Methods and materials for calibrating a caloric test

Abstract

This document provides methods and materials for calibrating a caloric assay. For example, caloric calibration devices and methods for using caloric calibration devices to calibrate a caloric test are provided.

Claims

1. A kit for calibrating a caloric medium, wherein said kit comprises a calibration device and a temperature measurement instrument, wherein said calibration device comprises a housing defining a channel having a proximal end and a distal end, wherein said proximal end is open, wherein said distal end comprises a cap having an inner surface that faces towards said proximal end and an outer surface that faces away from said proximal end, wherein the length of said channel is between 15 mm and 200 mm, wherein the diameter of said channel is between 3 mm and 12 mm, wherein an air or water caloric stimulus is capable of being delivered into said channel from said proximal end, and wherein said temperature measurement instrument is adapted to measure a temperature change at said outer surface of said cap resulting from delivery of said air or water caloric stimulus into said channel.

2. The kit of claim 1, wherein said housing insulates said channel from temperature changes outside of said housing.

3. The kit of claim 1, wherein said cap is a membrane.

4. The kit of claim 1, wherein said cap comprises latex or rubber material.

5. The kit of claim 1, wherein said cap comprises piezoelectric crystal, glass, metal, a composite material, or a ceramic material.

6. The kit of claim 1, wherein said temperature measurement instrument is an infrared thermometer.

7. The kit of claim 1, wherein said kit comprises a caloric irrigator configured to deliver said air or water caloric stimulus.

8. The kit of claim 1, wherein said kit comprises an ear speculum configured to assist delivery of said air or water caloric stimulus into said channel.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a side view of an exemplary embodiment of a caloric calibration device.

(2) FIG. 2 is a side view of an exemplary embodiment of a kit containing an exemplary caloric calibration device.

(3) FIG. 3 is a side view of an exemplary cap for a caloric calibration device.

(4) FIG. 4 is a photograph of one surface of an exemplary embodiment of a caloric calibration device.

(5) FIG. 5 is a photograph of an opposite surface of the caloric calibration device of FIG. 4.

DETAILED DESCRIPTION

(6) This document provides methods and materials related to calibrating a caloric assay. For example, this document provides caloric calibration devices and methods for using caloric calibration devices to calibrate an air or water medium for use as a stimulus for a bilateral, bithermal caloric test or a monothermal caloric test. A caloric calibration device provided herein can include a channel having dimensions that approximate the dimensions of a human's ear canal. For example, a caloric calibration device provided herein can have a channel with a length between 10 mm and 40 mm (e.g., between 10 mm and 35 mm, between 10 mm and 30 mm, between 15 mm and 40 mm, between, 15 mm and 35 mm, or between 15 mm and 30 mm) and a diameter between 2 mm and 20 mm (e.g., between 2 mm and 15 mm, between 2 mm and 10 mm, between 3 mm and 20 mm, between, 3 mm and 15 mm, or between 3 mm and 12 mm) The channel can include a proximal end and a distal end. In some cases, the proximal end of the channel can be open, and a caloric stimulus (e.g., an air or water caloric stimulus) can be delivered into the channel via the proximal end. In some cases, the distal end can be open, and a temperature measurement instrument (e.g., a thermometer) can be configured to measure a temperature change at or near the distal end. In some cases, the distal end can be configured to include a cap. In such cases, a temperature measurement instrument (e.g., a thermometer such as an infrared thermometer) can be configured to measure a temperature change at or near the cap.

(7) The methods and materials provided herein can be used by any appropriate person or patient. For example, a clinician or medical technician can use a caloric calibration device provided herein.

(8) With reference to FIG. 1, caloric calibration device 10 can be configured to include a housing 12 defining a channel 14. Housing 12 can be configured to insulate channel 14 from temperature changes originating from outside channel 14. For example, housing 12 can be configured to insulate channel 14 from temperature changes that can occur when a medical technician holds caloric calibration device 10 with his or her fingers. Any appropriate material can be used to make housing 12. For example, housing 12 can be constructed from a sponge material, a metal material, a plastic material, or a composite material. Other examples of materials that can be used to make housing 12 include, without limitation, ceramics, rubbers, and various fluid or gel filled cavities.

(9) Any appropriate dimensions of housing 12 can be used. For example, housing 12 can have a length (identified as A in FIG. 1) between 15 mm and 200 mm (e.g., between 20 mm and 200 mm, between 30 mm and 200 mm, between 40 mm and 200 mm, between 20 mm and 150 mm, between 20 mm and 100 mm, between 20 mm and 75 mm, and between 30 mm and 50 mm), a width (identified as B in FIG. 1) between 15 mm and 200 mm (e.g., between 20 mm and 200 mm, between 30 mm and 200 mm, between 40 mm and 200 mm, between 20 mm and 150 mm, between 20 mm and 100 mm, between 20 mm and 75 mm, and between 30 mm and 50 mm), and a height (identified as C in FIG. 1) between 15 mm and 200 mm (e.g., between 20 mm and 200 mm, between 30 mm and 200 mm, between 40 mm and 200 mm, between 20 mm and 150 mm, between 20 mm and 100 mm, between 20 mm and 75 mm, and between 30 mm and 50 mm) In addition, channel 14 can have any appropriate dimensions. For example, channel 14 can have a length (identified as A in FIG. 1) between 10 mm and 40 mm (e.g., between 10 mm and 35 mm, between 10 mm and 30 mm, between 10 mm and 25 mm, between 15 mm and 40 mm, between 20 mm and 40 mm, and between 15 mm and 30 mm) and a diameter (identified as D in FIG. 1) between 2 mm and 20 mm (e.g., between 2 mm and 15 mm, between 2 mm and 10 mm, between 3 mm and 20 mm, between, 3 mm and 15 mm, or between 3 mm and 12 mm) Housing 12 and channel 14 can have the same length or different lengths. For example, housing 12 can have a length that is longer or shorter than the length of channel 14. In some cases, channel 14 can have a non-uniform diameter and bend to approximate the curves of an ear canal.

(10) In some cases, housing 12 can define channel 14 in that channel 14 is a channel formed in the material of housing 12. In some cases, housing 12 can define channel 14 in that a separate tubular member is inserted into housing 12. In such cases, the housing and tubular member can be constructed of the same or different material. In some cases, a tubular member can be constructed from a metal, a plastic, or a composite material. Other examples of materials that can be used to make a tubular member include, without limitation, piezoelectric crystal, rubber, or ceramic materials.

(11) In some cases, channel 14 can have a proximal end 16 and a distal end 18. Proximal end 16 can be open such that a caloric stimulus (e.g., an air or water caloric stimulus) can be delivered into channel 14. Distal end 18 can be open or closed. For example, distal end 18 can include a cap as shown in FIG. 1. Such a cap can be constructed from any appropriate material including, without limitation, latex, rubber, piezoelectric crystal, glass, metal materials, composite materials, and ceramic materials. In some cases, a cap can be a membrane or can have a disc or puck configuration. For example, with reference to FIG. 3, cap 50 can be puck shaped. In some cases, a cap can be a fluid filled cap. For example, a cap can be a hermetically-sealed cap that contains water, saline, gelatin, or other material of caloric capacity.

(12) With reference to FIG. 2, a kit 45 can include caloric calibration device 10 and optionally a caloric irrigator 20, an ear speculum 22, a water basin 24, a temperature measurement instrument 26, or any combination thereof. Caloric irrigator 20 can be configured to deliver an air or water caloric stimulus. For example, caloric irrigator 20 can be an Air Fx air caloric irrigator or an AquaStar water caloric irrigator commercially available from Micromedical Technologies, Inc. (Chatham, Ill.) or an ICS NCS-200 air caloric irrigator or an ICS NCI-480 water caloric irrigator available from GN Otometrics North America (Schaumburg, Ill.).

(13) Ear speculum 22 can be a soft ear speculum. Ear speculums can be obtained commercially from Cardinal Health (Dublin, Ohio), Henry Schein Inc. (Melville, N.Y.), or McKesson Medical (San Francisco, Calif.). Water basin 24 can be any type of container configured to hold fluid. For example, water basin 24 can be a water basin obtained commercially from Novation (Irving, Tex.), Jansen Medical Supply, LLC (Houston Tex.), or Medline Industries, Inc. (Mundelein, Ill.). Temperature measurement instrument 26 can be any appropriate type of instrument capable of measuring temperature. Examples of temperature measurement instruments include, without limitation, mercury thermometers, piezoelectric thermometers, and infrared thermometers. Infrared thermometers can be obtained commercially from Ray-Tec Corporation (Santa Cruz, Calif.) or SPER Scientific (Scottsdale, Ariz.).

(14) With reference to FIGS. 4 and 5, caloric calibration device 100 can include a housing 102. Housing 102 can be a sponge material to provide insulation to a tubular member inserted into the sponge material. Proximal end 104 of the tubular member can be open as shown in FIG. 4, while distal end 106 can be closed via a cap (e.g., a membrane).

(15) During use of a caloric calibration device provided herein or a kit provided herein, a caloric stimulus (e.g., an air or water caloric stimulus) can be delivered from caloric irrigator 20 into channel 14 such that air or water travels along the length of channel 14 toward distal end 18. Ear speculum 22 can be used to aid in the delivery of the caloric stimulus into channel 14. Temperature measurement instrument 26 (e.g., a thermometer or infrared thermometer) can be used to measure a change in temperature that occurs at a point or region at or near distal end 18 as a result of the caloric stimulus. For example, an infrared thermometer (e.g., Raynger MX infrared thermometer commercially available from Ray-Tec Corporation (Santa Cruz, Calif.)) can be used to measure a temperature change at an outer surface of a cap located at distal end 18. In some cases, a thermometer can be inserted into an open-ended distal end to measure a temperature change at the distal end. Water basin 24 can be used to collect any excess or discharged water, when a water caloric stimulus is used.

(16) Once the measured temperature change is obtained, the same caloric stimulus can be applied to a human to be tested using a caloric test. The measured temperature change obtained using a caloric calibration device or kit provided herein can be used to provide an indication of the actual temperature change that occurs within the human's ear canal, thereby calibrating the measurements.

(17) In some cases, if similar irrigation durations are used, a given clinic can use the measurement methods and devices described herein to set the temperature of their caloric medium to produce the same temperature in the test cavity that was used to generate a normal reference data set at a reference laboratory. This can result in the given clinic's caloric test performing in a statistically similar way to the reference laboratory and thus facilitate a valid use of the reference laboratory's normal reference values. Use of the methods and materials (e.g., devices) provided herein can facilitate the standardization of clinical caloric nystagmus tests.

OTHER EMBODIMENTS

(18) It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.