Automatic irrigation system with a fiber-optic pressure sensor regulating intrapelvic pressure for flexible ureteroscopy.

Increased intrapelvic pressure (IPP) due to irrigation during flexible ureteroscopy (f-URS) can pose a risk of postoperative severe urinary tract infection associated with pyelovenous backflow. An automatic regulation system for maintaining safe IPP levels could enable surgeons to perform f-URS safely without postoperative complications. This study aimed to assess the measurement accuracy of an ultra-miniature fiber-optic pressure sensor incorporated into a small-caliper ureteroscope for assessing IPP and to develop an automatic irrigation system linked to this sensor.

Examining the Impact of Different Properties of Ureteral Access Sheaths in Reducing Insertion Force During Retrograde Intrarenal Surgery: An Study.

This study aimed to evaluate the characteristics of ureteral access sheaths (UASs) that can reduce the insertion force while accessing the upper urinary tract. Six different types of 12/14F UASs were used. We evaluated the properties of UASs such as the diameter of the outer sheath, length of the inner dilator tip exposed from the outer sheath, sheath flexibility (assessed in terms of bending force of the tip or base), flexibility ratio (i.

Focused Ultrasound PC-6 Stimulation Effects on Blood Flow Volume, Skin Temperature, and Coldness of the Finger and Toe.

Introduction: Focused ultrasound can stimulate a specific point of tissue and can be a noninvasive method for acupoint stimulation. The aim of this study was to clarify the effects of acupoint stimulation by focused ultrasound on blood flow volume and coldness of the fingers and toes.

Materials And Methods: Forty healthy volunteers were included in this experiment.

Fabrication and Packaging of CMUT Using Low Temperature Co-Fired Ceramic.

This paper presents fabrication and packaging of a capacitive micromachined ultrasonic transducer (CMUT) using anodically bondable low temperature co-fired ceramic (LTCC). Anodic bonding of LTCC with Au vias-silicon on insulator (SOI) has been used to fabricate CMUTs with different membrane radii, 24 µm, 25 µm, 36 µm, 40 µm and 60 µm. Bottom electrodes were directly patterned on remained vias after wet etching of LTCC vias.

Viscosity measurement of Xanthan-Poly(vinyl alcohol) mixture and its effect on the mechanical properties of the hydrogel for 3D modeling.

Biomodels made of poly(vinyl alcohol) (PVA) are demanded because they can represent the geometries and mechanical properties of human tissues realistically. Injecting and molding, commonly used in three-dimensional (3D) modeling, help to represent the blood vessels accurately. However, these techniques sometimes require higher pressures than the upper pressure limit of the dispensers for pouring in high viscosity materials; the material viscosity should therefore be lower.

A new manometry device for evaluating the sphincter of Oddi using a fiber-optic pressure sensor.

Introduction: Although measuring the pressure of the sphincter of Oddi and the bile duct is considered to be an important examination, called Sphincter of Oddi manometry (SOM), some complications related to the SOM device remain unsolved.

Material And Methods: To decrease adverse complications, we developed a 0.46 mm manometry and we performed some in vitro studies.

Oesophageal mucosal blood flow changes after thoracic endovascular stent graft implantation using a novel sensor probe.

Objectives: Secondary aorto-oesophageal fistula is a rare, lethal complication occurring after thoracic endovascular aneurysmal repair. The cause of secondary aorto-oesophageal fistula is unknown, but a reduction in local oesophageal mucosal blood flow (OMBF) may be a basis for such a devastating sequela. Our study aims to develop a novel blood flow sensor probe to detect changes in OMBF after thoracic stent graft implantation in an experimental swine model.

Lactate and glucose measurement in subepidermal tissue using minimally invasive microperfusion needle.

Knowing the concentrations of biological substances can help ascertain physiological and pathological states. In the present study, a minimally invasive microperfusion needle was developed for measuring the concentrations of biological substances in subepidermal tissue. The microperfusion needle has a flow channel with a perforated membrane through which biological substances from subepidermal tissue are extracted.

Intraparenchymal ultrasound application and improved distribution of infusate with convection-enhanced delivery in rodent and nonhuman primate brain.

OBJECT Convection-enhanced delivery (CED) is an effective drug delivery method that delivers high concentrations of drugs directly into the targeted lesion beyond the blood-brain barrier. However, the drug distribution attained using CED has not satisfactorily covered the entire targeted lesion in tumors such as glioma. Recently, the efficacy of ultrasound assistance was reported for various drug delivery applications.

Real-time monitoring of spinal cord blood flow with a novel sensor mounted on a cerebrospinal fluid drainage catheter in an animal model.

Objective: The aim of our study was to develop a novel monitoring system for spinal cord blood flow (SCBF) to test the efficacy of the SCBF sensor in an animal model.

Methods: The sensor system consisted of 2 optical fibers, a pedestal for fiber fixation, and a mirror for the laser reflection and was incorporated into a cerebrospinal fluid drainage catheter. In vivo studies were performed in a swine model (n=10) to measure SCBF during spinal cord ischemia induced by clamping the descending thoracic aorta and supra-aortic neck vessels, when necessary.

Brief effect of acupoint stimulation using focused ultrasound.

Background: Acupuncture is used worldwide in medical treatment. However, needle insertion damages the skin and patients sometimes feel pain. To avoid such drawbacks, an acupoint stimulation device using focused ultrasound has been developed.

Minimally invasive diagnostics and treatment using micro/nano machining.

Several medical tools with various functions have been developed for minimally invasive diagnostics and treatment. Microfabrication techniques such as MEMS technology are useful for the realization of high-performance multifunctional minimally invasive medical tools with small sizes. An ultra-miniature pressure sensor and an intravascular ultrasonic forward-viewing imager have been developed as microsensors for use in the human body.