Microsurgery in Otology 01 24 02 - Department of Computer Science · 2002-01-25 · Instruments wSawbones Corporation wDentsply Caulk Corporation wHarwick Chemical wJeneric / Pentron

Otologic Surgery

Daniel L. Rothbaum, MD

Jaydeep Roy, PhD

Louis L. Whitcomb, PhD

Russell Taylor, PhD

Gregory Hager, PhD

Dan Stoi

John K. Niparko, MD

Howard Francis, MD

Otologic Surgery

w Operating microscopew High dexterityw Constrained access

n Restricted range of motion

n Obstructed view

Ear Anatomy

wExternal earwMiddle earw Inner ear

External Ear

w Auriclew External auditory canalw Tympanic membranew Canal dimensions

n 1 cm diametern 2.5 cm long

Middle Ear

w Tympanic membranew Ossicles

n Malleusn Incusn Stapes

w Oval windoww Round windoww Eustachian tube

Myringotomy and PE Tubes

w Recurrent otitis mediaw Most common ear

surgeryw Approximately 1.4

million tubes placed annually

Myringotomy and PE Tubes

Tympanoplasty (type I)

w Reconstruct eardrumw Secondary to chronic

middle ear infections and non-healing perforations

Tympanoplasty with Ossicular Reconstruction

w Replace malleus (type II) or malleus and incus (type III) with prosthesisw Eardrum repair (as

necessary)

Tympanoplasty withOssicular Reconstruction

w Replace all three ossicles (stapes, incus, malleus) with prosthesisw Type IV tympanoplastyw Repair eardrum (as

necessary)

Stapedotomy

w Otosclerosis with stapes footplate fixationw Prosthetic stapes

(piston prosthesis)

Inner Ear

w Cochleaw Semicircular

canalsw Utricle and

Saccule

Cochlear Implantation

w Sensorineural hearing lossw Electronic stimulation of the cochlea

Considerations in Otologic Surgery

Considerations in Ear Surgery

wAccessn Space versus invasiveness trade-off

wManipulationn Confined spacesn Micro-manipulations

Transmeatal Approach

w Most minimally invasive approachw Confined space

n Decreased range of motion

w Coaxialn Reduced depth

perceptionn Obstruction of view

Limitations of Microsurgery

uLimitations- Positional accuracy (15-20 microns)- Optical limitation of 10 microns

uReducing limitations will:- Increase surgical performance- Allow new surgical procedures- Make surgery better, safer, faster, cheaper

Conceptual Overview

Part I: Stapedotomy• Use stapedotomy as a model procedure to

develop a robotic-assist for otologic surgery• Improve existing surgeriesPart II: Accessing the Scala Media• Use robotic assistance to permit new surgical

approaches

Part I: Middle Ear Surgery

Stapedotomy

Part I:Stapedotomy

w Technically difficult operationw Clear variations in outcome based on surgeon

experiencew Potential complications

n Hearing lossn Vertigon Tinnitus

Applying the Steady Hand robot to Stapedotomy

w Fenestration of the stapes footplate with a micro-pick

w Crimping of the piston prosthesis to the incus

Steady Hand Robot

Steady Hand in Stapedotomy

Fenestration Trials

Force Scaling:

w Tactile feedbackw Test various robot

modes (vs. free-hand):n Unscaled force feedbackn Amplified force

feedback

Locating the Fenestration:Displacement

w Mark desired fenestration site

w Before and after images

w Measure difference between centers of desired and actual fenestrations

w Displacement (mm)

Forces at the Oval Window:Load Cell Measurements

w Max Force (N)

w Cumulative Force (Ns)

Steady Hand in Stapedotomy

Fenestration TrialsDATA

Free-Hand vs SH 1:1 vs SH 2:1Fellows & Attendings TOGETHER

1-way ANOVA0.0875.356.086.43Max Force

(N)

37.83

0.150

SH Robot1:1 Force Feedback

(mean)

0.081

0.648

P-value

1-way ANOVA

1-way ANOVA

Test

47.43

0.160

SH Robot2:1 Force Feedback

(mean)

69.93Cumulative Force (Ns)

0.178Displacement (mm)

Free-Hand(mean)

Free-Hand vs. SH Robot 2:1Adjusted for Fellow/Attending

0.04

0.08

0.032

R2

Robotic Assistance

Surgeon

Independent Variables:

0 = Free-Hand1 = SH Robot

with 2:1 Force Scaling

0 = Fellow (F)1 = Attending

(A)

0.17

0.04

0.60

P-value

-22.09Cumulative Force (Ns)

-1.08Max Force (N)

-0.017Displacement (mm)

Coefficient(Robotic

Assistance:0=FH; 1=SH

2:1)

Dependent variable

(multiple linear regression)

DisplacementGrouping SH 1:1 & SH 2:1 together


0.81-0.006

Dependent Variable:Displacement (mm)

-0.023

Coefficient Value(mm)

Robotic Assistance

Surgeon

0 = Free-Hand1 = SH Robot with

either 1:1 or 2:1 Force Scaling

0 = Fellow (F)1 = Attending (A)

0.40SurgeonCoefficient

Robotic Assistance Coefficient

P-Value

DisplacementFH vs SH 2:1


0.601-0.017

Dependent Variable:Displacement (mm)

-0.037

Coefficient Value(mm)

Robotic Assistance

Surgeon

0 = Free-Hand1 = SH Robot with

2:1 Force Scaling

0 = Fellow (F)1 = Attending (A)

0.251SurgeonCoefficient

Robotic Assistance Coefficient

P-Value

Fellows vs AttendingsFH, SH 1:1 & SH 2:1 TOGETHER

Student t-test for 2 samples0.845.895.97Max Force

(N)

57.99

0.166

Fellow(mean)

0.26

0.75

P-value

Student t-test for 2 samples

Student t-test for 2 samples

Test

44.66

0.159

Attending(mean)

Cumulative Force (Ns)

Displacement (mm)

Fellow vs. Attending:Free-Hand ONLY

Student T-test for 2 samples0.010.1000.236Displacement

(mm)

Student T-test for 2 samples


Test

0.92

0.72

P-value

71.53

6.60

Attending(mean)


6.30Max Force (N)

Fellow(mean)

Dependent variable

Fellow vs. Attending:SH 2:1 ONLY


(mm)



Test

0.36

0.72

P-value

39.46

5.22

Attending(mean)


5.46Max Force (N)

Fellow(mean)

Dependent variable

FH vs. SH 2:1:Fellows ONLY


(mm)



Test

0.55

0.25

P-value

54.87

5.46

SH 2:1(mean)


6.30Max Force (N)

FH(mean)

Dependent variable

FH vs. SH 2:1:Attendings ONLY


(mm)



Test

0.21

0.11

P-value

39.46

5.22

SH 2:1(mean)


6.60Max Force (N)

FH(mean)

Dependent variable

Fenestration Trial Summary:SH Robot (vs. Free-Hand)

w Applies less force at oval window (particularly at 2:1 force scaling)n Maximum force: decreases 17% from 6.4 to 5.4 N

l p-value = 0.04

n Cumulative force: decreases 32% from 70 to 47 Nsl p-value = 0.17

w No real difference in ability to target the fenestration

Fenestration Trial Summary:Fellows (vs. Attendings)

w DISPLACEMENT:n Free-Hand

l Worse at targeting the fenestrationn SH Robot

l Improved targeting of the fenestration using the SH Robotl In contrast to attendings who have decreased ability to target the

fenestration using the robot

w FORCE:n Free-Hand

l No difference in forces applied at oval window (Maximum and Cumulative Force)

n SH Robotl No significant difference in effect of SH Robot on forces applied at

oval window (Maximum and Cumulative Force)

Steady Hand in Stapedotomy:Future Directions

w Enhance Robot Capabilitiesn More sophisticated control algorithmsn Force Scalingn Better end effectors

w Better match robot strengths to appropriate tasksn For example, fenestration versus crimping

w Animal trialsn If demonstrate improved performance measures with the

robot

Part II: Inner Ear Surgery

Accessing the Scala Media of the Cochlea

Hearing Loss

w 28 million people in the United States1

w People losing hearing earlier in life2

w Age-related hearing loss n 30% of adults 65 years and older3

n 50% of adults 75 years and older4

1 National Institute on Deafness and Other Communication Disorde1 National Institute on Deafness and Other Communication Disorders (NIDCD). rs (NIDCD). National Strategic Research Plan:National Strategic Research Plan: Hearing Hearing and Hearing Impairment. and Hearing Impairment. Bethesda, MD: HHS, NIH, 1996.Bethesda, MD: HHS, NIH, 1996.

2 2 WallhagenWallhagen, M.I.; Strawbridge, W.J.; Cohen, R.D.; et al. An Increasing pre, M.I.; Strawbridge, W.J.; Cohen, R.D.; et al. An Increasing prevalence of hearing impairment and associated risk valence of hearing impairment and associated risk factors over three decades of the Alameda County Study. factors over three decades of the Alameda County Study. American Journal of Public HealthAmerican Journal of Public Health 87(3):44087(3):440--442, 1997.442, 1997.

3 Gates, G.A.; Cooper, Jr., J.C.;3 Gates, G.A.; Cooper, Jr., J.C.; KannelKannel, W.B.; et al. Hearing in the elderly: The Framingham Cohort, 19, W.B.; et al. Hearing in the elderly: The Framingham Cohort, 198383––1985. Part I. Basic 1985. Part I. Basic audiometric test results. audiometric test results. Ear and Hearing Ear and Hearing 11(4):24711(4):247--256, 1990.256, 1990.

44 CruickshanksCruickshanks, K.J.; Wiley, T.L.; Tweed, T.S.; et al. Prevalence of hearing l, K.J.; Wiley, T.L.; Tweed, T.S.; et al. Prevalence of hearing loss in older adults in Beaver Dam, Wisconsin: oss in older adults in Beaver Dam, Wisconsin: TheThe EpidemiologyEpidemiology of Hearing Loss Study. of Hearing Loss Study. American Journal ofAmerican Journal of EpidemiologyEpidemiology 148(9):879148(9):879--886, 1998.886, 1998.

Hearing Aids

w Only 25% of those who could benefit from a hearing aid actually use one1

w $1.5 billion market worldwide2

11 PopelkaPopelka, M.M.;, M.M.; CruickshanksCruickshanks, K.J.; Wiley, T.L.; et al. Low prevalence of hearing aid use am, K.J.; Wiley, T.L.; et al. Low prevalence of hearing aid use among older adults with hearing ong older adults with hearing loss: The Epidemiology of Hearing Loss Study. loss: The Epidemiology of Hearing Loss Study. Journal of the American Geriatrics SocietyJournal of the American Geriatrics Society 46(9):107546(9):1075--1078, 1998.1078, 1998.

2 2 Baker, S.; Palmer, A.T. Baker, S.; Palmer, A.T. A microchip in your ear: the Danes’ lead in miniature audio spaA microchip in your ear: the Danes’ lead in miniature audio spawns a slew of fresh applications: wns a slew of fresh applications: Business Week Online, Aug 9, 1999.Business Week Online, Aug 9, 1999.

Pathophysiology of Hearing Loss

w Conductive hearing lossn Problem in conduction of the

acoustic signaln Outer and Middle ear

w Sensorineural hearing lossn Problem in conduction and/or

processing of the neural impulse

n Inner Ear, Auditory Nerve, Brain

Sensorineural Hearing Loss

w Loss of inner hair cellsw Located in

the scala media of the cochlea

Surgical Problem:Access the Scala Media

w Insert a needle in the Scala Median Deliver therapyn Hair cell

regenerationn Treat cause instead

of symptom

Defining the problem:Access the Scala Media

w Navigationn 20 micron

resolutionw Positioning

n 25 micron resolution

w Injectionn 1 nanoliter

Navigation:Imaging the Scala Media

Navigation:Imaging the Scala Media

Academic Acknowledgements:

w MADLABn Eugene de Juann Patrick S. Jensenn Aaron Barnesn Sue L. Wun Terry Shelleyn Jay Burns

w ERCn Rajesh Kumarn Jason Wachs

w Surgeonsn John Niparkon Howard Francisn Lawrence Lustign Daniel Leen David Friedlandn Andre Haenggeli

w Materials testingn Robert Cammaratan Ingrid Shaon Han Seo Cho

Corporate Acknowledgements:

w Xomedn Tino Schulern George Bowen

w Storz Instrumentsw Smith and Nephew

Instrumentsw Sawbones Corporationw Dentsply Caulk

Corporation

w Harwick Chemicalw Jeneric / Pentron

Corporationw Kerr Corporationw Stryker Leibingerw Dow Corningw Ferro Corporation

Documents

Microsurgery in Otology 01 24 02 - Department of Computer Science · 2002-01-25 · Instruments wSawbones Corporation wDentsply Caulk Corporation wHarwick Chemical wJeneric / Pentron