Hernandez-Silveira M.A.,Toumaz Healthcare Ltd |
Ang S.S.,Toumaz Healthcare Ltd |
Burdett A.,Toumaz Microsystems Ltd
IFMBE Proceedings | Year: 2014
Patient monitoring is an important part of healthcare workflow in hospitals. In the general ward, nurses typically check on patients three times a day by manually measuring and taking note of vital signs every eight hours. Sometimes this results in misdetection of adverse physiological events, which in turn may lead to severe and irreversible conditions. Although conventional bedside monitors could be used in general wards, they are expensive and impractical for ambulatory patient monitoring (bulky size and wires restricting patients’ mobility). Based on our Sensium® system-on-chip Toumaz has recently developed wearable, low cost technologies for healthcare ambulatory monitoring. The SensiumVitals® is an end to end system that incorporates a new and alternative concept in wireless monitoring – the digital patch. This wireless, unobtrusive, lightweight and disposable body-worn device is capable of continuously acquiring and processing vital signs information from patients (temperature, hear rate and respiration rate) in real-time. To achieve this, the digital patch runs a number of embedded algorithms, and then wirelessly transmits every two minutes the data to bridges and servers for interpretation and display. This enables continuous monitoring of patients and early detection of physiological adverse events; thus alerting clinical staff about potential patient deterioration that may cause irreversible damage and in some cases fatal consequences if untreated. Unfortunately, one major issue of healthcare ambulatory monitoring technologies is the negative impact of body movement on the quality of the physiological data. Motion artifacts (MAs) often distort the ECG signals and compromise the reliability of vital signs computation. Furthermore, MA and heart contaminants are responsible for inaccurate results when processing respiration rates from impedance pneumography signals. In this paper we briefly describe of our system and embedded algorithms, including how we dealt with different disturbances affecting the quality of the signals. Finally, we present preliminary results of the evaluation of our SensiumVitals® in terms of accuracy and performance of our algorithms when compared with a validated/clinical vital signs monitor. © Springer International Publishing Switzerland 2014.
Wong A.C.W.,Toumaz MicroSystems Ltd. |
Dawkins M.,Toumaz MicroSystems Ltd. |
Devita G.,Toumaz MicroSystems Ltd. |
Kasparidis N.,Toumaz MicroSystems Ltd. |
And 5 more authors.
IEEE Journal of Solid-State Circuits | Year: 2013
This paper presents a 1 V multi-mode RF transceiver for wireless body area network (WBAN) applications. Operating in the 2.36 GHz Medical Body Area Networks (MBANs) and the 2.4 GHz Industrial, Scientific & Medical (ISM) frequency bands, the transceiver implements rotated differential-phase shift keying (DPSK) and Gaussian filtered frequency shift keying (GFSK) modulation for both IEEE 802.15.6 Narrow Band (NB) and Bluetooth Low-Energy (LE) PHY standards. Also included is a proprietary 900 MHz ISM band transmitter utilizing FSK modulation. The wireless transceiver operates half-duplex, and for IEEE 802.15.6 achieves-104-96.5 dBm receiver input sensitivity (for 10% packet error rate) at data rates of 121.4/971.4 kbps and-94 dBm for Bluetooth LE (for 0.1% bit error rate) at 1 Mbps. Transmit power up to +3/+5 dBm is achievable for IEEE 802.15.6 and Bluetooth LE respectively. The transceiver consumes 4.8 mA during IEEE 802.15.6 & Bluetooth LE receive, and 4.6 mA during Bluetooth LE transmit at-10 dBm output power, from a 1.0 V supply. For IEE802.15.6 transmission at-10 dBm output power, 5.9 mW is consumed, dropping to 1.7 mW for proprietary 900 MHz transmission. This performance surpasses state-of-the-art power consumption and represents the first published transceiver for the IEEE 802.15.6 NB PHY standard. It is fabricated in a 0.13 μ m CMOS technology and occupies approximately 5.9 mm2. © 1966-2012 IEEE.
TOUMAZ MICROSYSTEMS Ltd | Date: 2015-01-13
A switched mode power supply, SMPS. The SMPS comprises a switch, one or more inductors, an output smoothing capacitor, and a controller. The controller is configured to determine a first energy difference that is an instantaneous energy in the inductor(s) minus an energy in the inductor(s) at a load current, and determine a second energy difference that is an energy in the output smoothing capacitor at a reference voltage minus an instantaneous energy in the output smoothing capacitor. The controller is further configured to turn the switch on and off with a clock rate and a variable duty cycle such that the switch is on from the start of each period of the clock until the first energy difference is substantially equal to the second energy difference, and such that the switch is otherwise off.
Toumaz Microsystems Ltd | Date: 2015-07-15
A switched mode power supply comprises a switch, one or more inductors, an output smoothing capacitor, and a controller. The controller is configured to determine a first energy difference (503) that is an instantaneous energy in the inductor(s) minus an energy in the inductor(s) at a load current, and determine a second energy difference (506) that is an energy in the output smoothing capacitor at a reference voltage minus an instantaneous energy in the output smoothing capacitor. The controller is further configured to turn the switch on and off with a clock rate (CLK) and a variable duty cycle such that the switch is on from the start of each period of the clock until the first energy difference is equal (507) to the second energy difference, and such that the switch is otherwise off.
Toumaz Microsystems Ltd | Date: 2014-02-05
Method and apparatus for providing amplitude control for a voltage controlled oscillator (VCO). An output of a VCO is passed through a rectifier to produce a rectified signal. The rectified signal is then compared to a reference signal. The result of this comparison is then passed through a filter of variable bandwidth to produce a bias signal which is input into the VCO. The selection of the resistance experienced to produce the bandwidth for the bias signal may be achieved by selecting between two resistors or selecting the resistance of a variable resistor.