Wireless intravesical device for real-time bladder pressure measurement: Study of consecutive voiding in awake minipigs

Abstract

Traditional urodynamics have poor correlation with urological symptoms. Ambulatory urodynamics may improve this correlation but the need for a transurethral catheter and the time-consuming nature of this examination limits its use. Therefore, the objective of this study was to develop a wireless real-time bladder pressure measurement device for repeated and prolonged-term measurement of bladder behavior in awake pigs. The Bladder Pill is an intravesical device with a pressure microsensor and a 3-dimensional inductive coupling coil for energy supply. A corresponding external coil provides wireless power transmission and real-time communication of bladder pressure data. To test the correlation between the pressure data measured by the device and by standard methods, we compared static water column pressures with this device and water-filled urodynamic catheter systems. In vivo assessment of awake voiding by the pill was done by introducing the bladder pill into the bladder of Göttingen minipigs. An air-charged urodynamic catheter was introduced transurethrally as control for pressure measurements. The optimal physical configuration of the pill was investigated to maximize the containment in the bladder. We used two versions of external signal receivers (one waistband and one rectangular frame) to test the optimal external signal capture. Next to that, we performed short-term and medium-term comparative pressure studies. The in vitro static pressure measurement demonstrated a mean difference of less than 1 cm H2O between the methods. The optimal design of the pill for maximal retainment in the bladder proved to be a pigtail configuration. The bending of the device during bladder contractions caused offset of 2.7 +/- 1.4 cm H2O (mean +/- SD) on the pressure measurements. The rectangular frame performed signal capture during 5 consecutive voids with a good correlation of the pressure measurements. The device can be inserted through the urethra and is retrieved using string or endoscopic extraction. In conclusion, wireless long-term measurement of bladder pressure is demonstrated and yields comparable results to current available catheter methods of measurement in a pig model.

Novel implantable pressure and acceleration sensor for bladder monitoring

“…Additionally, sensing membrane characteristics might become augmented as a result of mucosal contact, and adherent mucus precipitation might play a role. Similar decreases in sensitivity were previously reported in the measurement of consecutive voiding 20 . In the last week, pressure measurements showed a similar range of correlations with the initial measurements.…”

Advances in Assistive Electronic Device Solutions for Urology

“…Then, verified by in vivo wireless bladder pressure sensing, the data quality was sufficient to detect bladder compressions in large animals, with an average correlation coefficient of 0.90, which correlates well with the reference catheter device and the trend of the pressure curves is consistent (Figure 7b). Furthermore, Soebadi et al [94] have created a wireless intravesical device for realtime bladder pressure measurement in awake pigs. The measurement system consists of the bladder pill and a corresponding external device (Figure 7c).…”

“…The pill contains an MS5637 pressure sensor microchip and a custom three-dimensional power-receiving coil, all encapsulated in medical-grade silicone tubing at approximately 4.6 mm in diameter. The pill is designed for soft encapsulation and flexibility for easy urethral insertion in Furthermore, Soebadi et al [94] have created a wireless intravesical device for realtime bladder pressure measurement in awake pigs. The measurement system consists of the bladder pill and a corresponding external device (Figure 7c).…”

“…(b,i) The wireless pressure sensor circuit diagram, (ii) the size compared to a coin, (iii) the different polymer coatings, and (iv) graphs of catheter and wireless pressure monitoring pressure recordings versus time [93].Copyright 2016, IEEE. (c,i) The bladder pill device, the non−encapsulated and the encapsulated bladder bill, (ii) details of a single void marked on a graph, (iii) the waistband device, and (iv) rectangular frame setup[94].…”

Telmisartan inhibits bladder smooth muscle fibrosis in neurogenic bladder rats

“…A significant pathological feature of NB is detrusor fibrosis, which occurs when a large number of collagen fibers are deposited between the muscle bundles ( 4 ). This collage deposition leads to detrusor contracture, detrusor weak contraction, bladder storage and emptying disorders, upper urinary tract damage and serious complications, such as renal failure ( 5 , 6 ).…”