This article presents the results of a study on patients with diabetic neuropathy to find the relationships between the foot pressures characterized by power ratio (PR), foot sole hardness (Shore values), and foot sole soft tissue thickness. The results showed that the increase in PR values for diabetic patients in the upper sensation loss levels (S = 7.5 to 10 g) compared to the corresponding increase in lower sensation loss (S=3 to 4.5 g)were of the order of 5 times in the lateral heel and big toe, respectively, and 4 times in the first metatarsal head regions. The increase in PR values for diabetic patients in the upper Shore value regions (30 to 40) compared to the corresponding increase in lower Shore value regions (20 to 30) were of the order of 3.4 times in lateral heel and 2.4, 2.0, and 2.3 times in the first, second, and lateral metatarsal head regions, respectively. At sites contiguous to frank ulcers for foot sole hardness (Shore values of 50) at sensation level > 10 g PR was as high as 59, and foot sole thickness values were also greater than the corresponding normal values. The study shows all measured parameters may play a part in the development of plantar ulcers.

An analysis of force distribution in the hand during maximum isometric grasping actions is reported in a detailed and accurate manner. A microcomputer-controlled instrument which measures all 12 phalangeal forces of fingers simultaneously, in a single attempt at squeezing a cylindrical object, is described. The study involved 20 normal subjects of different weights and age groups grasping tubes of 50 mm, 75 mm, 90 mm and 110 mm diameters. Normal grasp forces decreased significantly with the increase in tube diameter, with the force being concentrated more on the distal segments of the fingers on the proximal and middle segments. The mean percentage contributions of finger forces to total grip strength, from index to little fingers, were 31, 33, 22 and 14 per cent, respectively. The study was extended to cover leprotic and paralytic hands to assess their functional capabilities. In the case of leprosy subjects, the grip strength decreased with the severity of the disease and was only about 50 per cent of that of normal subjects. In hemiplegics, the grip strength was only about one-eighth of the normal values. The above assessment procedure provides baseline data which could serve as guidelines to a clinician in assessing the severity of the disease and observing the patient's recovery following the treatment. It would also be useful in the design of hand-operated controls and prosthetic arms.

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Three-dimensional time-of-flight MR angiography was performed in 16 patients with Takayasu's arteritis. Two regions were evaluated, the arch of aorta and its intrathoracic major branches, and the abdominal aorta with proximal portions of its major visceral and renal branches. Individual arteries and aortic segments, i. e. aortic arch and abdominal aorta, were evaluated for abnormalities such as stenosis, occlusion, dilatation and aneurysm formation. The results were compared with contrast angiography. Follow-up MR angiography was performed in three patients after 9-12 months. MR angiography demonstrated steno-occlusive lesions in all the patients and aneurysms in 2. In comparison with contrast angiography, good correlation was found in 129 of the 145 arteries and aortic segments. For the 12 false-positive results, incorrect slab placement and overestimation of stenosis were implicated. Interestingly, there were three false-negative results and one occlusion was underestimated as stenosis. A new lesion developed in 1 patient and one stenosis progressed in another patient upon follow-up. Three-dimensional time-of-flight MR angiography is a simple and fairly accurate method for documenting the lesions in Takayasu's arteritis and for its follow-up.

In diabetic neuropathic subjects, the hardness of foot sole soft tissue increases, and its thickness reduces, in different foot sole areas. Finite element analysis (FEA) of a three-dimensional two-arch model of the foot was performed to evaluate the effect of foot sole stresses on plantar ulcer development. Three sets of foot sole soft-tissue properties, i.e. isotropic (with control hardness value), diabetic isotropic (with higher hardness value) and anisotropic diabetic conditions, were simulated in the push-off phase, with decreasing foot sole soft-tissue thicknesses in the forefoot region, and the corresponding stresses were calculated. The results of the stress analyses for diabetic subject (anisotropic) foot models showed that, with non-uniformly increased hardness and decreased foot sole soft-tissue thickness, the normal and shear stresses at the foot sole increased (compared with control values) by 52.6% and 53.4%, respectively. Stress analyses also showed high ratios of gradients of normal and shear stresses of the order of 6.6 and 3.3 times the control values on the surface of the foot sole, and high relative values of stress gradients for normal and shear stresses of 6.25 and 4.35 times control values, respectively, between the foot sole surface and the adjacent inner layer of the foot sole, around a particular region of the foot sole with anisotropic properties. These ratios of high gradients and relative gradients of stresses due to changes in soft-tissue properties may be responsible for the development of plantar ulcers in diabetic neuropathic feet.

A head injury model consisting of the skull, the CSF, the brain and its partitioning membranes and the neck region is simulated by considering its near actual geometry. Three-dimensional finite-element analysis is carried out to investigate the influence of the partitioning membranes of the brain and the neck in head injury analysis through free-vibration analysis and transient analysis. In free-vibration analysis, the first five modal frequencies are calculated, and in transient analysis intracranial pressure and maximum shear stress in the brain are determined for a given occipital impact load.

Persistent atrial standstill (PAS) is a rare disorder characterized by absence of atrial activity on the surface and intracavity electrograms, absence of atrial mechanical activity, and inability to electrically stimulate the atria. Four patients (ages 18-60 years) with PAS were evaluated. One of these (no. 3) only had right atrial (RA) standstill, whereas left atrium (LA) showed spontaneous activity and could be stimulated electrically. As RA biopsy is not possible, right ventricular (RV) endomyocardial biopsy (EMB) was obtained to identify possible atrial pathology that revealed inflammatory myocarditis, 2; amyloidosis, 1; and myocardial hypertrophy with fibrosis, 1. Three patients were given permanent pacemakers. One of these with amyloidosis died suddenly. One is lost to follow-up. The others cases are persisting with PAS.

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