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System on Chip...
public project

Research Goals

The main objectives of this project are discussed in phases below and shown in detail in Figure 1. These three passive measurements can be mapped to three main influenza symptoms (fever, low blood oxygen, and fluid accumulation in lungs) along with detection of heart rate. Using this low-cost SoC, influenza symptoms can be monitored constantly. The data is secured and translated to convenient digital data to be transmitted off-chip. Our design is inspired by [1, 2], adding environmental and physiological feedback that can control the gain and frequency band of the blocks to decrease errors. These errors are caused by physiological differences (age, skin pigmentation, skin type), or environmental variations (Environment temperature, light, and movement).

As seen from the picture, phase 1 has been implemented and published during my Ph.D. (Graduated in August 2020), with secure temperature [3-5] and impedance sensors [6-7]. I have since moved to California State University Long Beach (CSULB) as an assistant professor with fewer resources in chip fabrication. Each fall, I teach a graduate-level analog design class at CSULB, EE532. Our class EE532 is a project-based class where students do literature reviews and aim to improve state-of-art analog designs as teams, presenting their simulation results, with a design deadline in November. Last semester, I was amazed by their passion and had more than a handful of fabrication-worthy designs in my class. Without the resources, these amazing designs got stuck in the simulation stage. With the help of 2 master's students, working on this project and with the contribution of my motivated class of Fall 2022, We aim to integrate Fabless blocks of power management (LDO, Power Swicth and BGR), data processing (Analog Comparator, 8-bit SAR ADC and DPGA) with our Impedance (Schematic 1), temperature (Schematic 2), blood oxygen sensor (Work of my master student under review) and ciphering block (Schematic 2), to have an SoC that can be used at clinical experiments. 


Figure 1: Implemented sensors (Phase 1), Proposed  Fabless implemented (Phase 2), and research outlook (Phase 3) for monitoring patients withinfluenza-likee symptoms.

Figure 1: Implemented sensors (Phase 1), Proposed  Fabless implemented (Phase 2), and research outlook (Phase 3) for monitoring patients with influenza-like symptoms.

Schematic and preliminary design 1: Impedance Sensor





Range Ω



1 Ω




3 mW

Size (mm×mm)


Weight (g)


Data Transfer


Schematic and preliminary design 2: Temperature Sensor with encryption




Voltage (V )



Power (nW )



Accuracy (C)


± 0.15

Resolution (C)



Area (mm2)



Technology (µm)



Temperature sensor


[1] S. Song, M. Konijnenburg, R. van Wegberg, J. Xu, H. Ha, W. Sijbers, S. Stanzione, D. Biswas, A. Breeschoten, P. Vis et al., \A 769 μw battery-powered single-chip soc with ble for multi-modal vital sign monitoring health patches," IEEE transactions on biomedical circuits and systems, vol. 13, no. 6, pp. 1506-1517, 2019.

[2] Y. Luo, K.-H. Teng, Y. Li, W. Mao, Y. Lian, and C.-H. Heng, \A 74-w 11-mb/s wireless vital signs monitoring SoC for three-lead ECG, respiration rate, and body temperature," IEEE transactions on biomedical circuits and systems, vol. 13, no. 5, pp. 907-917, 2019.

[3] A. Hedayatipour and N. McFarlane, "An Encryption Architecture Suitable for on Chip Integration With Sensors," in IEEE Journal on Emerging and Selected Topics in Circuits and Systems, vol. 11, no. 2, pp. 395-404, June 2021.

[4] A. Hedayatipour, K. Anderson, S. Aslanzadeh, D. Brown, D. Materassi and N. McFarlane, "A Temperature Sensing System With Encrypted Readout Using Analog Circuits," IEEE 62nd International Midwest Symposium on Circuits and Systems (MWSCAS), 2019, pp. 152-155.

[5] A. Hedayatipour, M. A. Haque, and N. McFarlane, "Quasi-digital output low power cmos temperature sensor," IEEE 61st International Midwest Symposium on Circuits and Systems (MWSCAS), pp. 992-995, 2018.

[6] S. Aslanzadeh, A. Hedayatipour, M. Smalley and N. McFarlane, "A Combined pH-Impedance System Suitable for Portable Continuous Sensing," IEEE Transactions on Biomedical Circuits and Systems, vol. 15, no. 3, pp. 390-401, June 2021.

[7] A. Hedayatipour, S. Aslanzadeh, S. H. Hesari, A. Haque, and N. McFarlane, "A wearable CMOS impedance to frequency sensing system for non-invasive impedance measurements," IEEE Transactions on Biomedical Circuits and Systems, vol. 14, no. 5, pp. 1108-1121, Oct. 2020.


Team Members:

Ava Hedayatipour, PhD, Assistant Professor, CSULB

Ricardo Baurto, MS, Student, CSULB

Harshitha Gowdara, MS,  Student, CSULB 

Ava Hedayati
Organization URL



The goal of this research is to take advantage of today's technology in the implementation of robust, inclusive sensor systems that are compatible with of wearable/portable devices. The System on Chip (SoC), detects temperature, impedance, and changes in light absorption on a low-power, low-area integrated chip that includes power management, data transmitting, and initial processing blocks. The processing block aims to remove inaccuracies due to skin pigmentation, environment temperature, and movement using active feedback.