Method and device for differential olfactometry

• US 3,885,550 A
• Filed: 11/30/1973
• Issued: 05/27/1975
• Est. Priority Date: 12/08/1972
• Status: Expired due to Term

• Current Assignee: Patrick Macleod
• Original Assignee: Patrick Macleod
• Inventors: MacLeod, Patrick
• Primary Examiner(s): Howell, Kyle L.
• Application Number:
  US05/420,613
• Time in Patent Office: 543 Days
• Field of Search: 128/2C,2R,198,200,206,207
• US Class Current: 600/303
• CPC Class Codes: A61B 5/4011 Evaluating olfaction, i.e. sense of smell
• CPC Class Codes: G01N 33/0001 by organoleptic means

Abstract

By means of a manually operated electronic control unit, a standard olfactory stimulus and an olfactory stimulus to be measured are each applied respectively and simultaneously to one nostril of an experimenter'"'"''"'"'s nose through two odor injectors with nozzles mounted on a nose-centering support, the nozzles being controlled by a respiration detection device and cut-off during the intervals between stimulation periods by means of a retractable anti-diffusion device. The respective odor intensities of the stimuli are compared by means of the strongest sensation perceived within one nostril and the intensities are equalized by adjusting the amplitude of the stimulus to be measured with respect to the standard stimulus.

Claims

1. Method for measuring respective odor intensities of olfactory stimuli, comprising the steps of:

a. presenting two olfactory stimuli simultaneously to the nose, one to each nostril, one of the stimuli comprising a standard stimulus and the other of the stimuli comprising a stimulus to be measured, b. comparing the respective intensities of the stimuli by determining which of the stimuli is the stronger as perceived within one of the nostrils, c. adjusting the amplitude of the stimulus to be measured relative to the amplitude of the standard stimulus until the intensities perceived in both nostrils are about equal, and d. determining the difference in amplitude between the standard stimulus and the stimulus to be measured when the intensities perceived in both nostrils are about equal.

2. The method of claim 1, and further including the steps of:

a. equalizing the intensity of the standard stimulus as perceived in both nostrils by means of a calibration stimulus at the entrance of one of the nostrils before presenting the stimulus to be measured to said one of the nostrils, and b. presenting the stimulus to be measured to said one of the nostrils while the calibration stimulus remains constant.

3. A differential olfactometer for carrying out the method in claim 1, comprising:

a. a nose-centering support, b. two stimulus injecting means mounted on the support, each injecting means including a nozzle adapted to inject a stimulus into a nostril, c. means for preventing the stimuli from being detected by the nose at selected time intervals, and d. means for controlling the injection of stimuli.

4. The device in claim 3, wherein each injecting means includes a reservoir connected to the nozzle, at least a portion of the reservoir being capable of being deformed, and the means for controlling the injection including means for deforming the reservoir in response to breathing rhythm.

5. The device in claim 3, wherein the means for prevenTing includes a hollow end piece that is capable of fitting over each nozzle, means for selectively moving the end piece over and away from the nozzle, and means for providing a suction in the end piece.

6. The device in claim 3, wherein the means for controlling further includes a respiration detection device, a circuit for shaping the variations in potential of the detection device so as to generate a pulse of short duration which coincides with the beginning of an inspiration, a circuit for controlling the means for preventing a first flip-flop for delaying the signal produced by said short pulse, two further flip-flops assigned respectively to two amplifiers so as to obtain rectangular current pulses which are independently adjustable in duration and in intensity, said rectangular pulses being applied to activate the injecting means, a manual control system for simultaneously closing said flip-flops.

7. The device in claim 3, wherein the means for controlling comprises a measuring bridge that includes a thermistor located in the vicinity of one of the nozzles.

8. The device in claim 3, wherein each nozzle is formed in an end-cap pierced by a calibrated orifice.

9. The device in claim 4, wherein each reservoir comprises a bottle-shaped container that includes a bottom wall capable of axial displacement.

10. The device in claim 4, wherein the means for controlling includes electromagnetic motors capable of performing reciprocating linear movements.

11. The device in claim 9, wherein the bottom wall includes a corrugated diaphram.

12. The device in claim 3, wherein at least one stimulus includes an odorous charge of liquid odorous material.

13. The device in claim 3, wherein at least one stimulus includes a solid odorous material.

14. The device in claim 4, wherein each reservoir includes means for circulating a gaseous odorous substance which serves to maintain a constant internal atmosphere.