Assessment of deformation of the mitral valve complex during off-pump coronary artery bypass surgery using three-dimensional echocardiography in a porcine model.

Background: This study aimed to assess the deformation of the mitral valve complex during the displacement of the beating heart by using three-dimensional echocardiography in a porcine off-pump coronary artery bypass grafting (OPCAB) model.

Methods: In nine healthy swine, we positioned the beating heart as an OPCAB model, i.e.

Tactile sensor is useful for estimating liver hardness and liver fibrosis compared with ultrasonography and computed tomography.

Background/aims: We examined whether conventional ultrasonography (US) and computed tomography (CT) were useful to evaluate liver hardness and hepatic fibrosis by comparing the results with those obtained by a tactile sensor using rats with liver fibrosis.

Methodology: We used 44 Wistar rats in which liver fibrosis was induced by intraperitoneal administration of thioacetamide. The CT and US values of each liver were measured before laparotomy.

Effects of phenylephrine and noradrenaline on coronary artery motion in an open-chest porcine beating heart model.

Purpose: During off-pump coronary artery bypass (OPCAB), surgeons are required to perform a precise anastomosis on the beating heart. The hypotension caused by vertical displacement of the heart during OPCAB is usually treated with vasopressors, such as noradrenaline and phenylephrine. However, the effects of these agents on coronary artery motion are unknown.

Surface density mapping of natural tissue by a scanning haptic microscope (SHM).

To expand the performance capacity of the scanning haptic microscope (SHM) beyond surface mapping microscopy of elastic modulus or topography, surface density mapping of a natural tissue was performed by applying a measurement theory of SHM, in which a frequency change occurs upon contact of the sample surface with the SHM sensor - a microtactile sensor (MTS) that vibrates at a pre-determined constant oscillation frequency. This change was mainly stiffness-dependent at a low oscillation frequency and density-dependent at a high oscillation frequency. Two paragon examples with extremely different densities but similar macroscopic elastic moduli in the range of natural soft tissues were selected: one was agar hydrogels and the other silicon organogels with extremely low (less than 25 mg/cm(3)) and high densities (ca.

Observation of local elastic distribution in aortic tissues under static strain condition by use of a scanning haptic microscope.

The purpose of this study was to observe variation in the local elastic distribution in aortic tissue walls under different static strain conditions, including physiological strain, by use of a scanning haptic microscope (SHM). Strain was applied by stretching aortic tissues in the circumferential direction by the simple tensile method or by the rod-insertion method to mimic in vivo internal pressure loading. SHM measurements in a saline solution at room temperature were performed on canine thoracic aorta using a glass needle probe with a diameter of ca 5 μm and a scanning area and point pitch of 160 × 80 μm and 2 μm, respectively.

Biomechanical properties and associated collagen composition in vaginal tissue of women with pelvic organ prolapse.

Purpose: The pelvic tissue of women with pelvic organ prolapse is stiffer than that of controls but there are scant data on the collagen composition that corresponds to these mechanical properties. We evaluated human vaginal wall stiffness using the novel scanning haptic microscope and correlated these measurements to collagen expression in women with and without pelvic organ prolapse. In this simultaneous biomechanical and biochemical assessment we evaluated the usefulness of this measurement technology for pelvic floor disorder research and confirmed an association between mechanical properties and composition.

Softness sensor system for simultaneously measuring the mechanical properties of superficial skin layer and whole skin.

Background/aims: Few attempts have been made to distinguish the softness of different skin layers, though specific measurement of the superficial layer would be useful for evaluating the emollient effect of cosmetics and for diagnosis of skin diseases.

Materials And Methods: We developed a sensor probe consisting of a piezoelectric tactile sensor and a load cell. To evaluate it, we firstly measured silicone rubber samples with different softness.

Stiffness mapping prostate biopsy samples using a tactile sensor.

Previous studies have demonstrated that the stiffness of cancerous cells reflects their pathological stage and progression rates, with increased cancerous cell stiffness associated with increased aggressiveness. Therefore, the elasticity of the cancerous cells has the potential to be used as an indicator of the cancer's aggressiveness. However, the sensitivity and resolution of current palpation and imaging techniques are not sufficient to detect small cancerous tissues.

Pyrrole-imidazole polyamide targeting transforming growth factor β1 ameliorates encapsulating peritoneal sclerosis.

Objective: Encapsulating peritoneal sclerosis (EPS) is a devastating fibrotic complication in patients treated with peritoneal dialysis (PD). Transforming growth factor β1 (TGF-β1) is a pivotal factor in the induction of EPS.

Methods: To develop pyrrole-imidazole (PI) polyamide, a novel gene silencer, targeted to the TGF-β1 promoter (Polyamide) for EPS, we examined the effects of Polyamide on messenger RNA (mRNA) expression of TGF-β1, vascular endothelial growth factor (VEGF), and extracellular matrix (ECM) in mesothelial cells in vitro, and on the thickness of injured peritoneum evaluated by histology and high-resolution regional elasticity mapping in rats in vivo.

Landiolol reduces coronary artery motion in an open-chest porcine model: implications for off-pump coronary artery bypass surgery.

Reduction of target coronary artery motion is imperative for successful off-pump coronary artery bypass surgery. We hypothesized that landiolol, a novel ultra-short-acting selective β-1 blocker, would reduce such coronary artery motion. To test this hypothesis, the motion of the left anterior descending artery of the porcine heart (n = 8) was analyzed by three-dimensional digital motion capture and reconstruction technology with or without continuous landiolol infusion.

Variations in local elastic modulus along the length of the aorta as observed by use of a scanning haptic microscope (SHM).

Variations in microscopic elastic structures along the entire length of canine aorta were evaluated by use of a scanning haptic microscope (SHM). The total aorta from the aortic arch to the abdominal aorta was divided into 6 approximately equal segments. After embedding the aorta in agar, it was cut into horizontal circumferential segments to obtain disk-like agar portions containing ring-like samples of aorta with flat surfaces (thickness, approximately 1 mm).

Simulation of vaginal wall biomechanical properties from pelvic floor closure forces map.

We simulated the way that pelvic floor muscles (PFM) generate zonal compression on the vagina and urethra in order to maintain urinary continence. Raw data were obtained using a probe to map the distribution of vaginal closure forces. Simulation model was made using ordinary Spring-mass model.

Selective beta-1 receptor blockade further reduces the mechanically stabilized target coronary artery motion during beating heart surgery.

Objective: Adequate stabilization of anastomosis sites during off-pump coronary artery bypass is essential to obtain excellent graft patency. We examined the effect of beta-1 adrenergic receptor blockade on the target coronary artery motion by three-dimensional (3D) digital motion capture and reconstruction technology.

Methods: Eight pigs underwent a sternotomy.

Surface elasticity imaging of vascular tissues in a liquid environment by a scanning haptic microscope.

The objective of this study was to make an elasticity distribution image of natural arteries in a liquid environment at high resolution at the micrometer level and at a wide area at the sub-square millimeter level by improving the scanning haptic microscope (SHM), developed previously for characterization of the stiffness of natural tissues. The circumferential sections (thickness, 1.0 mm) of small-caliber porcine arteries (approximately 3-mm diameter) were used as a sample.

Tactile mapping system: a novel imaging technology for surface topography and elasticity of tissues or organs.

Objective: : We demonstrated that the tactile mapping system (TMS) has a high degree of spatial precision in the distribution mapping of surface elasticity of tissues or organs.

Methods: : Samples used were a circumferential section of a small-caliber porcine artery (diameter: ∼3 mm) and an elasticity test pattern with a line and space configuration for the distribution mapping of elasticity, prepared by regional micropatterning of a 14-μm thick gelatin hydrogel coating on a polyurethane sheet. Surface topography and elasticity in normal saline were simultaneously investigated by TMS using a probe with a diameter of 5 or 12 μm, a spatial interval of 1 to 5 μm, and an indentation depth of 4 μm.

Improvement of hydrogelation abilities and handling of photocurable gelatin-based crosslinking materials.

Three types of eosin-derivatized gelatins (eosin-gelatins) with different molecular weights (M(w)) of ca. 15 kDa (low-molecular-weight eosin-gelatin, LEG), ca. 30 kDa (medium-molecular-weight eosin-gelatin, MEG), and ca.

Local elasticity imaging of vascular tissues using a tactile mapping system.

This study aimed to map the elasticity of a natural artery at the micron level by using a tactile mapping system (TMS) that was recently developed for characterization of the stiffness of tissue slices. The sample used was a circumferential section (thickness, approximately 1 mm) of a small-caliber porcine artery (diameter, approximately 3 mm). Elasticity was measured with a probe of diameter 1 microm and a spatial resolution of 2 microm at a rate of 0.

Influence of pelvic floor muscle contraction on the profile of vaginal closure pressure in continent and stress urinary incontinent women.

Purpose: We characterized the vaginal pressure profile as a representation of closure forces along the length and circumference of the vaginal wall. Vaginal pressure profile data were used to test the hypothesis that the strength of pelvic floor muscle contractions differs significantly between continent women and women with stress urinary incontinence.

Materials And Methods: Vaginal pressure profile recordings were made in 23 continent subjects and in 10 patients with stress urinary incontinence.

High resolution regional elasticity mapping of the human prostate.

What is it that the clinician "feels" during a digital rectal examination? To answer this question, it is necessary to measure the elastic properties of the prostate and verify the stiffness values with histological examination. Therefore, we devised an Elasticity Mapping System to evaluate the elastic properties of various histopathological grades of prostate cancer in relation to benign prostatic hyperplasia (BPH) and normal tissue. The system consists of a micro tactile sensor, a three-axis (XYZ) with one (fine Z) micromanipulation stage, a stereoscope camera and a measurement chamber.

Spatial distribution of vaginal closure pressures of continent and stress urinary incontinent women.

Clinically the strength of the contraction of the female pelvic floor is qualitatively evaluated by vaginal tactile palpation. We therefore developed a probe to enable the quantitative evaluation of the closure pressures along the vagina. Four force sensors mounted on the four orthogonal directions of an intra-vaginal probe were used to measure the vaginal pressure profile (VPP) along the vaginal wall.

The stiffness of normal and abnormal mitral valves.

Background: Although it is well known that valvular lesions show changes in stiffness, this fact has not been studied objectively or quantitatively.

Methods: Using a tactile sensor, stiffness of the mitral valve was measured at 11 autopsies and 19 surgically excised specimens. The relationships between stiffness and histological state were investigated in 394 points of resected specimens.

Evaluation of the dynamic responses of female pelvic floor using a novel vaginal probe.

The female pelvic floor (PF) provides anatomical support to many visceral organs, such as uterus, bladder, urethra, vagina, and rectum. Physiologically, the PF is made up of a number of highly coordinated muscle groups organized to respond to postural and abdominal stresses to maintain continence. In this article, we describe a new methodology for the evaluation of PF strength using a novel vaginal probe design, having force and displacement sensors.

Direction sensitive sensor probe for the evaluation of voluntary and reflex pelvic floor contractions.

Aims: The development of a vaginal probe for the evaluation of the dynamics of pelvic floor function is described. Fundamental criteria in the design of this probe involves the incorporation of a means of assessing whether the isotonic forces closing the vagina are equally distributed or whether they are greater in some directions than others. The aim of this study is to present the design of directionally sensitive multi-sensor probe, having circumferential spatial resolution, constructed to identify the distribution of anisotropic forces acting on the vagina following voluntary and reflex pelvic floor contractions.

Mouse zona pellucida dynamically changes its elasticity during oocyte maturation, fertilization and early embryo development.

A change in the elasticity of mouse zona pellucida was quantitatively evaluated during oocyte maturation, fertilization and early embryo development. Young's modulus of zona pellucida of germinal vesicle (GV), metaphase-II (MII), pronuclear (PN), 2cell, 4cell, 8cell, morulae (M) and early blastocyst (EB) stages was measured using a micro tactile sensor (MTS) and a chamber exclusively designed for the measurement. The MTS has very high sensitivity and a deformation of only 5 microm was sufficient to calculate the Young's modulus and the oocyte/embryo maintained its original spherical shape during the measurement.

Three-dimensional quantification of cardiac surface motion: a newly developed three-dimensional digital motion-capture and reconstruction system for beating heart surgery.

Objective: This study aimed to evaluate our newly developed 3-dimensional digital motion-capture and reconstruction system in an animal experiment setting and to characterize quantitatively the three regional cardiac surface motions, in the left anterior descending artery, right coronary artery, and left circumflex artery, before and after stabilization using a stabilizer.

Methods: Six pigs underwent a full sternotomy. Three tiny metallic markers (diameter 2 mm) coated with a reflective material were attached on three regional cardiac surfaces (left anterior descending, right coronary, and left circumflex coronary artery regions).