About The Rubin Model

Two healthcare professionals performing an ultrasound procedure on a pregnant patient, with ultrasound images visible on the monitor screen.
Diagram showing a pig's abdomen with a needle inserting into the pork belly, targeting the fetus inside the amniotic sac within the abdomen.

A Novel Simulation System to Teach Intrauterine, Intrafetal, and Intracardiac Injection

The ability to induce fetal demise is an advanced obstetrical skill that permits expansion of abortion care to later gestations without risking an unintended live birth, but it is a skill that is not routinely taught in residency and abortion training programs. 

The Rubin Model is a high-fidelity system to teach ultrasound-guided intra-amniotic, intrafetal, and intracardiac injections in a low-risk simulated setting, before incorporating this skill into clinical practice.  It can also be used to teach amniocentesis, amnio-infusion, and other intrauterine procedures.

Components of The Rubin Model Simulation System

The Rubin Model simulation system consists of three primary components

Medical ultrasound machine and a laser device on a hospital bed.

The Rubin Model base

The Rubin Model base can be 3D-printed at home.  A free 3D-print file and assembly instructions can be found here. 

Pre-assembled Rubin Model bases can be purchased here

The Rubin Model base is reusable and dishwasher-safe for easy cleaning

Medical ultrasound machine with monitor, keyboard, and transducer probe, and a spherical object on a black rubberized platform in a clinical setting.
Ultrasound image showing a fetus inside the womb, with various measurement and setting labels on the screen.

The Rubin Model balloon simulation system

Utilizes a series of nested balloons to simulate the fetal heart, fetus, and amniotic sac. Balloons are coated in sealant to permit repeated puncture

  • The fetal heart balloon contains an echogenic fishing sinker target, and red fluid (“blood”) which can be aspirated to confirm intracardiac needle position

  • The fetus balloon contains the fetal heart and gelatin so that the fetus has mass, and can move independently within the amniotic sac

  • The amniotic sac balloon contains the fetus balloon and water

A video describing the Rubin Model balloon simulation system and appearance on ultrasound can be found here. 

Instructions for building the Rubin Model balloon simulation system can be found here.

Supplies can be self-sourced, or purchased as part of the Rubin Model kit here.

Pre-assembled balloon simulation systems can also be purchased here, and can be frozen indefinitely for future use.

A veterinary ultrasound machine displaying an ultrasound image of a developing fetus, with a cutting of raw pork on a black cutting board in the foreground.
Medical ultrasound probe connected to an ultrasound device, placed on a draped surface beside a black rectangular X-ray or imaging platform with a large, folded medical specimen or tissue sample on top.

Skin-on pork belly

Realistically simulates maternal skin and subcutaneous tissue

Pork belly is NOT included in the Rubin Model kit and must be sourced separately

A Kombucha SCOBY can be substituted for pork belly, as a vegan/Kosher alternative

A video demonstrating use of the Rubin Model to simulate ultrasound-guided intracardiac injection can be found here

Appearance of the Rubin Model on Ultrasound

Simulated Intracardiac Injection Using the Rubin Model

Medical ultrasound machine with a probe and a black rubber mold on a hospital bed, with a monitor displaying an ultrasound scan.
An ultrasound machine with a monitor displaying a scanned image, a keyboard, and control panel. In front, there is a white spherical object on a black frame labeled 'RUBIN 3000' placed on a medical drape.
Ultrasound machine screen displaying an image of a fetus, with a piece of raw pork placed on a black mat in front of the machine.
Ultrasound image showing a developing fetus inside the womb, with visible head and body.