A New Low Power Photoplethysmography Signal Acquisition System For Mental Stress Estimation

Author(s):  
Rajeev Kumar Pandey ◽  
Paul C.-P. Chao

Abstract This study presents a new low power and robust reflectance type optical Photoplethysmography (PPG) acquisition system for the mental distress estimation. The front-end circuit is implemented in the integrated chip with chip area of 1200μm × 1200μm and fabricated via TSMC T18 process. The sensing range of the readout circuit is 20nA to 11μA, and the total power consumption of the readout system is 100μW. The total power consumption of the design chip including the OLED driver power is 1.64mW. The designed acquisition system is applied to the wrist artery of the two healthy patients when they are calculating the pictorial puzzles and when they are in relax state. The statistical deviation of the heart rate (HR) from the average HR is increased when subjects are in the stress. Also, the standard deviation of pulse rate variability (PRV), the dynamic range of pulse repetition time (PRT), and the standard deviation of PRV derivative show the increasing temporal value when subjects are in the stress.

Author(s):  
Yue Zhang ◽  
Linwei Tao

In order to realize the acquisition and storage of underwater acoustic signals for aiming at the requirements of multi-channel, low power consumption and small volume for underwater receiver extension of sonar system, a multi-channel signal acquisition and storage system based on FPGA and STM32 with variable number of working channels and sampling frequency is designed, in which the system is consisted of 8 pieces, 8 channel and 24 bits high dynamic range Δ-Σ ADS1278 ADC chip to synchronous multi-channel analog signal acquisition. FPGA, as the acquisition sequence and logic control, reads and collates the ADC chip data and writes it into the internal high-capacity FIFO, and adds corresponding operations according to the characteristics of FIFO in an application. SMT32 single-chip microcomputer reads the FIFO data through the high-speed SPI interface with FPGA and writes the multi-channel data into the high-capacity SD card. The testing results have verified that the system has characteristics such as stable and reliable, easy configuration, low power consumption, can guarantee the multichannel data serial transmission, storage, accurate, up to 64 analog signals at the same time the real-time collection and storage, top 20 kHz sampling rate, the system total power of the system of about 3W, data rates up to 100 Mb/s, fully meet the needs of underwater sound acquisition system.


Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1429 ◽  
Author(s):  
Jin-Fa Lin ◽  
Cheng-Yu Chan ◽  
Shao-Wei Yu

In this paper, a novel latch-adder based multiplier design, targeting low voltage and low power IoT applications is presented. It employs a semi-dynamic (dynamic circuit with static keeper circuit) full adder design which efficiently incorporates the level sensitive latch circuit with the adder cell. Latch circuit control signals are generated by a chain of delay cell circuits. They are applied to each row of the adder array. This row-wise alignment ensures an orderly procedure, while successfully removing spurious switching resulting in reduced power consumption. Due to the delay cell circuit of our design is also realized by using full adder. Therefore, it is unnecessary to adjust the transistor sizes of the delay cell circuit deliberately. Post-layout simulation results on 8 × 8 multiplier design show that the proposed design has the lowest power consumption of all design candidates. The total power consumption saving compared to conventional array multiplier designs is up to 38.6%. The test chip measurement shows successful operations of our design down to 0.41 V with a power consumption of only 427 nW with a maximum frequency 500 KHz.


Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3649
Author(s):  
Minhyun Jin ◽  
Hyeonseob Noh ◽  
Minkyu Song ◽  
Soo Youn Kim

In this paper, we propose a complementary metal-oxide-semiconductor (CMOS) image sensor (CIS) that has built-in mask circuits to selectively capture either edge-detection images or normal 8-bit images for low-power computer vision applications. To detect the edges of images in the CIS, neighboring column data are compared in in-column memories after column-parallel analog-to-digital conversion with the proposed mask. The proposed built-in mask circuits are implemented in the CIS without a complex image signal processer to obtain edge images with high speed and low power consumption. According to the measurement results, edge images were successfully obtained with a maximum frame rate of 60 fps. A prototype sensor with 1920 × 1440 resolution was fabricated with a 90-nm 1-poly 5-metal CIS process. The area of the 4-shared 4T-active pixel sensor was 1.4 × 1.4 µm2, and the chip size was 5.15 × 5.15 mm2. The total power consumption was 9.4 mW at 60 fps with supply voltages of 3.3 V (analog), 2.8 V (pixel), and 1.2 V (digital).


1996 ◽  
Vol 07 (02) ◽  
pp. 305-322
Author(s):  
KAI-YUAN CHAO ◽  
D. F. WONG

In this paper, a floorplanner for low power design is presented. Our objective is to optimize total power consumption and area during the selection and placement of various implementations for circuit modules. Furthermore, the proposed method considers performance requirements, power line noises, and distribution of power consumption in order to generate lower and evenly distributed power dissipation over the resulting circuit floorplan with a specified performance. For a set of benchmark circuits we tested, on the average, our floorplanner can achieve decreases of total power consumption, wire-length, and power/ground network size by 18.3%, 4.6%, and 24%, respectively, at the cost of an area increase of 8.8% when compared with an existing area/wire-length driven floorplanner.


2019 ◽  
Vol 25 (6) ◽  
pp. 35-39
Author(s):  
Libor Chrastecky ◽  
Jaromir Konecny ◽  
Martin Stankus ◽  
Michal Prauzek

This article describes implementation possibilities of specialized microcontroller peripherals, as hardware solution for Internet of Things (IoT) low-power communication, interfaces. In this contribution, authors use the NXP FlexIO periphery. Meanwhile, RFC1662 is used as a reference communication standard. Implementation of RFC1662 is performed by software and hardware approaches. The total power consumption is measured during experiments. In the result section, authors evaluate a time-consumption trade-off between the software approach running in Central Processing Unit (CPU) and hardware implementation using NXP FlexIO periphery. The results confirm that the hardware-based approach is effective in terms of power consumption. This method is applicable in IoT embedded devices.


Author(s):  
Fahmi Elsayed ◽  
◽  
Mostafa Rashdan ◽  
Mohammad Salman

This paper presents a fully integrated CMOS Operational Floating Current Conveyor (OFCC) circuit. The proposed circuit is designed for instrumentation amplifier circuits. The CMOS OFCC circuit is designed and simulated using Cadence in TSMC 90 m technology kit. The circuit aims at two different design goals. The first goal is to design a low power consumption circuit (LBW design) while the second is to design a high bandwidth circuit (HBW design). The total power consumption of the LBW design is 1.26 mW with 30 MHz bandwidth while the power consumption of the HBW design is 3 mW with 104.6 MHz bandwidth.


Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5309
Author(s):  
Shengbiao An ◽  
Shuang Xia ◽  
Yue Ma ◽  
Arfan Ghani ◽  
Chan Hwang See ◽  
...  

Analogue-to-digital converters (ADC) using oversampling technology and the Σ-∆ modulation mechanism are widely applied in digital audio systems. This paper presents an audio modulator with high accuracy and low power consumption by using a discrete second-order feedforward structure. A 5-bit successive approximation register (SAR) quantizer is integrated into the chip, which reduces the number of comparators and the power consumption of the quantizer compared with flash ADC-type quantizers. An analogue passive adder is used to sum the input signals and it is embedded in a SAR ADC composed of a capacitor array and a dynamic comparator which has no static power consumption. To validate the design concept, the designed modulator is developed in a 180 nm CMOS process. The peak signal to noise distortion ratio (SNDR) is calculated as 106 dB and the total power consumption of the chip is recorded as 3.654 mW at the chip supply voltage of 1.8 V. The input sine wave of 0 to 25 kHz is sampled at a sampling frequency of 3.2 Ms/s. Moreover, the results achieve a 16-bit effective number of bits (ENOB) when the amplitude of the input signal is varied between 0.15 and 1.65 V. By comparing with other modulators which were realized by a 180 nm CMOS process, the proposed architecture outperforms with lower power consumption.


Author(s):  
Ow Tze Weng ◽  
Suhaila Isaak ◽  
Yusmeeraz Yusof

The trend of health care screening devices in the world is increasingly towards the favor of portability and wearability. This is because these wearable screening devices are not restricting the patient’s freedom and daily activities. While the demand of low power and low cost biomedical system on chip is increasing in exponential way, the front-end electrocardiogram (ECG) amplifiers are still suffering from flicker noise for low frequency cardiac signal acquisition, 50Hz power line electromagnetic interference, and the large unstable input offsets due to the electrode-skin interface is not attached properly. In this paper, a CMOS based ECG amplifier that suitable for low power wearable cardiac screening is proposed. The amplifier adopts the highly stable folded cascode topology and later being implemented into RC feedback circuit for low frequency DC offset cancellation. By using  0.13µm CMOS technology from Silterra, the simulation results show that this front-end circuit can achieve a very low input referred noise of  1pV/Hz1/2 and high common mode rejection ratio of 174.05dB. It also gives voltage gain of 75.45dB with good power supply rejection ratio of 92.12dB. The total power consumption is only 3µW and thus suitable to be implemented with further signal processing and classification back end for low power wearable biomedical device.<br /><br />


Author(s):  
Aswini Valluri ◽  
◽  
Sarada Musala ◽  
Muralidharan Jayabalan ◽  
◽  
...  

There is an immense necessity of several kilo bytes of embedded memory for Biomedical systems which typically operate in the sub-threshold domain with perfect efficiency. SRAMs (Static Random Access Memory) dominates the total power consumption and the overall silicon area, as 70% of the die has been occupied by them. This brief proposes the design of a Transmission gate-based SRAM cell for Bio medical application eliminating the use of peripheral circuitry during the read operation. It commences the read operation directly with the help of Transmission gates with which the data stored in the storage nodes can be read, instead of using the precharge and sense amplifier circuits which suits better for the implantable devices. This topology offers smaller area, reduced delay, low power consumption as well as improved data stabilization in the read operation. The cell is implemented in 45nm CMOS technology operated at 0.45V.


Sign in / Sign up

Export Citation Format

Share Document