hearrestore - nano-tera, 2016

8/17/2019 HearRestore - Nano-Tera, 2016

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Hear Restore: Robotic Cochlear Implantation

Stefan Weber

University of Bern


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• Cochlea implants

• Robotic cochlear implantation

• From research to product

2


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3

45’000 im

plants p.a.

Deaf patients

Cochlear Implants


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But: Inconsistent preservation of residual hearing

• No treatment for patients with partly impaired hearing

• Re-implantation in children causes further deterioration

Solution: Robotic cochlear implantation

• Consistent hearing preservation

• More patients to benefit from CI technology

• Better individual implant performance

• Enable future treatments (i.e. drug delivery)

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Robotic cochlear implantation

1. Software based planning

2. Robotic Drilling

3. Insertion of array

4.

Completion of surgery

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Advantages

•

Minimally invasive

• Potentially atraumatic

• Consistent array insertion


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Stage 1

Plan a safe route, optimal for insertion

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Gerber N., Bell B., Gavaghan K., Weisstanner C., Caversaccio M., Weber S. (2013): Surgical planning tool for robotically assisted hearing aid implantation, InternationalJournal of Computer Assisted Radiology and Surgery, June 2013, Int J Comput Assist Radiol Surg. 2014 Jan;9(1):11-20


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Fiducial placement

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• Standard screws

1.5!3 mm

Medartis

• Percutaneous

• Placed before CT

• Local anaesthesia


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Preoperative imaging

• Resolution: 150 micron

• Available in current scanners

We use

• Siemens SOMATOM

• Temporal Bone protocol

• 0.156 ! 0.156 ! 0.2 mm3


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Identify facial nerve

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1

Plan trajectory


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Defining cochlea access

1

Basal turn deviation

Wimmer et al. Semiautomatic Cochleostomy Target and Insertion Trajectory Planning for Minimally Invasive Cochlear Implantation. Biomed Res Int 2014


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Safety measures for drilling process

1

6 – 10 mm

S

Pecking depth: 1 mm

S2

0.5 mmS3

1 mm

CT EMGTPE


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Stage 2

Drill along the safe route

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Setup & Drilling


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Intraoperative Imaging (for clinical trial)

Facialis Monitoring during drilling

Redundant tracking via analysis of bone density

Safety layers for facial nerve protection

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Heat minimization of drill process

High Precision Image Guidance


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High precision robotic guidance

Process accuracy (n=37 heads): 0.14 ± 0.07 mm

Recess: 2.5 ± 0.5 mm

Tunnel: 1.8 mm

Distance FN: 0.5 mm

Facial Nerve

Trajectory

External Auditory CanalOssicles

ChordaTympani

B Bell, T Williamson, N Gerber, K Gavaghan, W Wimmer, M Caversaccio, S Weber (2013) In Vitro Accuracy Evaluation of Image-Guided Robot System forDirect Cochlear Access Otology & Neurotology, Otol Neurotol. 2013 Sep;34(7):1284-90.


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Heat optimization of drill process

•

Optimized drill geometry

• RPM 1000 s-1

• Pecking (1mm, 0.5mms-1)

• Integrated Irrigation

• Consistent chip removal

• Indirect Heat sensing

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Conventional surgical drill, no chip removal

Heat optimized drill, chip removal

A. Feldmann, J. Anso, B. Bell, T. Williamson, K. Gavaghan, N. Gerber, H. Rohrbach, S. Weber, P. Zysset: Temperature Prediction Model for Bone DrillingBased on Density Distribution and In Vivo Experiments for Minimally Invasive Robotic Cochlear Implantation, Annals of Biomedical Engineering


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Accuracy 0.29±0.14 mm

1

Correlate bone density with drilling force

Williamson T, Bell B, Gerber N, Salas L, Zysset P, Caversaccio M, Weber S. (2013) Estimation of tool pose based on force-density correlation during robotic drilling.IEEE Trans Biomed Eng 2013 Apr;60(4):969-76.


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•

Neuromonitoring integrated in drill system• Specific multi-electrode probe

• Detect minimum current responses via various electrodes

•

Determine safe / unsafe proximity

Facialis Monitoring (EMG) during drilling


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Drilling to access next measurement point

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Data analysis work flow

2

Mastoid

MicroCT scan

FN

FN distance measurement Histopathology

-1 0 1

0 .10 .30 .5

1

1 .5

S t i m

u l u s

t h r e s h o l d

( m

A )

Ax ia l d is ta nc e (m m)

Sheep 2

Trajectory 7

LD = 0

d = 2

d = 4

d = 7

Mono

Stimulus threshold mapping Safe vs. unsafe?

D

FN Drill


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2

• Safe (>0.6mm, >95%)

•

Uncertain

• Not safe (


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Intraoperative imaging (clinical trial)


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Stage 3

INSERTION

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Wimmer et al. Cochlear Duct Length Estimation: Adaptation of Escude’s Equation. CI2014 Munich, Germany

Selection of optimal electrode array

1. Define insertion depth

2. Estimate CDL

3. Select appropriate array Array length mm


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Array insertion using a guide tube


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Visualization

Endoscopic (future)Microscopic (clinical trial)

Wimmer et al. Cone beam and micro-computed tomography validation of manual array insertion for minimally invasive cochlear implantation. Audiol Neurotol 2014; 19:22-30


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• Full scala tympani insertion

• 25/26 cases

• Scala vestibuli insertion

• 1/26

• Unrelated to planning

Postoperative Assessment

Venail et al. Manual Electrode Array Insertion Through a Robot-assisted Minimal Invasive Cochleostomy: Feasibility and Comparison of Two Different Electrode Array Subtypes. OtolNeurotol 2015; 36:1015-22

Special flex28


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From Research to product

3


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Clinical trial (KEK and Swissmedic approved)

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Translation aspects

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First in man trial (KEK and Swissmedic approved)

• Build evidence base for clinical benefit

• International multi-center trials in preparation

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Health technology assessment (i.e. GB, GER, US)

• Create awareness among surgeons

• Development of sustainable business models

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Summary

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Concept: Robotic cochlea implantation

• Accurate: : 0.14 ± 0.07 mm

• Safe: EMG, Heat, Bone density

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Consistent: atraumatic insertion

• Approved: 13 patients for clinical trial

• Commercial development ongoing

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Thank You

3

•

Prof. Marco Caversaccio, Inselspital Bern

• Teams at ARTORG, ISTB, CSEM...

• Clinical partners (CH, UK, GER)

•

Industrial partners

... and of course the Nano-Tera Initiative

hearrestore - nano-tera, 2016

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