Removable tamper-resistant breath alcohol sampling system
A breath alcohol testing device has a removable tamper-resistant sampling chamber assembly that provides a disposable interface between the test subject and the alcohol sensor, other sensors and electronics of the testing device. Hydrophobic membranes prevent bodily fluids and other liquids from entering the alcohol sensor and other sensitive components of the testing device. A set of chambers with one-way valves direct the gas flow within the sample chamber assembly to ensure the breath sample delivered to the alcohol sensor is not diluted by the subject inhaling, and is a deep-lung breath sample.
1. A breath alcohol testing device comprising:
a housing;
a pressure transducer within the housing;
an alcohol sensor within the housing; and
a sample chamber assembly removably attached to the housing having:
(a) an inlet for receiving a breath sample from a test subject;
(b) an inlet chamber receiving the breath sample from the inlet and having: (i) a port to the pressure transducer; and (ii) an outlet for the breath sample to flow from the inlet chamber;
(c) a sample chamber receiving the breath sample from the outlet of the inlet chamber and having a port to the alcohol sensor;
(d) a filter in the port of the sample chamber preventing liquids from entering the alcohol sensor; and
(e) a one-way valve in the outlet of the inlet chamber preventing the backflow of gas from the sample chamber into the inlet chamber;
wherein the outlet and one-way valve of the inlet chamber create back-pressure during the breath sample that is measured by the pressure transducer.
2. The breath alcohol testing device of claim 1 wherein the filter comprises a hydrophobic membrane.
3. The breath alcohol testing device of claim 1 wherein the sample chamber assembly further comprises a filter in the port of the inlet chamber preventing liquids from entering the biometric sensor.
4. The breath alcohol testing device of claim 1 wherein the sample chamber further comprises an outlet with a one-way valve allowing excess gas in the breath sample to escape, and preventing gas from being inhaled by the test subject into the sample chamber.
5. The breath alcohol testing device of claim 1 wherein the sample chamber assembly further comprises an exhaust port for the alcohol sensor with a filter in said exhaust port protecting the alcohol sensor.
6. The breath alcohol testing device of claim 1 further comprising a pump within the housing drawing gas from the breath sample in the sample chamber into the alcohol sensor.
7. A breath alcohol testing device comprising:
a housing;
a biometric sensor within the housing;
an alcohol sensor within the housing; and
a sample chamber assembly removably attached to the housing having:
(a) an inlet for receiving a breath sample from a test subject;
(b) an inlet chamber receiving the breath sample from the inlet and having: (i) a port to the biometric sensor; and (ii) an outlet with a one-way valve allowing the breath sample to flow from the inlet chamber;
(c) a sample chamber receiving the breath sample from the outlet of the inlet chamber and having: (i) a port to the alcohol sensor; and (ii) an outlet with a one-way valve allowing excess gas in the breath sample to escape from the sample chamber; and
(d) a filter in the port of the sample chamber preventing liquids from entering the alcohol sensor.
8. The breath alcohol testing device of claim 7 wherein the filter comprises a hydrophobic membrane.
9. The breath alcohol testing device of claim 7 wherein the sample chamber assembly further comprises a filter in the port of the inlet chamber preventing liquids from entering the biometric sensor.
10. The breath alcohol testing device of claim 7 wherein the sample chamber assembly further comprises an exhaust port for the alcohol sensor with a filter protecting the alcohol sensor.
11. The breath alcohol testing device of claim 7 further comprising a pump within the housing drawing gas from the breath sample in the sample chamber into the alcohol sensor.