Bioloch project meeting, Heraklion, March 7th and 8th Daniel Kalanovic, Marc O. Schurr

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1 Bioloch project meeting, Heraklion, March 7th and 8th 2003 Daniel Kalanovic, Marc O. Schurr

2 Steinbeis University and IHCI. Steinbeis University and IHCI focus on interdisciplinary academic education and research. Private University owned by the Steinbeis Foundation: Founded 1998 Focus on post-graduate education SHB Steinbeis University Berlin IHCI, Institute at the Crossroads between medicine, technology and management: 2 directors and Professors HealthcareMBA program Research in technology, experimental medicine and management science. IHCI Institute of Healthcare Industrie Berlin Cologne - Tuebingen

3 Steinbeis University and IHCI. Steinbeis is a start-up University, student numbers reach 500 in Year (31.12.) /2002

4 Work package 7: Experimental validation of biomimetic locomotion mechanisms The purpose of WP 7 is to assess different biomimetic locomotion mechanisms and systems by development of a tailored anatomical test-bed (biohybrid phantom model) and in-vivo testing. Prototypes for biomimetic locomotion systems or mechanisms Benchtop tests in developers labs Biohybrid phantom testing at IHCI with fresh pig colon: - Proof of locomotion concept - Simulation of specific anatomic challenges Animal in-vivo testing in domestic pigs at IHCI: - Verification of in-vitro results - Safety assessment Testing algorithm as defined in the BIOLOCH project proposal

5 Work package 7: Realization of a biohybrid phantom model for assessment of locomotion systems Steinbeis has developed a biohybrid phantom model which consists of a combination of plastic bodyform and specifically modified fresh animal tissue. The animal tissue (e.g., pig colon) is fixed in a humanoid geometry. After preparation Sequence of preparation 1. Attachment to the sphincter 2. Attachment to peritoneal fixation points 3. Adjusting looseness of bowel loops Biohybrid phantom model with fresh pig colon

6 Work package 7: Assessment in phantom models Preliminary experiments with the model have proven its suitability for the assessment for novel locomotion mechanisms. However, some disadvantages of the model were also found. Advantages of the biohybrid model Adjustable and variable humanoid geometry (acute bents, different degrees of bowel looseness) Reproducible testing conditions (allows for comparative testing) Good visual control during testing Easy and quick set-up Assessable parameters and observations Time per covered distance: efficiency of the tested locomotion mechanism Degree of deformation of tissue (macroscopic) Device handling and procedure feasibility Disadvantages Assessment of attachment mechanisms biased by necrosis of mucosa (slippery surface and debris) Limited simulation of adjacent structures and organs (weight of abdominal wall, interaction with adjacent organs, entrapment?)

7 Work package 7: Assessment in animal models In-vivo experiments reflect most realistically the direct interaction between locomotion mechanisms and living tissue Advantages of the pig model Realistic tissue reaction (bleeding, hematoma, swelling, smooth muscle reaction, peristalsis, etc) Simulation of organ entrapment possible (vessels, small bowel, urogenital structures) Disadvantages Geometry of bowel significantly different to situation in humans Tissue properties of the young pig (e.g., 50 KG) different from the typical colonoscopy patient (45y +) Left: Domestic pig Up: Entrapment of ovarian tube during suction Right: Superficial mucosa traces of endoluminal locomotion

8 Work package 7: Experimental validation of biomimetic locomotion mechanisms As a conclusion of first experiments and device testing we conclude that different aspects of biomimetic locomotion have to be assessed with different approaches. Benchtop Biohybrid phantom Animal in-vivo Measurable parameters Time / distance Deformation (macroscopic) Tissue damage (macroscopic) Performance in different anatomies Performance in specific pathologies 1. System performance, with limited conclusions about attachment. 2. Safety assessment on macroscopic level Measurable parameters Time / distance (limited) Attachment capabilities Deformation (macroscopic, microscopic) Tissue damage (macroscopic, microscopic) 1. Safety assessment, but no overall human geometry 2. Attachment / bowel interaction studies, but repeatability is limited Extension of testing capabilities?

9 Extension of assessment capabilities: Anatomy model by Thiel preservation In collaboration with the University of Tübingen, IHCI is able to perform experiments in actual human anatomy. A novel preservation method provides highly realistic tissue properties. Advantages of Thiel preservation Most realistic geometry possible Complete neighboring structures Highly realistic human tissue properties (consistency, elasticity) However Ethical considerations, costly Dead tissue, no blood flow Left: Device set-up / endoscopy in the Anatomy institute Right: Introduction of an inchworm robot into the bowel

10 Extension of assessment capabilities: Pig organ model by Thiel preservation plus new sensory equipment An ideal model for comparative realistic performance testing could be the Thiel-preserved biohybrid phantom in combination with precise force measurement capabilities. Thiel preservation Measurable parameters Time / distance Deformation Tissue damage Performance in different anatomies Performance in specific pathologies + Attachment capabilities (mechanical) Deformation (microscopic) Tissue damage (microscopic) Repetitive performance test + New force measurement set-up with adaptable sensors Objective assessment of biomimetic locomotion mechanisms: -Attachment / tissue contact -Locomotion characteristics -Force measurement for deformation, stress, strain -> pain