A Sensorized Nuss Bar for Patient-Specific Treatment of Pectus Excavatum

Abstract

Pectus Excavatum is an anatomical deformation characterized by a depression of the anterior chest wall. Nuss technique (representing the current clinical golden standard) consists in the introduction of a corrective metal bar, in order to raise the sternum in its anatomic natural position. Nowadays, the bar plays purely a mechanical/corrective action and is kept implanted for about three years, supporting up to a maximum force of 250 N. Our study aims at optimizing the procedure of correction, in terms of monitoring the bar effect, minimizing the body response, and facilitating the bar removal. The sensorized Nuss bar prototype inserted in a platform for telemedicine described in this article is able to monitor in vitro pressure data variations, with more than 150 discrete measurements during the operating period. This behavior is promising for future clinical applications, in which the device could be exploited to monitor the forces at work, thus, providing a customized therapeutic protocol, which in turn may optimize the period of implant. The sensorized bar was also provided with a polymeric coating, able to influence human dermal fibroblast behavior in vitro. This highlights the possibility to minimize, in future in vivo applications, tissue fibrotic responses.

A Simple, Low-Cost Micro-Coating Method for Accuracy Improvement and Its Application in Pressure Sensors

“…(5) This method has excellent performance in waterproofing, corrosion resistance, and biocompatibility. Therefore, this simple, efficient, and low-cost method for improving the accuracy of pressure sensors has desirable application prospects in industrial production [32,33], biochemical detection, medical diagnosis [34], marine exploration [35], environmental protection, experimental testing, and other industrial automation. This method should also be useful for improving the accuracy of other kinds of sensors.…”

Implant Safety Tool Application to Assist the Assessment of Radio-Frequency Radiation Exposure

“…Nuss bars have only corrective functions and are implanted in the patient's trunk for a period of 2-3 years (see Figure 3). They usually interact mechanically on the thoracic costal cartilages with a maximum force up to 250 N [Betti et al, 2014]. What is important, a Nuss bar-implant displacement may occur during the implantation period; thus, the continuous real-time monitoring of the progressive thoracic wall correction is necessary, which can detect health problems in advance, provide better treatment for the pectus patients, and determine the best time to remove the metal implant [Wang et al, 2017].…”

“…In [Antonowicz et al, 2016], based on the 3D CT scans of the skeletal system, the authors demonstrated the model and developed a prototype of an external stabilizer supporting the treatment of pectus carinatum in young men. Other researchers [Betti et al, 2014] proposed advanced sensorized Nuss bar prototype to monitor changes in pressure (forces) acting on the chest wall of the PE patients during the period of bar-implant. Owing to such device, the treatment time is limited to the minimum necessary to achieve lasting pectus correction, and thus the probability of negative tissue-implant interactions is reduced.…”