Real‐time bladder volume monitoring by the application of a new implantable bladder volume sensor for a small animal model

Lee

The Kaohsiung J of Med Scie

et al. 2012

As the applications for implantable medical devices have increased, the need for biocompatible packaging materials has become important. Recently, we reported an implantable sensor for real-time monitoring of the changes in bladder volume, which necessitated finding a safe coating material for use in bladder tissue. At present, materials like polyethylene glycol (PEG), polydimethylsiloxane (PDMS) and parylene-C are used in biomedical devices or as coating materials, owing to their excellent safety in various medical fields. However, few studies have assessed their safety in bladder tissue, therefore, we evaluated the biocompatibility of PEG, PDMS and parylene-C in the bladder. All three materials turned out to be safe in in vitro tests of live/dead staining and cell viability. In vivo tests with hematoxylin and eosin and immunofluorescence staining with MAC387 showed no persistent inflammation. Therefore, we consider that the three materials are biocompatible in bladder tissue. Despite this safety, however, PEG has biodegradable characteristics and thus is not suitable for use as packaging. We suggest that PDMS and parylene-C can be used as safe coating materials for the implantable bladder volume sensor reported previously.

“…For these reasons, PEG, PDMS and parylene-C may all be appropriate packaging materials for the implantable bladder volume sensor that we have reported previously [3].…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Evaluation of the biocompatibility of a coating material for an implantable bladder volume sensor

Lee

The Kaohsiung J of Med Scie

et al. 2012

“…Therefore, this prototype device may be too large for implantation inside of living animals. In the next stage, we need to integrate all of these elements into a single integrated-circuit sensor to develop a fully-functioning microelectromechanical system (MEMS) [ 23 , 24 ]. However, our potentiometric sensor was designed to be placed on the bladder outer wall, and thus, it is expected that the size restriction for implanting such a sensor will be more flexible than other bladder sensors that are totally implanted inside the bladder cavity [ 25 , 26 ].…”

Section: Discussionmentioning

confidence: 99%

Design and Evaluation of Potentiometric Principles for Bladder Volume Monitoring: A Preliminary Study

Chen

Hsieh

Fan

et al. 2015

Sensors

Recent advances in microelectronics and wireless transmission technology have led to the development of various implantable sensors for real-time monitoring of bladder conditions. Although various sensing approaches for monitoring bladder conditions were reported, most such sensors have remained at the laboratory stage due to the existence of vital drawbacks. In the present study, we explored a new concept for monitoring the bladder capacity on the basis of potentiometric principles. A prototype of a potentiometer module was designed and fabricated and integrated with a commercial wireless transmission module and power unit. A series of in vitro pig bladder experiments was conducted to determine the best design parameters for implementing the prototype potentiometric device and to prove its feasibility. We successfully implemented the potentiometric module in a pig bladder model in vitro, and the error of the accuracy of bladder volume detection was <±3%. Although the proposed potentiometric device was built using a commercial wireless module, the design principles and animal experience gathered from this research can serve as a basis for developing new implantable bladder sensors in the future.

“…Moreover, the characteristics of voiding dysfunction are very diverse and depend on the patient condition; therefore, implantable intravesical devices capable of real-time monitoring are necessary to satisfy patient need [ 7 ]. To this end, we developed implantable bladder pressure- and volume-monitoring sensors [ 8 , 9 ].…”

Section: Introductionmentioning

confidence: 99%

The Potential Role of Polymethyl Methacrylate as a New Packaging Material for the Implantable Medical Device in the Bladder

Choi

BioMed Research International

et al. 2015

Self Cite

Polydimethylsiloxane (PDMS) is used in implantable medical devices; however, PDMS is not a completely biocompatible material for electronic medical devices in the bladder. To identify novel biocompatible materials for intravesical implanted medical devices, we evaluated the biocompatibility of polymethyl methacrylate (PMMA) by analyzing changes in the levels of macrophages, macrophage migratory inhibitory factor (MIF), and inflammatory cytokines in the bladder. A ball-shaped metal coated with PMMA or PDMS was implanted into the bladders of rats, and after intravesical implantation, the inflammatory changes induced by the foreign body reaction were evaluated. In the early period after implantation, increased macrophage activity and MIF in the urothelium of the bladder were observed. However, significantly decreased macrophage activity and MIF in the bladder were observed after implantation with PMMA- or PDMS-coated metal in the later period. In addition, significantly decreased inflammatory cytokines such as IL-1β, IL-6, and TNF-α were observed with time. Based on these results, we suggest that MIF plays a role in the foreign body reaction and in the biocompatible packaging with PMMA for the implanted medical devices in the bladder.