title: Design Considerations of a Fiber Optic Pressure Sensor Protective Housing for Intramuscular Pressure Measurements.
abstract: Intramuscular pressure (IMP), defined as skeletal muscle interstitial fluid pressure, reflects changes in individual muscle tension and may provide crucial insight into musculoskeletal biomechanics and pathologies. IMP may be measured using fiber-optic fluid pressure sensors, provided the sensor is adequately anchored to and shielded from surrounding muscle tissue. Ineffective anchoring enables sensor motion and inadequate shielding facilitates direct sensor-tissue interaction, which result in measurement artifacts and force-IMP dissociation. The purpose of this study was to compare the effectiveness of polyimide and nitinol protective housing designs to anchor pressure sensors to muscle tissue, prevent IMP measurement artifacts, and optimize the force-IMP correlation. Anchoring capacity was quantified as force required to dislodge sensors from muscle tissue. Force-IMP correlations and non-physiological measurement artifacts were quantified during isometric muscle activations of the rabbit tibialis anterior. Housing structural integrity was assessed after both anchoring and activation testing. Although there was no statistically significant difference in anchoring capacity, nitinol housings demonstrated greater structural integrity and superior force-IMP correlations. Further design improvements are needed to prevent tissue accumulation in the housing recess associated with artificially high IMP measurements. These findings emphasize fundamental protective housing design elements crucial for achieving reliable IMP measurements.
authors: Mayo Graduate School, Mayo Clinic, Rochester, MN, USA.|Mayo Medical School, Mayo Clinic, Rochester, MN, USA.
authors: Shanette A
authors: SA
authors: Go
authors: Mayo Graduate School, Mayo Clinic, Rochester, MN, USA.
authors: Elisabeth R
authors: ER
authors: Jensen
authors: Department of Orthopaedic Surgery, University of California at San Diego, La Jolla, CA, USA.|Department of Bioengineering, University of California at San Diego, La Jolla, CA, USA.
authors: Shawn M
authors: SM
authors: O'Connor
authors: Mayo Graduate School, Mayo Clinic, Rochester, MN, USA.
authors: Loribeth Q
authors: LQ
authors: Evertz
authors: Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA.
authors: Duane A
authors: DA
authors: Morrow
authors: Department of Orthopaedic Surgery, University of California at San Diego, La Jolla, CA, USA.|Department of Bioengineering, University of California at San Diego, La Jolla, CA, USA.
authors: Samuel R
authors: SR
authors: Ward
authors: Department of Orthopaedic Surgery, University of California at San Diego, La Jolla, CA, USA.|Department of Bioengineering, University of California at San Diego, La Jolla, CA, USA.|Veterans Affairs San Diego Healthcare System, University of California at San Diego, La Jolla, CA, USA.|Rehabilitation Institute of Chicago, Chicago, IL, USA.
authors: Richard L
authors: RL
authors: Lieber
authors: Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA. kaufman.kenton@mayo.edu.
authors: Kenton R
authors: KR
authors: Kaufman
mesh_terms: D000818:Animals; D005260:Female; D005336:Fiber Optic Technology; D007537:Isometric Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D011312:Pressure; D011817:Rabbits
keywords: Force; Isometric activation; Microsensor; Skeletal muscle; Tibialis anterior