Nine degree of freedom motion estimation for wrist PPG heart rate measurements.

In recent years there has been substantial interest in wearable devices that measure heart rate via photoplethysmography (PPG) sensors placed at the wrist. This is challenging as the wrist PPG signal is severely corrupted by artefacts during motion, and although a number of algorithms are now available commercially and academically there is still a need for improved performance, especially when examining physical activities other than running. To date, algorithms for motion artefact removal from the PPG have focused on the use of a co-located accelerometer to record the motion. In this work, we introduce co-located accelerometer, gyroscope and magnetometer sensors to allow three, six and nine degrees of freedom estimates of the motion present. Assessed during a bike riding task the results show that the heart rate estimation is improved by up 0.57 beats per minute by using the additional information from these new sensors.

An 8q21 deletion in a patient with comorbid psychosis and mental retardation.

Systematic investigations indicate that some of the recognized psychiatric disorders can be identified among those with mental retardation due to chromosomal abnormalities. We report a psychotic patient with mild mental retardation (intelligence quotient: 68) and minor anomalies that had a chromosomal aberration not previously described in a psychotic patient. Our patient highlights the importance of the cytogenetic study in psychiatric patients with comorbid mental retardation or minor anomalies. In addition, her psychosis symptoms may be helpful to propose a new candidate gene for psychosis.

Effects of exercise on bone mineral density in calcium-replete postmenopausal women with and without hormone replacement therapy.

Osteoporosis is a major public health concern. The combination of exercise, hormone replacement therapy, and calcium supplementation may have added benefits for improving bone mineral density compared to a single intervention. To test this notion, 320 healthy, non-smoking postmenopausal women, who did or did not use hormone replacement therapy (HRT), were randomized within groups to exercise or no exercise and followed for 12 months. All women received 800 mg calcium citrate supplements daily. Women who exercised performed supervised aerobic, weight-bearing and weight-lifting exercise, three times per week in community-based exercise facilities. Regional bone mineral density (BMD) was assessed by dual energy X-ray absorptiometry. Women who used HRT, calcium, and exercised increased femoral neck, trochanteric and lumbar spine bone mineral density by approximately 1-2%. Trochanteric BMD was also significantly increased by approximately 1.0% in women who exercised and used calcium without HRT compared to a negligible change in women who used HRT and did not exercise. The results demonstrate that regional BMD can be improved with aerobic, weight-bearing activity combined with weight lifting at clinically relevant sites in postmenopausal women. The response was significant at more sites in women who used HRT, suggesting a greater benefit with hormone replacement and exercise compared to HRT alone.