Fig 1.
(a) Illustration of the catheter-free, wired pressure monitor as implanted within the bladder wall and (b) photograph of the fabricated implantable prototype.
Table 1.
Prototype Pressure Sensor Bench Test Summary.
Fig 2.
Feline Contraction Recordings.
Examples of device (solid blue line) and reference (dashed red line) recordings of (a) bladder pressure as-recorded and (b) normalized contractions induced by electrical stimulation in the feline and (c) bladder pressure as-recorded and (d) normalized fast pressure changes due to manual bladder compression in the feline showing a faster rise time and slower decrease in pressures measured by the device.
Fig 3.
A slow drift of approximately 2 cm H2O per minute was noted between vesical reference (a) and suburothelial pressure monitor (b) recordings in the feline.
Fig 4.
Pooled Multi-Contraction Correlation Coefficients from all animal experiments.
Boxplots of measured correlation coefficients between prototype device and reference catheter in (a) anesthetized feline with submucosal device placement, (b) anesthetized canine with submucosal device placement, (c) anesthetized canine with intraluminal device placement, and (d) anesthetized canine terminal procedure with intraluminal device placement after 10-day implant period. Each box represents correlation coefficients obtained from 9–16 ten second recording windows comparing prototype device and reference catheter measurements. The box width depicts the interquartile range of measured correlation coefficients, while the box whiskers represent the full range of measured data after excluding statistical outliers identified with Peirce’s criterion. The central line within each box represents the median, and the data mean is indicated with a cross symbol. Raw data is shown in S1 Table.
Fig 5.
Example Recordings in the Nonsurvival Canine.
Examples of device (solid blue line) and reference (dashed red line) recordings of electrically-induced isometric contractions in canine (a) as-recorded and (b) normalized recordings with the device in the submucosal location. Manual bladder compressions from the submucosal sensor (c) as-recorded and (d) normalized were correlated with reference lumen pressure but showed rate-change variation. Lumen pressure (e) as-recorded and (f) normalized recordings with the device in the bladder lumen showed good agreement with the reference.
Fig 6.
Examples of Pressure Data from the Device during Ambulation.
Data captured in the ambulatory canine due to (a) walking (step frequency indicated approximately by dots) and (b) sit-to-stand posture change (black arrows indicate approximate start/stop of motion). Bladder contractions (onset denoted by black arrow) measured in ambulatory canine showing both (c) voiding and (d) non-voiding contractions.