A bio-inspired attachment mechanism for long-term adhesion to the small intestine

Abstract

To achieve long-term attachment of capsule endoscopes (CEs) and miniature biosensors in the human gastrointestinal (GI) tract, a tissue attachment mechanism (TAM) was designed, optimized and tested for safety and adhesive capabilities on excised tissue in vitro and in vivo on a live pig model. Six TAMs were tested for their attachment strength in an in vitro attachment tensile experiment in which each TAM was tested on three different proximal intestine tissue samples. The maximum strength and average value are 8.09 N and 4.54 N respectively. The initial attachment damage was tested for 10 min using a sine wave pull force on the TAM with a 0.4 N peak value and 6 s period, which represents typical human intestinal traction force from peristalsis. The in vitro attachment tensile test verified that the tissue was not visually damaged nor perforated by the attachment process. In the in vivo experiment, four TAMs were placed in the intestine of a pig through individual longitudinal enterotomies. X-ray images were taken each hour after the surgery and showed zero migration of the TAMs after 24 h of adhesion. X-ray images taken each day indicated the attachment duration of this mechanism lasted up to 6 days. Post experiment inspection confirmed the attachment did not cause visible damage to tissue. These results confirmed the reliability of the TAM in vivo and demonstrated preliminary feasibility of long-term sensor adhesion to the GI tract.

Design and Validation of a Biosensor Implantation Capsule Robot

“…For the latter, tapeworms and other organisms that employ a strategy of mechanical adhesion to the soft tissue via the combined use of hooks and suckers inspired the design. Previous work provides details of these bioinspired Transactions of the ASME features [13,15,16], and a component on the ICR called the TAM has been designed and optimized and consists of a sucker and a needle array around the sucker. During the attachment process, tissue is aspirated by the sucker and then fixed via needles.…”

“…Since the aim of this research was to explore the ICR, a TAM with a sham biosensor was used for all tests described above. Exact geometry, functionality, and tissue adhesion features of the TAM were optimized and tested in a live porcine model in previous work [13]. Briefly, three parameters that determine TAM geometry were varied in the previous study: hole diameter, needle length, and needle angle.…”

“…The previous work focused on the design, fabrication, and in vitro and in vivo testing of the TAM, a subsystem of the capsule, and an adhesive device that anchors a biosensor to the mucosal and submucosal tissue long-term in vivo [13]. As described in that work, the TAM uses a combination of suction and needles to capture and grip mucosal tissue, a method that is inspired by some species of tapeworm which benignly adhere to the GI wall for long periods of time [14].…”

Pneumatically Attachable Flexible Rails for Track-Guided Ultrasound Scanning in Robotic-Assisted Partial Nephrectomy—A Preliminary Design Study

“…In [19] the use of vacuum has been investigated for the navigation of a micro-robotic system on the surface of the heart, whereas in [20] a vacuum-based device has been investigated for its stabilisation. The use of vacuum for short-and long-term anchoring of medical devices in surgical procedures has been also investigated in [21] and [22]. Similar actuation systems and attachment mechanisms are also found in non-medical applications such as the system proposed in [23].…”

A method for measuring the attachment strength of the cestode Hymenolepis diminuta to the rat intestine

“…Artificial hooks inspired by those that occur on the rostellum of the scolex of Taenia solium have shown a remarkable ability to adhere to biological substrates (La Spina et al ., 2005). An attachment mechanism for swallowable robotic capsules using needles to successfully fix sensors to a pig's GI tract for 6 days was developed in our previous work (Xie et al ., 2015). Despite implementing the attachment mechanism from small-diameter needles, these hooks still penetrate into the mucosa and may cause minor tissue damage and subsequent inflammation.…”