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Integrating Ultrasound Technology into a Fitness Tracking Device (1M, 2 B/S)

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Short Description

Ultrasound is a key technology in healthcare, and it is being explored for non-invasive, wearable, continuous monitoring of vital signs. However, its widespread adoption in this scenario is still hindered by the size, complexity, and power consumption of current devices. Moreover, such an application demands adaptability to human anatomy, which is hard to achieve with current transducer technology. In this work, we develop strategies and prototypes to advance ultrasound into a wrist-worn application, e.g. for monitoring personal fitness and well-being.

Status: Available

Looking for 1 Master or 2 Semester students
Contact: Christoph Leitner (iis), Marco Giordano (pbl)


  • Creativity and solid research methodology (highly appreciated).
  • Showing participation in non-curricular analog/digital projects is a plus.
  • Circuit design tools (e.g., Altium Designer).
  • Knowledge of MCU programming as well as mixed-signal and RF design know-how is an advantage.


40% Hardware design
30% Firmware programming
10% Characterization and testing
20% Data analyses and documentation


Luca Benini

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Detailed Task Description

The focus of this work is to support the development of an ultrasound technology and its adaptation to a wrist-worn application. The main task of this project is the design of a "flat" development board with all necessary components for ultrasound transmit (TX) and receive (RX) stages as well as the corresponding firmware. Depending on the level of the student and the type of work chosen (B/S/M), this could be extended to achieve even tighter integration of the system. The these will include some or all of the following tasks:



We aim to use a new type of piezoelectric transducers that are printed on a flexible substrate. These transducers can be bent into the anatomical shape of the wrist. However, compared to conventional piezos, they are quite lossy, placing special demands on the electronic drive system. Therefore, characterisation of these transducers is essential for the design of the circuit board:

  • Fabrication of transducers on flexible substrate
  • VNA measurements of transducers
  • Matching circuit design
Hardware Design

Medical ultrasound systems work according to the pulse-echo scheme. Similar to the tracking system of bats, a short high-frequency and high-voltage pulse is generated in a TX stage, and the returning echoes (reflections of tissue structures) are recorded and digitised in the RX stage for further processing:

  • Design of a "flat" development board for an existing TX and RX circuit prototype.
  • Integration of an ARM Cortex microcontroller as control unit for TX and RX.
  • TX pulse tuning (based on the STHVUP32, STMicroelectronics) to optimise acoustic power transmission.
  • Optimisation of the RX circuit (Amps and filters) for best possible amplification at reduced bandwidth and power consumption.
  • Design proposal for an optimized and integrated TX and RX circuit.

Hardware and firmware developments can be done in a single thesis or split into two separate works.

  • Programming of an ARM Cortex MCU as the control unit for the ultrasonic TX and RX stages.

The evaluation of the overall system is important to determine the scientific contribution and to differentiate from already existing solutions as well as to plan further development steps:

  • Insertion loss
  • System power consumption

Practical Details


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