BME 273BME 273Fetal Stabilizer for Fetal Stabilizer for

Intrauterine SurgeryIntrauterine Surgery

Michael DinhMichael Dinh

Advisor: Dr. Joseph BrunerAdvisor: Dr. Joseph Bruner

Spina BifidaSpina Bifida

One of the most common debilitating One of the most common debilitating neural tube defect neural tube defect • Incomplete closure in the spinal column Incomplete closure in the spinal column

usually in the lower section during initial usually in the lower section during initial pregnancy.pregnancy.

Spina Bifida affects approximately 1 out of Spina Bifida affects approximately 1 out of every 1,000 newborns in the U.Severy 1,000 newborns in the U.S

Degree of Spina BifidaDegree of Spina Bifida Spina Bifida OccultaSpina Bifida Occulta

• Spina bifida occulta is a small gap in one or more of the Spina bifida occulta is a small gap in one or more of the vertebrae. This is the mildest form of spina bifida as vertebrae. This is the mildest form of spina bifida as there is no apparent damage to the spinal cord.there is no apparent damage to the spinal cord.

MeningoceleMeningocele• Meninge (protective layer covering the spinal cord) Meninge (protective layer covering the spinal cord)

protrudes through the gap in the spinal column in a form protrudes through the gap in the spinal column in a form of a sac. The spinal cord itself remains intact and repairs of a sac. The spinal cord itself remains intact and repairs can be made with little or no damage. Least common can be made with little or no damage. Least common occuring form.occuring form.

MylemeningoceleMylemeningocele• Most severe form. This term is generally used Most severe form. This term is generally used

interchangeably with spina bifida. Spinal cord itself interchangeably with spina bifida. Spinal cord itself protrudes through the gap in the spinal column. protrudes through the gap in the spinal column.

Spina Bifida ManifestaSpina Bifida Manifesta Protrusion of spinal Protrusion of spinal

cord membrane, cord membrane, spinal cord, and nerve spinal cord, and nerve rootsroots

Spinal cord exposure Spinal cord exposure result in progressive result in progressive damagedamage

Most often found in Most often found in the lumbo-sacral the lumbo-sacral regionregion

Adverse AffectAdverse Affect

HydrocephalusHydrocephalus• Accumulation of spinal fluid in brain is Accumulation of spinal fluid in brain is

common among infants with spina bifidacommon among infants with spina bifida

Permanent weakness or paralysis in Permanent weakness or paralysis in lower extremity below defectlower extremity below defect

Loss of bowel and bladder control Loss of bowel and bladder control due to the nerve damage due to the nerve damage

Vanderbilt UniversityVanderbilt University

165 cases of spina 165 cases of spina bifida repairbifida repair• Age range of infants 19-Age range of infants 19-

30 weeks30 weeks

Mean operating time Mean operating time is about 87 minis about 87 min• Ranges from 62-131 Ranges from 62-131

minmin

Design ObjectiveDesign Objective

Design a fetal Design a fetal stabilizer to assist stabilizer to assist in surgeryin surgery• Hold fetus steady Hold fetus steady

while providing an while providing an opening for opening for operationoperation

ApproachApproach

Observe open repair Observe open repair of spina bifidaof spina bifida

Collect fetal Collect fetal biometrical databiometrical data

Look at similar device Look at similar device in handling fetusin handling fetus• Simpson Forceps: Used Simpson Forceps: Used

in deliveryin delivery

Fetal DataFetal Data

19 week old fetus19 week old fetus• 6 inches head to 6 inches head to

endend• Weight about 8.5 Weight about 8.5

ouncesounces• Abdominal Abdominal

Circumference Circumference about 133 mmabout 133 mm

• Width about 60 mmWidth about 60 mm

Device DesignDevice DesignTop View Front View

Side View

Device SpecificationDevice Specification

Overall Length: 20 Overall Length: 20 cmcm

Depth of Paddle Depth of Paddle Arm: 6 cmArm: 6 cm

Width of Paddle Width of Paddle Arm: 4 cmArm: 4 cm

Width of device: Width of device: 7.5 cm7.5 cm

Space b/w Arm Space b/w Arm Center: 6 cmCenter: 6 cm

Space b/w Arm Space b/w Arm bottom: 5 cmbottom: 5 cm

Width of opening: 5 Width of opening: 5 cmcm

Length of opening: Length of opening: 7 cm7 cm

Side handle about Side handle about 45 mm in length45 mm in length

ConclusionConclusion Design stabilizes fetus using forces Design stabilizes fetus using forces

presentpresent• Contracting uterine wall force & fetal outward Contracting uterine wall force & fetal outward

forceforce

Facilitate in operationFacilitate in operation• No need for retaining hooksNo need for retaining hooks

Simple in useSimple in use• Two piece deviceTwo piece device• Varying degree of adjustability for variation in Varying degree of adjustability for variation in

fetal sizefetal size