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Biomedical subjects

H Inaoka

Publications and source records attributed to H Inaoka.

16 recordsLinked to original sources
PubMed2005

The lower lumbar spine moment and the axial rotational motion of a body during one-handed and double-handed backhand stroke in tennis.

To analyze the load on the lumbar spine and the motion pattern of a body during a backhand stroke when playing tennis, kinematic and kinetic data of eleven amateur tennis players were collected. Each subject performed one-handed and double-handed strokes at low, medium, and high racket speeds. The three-dimensional motion of the strokes was optically measured by tracking markers attached to their body segments. Floor reaction forces were measured for the right and left feet separately. Using the body motion and the floor reaction force data, the lower lumbar spine moment was calculated based on a segment-link model. Peak and plateau values of the joint moment before and after ball impact were analyzed statistically using a factorial ANOVA (stroke, racket speed). Similarly, the axial rotation angle of the pelvis against the feet and that of the shoulder against the pelvis were analyzed. In all the moments except the lateral bending moment before ball impact and all the rotation angles, there were significant main effects of racket speed. The one-handed strokes showed significantly smaller extension moment before ball impact as well as smaller lateral bending and axial rotation moments after ball impact than the double-handed strokes. The one-handed strokes also showed a significantly smaller axial rotation angle of the shoulder against the pelvis and that of the pelvis against the feet. These results indicate that during one-handed strokes the shoulder and elbow joints share the rotational motion necessary for backhand strokes and consequently reduce the maximal moments imposed on the spinal joints.

Adult↗
PubMed2003

Pose estimation of artificial hip joint using a single radiographic projection.

Total hip joint arthroplasty is commonly used in cases of osteoarthritis and rheumatoid arthritis. A hip joint prosthesis consists of a cup and a stem. The relative pose (position and orientation) of the prosthesis, when the patient is standing naturally, is planned pre-operatively; however, there is no guarantee that the pre-operatively planned pose will be accurate. Prosthesis component malposition, which is inadequate positioning of the acetabular or femoral component, results in limited joint movement and a large prosthetic joint contact area, and this can cause dislocation of the femoral head from the cap. Because the range of motion after total hip joint arthroplasty is determined by the relative pose of the cup and the stem, it is important to know the relative pose after hip arthroplasty. Several pose estimation methods using single-plane fluoroscopy or conventional roentgenography have been proposed. Because a conventional radiograph system is commonly used at small cost, a method using conventional radiograms is desirable for use in a clinical setting. In this study, a pose estimation method using conventional radiography is proposed, and an in vitro experiment is performed to evaluate its accuracy. The rotational errors of the relative pose of the cup with respect to the stem were smaller than 2.3 degrees.

Hip Joint↗
PubMed2001

Area-slope relation in a simple erosion model.

We discuss area-slope relation of a landform evolved by a simple lattice model of an erosion process. Observing a steady state of the model, where river networks on the surface are stationary, we present the relation between the power exponent of the area-slope relation and the parameters of the erosion process of the model. We show how to determine the parameters of the erosion process from observations of landform by making use of the area-slope relation. This method may be useful for morphological simulations of the landforms.

Journal Article↗
PubMed1996

Extracellular polysaccharides produced by tuberose callus.

A high yield of extracellular polysaccharide (ECP) was obtained from callus cultures of tuberose (Polianthes tuberosa), which could be separated into an unadsorbed and two acidic fractions (TPS-1, -2) by ion-exchange column chromatography. The yields of each fraction were markedly increased by the addition of 10(-5) M 2,4-dichlorophenoxyacetic acid to the medium. Of the three fractions, the amount of TPS-1 accounted for over 60% of total yield of ECP, which was a predominant polysaccharide consisting of arabinose (Ara), mannose (Man) and galactose (Gal) as major neutral monosaccharides. Judging from the patterns of electrophoresis and ultra-centrifugation, TPS-1 was identified to be homogeneous. Methylation and GC-mass spectrometry analyses of this fraction revealed the presence of 1,2,3-linked Man, 1-linked Ara, 1,3-linked Ara, 1-linked Gal and 1,3,4-linked glucuronosyl (GlcUA) residues in a molar ratio of 1.0:1.08:0.85:0.75:1.08. Based on additional analyses of the mild acid hydrolysate and the absolute configuration of the constituent monosaccharides, a possible structure for TPS-1 was a glucuronomannan possessing the unit of -->4)-beta-D-GlcUAp-(1-->2)-alpha-D-Manp-(1--> with branching at the C-3 position, where -->1)-alpha-L-Araf, -->1)-beta-D-galp, -->1)-alpha-L-Araf-(3-->1)-alpha-L-Araf or -->1)-alpha-L-Araf-(3-->1)-beta-D-Galp were attached randomly. About 35% of the GlcUA moieties were present as methyl esters. Further confirmation was made by 1H and 13C NMR spectroscopy.

Carbohydrate Conformation↗
PubMed1996

Indirect measurement of tidal volume by multi-lead electrocardiograms: effect of filtering, deep breath, lead and posture.

We examined a new method for estimating tidal volume from the electrocardiogram (ECG) in order to dispense with the need for sensors used exclusively for tidal volume measurement. The direction of the vector loop in the QRS complex (DVL) was defined as the direction of the diagonal line of the rectangle which circumscribed the vector loop obtained from two orthogonal leads. Two leads of the ECG were transformed into the orthogonal leads using Einthoven's triangle. The peak-to-peak change in the direction (the change in the DVL) was highly correlated with tidal volume. Low-pass filtering of the ECG produced a better correlation between tidal volume and the change in the DVL, when the cutoff frequency was set at 20-45 Hz. A tidal volume of less than 1.21 was correlated more highly with the change in the DVL than a tidal volume of more than 1.21 A combination of leads I and III produced the best correlation between tidal volume and the change in the DVL, compared with other combinations. The posture of the subject had some effects on the slope of the linear regression between tidal volume and the change in the DVL.

Electrocardiography↗
PubMed1985

Detection of tetrodotoxin-like compounds in two species of puffer fishes (Lagocephalus lunaris lunaris and Fugu niphobles).

The toxins in the muscle, skin and liver of the puffer fish Lagocephalus lunaris lunaris and those in the skin and liver of another puffer fish Fugu niphobles were purified by successive column chromatography on activated charcoal, Bio-Gel P-2 and Bio-Rex 70 and analyzed by electrophoresis and thin layer chromatography. Although, regardless of the tissues and species, tetrodotoxin was predominant and accounted for more than 90% of the total toxins, the following minor toxins were newly detected; toxin A and toxin B in L. lunaris lunaris and toxin C in F. niphobles. Since these minor toxins, like tetrodotoxin, were positive to the Weber reagent and 10% KOH, but negative to 1% H2O2, they were assumed to be tetrodotoxin-like compounds. Interestingly, the electrophoretic and thin layer chromatographic analyses showed that toxin A and toxin C are probably identical with AFT3 and AFT1, the minor toxins in the crab Atergatis floridus from Chiba, Japan, respectively.

Animals↗