FIELD OF THE INVENTION

The present invention relates to energy-based treatments and, more specifically, systems and methods for improving the accuracy of temperature measurements used during an energy-based dermatological treatment.

BACKGROUND OF THE INVENTION

Sebaceous glands and other chromophores embedded in a medium such as the dermis, can be thermally damaged by heating the chromophore with a targeted light source, such as a laser. However, the application of enough thermal energy to damage the chromophore can also be damaging to the surrounding dermis and the overlying epidermis, thus leading to epidermis and dermis damage as well as pain to the patient.

Previous approaches to prevent epidermis and dermis damage, as well as patient pain include:

1. Cooling the epidermis, then applying the photo-thermal treatment; and

2. Cool the epidermis, also condition (i.e., preheat) the epidermis and dermis in a preheating protocol, then apply photo-thermal treatment in a distinct treatment protocol. In certain instances, the preheating protocol and the treatment protocol are performed by the same laser, although the two protocols involve different laser settings and application protocols, thus leading to further complexity in the treatment protocol and equipment.

For either of these approaches, as well as in many energy-based dermatological procedures, measuring the temperature of the skin surface during the treatment provides valuable information that can be used to adjust the treatment protocol and/or equipment settings in real time. For example, there are contact-less temperature measurement methods, such as those based on optical and imaging techniques, that provide useful avenues for measuring skin surface temperatures during dermatological procedures.

However, accurate contact-less measurements of of the skin surface are challenging to perform, particularly when the dermatological procedure involves external mechanisms that can affect the temperature measurement apparatus as well as the skin temperature. For instance, the use of air cooling prior to and during the dermatological procedure can cool the skin surface as well as impact the performance of the sensor that is making the contact-less skin surface measurement.

As an example, one approach to make contact-less skin surface temperature measurements is to utilize a multi-pixel infrared (IR) sensor, such as an IR camera. For IR cameras, the measurement uniformity (i.e., the difference in temperature measured by different pixels of the IR camera when viewing a surface with a uniform temperature) is quite good. However, the absolute accuracy (i.e., the absolute recorded value of the temperature measured by each pixel or by averaging the measurements recorded by several adjacent pixels) has a measurement error that may prohibit the use of a contact-less sensor for skin surface measurements. For instance, even the most sophisticated IR cameras are subject to poor absolute accuracy, where a surface measured as 5° C. is actually at 8° C. due to a calibration offset error in the camera.

Another inaccuracy phenomenon is “camera drift” where the accuracy of the camera varies over time, such as due to changes in the overall environmental temperature of the environment in which the procedure is taking place, or for reasons related to the dermatological procedure, such as when, over time, a laser source heats the structure onto which the camera is mounted or when spill-over air from air cooling impinges on the camera and affects the temperature of the camera body, which in turn leads to a measurement error.

SUMMARY OF THE INVENTION

In accordance with the embodiments described herein, there is disclosed a temperature measurement system for measuring a temperature of a measured surface. The system includes: 1) a first temperature sensor; and 2) a reference surface including a second temperature sensor integrated therein. The first temperature sensor includes a field of view simultaneously covering both at least a portion of the measured surface and at least a portion of the reference surface, thus is configured for simultaneously taking a first measurement of both the portion of the measured surface and the portion of the reference surface.

The first measurement of the reference surface taken by the first temperature sensor is compared to a second measurement taken by the second temperature sensor for use in calibrating the first temperature sensor. In an example, the second temperature sensor includes one or more individual sensors in the cases where redundancy is desired, for instance. The first measurement is then adjusted using the reading made by the second temperature sensor.

In accordance with another embodiment, a photo-thermal targeted treatment system for targeting a chromophore embedded in a medium includes a controller; a photo-thermal treatment unit; and a temperature measurement system for measuring a temperature of a measured surface covering at least a portion of the medium. The controller is configured for administering a treatment protocol using the photo-thermal treatment unit. The temperature measurement system includes 1) a first temperature sensor, and 2) a reference surface with a second temperature sensor integrated therein, wherein the first temperature sensor includes a field of view simultaneously covering both at least a portion of the measured surface and at least a portion of the reference surface.

In accordance with yet another embodiment, a method for continuously calibrating a temperature measurement system for use with a dermatological treatment includes: 1) using a first temperature sensor, simultaneously taking a first measurement of a measured surface and a first reference measurement of a reference surface; 2) using a second temperature sensor embedded within a reference surface, taking a second reference measurement of the reference surface; 3) calculating a comparison value between the first and second reference measurements; and 4) calibrating the first temperature sensor in accordance with the comparison value.

