Faculty of Medicine, Airlangga University, Surabaya, Indonesia.
Department of Urology, Dr Soetomo Hospital, Surabaya, Indonesia.
Int J Urol. 2020 Jun;27(6):543-550. doi: 10.1111/iju.14238. Epub 2020 Apr 7.
To test the hypothesis that an implantable sensing system containing accelerometers can detect small-scale autonomous movements, also termed micromotions, which might be relevant to bladder physiology.
We developed a 6-mm submucosal implant containing a pressure sensor (MS5637) and a triaxial accelerometer (BMA280). Sensor prototypes were tested by implantation in the bladders of Gottingen minipigs. Repeated awake voiding cystometry was carried out with air-charged catheters in a standard urodynamic set-up as comparators. We identified four phases of voiding similar to cystometry in other animal models based on submucosal pressure. Acceleration signals were separated by frequency characteristics to isolate linear acceleration from the baseline acceleration. The total linear acceleration was calculated by the root mean square of the three measurement axes. Acceleration activity during voiding was investigated to adjacent 1-s windows and was compared with the registered pressure.
We observed a total of 19 consecutive voids in five measurement sessions. A good correlation (r > 0.75) was observed between submucosal and catheter pressure in 14 of 19 premicturition traces. The peak-to-peak interval between maximum total linear acceleration was correlated with the interval between submucosal voiding pressure peaks (r = 0.760, P < 0.001). The total linear acceleration was higher during voiding compared with pre- and postmicturition periods (start of voiding/phase 1).
To the best of our knowledge, this is the first report of bladder wall acceleration, a novel metric that reflects bladder wall movement. Submucosal sensors containing accelerometers can measure bladder pressure and acceleration.
验证植入式感测系统（内含加速计）是否能检测到与膀胱生理相关的小幅度自主运动（亦称为微运动）的假设。
我们研发了一个 6 毫米的黏膜下植入物，内含压力传感器（MS5637）和三轴加速计（BMA280）。通过在哥廷根小型猪的膀胱内植入传感器原型进行测试。使用标准尿动力学设备中的空气充电导管进行多次清醒排尿膀胱测压，作为对照。我们基于黏膜下压力，识别出类似于其他动物模型中的排尿的四个阶段。通过频率特性对加速信号进行分离，以将线性加速度与基线加速度隔离开来。通过三个测量轴的均方根计算总线性加速度。研究相邻 1 秒窗口内的排尿时加速活动，并与记录的压力进行比较。
我们在五次测量中观察到总共 19 次连续排尿。在 19 次预排尿轨迹中的 14 次中，黏膜下压力和导管压力之间观察到很好的相关性（r>0.75）。最大总线性加速度的峰峰值间隔与黏膜下排尿压力峰值之间的间隔呈相关性（r=0.760，P<0.001）。与排尿前和排尿后时期（排尿开始/阶段 1）相比，排尿时的总线性加速度更高。
据我们所知，这是首次报告膀胱壁加速度，这是一种反映膀胱壁运动的新指标。内含加速计的黏膜下传感器可测量膀胱压力和加速度。
