Validation of Serenno CUO and IAP Measuring Device
Condition: Urinary Catheter; Laparoscopic Surgery
Study type: Observational

Summary: 
      Serenno Medical Automatic Urine Output measuring device is intended to measure volumetric
      flow rate (total volume and rate) of urine produced per minute over long periods by a patient
      with a urinary catheter as well as high resolution IAP via bladder pressure (IBP). The device
      comprises a control unit located near the bed, and a disposable unit connected between the
      catheter and the urine collection tube/bag. The disposable unit is connected to the control
      unit with a tube.

      Frequent and accurate Intra-Abdominal Pressure measurements facilitate management of critical
      care patients, yet this parameter is normally measured manually, intermittently, and
      inaccurately. Automating IAP measurement will increase responsiveness, reduce workload, and
      potentially improve outcomes. The investigators goal is to validate the accuracy urinary
      catheter estimates of IAP compared to the gold standard during the application of a wide
      range of pressures controlled by a validated closed-loop insufflation reference.

      Primary Objective:

      The study objective is to evaluate the accuracy of the Serenno Medical IAP measurements in
      patients with indwelling urinary catheters vs. the gold standard - the Foley Manometer
    

Detailed description: 
      The system which is the subject of the current study comprises two connected parts, the
      controller and the disposable.The disposable is a special pressure sensing fluid pump
      connected serially between the catheter and urine bag. The pump is operated by controlled air
      pressures sent via three tubes from the controller. The pump operates in strokes, with each
      stroke passing exactly 1ml of fluid from the input port which is connected to the catheter in
      the patients' bladder, to the output port, which is connected via a long tube to the urine
      collection container (bag or other). Since each stroke of the pump is known and constant, and
      the monitor is counting and timing the strokes both current urine production rate, flow rate
      and cumulative urine volume over any period can be measured. The pump is also unique in that
      its design allows the controller to measure the fluid pressure at both the input port, as
      well as in the output port allowing automatic high resolution Intra-Abdominal pressure
      monitoring in parallel and without interrupting the Urine Output monitoring.

      Ongoing pressure monitoring and supporting algorithm remove the need to manually fill and
      empty the bladder and avoid interrupting urine output monitoring. The method also delivers
      multiple per-hour IAP measurements and is able to show trends to correlate to patient angle
      and condition.

      Urine pumping eliminates all problems associated with existing systems and methods for
      measuring urine output. The volume measurement is accurate since it is measured in a
      "digital" format, by calculating of number of fixed bolus units transferred. Dependent loop
      and tube related accumulation are avoided since the pump passes a fixed volume of urine, no
      matter how it is distributed in the drain tube. Similarly, urine composition, temperature,
      production rate, specific weight are irrelevant to the pumping accuracy, as well as
      patient/bed motions and vibrations.

      The controller operates the pump in a cyclic fashion. First, it measures the urine pressure
      inside the patients' bladder, as it is expressed as the pressure in the pump input port. A
      positive pressure of a few mmHg indicates that there is a minimal volume of urine in the
      bladder (and also indicate IAP). The controller then runs the pump for a single cycle,
      removing 1cc of urine from the bladder and repeating the pressure measurement and pump
      operation until the pressure at the input port drops back to zero - indicating an empty
      bladder, then stops. This process repeats for the duration of use. UO is calculated by the
      number of cycles and time of each divided by the relevant timeframe, normally cc/h.Providing
      a continuous fully automated and accurate method to measure IAP could be important in several
      clinical setups. Current reference methods for IAP measurement are intermittent and
      cumbersome. They are affected by body position, zero reference, and highly user dependent.

      Study design allows a large range of pressure levels assessed simultaneously between the
      study device and the gold standard.

      The study population is a good representation of the target population, being sedated in the
      supine position.

      Subjects will be recruited in the pre-operative period by the study staff. b. Study Duration
      (per subject and total):

      33 patients (3 pilot patients) Durations from study device connection to removal during the
      OR procedure. Estimated 15 minutes.

      Total study duration is estimated as 12 months from its initiation. c. Study procedure:
      Screening Subjects will be screened according to eligibility criteria. The investigator will
      explain to the patient the nature of the study, its purpose, the procedures involved, the
      expected duration, the potential risks and benefits involved and any discomfort it may
      entail. The patients will be informed that participation in the study is voluntary, that the
      participants may withdraw from the study at any time and that withdrawal of consent will not
      affect his/her subsequent medical treatment (if any) or relationship with the treating
      physician.

      System set up, initiate data collection and follow up.

      A sealed envelope containing a set of 5 computer-generated random pressure insufflation
      targets will be opened. This will be used for stage 9.

      A new and sterile study device disposable pump will be used for each patient (study device).

      A new and sterile IAP Foley Manometer will be used for each patient. The Foley Manometer will
      be positioned so it is visible, stationary and it's zero point is at the same level as
      required in the device installation requirements at the level of the bladder.

      The study device Controller unit will be cleaned per OR procedures between uses (study
      device).

      If catheter is installed in the OR (as part of the OR requirements) it should not be drained
      to a bag and immediately connected to the Foley Manometer The investigator or study staff in
      the OR will connect the study device and IAP Foley Manometer to the patient urine line,
      noting the date and time.

      If needed for the IAP Foley Manometer reading and/or study device a fluid bolus of 25cc will
      be introduced and recorded.

      If needed, the battery of the device will be replaced as needed. Data storage card from the
      device will be backed up between uses.

      An investigator or study staff will perform a series of intermittent measurements using the
      Foley Manometer (manual IAP measurement) while the surgeon is changing the insufflation
      pressures to the preselected random targets, all between 8-25 mmHg. Each level will be
      maintained for a duration of 30 seconds.

      The study device will measure and save ongoing IAP during the process, measurements gathered
      by the study device will not be visible once measurements have started and can only be
      retrieved from the device memory during analysis. Urine Output functions will be turned off.

      After the set of measurements, the study device disposable unit and the manometer unit will
      be disconnectedNote: Disconnection of the patient from the study device control unit is
      considered as study termination.

      The surgical procedure will resume as normal.

      Study termination: system removal and documentation

        1. The investigator in the OR will disconnect the study device and IAP Foley Manometer from
           the patient urine line.

        2. The disconnected equipment will be sealed in a bio-hazard bag marked with the subject
           study number and returned to Serenno as soon as possible. After inspection it will be
           destroyed at the responsibility of Serenno.

        3. The SD card carrying the patients' data will be removed from the controller, marked with
           the subject study number,. A new, blank SD card will be inserted in the controller in
           preparation for the next patient.

        4. The controller can be used with the next patient after cleaning and disinfection per the
           OR normal operating procedures and IFU (instruction for use).

        5. Patients' CRF will include information covering the study period will be extracted from
           the patient's medical files. The data included in the CRF shall include, at a minimum:
           i. Hospital records,, weight, BMI, ASA score or equivalent at admission. ii. The set of
           Foley Manometer IAP measurements and the set of insufflation levels and their timing
           preformed during the procedure (corresponding to the random values from the envelope).

      iii. Record of any unusual events during the study period, made by the OR staff iv. Record of
      any unusual events during the study period, made by a technical representative.

      v. Control unit and disposable units serial numbers used per session
    

Intervention name(s): Serenno Sentinel, model Alpha 2.0, software version: 8.0
Intervention type(s): Device
Intervention description(s): intra-abdominal pressure measurements compared to a Foley Manometer at different insufflation pressures between 5 and 25 cmH20 at 30seconds intervals.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        patients undergoing laparoscopic surgical procedure requiring an indwelling urinary
        catheter.