SATPC0039684 Tab 04 4 SOW.pdf

Hypobaric Chamber Services Statement of Work (Exercise Prebreathe Tests)

This statement of work defines the use of an individual altitude chamber(s) for the execution of the prospective hypobaric testing needed to support the development of a decompression sickness (DCS) risk estimation tool, the Aerospace Estimation Tool for Hypobaric Exposure Risk (AETHER), led by NASA Johnson Space Center (JSC).

The results of these tests will inform requirements for future space vehicles, habitats, suits, and mission planning. NASA’s own facilities also will support this work in part, but those facilities are shared with other programs, limiting the overall availability of NASA facilities. Use of non- NASA resources to support these objectives are important to facilitating timely development and implementation of safe and successful prebreathe procedures during extravehicular activities (EVAs) in weightlessness and in partial gravity during exploration missions. NASA’s main objective in engaging other facilities is to support an increased tempo of data collection to develop a comprehensive model of altitude physiology (focused on DCS risk) during missions across a range of conditions.

Facilities are requested to perform single day chamber-based tests as defined by NASA and deliver data (including but not limited to raw and processed data, images, video) to NASA.

NASA will perform the analysis of these data. Also, data collection will include assessing subjects for patent foramen ovale (details are described below). NASA will coordinate planning meetings and training for protocols, as needed. NASA will attend tests as necessary to verify correct implementation and conduct of protocols.

Organizations conducting these chamber tests will have completed pilot chamber tests to demonstrate their capabilities and have their data reviewed by NASA. Chambers selected for the tests described in the current Statement of Work will have documented and verified resolution of any deficiencies identified in their execution of NASA-defined DCS pilot test protocols.

Budget for this work is firm fixed price. Budget quotes can include payments for interim milestone completion. Dates for each interim milestone should be set by the vendor.

Subjects Facilities will recruit and screen applicants to provide at least 3 subjects per chamber test day.

Screening, training and availability of at least 1 back-up subject per test day is required in case of subject availability issues, withdrawal, or disqualification. Facilities should recruit and screen subjects per their standard procedures. NASA will provide inclusion and exclusion criteria to recruit a sample of subjects with similar demographics to the NASA astronaut corps. For this procurement of 3 subjects, at least two participants to complete all three conditions shall be female.

Subjects must complete peak aerobic capacity (VO2pk) testing with metabolic gas analysis as part of the subject screening. NASA will provide the VO2pk test protocols but facilities will be responsible for conducting the test. Metabolic gas analysis hardware may be loaned upon request to the facility by NASA for the duration of this work, if necessary.

Following the screening and qualification for study participation, candidate subjects (including back-up subjects) will participate in an informed consent briefing during which they will receive verbal and written descriptions of the test protocol, be encouraged to ask questions, and will provide written consent before proceeding to participation in the testing. Thereafter, subjects will be trained and familiarized with the chamber protocol and safety procedures, and on safely using the appropriate oxygen delivery device. An oronasal mask is preferred for these tests but discussions on using hoods, can be acceptable, pending NASA approval. For these tests, which oxygen delivery device is used by the facility must be consistent within subjects across all conditions described in this SOW. Subjects also will be familiarized with the EVA simulation workstations and associated workloads (submaximal exercise intensity, 25-80% VO2pk).

Individual workload at each station will be determined and verified by metabolic rate measurements to ensure that cadence and work rates meet in-chamber exercise task requirements. Subjects who have participated in a previous familiarization session within the last 6 months will not have to repeat this session.

Test conditions will include control and experimental prebreathe protocols. This is a cross-over testing design so test subjects should agree to perform the control condition and the two experimental conditions. The order of the test conditions within an arm should be randomized and counterbalanced across subjects.

Test Plan In all conditions, subjects report to the facility in the morning and be briefed on the test conditions to which they will be exposed that day. Thereafter, subjects will be fitted with an oxygen delivery device (mask or hood), complete the prebreathe condition for that day, and then complete a simulation of EVA lasting 6 hours, or until signs and symptoms that require test termination (per NASA and facility standards), test termination by subject request, or facility or monitoring capabilities malfunctions.

Table 1. Control and experimental conditions. Descriptions provided below.

Test Prebreathe EVA

Condition Duration* Inspired

Gas Ambient Pressure

Exercise Duration Inspired

Gas Ambient Pressure

Control 1 hour 100% O2 14.7 psia None 6 hours 100% O2 6.2 psia

Low Exercise

1 hour 100% O2 14.7 psia 25%

VO2pk 6 hours 100% O2 6.2 psia

Moderate Exercise

1 hour 100% O2 14.7 psia 40%

VO2pk 6 hours 100% O2 6.2 psia

NOTE: Within a subject, consecutive test days should be separated by at least 72 hours.

*Prebreathe duration may be increased on NASA direction, (up to an additional 2hrs; total prebreathe time not to exceed 3 hrs.) if excessive DCS burden is observed.

Medical Monitoring The facility will provide the appropriate medical support to perform pre-chamber physical examinations before ingress, during the protocol, for treatment and management of subjects as needed; to support clearance of subjects after the protocol is completed; and to follow-up in the days after the chamber run. Responsibilities of the medical personnel include monitoring and interpretation of 2-D ultrasound imaging for VGE as well as monitoring of the subject’s self-report and symptoms of DCS or intolerance.

Pre-EVA Conditions Facilities will have the capability for continuous habitation of the chamber from the ingress through the performance of prebreathe and simulated EVA. Subjects will begin oxygen breathing at the start of the prebreathe and remain on oxygen throughout decompression and repressurization. NASA may provide the breathing masks and/or will review and provide approvals for suitable substitutions. During prebreathe and cabin depress, subjects should be provided fluids ad libitum without a break in prebreathe (using drink port as necessary).

Subjects should not eat during the prebreathe or the EVA. Subjects are not allowed to sleep during the test window (prebreathe, EVA, and post-run medical clearance).

EVA Simulation Facilities will perform a simulated 6-hour EVA and maintain standardized monitoring practices.

To simulate the suit environment, the chamber will be depressurized using the NASA-provided pressure profile before initiating the EVA simulation tasks described below. The start time of the EVA is defined by the start of decompression, and the end time of the EVA is defined by the start of repressurization.

EVA simulations will include rotation of each subject through a repetitive series of tasks, at predetermined intervals in a pre-determined order, at predetermined workloads using a NASA-defined or provided workstations (Error! Reference source not found.). The EVA is simulated using eight different stations, nominally performed in 2 sets of 4 stations, with subjects rotating between stations every 5 minutes. Subjects will rotate through three stations that simulate vigorous EVA-like activities across various muscle groups followed by a ‘rest’ stage for an echocardiogram to grade venous gas emboli. They then follow with three different exercise stations followed by another echocardiogram ‘rest’ stage, with each cycle of 8 stations lasting 40 minutes. Thus, in each cycle subjects will perform 15 minutes of low- to moderate-intensity exercise followed by 5 minutes of monitoring (see sections below) and rest. Work rates during arm ergometry (cadence and resistance) and stepping (cadence) will be prescribed based upon the results of the VO2pk test and the pre-test EVA simulation familiarization with metabolic gas analysis. During ultrasound imaging, at least 10 cardiac cycles will be monitored and recorded in each of three conditions in sequential order: rest, flexing/bending of limbs, and rest.

Compliance of the subjects with the prescribed procedures should be documented, including symptoms reported by the subjects, and test operator observations.

Standardized Measures Facilities will use a standardized set of measurements to monitor and document test subjects during the prebreathe, decompression, and recompression. NASA will provide the specific measures and timeline for data recording.

Logging of symptoms and definition of DCS Test operators (including medical support team) will record all medical symptoms reported by the test subjects throughout the duration of the protocol, in response to prompting by the test operators and spontaneous self-reporting. Subjects will be removed from the chamber and repressurized (airlock or chamber) if they exhibit any symptoms concerning for DCS (Type I or Type II).

Questionnaires Test operators will query subjects for responses to standardized questionnaires during each rotation through the resting/ultrasound station. Subjects will report a rating of perceived exertion (RPE), pain, and mask comfort using NASA-defined scales at the end of cycle of EVA simulation (i.e., every 40 minutes).

Ultrasound Echocardiograms for detection of VGE will be performed by a qualified test operator during each rotation through the resting/ultrasound station while the subject is at rest and following exercise. Echocardiograms will be recorded and stored electronically with relevant metadata (e.g., subject ID) for post-exposure review and analysis. Ultrasound will be scored in real-time using the modified Eftedal-Brubbak (EB) scale (0-7) (2). Each scan must be graded by at least 3 different individuals (up to two can be post-hoc), and both the individual and average of the 3 scores shall be documented.

Patent Foramen Ovale (PFO) Assessment Facilities should arrange for transthoracic ultrasound imaging with contrast (agitated saline), or equivalent, to test for the presence and severity of a PFO using standard procedures and scoring as defined, or approved, by NASA.

PFO assessment should not be used as a tool to exclude subject participation to avoid biased selection of the subject pool or prospectively to influence decisions regarding interpretation of subject symptoms or test termination. PFO currently is not used as exclusion criteria for astronauts to perform EVA, and its use for exclusion or test termination would not be representative of current NASA medical practices. If PFO image acquisition or assessment is performed prior to a chamber test, then test operators should be blinded to the results. If blood or urine samples are collected by the facility, these results also should be blinded to the subject and the test operators until after the completion of the test.

Imaging for and local interpretation of PFO assessments should be shared with NASA for inclusion in DCS modeling activities relevant to the AETHER project. Test results may be shared with the subject at their request or if the PFO assessment reveals clinical concerns; however, this may preclude this subject’s participation in future testing, unless NASA later changes its practices for the screening and selection of astronauts prior to EVA.

Additional Measures Facilities may perform additional data collection for IRB-approved studies on a non-interference basis with NASA approval. IRB approval from the local site IRB is the responsibility of the facility. NASA will obtain IRB approval from the JSC IRB using a multi-site protocol. Results from these data collections will be shared with NASA for archiving. For example, if blood or urine samples are collected by the facility for uses other than the standard data collection as defined above, the results of these assays will be shared with NASA.

Data Delivery and Validation At the conclusion of each test run, the facility will deliver electronic records to NASA using a secure, NASA-approved method within 14 days. The data package will include subject metadata, console and/or operator’s logs (including chamber event time, prebreathe records, EVA time, EVA station schedule), continuous recording of chamber pressure for the entire chamber run (demonstrating depress and repress rates as well as sustained chamber pressure), chamber environmental conditions (partial pressures of O2 and CO2, temperature, humidity), questionnaires, medical monitoring logs, ultrasound recordings and VGE scores, in-chamber video of EVA workstations, audio logs, and DCS case descriptions using the NASA-provided reporting format. Each facility will have ultrasound images of VGE scored by at least 3 reviewers in a blinded fashion. NASA will provide a template for the documentation of these.

NASA will verify completeness of the data set for each chamber run within 14 days of receipt.

Detailed statistical analysis and modeling will be performed by NASA.

Unexpected results and incidents should be reported to NASA within 12 hours of the event.

These include facility-related anomalies and subject specific events. As a NASA-funded service, this information is reported to NASA management and safety officers. NASA will request follow-up documentation, as appropriate. If a facility-related incident, NASA will require a corrective action plan and verification before proceeding to subsequent chamber tests.

Test Plan Verification, Training, and Reporting NASA will meet with each facility to discuss the test plan before submission of required documents to the facility’s governing IRB to verify expectations of the chamber runs, schedule, and data delivery.

NASA may attend and monitor chamber runs to answer questions in real-time and recommend changes to the procedures. At the completion of series of each test, NASA will coordinate a meeting with the facility to discuss results.

Hardware Loan and Training

Plans can be made for hardware loan (e.g., breathing masks, ultrasound, metabolic analyzer), if needed, and scheduling for operator training. NASA plans to have capability to loan the following equipment:

• Ultrasound/doppler (Vivid iQ)

• Breathing masks (Phantom+)

• Metabolic analyzer (Cosmed K5)

If borrowing Cosmed, vendors should provide:

- COSMED O2 Sensor Kit

- COSMED Batteries (at least prime and backup)

- COSMED Gas Tank + Cart

Facilities participating in this procurement need to already be proficient in the following or include the costs for vendor training:

• Mask fitting procedures, if applicable. If required, the facility should budget for 1.5 days of training at their facility by NASA;

Facilities participating in this procurement need already to be proficient in the following:

• EVA task simulation and workload calibration; and

• Operation of loaner equipment (if required); and

• Grading of VGE

Summary For the protocol listed in Table 1, provide the following for 6 subjects in each of those test conditions.

1. Estimated schedule for completing data collection

2. Budgets should include total budget plus breakdown of incremental payments including the milestones/schedule associated with those incremental payments.

Award for procurement will be made based on lowest price technically acceptable.

REFERENCES

1. Spencer MP, Johanson DC. Investigation of New Principles for Human Decompression

Schedules Using Doppler Ultrasonic Blood Bubble Detection: Defense Technical Information Center.

2. Eftedal O, Brubakk AO. Agreement between trained and untrained observers in grading intravascular bubble signals in ultrasonic images. Undersea Hyperb Med 24: 293–299, 1997.