Batteryless, Miniaturized Implantable Glucose Sensor Using a Fluorescent Hydrogel

We propose a biomedical sensor system for continuous monitoring of glucose concentration. Despite recent advances in implantable biomedical devices, mm sized devices have yet to be developed due to the power limitation of the device in a tissue. We here present a mm sized wireless system with backscattered frequency-modulation communication that enables a low-power operation to read the glucose level from a fluorescent hydrogel sensor. The configuration of the reader structure is optimized for an efficient wireless power transfer and data communication, miniaturizing the entire implantable device to 3 × 6 mm 2 size. The operation distance between the reader and the implantable device reaches 2 mm with a transmission power of 33 dBm. We demonstrate that the frequency of backscattered signals changes according to the light intensity of the fluorescent glucose sensor. We envision that the present wireless interface can be applied to other fluorescence-based biosensors to make them highly comfortable, biocompatible, and stable within a body.

Fabrication of Implantable Capsule-Type Channel Sounders for the High-Accuracy Measurement of the Signal Loss of Out-Body to In-Body Channels

This paper proposes a channel sounder to measure the channel properties of an implantable device that transmits data from inside to outside the human body. The proposed channel sounder measures the receiving power of a signal transmitted from outside the human body. The channel sounder is equipped with a Bluetooth module that enables the wireless transmission of the receiving power outside the human body. Wireless transmission enables the channel measurement by isolating the transmitter and receiver inside the channel sounder. Using the proposed channel sounder, the channel properties can be measured without any interference between the transmitter and the receiver.

Electromagnetic Compatibility Issues in Medical Devices

Electromagnetic compatibility (EMC) in biomedical applications is a significant issue related to the user’s life safety, especially in implantable medical devices. Cardiovascular diseases and neurodegenerative disorders are the main chronic disease worldwide that rely on implantable treatment devices such as cardiac pacemakers and vagus nerve stimulators. Both devices must have high EMC to avoid electromagnetic interference-induced health risks, even death during the treatment. Thus, it is important to understand how EMI can affect implantable devices and proactively protect devices from electromagnetic interference, providing reliable and safe implantable device therapy. To this end, this chapter comprehensively introduces the clinical issues and provides EMC requirements for the implantable device such as a cardiac pacemaker and vagus nerve stimulator. The significance of this chapter is to present the EMC important issues in medical engineering that can help to evolve reliable and secure implantable device development in the future.

Feasibility and prognostic value of adenosine stress perfusion cardiovascular magnetic resonance in patient with implantable device

Funding Acknowledgements Type of funding sources: None. Background stress CMR has a limited use in patients with implantable device, in order to the possible artefacts due to the metallic component and to the risk of adenosine interaction with cardiac pacing. The aim of the study was to assess the global feasibility and to assess the prognostic value of stress perfusion CMR in patients with implantable device. Materials and Methods we conducted a retrospective single-center longitudinal analysis of consecutive patients with an implantable device referred for stress CMR, performed using a 1.5 Tesla unit (Siemens Healthcare,MAGNETOM Aera, Erlangen-Germany). Protocol was adapted according to current guidelines. Cardiac follow-up [6 months to 7 years] was obtained by medical records of direct contact with patient’s cardiologist referral. Results 44 patients were enrolled. 34 patients needed a continuous pacing during adenosine stress, that was settled in DOO in 14 (32%) and in VOO in 20 (45%). Device integrity was not compromised by CMR and not competitive atrial or ventricular stimulation was observed during examination. Image quality was good in 95% cases. 26% cases had a perfusion deficit corresponding to a previous scar, while 12% of patients had a positive stress test. All of them needed continuous pacing during stress test and underwent to a coronary angiography who confirmed the coronary stenosis. In patients without inducible ischemia 2 patients experienced a Non-ST-elevation Myocardial Infarction after 6 and 2 years while no other cardiac symptoms or cardiac hospitalisation was remarkable during follow up. Conclusion adenosine stress CMR in patient who are pacemaker dependent during scanner is feasible, with an overall good image quality, proving an excellent diagnostic and prognostic value in a long term follow up even. Adenosine administration is safe and no the magnetic field interference with the correct functioning of the device have been shown in short or long term follow-up.