Training with Ultrasound Phantoms

Introduction

In the past, formal clinical training would occur within a teaching hospital environment, or possibly at an outside course, using live patients.

Medical professionals are expected to continuously acquire new knowledge and skills while treating their patients. Medical simulations offer clinicians the opportunity for hands-on experience without involving patients [1,2].

Simulations provides a safe method for teaching necessary skills. Clinicians can carry out procedures, refine techniques, and build confidence, without putting patients at risk.

Training using ultrasound phantoms allow for safe introduction to clinical skills and is associated with improved in-hospital performance.

Tissue Simulation

Many materials have been employed to simulate human tissue in phantoms, including commercial manikins, agar, gelatin, and ballistics gel.  The issue is that many existing phantom tissues could be improved to provide higher fidelity ultrasound imaging and tactile sensation.

We have been developing the latest ultrasound phantom fabrication technology to enhance the training process.  Our experience developing augmented reality injection training models, has prepared us to pivot into the development of realistic ultrasound phantoms. 

We believe we will be able to help elevate the level of care delivered to patients and improve treatment outcomes, by improving access to higher quality models that will provide more lifelike training.

Realistic Ultrasound Models

Our goal is to create robust musculoskeletal medical simulations using anatomically accurate models of the body.  These models can be palpated, having the look and feel of a live patient. 

Realistic palpation, ultrasound visualization, and hypodermic needle electrode “feel” will add the ability to experience realistic patient encounters.  The treatment approach can be followed as the injection needle navigates through the tissue to its target. 

Important considerations include, attention to:

• Realistic palpation > improves haptic senses
• Hypodermic needle electrode insertion feedback
• Realistic hypodermic electrode needle drag
• Ultrasound muscle tissue pattern visualization > teaches how to identify target structures
• Ultrasound bone pattern
• Vital structure modelling (e.g. nerves, and blood vessels)
• Outer skin “look and feel”
• Maintenance of distinct muscle borders
• Self-healing tissue formulas

The ideal phantom reproduces the texture and resistance of human tissue, has sufficient ultrasound penetration, is easy to reproduce and repair, is non-perishable, transportable, affordable, and has clearly distinguishable targets [3].

What’s Out There

There are a wide variety of both commercial and homemade phantoms being used.  The challenge is finding a platform that is realistic enough to actually learn without the need to use your imagination that you are actually injecting into human tissue. 

Many of the available simulations fall short on our list of must have characteristics. In fact, when it comes to musculoskeletal applications there is pretty wide void in available simulations, short of knee joints.  Homemade versions do not usually share the material characteristics on our list either. 

In fact, they usually provide weak tactile feedback with an added issue of decomposition characteristic of organic materials, such as agar and gelatine.  Longer lasting materials, like ballistic gel, are generally too hard and resistive, and do not provide realistic tactile feedback. Lack of self-healing properties on more stable models, will mean shorter defined lifespans.

Our Approach

Our approach is quite different, as we have perfected an excellent, self-healing ultrasound tissue, which is palpation friendly, and provides the right tactile feedback and needle feel.

Future additions of both live and remote learning, will be supplemented with self-taught explorations using palpable models and augmented reality, to reinforce situational awareness with visualization of the anatomy, needle pathways to target, and integrated anatomical education.

References

[1] Ma IWY, et al. Use of Simulation-Based Education to Improve Outcomes of Central Venous Catheterization: A Systematic Review and Meta-Analysis. Academic Medicine. 2011; 86(9):1137– 1147. [PubMed: 21785310]

[2] Evans LV, et al. Simulation Training in Central Venous Catheter Insertion: Improved Performance in Clinical Practice. Academic Medicine. 2010; 85(9):1462–1469. [PubMed: 20736674]

[3] Sultan SF, Shorten G, Iohom G. Simulators for training in ultrasound guided procedures. Medical Ultrasonography. 2013; 15(2):125–131. [PubMed: 23702502]