Requirements_for_Indirect_Calorimerty_System.pdf

Indirect Calorimetry System Requirements

The indirect calorimetry system shall be newly manufactured with no used or refurbished parts. It shall meet the following requirement-

A) High-speed calorimetry system: Subjects are to be scanned for VO2 & VCO2 measurements in looping succession with a single zirconia differential oxygen sensor and a non-dispersive infrared carbon dioxide sensor. Air flow through the cage must be adjustable and precisely controlled with thermo-mass flow controllers

1. O2 sensor accuracy +/- 0.01% of reading with resolution 0.01 ppm

2. CO2 sensor accuracy +/- 0.01% of reading with resolution 0.01 ppm

3. O2 and CO2 differential (in vs out of the cage) minimum of 0.1% maximum of

0.3%

4. Total settle time + measure time for gas sensors not to exceed 20 seconds per sample

5. Sample air drawn from each cage must be dried through a desiccating device without coming into contact with any chemical drying agent.

6. Values corrected to STP

B) Activity Measuring in X and Y Axes: Photocell based activity monitoring with an array of infrared photocells surrounding the cage at even intervals.

1. Ambulatory movement distinguished from fine, repetitive movements for each axis.

2. Reports ambulatory beam breaks vs total beam breaks for each horizontal axis

3. XY positional tracking of animal location recorded to disk 10 times per second

4. IR beams spaced at 1.27cm intervals

C) Sleep Detection: Bouts of inactivity can be automatically scored as sleeping bouts with adjustable inactivity epochs per the protocol described in: Novel method for high-throughput phenotyping of sleep in mice Allan I. Pack et al. Physiological Genomics 28:232-238 (2007)

D) Food Intake Monitor:

1. Food presented from overhead, suspended from a precision load cell

2. Load cell with 0.01g resolution or better

3. Feeding data reported synchronous with calorimetry data

4. Feeding bout data reported with an adjustable meal validation minimum weight (typically 0.02g)

5. Flexibility for user-defined intervals for reporting food intake

E) Respiration Frequency: Breaths per minute are measured non-invasively and reported synchronously with all other parameters. The device must utilize a pressure transducer to monitor subtle pressure changes within the cage that occur during normal respiration.

1. Breath rate range 0-1,000 BPM

F) Telemetry: Capable of measuring core body temperature and, optionally, heart rate. A transmitter is surgically implanted into the subject and readings are obtained wirelessly by radio signal into an antenna under the cage. The transmitters have no battery and are powered wirelessly, which results in a smaller transmitter and eliminates the need to surgically recover them for service.

1. Battery-less transmitter design for easier implantation into mice

2. Transmitters do not require any special servicing and are maintenance free

G) Running Wheel:

1. Has solid, textured running surface to eliminate injuries due to mis-steps.

2. Has magnetic hysteresis brake with programmable resistance from 0 – 2.5 oz/in with 100 adjustable steps that allows the researcher to apply a precise resistance to the wheels in order to calculate Work.

H) Temperature and Light Controlled Enclosure: Air inside the enclosure is circulated so the temperature is uniform from top to bottom.

1. Programmable temperature range of 5°C to 40°

2. Temperature accuracy +/- 1°C

3. Temperature uniformity +/- 1°C from top to bottom at 5°C

4. Interfaces with our software where temperature changes can be programmed in advance.

5. LED lighting with programmable color and brightness.

6. Humidity detection

I) Software: provide system control, data collection, and real time calculation of vO2, vCO2, RER, and heat/EE. Also allows quick screening of native data files (without having to export to CSV and setting up an Excel template), you can compare multiple data sets side by side, perform basic stat analysis, prepare graphs for export as .jpg to be inserted into a published paper, and to compare data obtained from the existing Oxymax/CLAMS system.

1. Real-time calculation of RER and heat and display of all data during the experiment

2. Program for quick screening of native data files, comparisons between data sets, with free unlimited licenses for use by collaborators.

3. Program for basic stat analysis of native data files

J) If selected system is not Oxymax indirect calorimetry system model CLAMS 12, it must be able to run 24 mice at the same time and meet all the above requirements.