A fracture mechanics approach was employed to develop a model that can predict the penetration force during quasi-static needle insertion in soft tissue. The model captures a mechanical process where the sharp needle produces a crack that is opened to accommodate the shaft of the needle. This process involves the interchange of energy between four distinct phenomena: the work done by the needle...

The technology for medical needle deburring and sharpening in mass-scale production was developed. The technology is based on the combined application of the high current microsecond electron beam irradiation and the ion sputtering in the low pressure glow discharge plasma with hollow cathode. As a result of the electron beam irradiation deburring and surface smoothening occur. Shape modificati...

We studied the validity of a "Streitberger" needle as a valid approach in a Chinese population with experience of acupuncture. Volunteers were recruited from students of the School of Acupuncture and Moxibustion, Guangzhou University of Chinese Medicine. Sixty students receiving education in acupuncture theory and experience in practical acupuncture were tested in study determining whether need...

INTRODUCTION This study was performed to investigate the effect of topical anesthesia on pain during needle penetration and infiltration injection as well as the effect of pain during injection on success rate of anesthesia in maxillary central incisors. METHODS In a crossover double-blind study, 25 volunteers randomly received either topical anesthesia or placebo before infiltration injectio...

BACKGROUND Traditionally, acupuncturists manipulate needles to enhance sensations referred to as de qi or 'acupuncture needle sensation'. Acupuncture needle sensations are complex and quantifying the experience has been difficult. The aim of this crossover study was to measure self-reported needle sensation during deep and bi-directional rotated needling in 15 healthy volunteers. METHODS Each...

INTRODUCTION The aim of this study was to compare the effect of the EndoVac irrigation system (SybronEndo, Orange, CA) and conventional endodontic needle irrigation on sealer penetration into dentinal tubules. METHODS Forty single-rooted, recently extracted human maxillary central incisors were randomly divided into 2 groups according to the irrigation technique used: conventional endodontic ...

OBJECTIVES The aim of this study was to compare the sharp and blunt needles in order to determine the incidence of complications during transforaminal anterior epidural steroid injections. METHODS In this retrospective study, 185 cases that undergo transforaminal epidural steroid injection with sharp or blunt needles were evaluated between June 2004 and December 2008. Patients age, sex, diagn...

BACKGROUND Multiple factors impact subcutaneous insulin injection pain. Injection devices [e.g., syringe or pen needle (PN)] affect pain due to needle length, diameter, needle polishing and lubrication, and needle tip geometry. METHODS We evaluated a modified 5-bevel PN tip in 32 G × 4 mm 31 G × 5 mm and 8 mm PNs vs the equivalent marketed 3-bevel PNs in laboratory penetration force testing, ...

Whether the inhomogeneity of mudstone foundation leads to abnormal bearing capacity driven pile remains controversial. This study introduces standard penetration test hammering number and needle strength for quantitative analysis by macroscopic observation engineering field on stratum self-structure microscopic simple feasible electronic magnification. The typical examples demonstrated that pil...

Objectives To determine the effect of size and insertion depth of irrigation needle on the amount of apical extruded debris and the amount of penetration depth of sealer using a confocal laser scanning microscope (CLSM). Materials and Methods Twenty maxillary premolars were assigned to 2 groups (n = 10), according to the size of needle tip, 28 G or 30 G. Buccal roots of samples were irrigated...