# US 12,004,808 B2 · Determination process and predictive closed-loop control of dosimetry using measurement of skin surface temperature and associated methods

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,004,808 B2
- Document ID: US12004808B2
- Status: Granted
- Kind: B2
- Application number: 17/735,056
- Filed: 2022-05-02
- Published: 2022-11-10
- Granted: 2024-06-11
- Earliest claimed: 2018-10-22
- Assignees: Accure Acne, Inc.
- Applicants: Accure Acne Inc.
- Inventors: Henrik Hofvander
- Web page: https://patentgrep.com/patent/US12004808B2

## CPC

- A61B 18/203: {applying laser energy to the outside of the body}
- A61B 18/22: the beam being directed along or through a flexible conduit, e.g. an optical fibre; {Couplings or} hand-pieces therefor
- A61B 2017/00199: {with a console, e.g. a control panel with a display}
- A61B 2017/00973: {pedal-operated}
- A61B 2018/00005: {Cooling or heating of the probe or tissue immediately surrounding the probe}
- A61B 2018/00017: {with gas}
- A61B 2018/00029: {open}
- A61B 2018/0047: {Upper parts of the skin, e.g. skin peeling or treatment of wrinkles}
- A61B 2018/00577: {Ablation}
- A61B 2018/00642: {with feedback, i.e. closed loop control}
- A61B 2018/00672: {lower}
- A61B 2018/00678: {upper}
- A61B 2018/00684: {using lookup tables}
- A61B 2018/00702: {Power or energy}
- A61B 2018/00708: {switching the power on or off}
- A61B 2018/00744: {Fluid flow}
- A61B 2018/00761: {Duration}
- A61B 2018/00779: {Power or energy}
- A61B 2018/00791: {Temperature}
- A61B 2018/00803: {with temperature prediction}
- A61B 2018/00809: {measured thermochromatically}
- A61B 2018/00988: {Means for storing information, e.g. calibration constants, or for preventing excessive use, e.g. usage, service life counter}
- A61B 2018/20351: {Scanning mechanisms}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

A method for determining parameters for operating a light source within a photo-thermal targeted treatment system is disclosed. The method includes cooling a treatment location, administering first laser pulses at the treatment location, the first laser pulses having thermal energy below a known damage threshold, tracking skin surface temperatures at the treatment location while administering the first laser pulses, estimating a relationship between parameters for operating the light source and the skin surface temperature by fitting tracked skin surface temperature to a correlation model, determining a safe operating range for the light source to avoid thermal damage at the treatment location while still effectively targeting the chromophore, administering second laser pulses at the treatment location, the second laser pulses staying within the safe operating range for the light source, and adjusting the light source according to the tracked skin surface temperatures to stay within the safe operating range.

## Claims

### Claim 1

A method for determining a suitable set of parameters for operating a light source within a photo-thermal targeted treatment system for targeting a chromophore embedded in a medium, the method comprising:
a. cooling a first treatment location;
b. administering a first set of laser pulses from the light source at the first treatment location, the first set of laser pulses having thermal energy below a known damage threshold of the medium;
c. tracking skin surface temperatures at the first treatment location at a refresh rate of 25 Hz to 400 Hz while administering the first set of laser pulses;
d. estimating a relationship between parameters for operating the light source and the skin surface temperature at the first treatment location by fitting the skin surface temperature to a correlation model;
e. using the correlation model, determining a safe operating range for the parameters for operating the light source to avoid thermal damage to the medium at the first treatment location while still effectively targeting the chromophore;
f. administering a second set of laser pulses from the light source at the first treatment location, the second set of laser pulses having thermal energy at least at a known damage threshold of the chromophore while staying within the safe operating range for the parameters for operating the light source; and
g. adjusting the parameters for operating the light source according to the tracked skin surface temperatures at the first treatment location to stay within the safe operating range.

### Claim 2 (depends on 1)

The method of claim 1, further comprising repeating steps a.-g. at a second treatment location on the first subject.

### Claim 3 (depends on 1)

The method of claim 1, further comprising repeating steps a.-g. on a second subject.

### Claim 4 (depends on 1)

The method of claim 1, wherein adjusting the parameters for operating the light source includes adjusting at least one of laser power, pulse width, pulse interval, maximum power output, and a skin surface cooling mechanism used for performing the cooling.

### Claim 5

A method for treating a subject with a photo-thermal targeted treatment system including a light source for targeting a chromophore embedded in a medium, the method comprising:
a. cooling a first treatment location of the subject from a first surface temperature to a second surface temperature;
b. administering a laser pulse from the light source to the first treatment location;
c. during application of the laser pulse, tracking skin surface temperatures at the first treatment location using an infrared camera operating at a refresh rate of 25 Hz to 400 Hz; and
d. terminating a treatment protocol based at least in part on the skin surface temperatures so measured.

### Claim 6 (depends on 5)

The method of claim 5, wherein cooling the first treatment location includes cooling the first treatment location from the first surface temperature of body temperature to second surface temperature less than body temperature.

### Claim 7 (depends on 5)

The method of claim 5, wherein cooling includes using a contact cooling mechanism.

### Claim 8 (depends on 5)

The method of claim 5, wherein terminating the treatment protocol includes fitting the skin surface temperatures so tracked to a model, determining appropriate laser parameters for the light source, and modifying the treatment protocol according to the appropriate laser parameters.

### Claim 9 (depends on 8)

The method of claim 8, wherein terminating the treatment protocol further includes determining appropriate cooling parameters for a cooling mechanism, and modifying the cooling parameters during the treatment protocol.

### Claim 10 (depends on 5)

The method of claim 5, wherein terminating the treatment protocol includes fitting the skin surface temperatures so tracked to a model, predicting a peak skin surface temperature, and adjusting at least one of laser power, pulse width, number of pulses, and cooling system parameters.

### Claim 11 (depends on 10)

The method of claim 10, wherein the peak skin surface temperature is a temperature in a range of 45° C. and 55° C.

### Claim 12 (depends on 5)

The method of claim 5, wherein a pulse duration of the laser pulse is 150 milliseconds.

### Claim 13 (depends on 5)

The method of claim 5, further comprising repeating steps b.-d., wherein each repetition of steps b.-d. is performed for an individual spot in a treatment matrix.

### Claim 14 (depends on 5)

The method of claim 5, wherein the treatment protocol includes determining a thermal energy to be provided by the laser pulse to damage a target chromophore while avoiding damage to a medium surrounding the target chromophore.

### Claim 15 (depends on 5)

The method of claim 5, wherein the light source operates at a wavelength of 1720 nm.

### Claim 16 (depends on 5)

The method of claim 5, wherein the light source operates at a wavelength of 1210 nm.

### Claim 17 (depends on 5)

The method of claim 5, wherein the chromophore is a sebaceous gland embedded within a dermis with an overlying epidermis, and terminating the treatment protocol includes terminating the laser pulse based on the skin surface temperatures so tracked reaching a terminal skin surface temperature indicative of damage to the sebaceous gland without damage to the epidermis.

### Claim 18 (depends on 5)

The method of claim 5, further comprising continuing to cool the first treatment location after terminating the treatment protocol.