Nishihara K.,Tokyo Metropolitan Institute of Medical Science |
Nishihara K.,Fatigue Science |
Horiuchi S.,St. Lukes College of Nursing |
Eto H.,St. Lukes College of Nursing |
And 2 more authors.
Chronobiology International | Year: 2012
Some infants show a free-running rhythm in their rest-activity. We do not know why, nor do we know exactly what the entrainment factors are for the development of the normal 24-h rest-activity rhythm. Actigraphic recordings on 10 primiparae during late pregnancy and these mothers and their infants during the 2nd, 6th, and 12th wks after birth were made over 35 continuous days to investigate maternal and infant entrainment. One infant showed a free-running rest-activity circadian rhythm. In late pregnancy, the period in the autocorrelogram of the mother with the free-running infant was longer than the significant period of the mean autocorrelogram of the mothers with non-free-running infants. The finding of this study indicates the free-running rhythm of infant is not reset by maternal entrainment factors. Copyright © Informa Healthcare USA, Inc. Source
Das A.,Fatigue Science |
Das A.,Bhabha Atomic Research Center
Philosophical Magazine | Year: 2015
The phenomenological theory of martensitic transformation is well understood that the displacive phase transformations are mainly influenced by the externally applied stress. Martensitic transformation occurs with 24 possible Kurdjomov-Sachs (K-S) variants, where each variant shows a distinct lattice orientation. The elegant transformation texture model of Kundu and Bhadeshia for crystallographic variant selection of martensite in metastable austenite at various stress/strain levels has been assessed in this present research. The corresponding interaction energies have also been evaluated. Encouraging correlation between model prediction and experimental data generation for martensite pole figures at many deformed austenite grains has been observed at different stress/strain levels. It has been investigated that the mechanical driving force alone is able to explain the observed martensite microtextures at all stress/strain levels under uniaxial tensile deformation of metastable austenite under low temperature at a slow strain rate. The present investigation also proves that the Patel and Cohens classical theory can be utilized to predict the crystallographic variant selection, if it is correctly used along with the phenomenological theory of martensite crystallography. © 2015 The Author(s). Source
News Article | July 2, 2015
As wearable activity trackers get increasingly smart and complex, Fatigue Science is measuring one thing and one thing only — how we sleep. Fatigue Science’s Readiband looks very similar to a Fitbit or Nike Fuelband. It has a 3D accelerometer that tracks movement, impact, velocity, speed and frequency, a battery that lasts 60 days between charges, and it’s both water and pressure resistant. The band alone is not a revolutionary development, considering that even the most basic wearable fitness trackers can monitor when you’re asleep. Fatigue Science has the ability to detect sleep quality at 93 percent of the accuracy of a hospital sleep lab, but the real feat is their ability to predict human effectiveness and reaction time. The startup takes the sleep data captured by the band and runs it through a biomathematical model developed by the U.S. Military. This level of accuracy may not be essential for most of us, but for elite athletes who are required to be in top physical condition, understanding quality of sleep and how it affects performance can be a game changer (literally). The Seattle Seahawks, the Seattle Mariners, the New York Giants and the Dallas Mavericks are among a growing group of pro sports teams that have their players wearing the Readiband at night. With Fatigue Science’s Team Platform, a dashboard that aggregates data collected from all players wearing the band, coaches can make informed decisions about training and scheduling to make sure athletes are fully rested at game time. “If the Seahawks, for example, have to cross multiple time zones to go play in New York on Sunday night, they need to be able to plan in advance the right amount of sleep for their players so at game time they’re playing their best,” says Fatigue Science CEO Sean Kerklaan. “If management can determine that the travel schedule affects their players’ ability to be ready for practice the next morning, maybe they should cancel that practice,” he says. By aggregating individual sleep data across an entire sports team, doctors and coaches can analyze how long it takes for players, on average, to fall asleep after a game, how much the team is sleeping when they have days off compared to when they’re playing and traveling, and how all of this effects game-time performance. Kerklaan tells me that the U.S. Men’s National Soccer team used the band to measure which players were mature about their sleeping habits before going to the World Cup in Brazil this year. And professional sports is only one application of this technology. Fatigue Science has partnered with construction equipment manufacturer Caterpillar to prevent employees from operating heavy machinery when they’re sleep deprived. For the time being, the company is solely focused on tracking sleep and fatigue, but it plans to open its API in the near future so that users can plug in data from other sensors. “We get a lot of questions about pulse, heart rate, sweat and other sensors,” says Kerklaan. “Our position is that none of that is scientifically valid for helping you understand how fatigued you are, but our API will enhance that research and correlation.” Fatigue Science closed $3 million in seed funding last Fall from a handful of strategic angels, and Kerklaan says they’re taking their time raising a Series A because the business is cash-flow positive.
News Article | September 17, 2013
If you're a Vancouver Canucks fan you've likely heard of Fatigue Science. Five years ago Vancouver Sun writer Iain MacIntyre wondered if Fatigue Science's sleep bracelet was the Canucks "secret weapon". Hockey Night in Canada's Elliotte Friedman followed up with a feature which included interviews on the technology with enforcer Darcy Hordichuk and GM Mike Gillis. With Fatigue Science's help, the Canucks were able to improve their road record dramatically and Gillis was able to convince the NHL to ease up on the Canucks historically unfair road schedule and travel requirements. But more important, the Canucks were able to secure exclusive rights to the sleep tracking technology for four years and have kept it off of other NHL teams' wrists. In the past five years wearable technology and the concept of "quantified self" has taken off. It's clear that consumers want wearable devices to track activities and gather their own data. And Silicon Valley is hot on this trend. Jawbone just raised $100 million but is still struggling to meet their client demands and Fitbit has raised over $43 million from hungry investors. But is simply tracking your number of daily steps or hours of sleep enough to make any sort of significant change to you lifestyle and well-being? Apps and smart watches that simply report ''hours of sleep'' are not enough to help consumers achieve their best, whether if be maximizing performance or cutting down reaction times. Fatigue Science has the only technology in the world that can calculate how "hours of sleep" equate to "performance, reaction times and effectiveness." And it looks like they are on two something with a growing client list that includes the Canadian Soccer Association, US Olympic Committee, Canadian Olympic Program, and the Australian National and Olympic Teams. According to Fatigue Science CEO Sean Kerklaan, professional teams in the MLS and Premier League as well as the NBA and NFL are also testing the technology with announcements pending. Considering the game-changing affects that the Vancouver Canucks were able to experience in the first year of use, first-mover advantage in other leagues could be worth millions. Kerklaan shared with Techvibes that Fatigue Science is "actively raising capital to scale their business to meet the demand for our technology and pursuing licensing partnerships to broaden the consumer reach of our algorithm so millions of people can benefit."
Murata Manufacturing Co. and Fatigue Science | Date: 2015-12-22
A biological state estimating apparatus includes a pair of electrocardiographic electrodes, a photoplethysmographic sensor, and a controller that includes a peak detecting section, a pulse transmission time measuring section, a correlation information storing section, and a biological state estimating section. The electrocardiographic electrodes detect an electrocardiogram signal and the photoplethysmographic sensor, which has light-emitting and light-receiving elements, detects a photoplethysmogram signal. The controller detects peaks of the electrocardiogram and photoplethysmogram signals and determines a pulse transmission time from the time difference between the respective peaks of the photoplethysmogram and the electrocardiogram signal. Memory stores information determined in advance based on the relationship between pulse transmission time and biological state. The controller further estimates the biological state of the user on the basis of the pulse transmission time, and the correlation information stored in the correlation information storing section.