Wireless and minimally invasive continuous monitoring





Millions of patients could benefit from continuous monitoring of biomedical parameters, as the measurement of pressure in cardiovascular diseases. This could help to trigger alarms or adjust pharmacological treatment when the parameters indicate adverse fluctuations.



Today, it is very difficult to accomplish this continuous monitoring. On one hand, non-invasive systems are cumbersome, require an action of the patient, and do indirect measurements of these parameters. On the other hand, invasive systems are currently too bulky and stiff, limiting their clinical applicability.





To accomplish continuous and direct monitoring, we are engineering a new generation of miniaturized sensors to improve monitoring of biomedical parameters. These devices use a novel method to power flexible and injectable devices, obtaining threadlike implants without precedents in the medical devices industry. 

What is Senso-eAXON



Senso-eAXON is a platform composed of a wireless injectable sensor and an external unit able to interrogate it for obtaining measurements in the implant or in its vicinity.

The implant can continuously obtain physical or chemical measurements such as pressure, temperature and ion concentrations. 

In contrast to previous implantable sensing technologies, our technology allows the implementation of thread-like implants; flexible and very thin (diameter < 1 mm). This is due to the method used to power and interrogate the injectable devices. 





The technology is based on wireless power transfer by volume conduction: the external unit delivers to the tissues innocuous high-frequency currents in the form of bursts, and these currents are picked up by the implantable devices to power their electronics and receive and send information.

As the devices do not require bulky and stiff components as batteries or coils, the implants can be shaped as thread-like devices that can be injected in the tissue of interest. 

Additionally, the implants can be wirelessly controlled from the exteral unit, making it possible to have a network of devices monitoring different biomedical parameters. 

A proof-of-concept of the use of this novel approach for impedance sensing, and its in vitro validation has been published in IEEE Trans Biomed Circuits Syst. 2020 Aug;14(4):867-878. We also developed and injectable temperature sensor based on the same approach, and presented the results in the 2021 IEEE Biomedical Circuits and Systems Conference (doi: 10.1109/BioCAS49922.2021.9645006).

In terms of the wireless power transfer method that supports this sensing technology, we have successfully tested in animal models different microstimulators based on this power transfer approach (J Neural Eng. 2022 Sep 14;19(5)J Neuroeng Rehabil. 2022 Jun 7;19(1):57J Neural Eng. 2015 Dec;12(6):066010 and IEEE Trans Neural Syst Rehabil Eng. 2017 Aug;25(8):1343-1352.), and we have demonstrated in humans that the high-frequency currents are innocuous and imperceptible if applied according to standards (IEEE Trans. Biomed. Eng. 2023 Feb 1;70(2):659–670).


In the case of Senso-eAXON, the external unit that interrogates the wireless implant can be shaped as a pod-like device that can be easily attached and detached from the skin. It delivers innocuous high frequency currents to power and interrogate the implantable sensor, and will be capable of sending this information wirelessly for its analysis. 

Minimally invasive implantation procedure

We envision a simple and clean implantation procedure in which the sensor is deployed by catheterization. The process is summarized in six basic steps: 

Adapted from our journal article "Injectable Sensors Based on Passive Rectification of Volume-Conducted Currents".
IEEE Trans Biomed Circuits Syst. 2020 Aug;14(4):867-878.


The Senso-eAXON technology has been developed within the framework of a research project supported by an ERC Consolidator Grant (724244 - eAXON), at the Biomedical Electronics Research Group of Universitat Pompeu Fabra. Our team does research on bioelectrical phenomena and on how to use of these phenomena for developing new methods and devices for biomedical applications.

Senso-eAXON has received funding from:

  • The CaixaResearch Validate programe 2021, from La Caixa Foundation.
  • The European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (963955 - SENSO-eAXON).
  • The intra-mural competitive grant UPF INNOValora 2019, which was co-financed by the Generalitat de Catalunya and the European Regional Development Fund.



Contact us



The Biomedical Electronics Research Group is part of the Department of Information and Communication Technologies (DTIC) of Universitat Pompeu Fabra.

We are located at:

Carrer Roc Boronat 138 (room 51.017)
Universitat Pompeu Fabra
08018, Barcelona, Spain

Contact e-mail: [email protected]

Contact phone: +34 93 542 1578