OBJECTIVES--To examine the relation between disproportionate fetal growth and adult blood pressure and to investigate whether arterial compliance in adult life is related to early development. DESIGN--A follow up study of a group of men and women whose birth weights and other measurements of body size had been recorded at birth. SETTING--Home and outpatient study. SUBJECTS--337 men and women born in the Jessop Hospital, Sheffield, between 1939 and 1940. MAIN OUTCOME--Adult systolic and diastolic blood pressures and arterial compliance as measured by pulse wave velocity in two arterial segments. RESULTS--Both systolic and diastolic blood pressures were higher in people whose birth weight was low, who were short or who had small abdominal or head circumferences at birth. Systolic blood pressure decreased by 2.7 mm Hg (95% CI 0.8 to 4.6) for each pound (454 g) gain in birth weight and by 3.4 mm Hg (95% CI 1.4 to 5.4) for each inch (2.54 cm) increase in crown-heel length. Diastolic pressure fell by 1.9 mm Hg (95% CI 0.9 to 2.9) for each pound (454 g) gain in birth weight and by 2.4 mm Hg (95% CI 1.4 to 3.5) for each inch (2.54 cm) increase in length. Systolic blood pressure was also higher in individuals whose mother's intercristal pelvic diameter was small or whose mother's blood pressure had been raised during pregnancy but these effects were statistically independent of the effects of low birth weight and other measurements that indicate fetal growth retardation. Arterial compliance was lower in those who had been small at birth. CONCLUSION--Impairment of fetal growth is associated with raised blood pressure in adult life and decreased compliance in the conduit arteries of the trunk and legs.

With the advance of computer and photonics technology, imaging photoplethysmography [(PPG), iPPG] can provide comfortable and comprehensive assessment over a wide range of anatomical locations. However, motion artifact is a major drawback in current iPPG systems, particularly in the context of clinical assessment. To overcome this issue, a new artifact-reduction method consisting of planar motion compensation and blind source separation is introduced in this study. The performance of the iPPG system was evaluated through the measurement of cardiac pulse in the hand from 12 subjects before and after 5 min of cycling exercise. Also, a 12-min continuous recording protocol consisting of repeated exercises was taken from a single volunteer. The physiological parameters (i.e., heart rate, respiration rate), derived from the images captured by the iPPG system, exhibit functional characteristics comparable to conventional contact PPG sensors. Continuous recordings from the iPPG system reveal that heart and respiration rates can be successfully tracked with the artifact reduction method even in high-intensity physical exercise situations. The outcome from this study thereby leads to a new avenue for noncontact sensing of vital signs and remote physiological assessment, with clear applications in triage and sports training.

Arterial wall stresses are thought to be a major determinant of vascular remodeling both during normal growth and throughout the development of occlusive vascular disease. A completely physiologic mechanical model of the arterial wall should account not only for its residual strains but also for its structural nonhomogeneity. It is known that each layer of the artery wall possesses different mechanical properties, but the distribution of residual strain among the different mechanical components, and thus the true zero stress state, remain unknown. In this study, two different sets of experiments were carried out in order to determine the distribution of residual strains in artery walls, and thus the true zero stress state. In the first, collagen and elastin were selectively eliminated by chemical methods and smooth muscle cells were destroyed by freezing. Dissolving elastin provoked a decrease in the opening angle, while dissolving collagen and destroying smooth muscle cells had no effect. In the second, different wall layers of bovine carotid arteries were removed from the exterior or luminal surfaces by lathing or drilling frozen specimens, and then allowing the frozen material to thaw before measuring residual strain. Lathing material away from the outer surface caused the opening angle of the remaining inner layers to increase. Drilling material from the inside caused the opening angle of the remaining outer layers to decrease. Mechanical nonhomogeneity, including the distribution of residual strains, should thus be considered as an important factor in determining the distribution of stress in the artery wall and the configuration of the true zero stress state.