiac hero, but if I were you, I’d give it a few „wet” runs prior to approaching tamponade on a real patient. Check out Dr. Zerth’s model!
Ingredients/equipment: 16 oz plain gelatin, 16-inch diameter ??punching balloon?? (available at party store), golf ball, red and green food coloring, non-stick cooking spray, wooden cooking skewer, 4 oz surgical iodine solution, 4 quarts cold water, 200-250 ml water, dyed red, 4-quart cubical plastic food storage container (hot and cold tolerant), 6-quart tall stock pot or saucepan, candy thermometer, refrigerator, stove
Now a special treat for the PEMPOCUS educators. Simple and ingenious intussusception phantom. Colorful and attractive as you’d expect for anything pediatric ;-). Dr. Alex Arroyo is the brain behind this project. Apparently made out of water snake toys. For those of you who need a Google consult in order to unravel the mystery of the water snake toys, here is the explanation: long water filled balloons with an open internal lumen. So you get a bunch of those and glue them to the bottom and a deep plastic bin. You use a single water snake to simulate a normal bowel. You stuff a larger one with a smaller one and so you get the sonographic looks of intussusception. No cheating though – fill the bin with a gelatinous mold of some sort. Dr. Arroyo used Psyllium to enhance appearance, dyed it opaque and placed in a refrigerator to harden. This phantom will last for about 1 week – just long enough to train an army of SonoNovices.
Ingredients/equipment: a few water snake toys, gelatin prepared as in any of the above recipes, Psyllium, dark food dye, large plastic bin
Let’s not forget about some haute cuisine… Hard tofu with angel hair pasta fancied in a bundle of 5? Sounds like an unbeatable nerve block simulator? I spotted it on Twitter – mentioned by my friend and hero: Dr. Rob Huang.
Not a big tofu fan? Finesse of a tender pork loin appeals to you more? Next time you prepare it, save an extra piece to make this HIGH FIDELITY NERVE BLOCK PHANTOM. The original recipe can be found in the Critical Ultrasound Journal – open access indeed! It is quite easy to manufacture so don’t let that CAT 5 ethernet cable convince you otherwise.Ingredients/equipment: Store-bought pork loin, 1 CAT 5 ethernet cable cut longer than pork loin, 1 peripheral IV tubing cut longer than pork loin, 10 cc syringe and starter IV connector to pressure inject, ultrasound gel, 1 straight Kelly clamp, 1 long Kelly clamp
And last, but surely not least, let’s mention the lumbosacral spine phantom. Drs. Dubiel and Kearsley developed it as a training model for ultrasound-guided neuraxial blockade, but I can definitely see its application for US-guided LP.
Ingredients/equipment: plastic lumbosacral spine model, plastic shoe box, epoxy adhesive (to mount the spine in the box), 300g gelatin, 4 L of warm/hot water, 1 cup of chlorhexidine, adhesive plastic sheet, (I’d add dark food dye if you want to make the spinal model invisible)
- Most phantoms can be made with readily available food and household items
- Consider adding chlorhexidine or EDTA for bacteriostatic properties
- Gelatin blocks made at a lower temperature result in a more desirable phantom
- If water is too hot – it can burn gelatin when added
- Use 10% (100 mg per cc of liquid) solution of gelatin (e.g. 100 g or gelatin per 1 L of water – do the math for the amount you need)
- Gelatin is clear – use food dyes
- Layered production process is advised for any kind of inclusions such as vessels, foreign bodies or cysts
- Cysts can be simulated with water-filled balloons, tips of examining gloves, grapes, or glycerine suppositories – though models need to be reconstructed after drainage
- Pipette bulb clipped with kitchen clip can be used to simulate a cyst – place it on the bottom – it will self-seal even after multiple needle punctures – can be drained and refilled multiple times
- Masses are simulated with carrot pieces, macaroni, olives or hot dog pieces
- Latex tubes (Penrose drains) or modelling balloons can be used to simulate vessels
- Refrigerate the models when not in use to extend their durability (but don’t freeze them, or they’ll crack)
- Use clear adhesive plastic or strip of gelatin impregnated gauze on top of your gelatinous phantoms to protect them from pressure damage
- Re-usable latex coating can increase durability
- Hydrocolloid skin dressings can be used to protect the gelatinous phantom surface – increase durability and probably reduce bacterial propagation
- Models should be kept in airtight containers when not in use
- Gelatin blocks can be reused – (re-melt & use again)
- Electric mixer, handheld drill, stove and refrigerator are the major appliances used
I am hoping you’ll find this overview useful. I apologize for non-scientific references in the text. Authors, please feel free to contact me for any updates or changes. Readers – any suggestions, tips or additional phantom recipes are obviously welcome!
Ultrasound, teach and spread the message of #FOAMed!
1. Creating thoracic phantoms for diagnostic and procedural ultrasound training – AJUM Available at: http://www.minnisjournals.com.au/ajum/article/Creating-thoracic-phantoms-for–diagnostic-and-procedural–ultrasound-training–290. Accessed 1/14/2013, 2013.
2. Anaesthesia Newsletters | AAGBI Available at: http://www.aagbi.org/publications/anaesthesia_news/2011. Accessed 3/15/2013, 2013.
3. Althoff S, Sudhir A, Woods WA. A study of the surface characteristics of homemade ultrasound phantoms Critical Ultrasound Journal. 2010; 2010;2:53-57.
4. Bellingham GA, Peng PW. A low-cost ultrasound phantom of the lumbosacral spine Reg Anesth Pain Med. 2010;35:290-293.
5. Bude RO, Adler RS. An easily made, low-cost, tissue-like ultrasound phantom material J Clin Ultrasound. 1995;23:271-273.
6. Chao SL, Chen KC, Lin LW, Wang TL, Chong CF. Ultrasound Phantoms Made of Gelatin Covered with Hydrocolloid Skin Dressing J Emerg Med. 2013.
7. Jafri F, Runde D, Saul T, Lewiss RE. An inexpensive and easy simulation model of ocular ultrasound that mimics normal anatomy as well as abnormal ophthalmologic conditions J Ultrasound Med. 2011;30:569-573.
8. Kendall JL, Faragher JP. Ultrasound-guided central venous access: a homemade phantom for simulation CJEM. 2007;9:371-373.
9. Lo MD, Ackley SH, Solari P. Homemade ultrasound phantom for teaching identification of superficial soft tissue abscess Emerg Med J. 2012;29:738-741.
10. Shokoohi H, Boniface K. Hand Ultrasound: A High-fidelity Simulation of Lung Sliding Acad Emerg Med. 2012; 2012;19:E1079-E1083.
11. Wells M, Goldstein L. The polony phantom: a cost-effective aid for teaching emergency ultrasound procedures International Journal of Emergency Medicine. 2010; 2010;3:115-118.
12. Zerth H, Harwood R, Tommaso L, Girzadas DV,Jr. An inexpensive, easily constructed, reusable task trainer for simulating ultrasound-guided pericardiocentesis J Emerg Med. 2012;43:1066-1069.
13. Sparks S, Evans D, Byars D. A low cost, high fidelity nerve block model Critical Ultrasound Journal. 2014, 6:12.