Active bandage suitable for applying pulsed radio-frequencies or microwaves to the skin for medical purposes

• US 6,463,336 B1
• Filed: 04/01/1999
• Issued: 10/08/2002
• Est. Priority Date: 04/01/1999
• Status: Expired due to Term

• Current Assignee: MMTC Limited (Government of India)
• Original Assignee: MMTC Limited (Government of India)
• Inventors: Mawhinney, Daniel D.
• Primary Examiner(s): Layno, Carl
• Application Number:
  US09/283,971
• Time in Patent Office: 1,286 Days
• Field of Search: 607/3, 607/50, 607/103, 607/155, 607/156, 600/14, 600/15
• US Class Current: 607/156
• CPC Class Codes: A61N 1/40 Applying electric fields by inductive or capacitive coupling microwave apparatus A61N5/00; Applying radio-frequency signals
• CPC Class Codes: A61N 5/04 Radiators for near-field treatment

Abstract

An active RF or microwave bandage, that incorporates any of various disclosed configurations of pliable planar microstrip or slotline antenna structures, is conformable to a selected area of the skin of a patient for use in therapeutically treating soft tissue of the patient underlying the selected area with pulsed electromagnetic field (PEMF) energy of a given frequency radiated from the planar antenna structure. The PEMF energy is supplied to the planar antenna structure by means including a PEMF generator (which generator may be a miniaturized portable generator employing a battery power supply that permits the patient being treated to be ambulatory).

Claims

1. An article of manufacture comprising an active bandage incorporating at least one pliable planar antenna that is conformable to a selected area of the skin of a patient for use in deriving a radiation pattern for therapeutically treating soft tissue of the patient underlying said selected area with pulsed electromagnetic field (PEMF) energy of a given frequency within a given one of the 915 MHz frequency band and the 2450 MHz frequency band radiated from said planar antenna for a purpose which includes (1) promoting improved healing of soft-tissue wounds and incisions proximate to said selected area of the skin of said patient and/or (2) enhancing the efficacy of transdermal drug delivery to said soft tissue of the patient underlying said selected area of the skin of said patient, wherein

said pliable planar antenna comprises a pliable dielectric panel having a given dielectric constant, which panel (1) has a first metallic clad having a first given configuration of first given dimensions disposed over a back surface thereof intended to be disposed distal to said selected area of the skin and (2) has a second metallic clad having a second given configuration of second given dimensions disposed over a front surface thereof intended to be disposed proximate to said selected area of the skin, whereby said radiation pattern is determined by said first and second given configurations, the respective values of said first and second given dimensions and the value of said given dielectric constant, and the respective values of said given dielectric constant and said second given dimensions are such as to result in substantial matching of said pliable planar antenna at said given frequency.

2. The article of manufacture defined in claim 1, wherein:

said active bandage comprises an outer layer made of a PEMF power absorbent material to minimize PEMF energy leakage from said active bandage and contain the PEMF energy to said selected area of the skin of said patient being treated.

3. The article of manufacture defined in claim 1, wherein:

said active bandage comprises an outer layer made of a metallic surface material that provides shielding to minimize PEMF energy leakage from said active bandage and contain the PEMF energy to said selected area of the skin of said patient being treated.

4. The article of manufacture defined in claim 1, wherein:

said pliable planar antenna is a microstrip planar antenna in which said first metallic clad comprises a ground plane of said microstrip planar antenna and said second metallic clad comprises a radiating element in which said second configuration is a given one of a substantially spiral configuration, a substantially meander-line configuration, a substantially folded-dipole configuration and a substantially patch configuration, and the respective values of said given dielectric constant and the given dimensions of said radiating element are such as to result in said metallic radiating element being substantially matched at said given frequency.

5. The article of manufacture defined in claim 4, wherein said active bandage incorporates a plurality of pliable microstrip planar antennas that are conformable to said selected area of the skin of said patient and wherein:

said pliable dielectric panel having said given dielectric constant, and said first metallic clad comprising said ground plane is common to said plurality of pliable microstrip planar antennas;

said second metallic clad comprises a plurality of spaced, corporately-fed radiating elements all of which have said given one of said second configurations distributed over said front surface, wherein each of said plurality of radiating elements individually corresponds to each of said plurality of pliable microstrip planar antennas.

6. The article of manufacture defined in claim 5, wherein:

said given one of said second configurations of all said radiating elements is a patch configuration.

7. The article of manufacture defined in claim 1, wherein:

said pliable planar antenna is a slotline antenna in which (1) said second metallic clad comprises a metallic ground plane with a slot of given-area dimensions cut through both said ground plane and said dielectric panel and (2) said first metallic clad on its back side comprises a metallic feed line clad which is located in cooperative spatial relationship with said slot.

8. The article of manufacture defined in claim 7, wherein:

said slotline antenna further comprises another pliable dielectric panel having (3) its front side bonded to the back side of said first-mentioned dielectric panel to thereby sandwich said metallic feed line in between said first-mentioned and said other dielectric panels, and (4) its back side clad with a second metallic ground plane.

9. The article of manufacture defined in claim 1, wherein:

said active bandage further incorporates liquid-absorbent material positioned in a location directly behind said back surface of said dielectric panel for absorbing liquid leakage from said selected area of the skin of said patient .

10. The article of manufacture defined in claim 9, wherein:

said liquid-absorbent material comprises gauze.

11. The article of manufacture defined in claim 9, wherein:

said liquid-absorbent material is affixed to said back surface of said dielectric panel.

12. The article of manufacture defined in claim 9, wherein said active bandage further incorporates:

an envelope being composed of a material which is (1) porous to said liquid leakage from said selected area of the skin of said patient and (2) is substantially non-absorbent of radiation emitted by said planar antenna within which said planar antenna and said liquid-absorbent material are situated.

13. The article of manufacture defined in claim 9, wherein:

said dielectric panel is perforated to enhance seepage of said liquid leakage from said selected area of the skin of said patient through said dielectric panel to said liquid-absorbent material.

14. In apparatus for therapeutically treating soft tissue of a patient underlying a selected area of the patient'"'"'s skin with pulsed electromagnetic field (PEMF) energy of a given frequency within a given one of the 915 MHz frequency band and the 2450 MHz frequency band for a purpose which includes (1) promoting improved healing of soft-tissue wounds and incisions proximate to said selected area of the skin of said patient and/or (2) enhancing the efficacy of transdermal drug delivery to said soft tissue of the patient underlying said selected area of the skin of said patient, wherein said apparatus comprises in combination:

an active bandage incorporating at least one pliable planar antenna that is conformed to said selected area of the skin of said patient for use in deriving a radiation pattern of said PEMF energy of said given frequency within said given one of the 915 MHz frequency band and the 2450 MHz frequency band which irradiates said soft tissue with said PEMF energy radiated from said planar antenna in response to said pliable planar antenna being supplied with a given limited amount of pulsed energy at said given frequency; and

means including a generator for supplying said given limited amount of pulsed energy at said given frequency from said generator to said pliable planar antenna, wherein said given limited amount of pulsed energy has a value which is insufficient to heat said irradiated soft tissue to a temperature higher than 39°

C.

15. The apparatus defined in claim 14 wherein:

said given frequency from said generator is in the 915 MHz frequency band, band, the peak power of each pulse is substantially of 57 watts, the pulse width is substantially 42 μ

s and the pulse repetition rate is substantially 0.5 kHz;

whereby there results a duty cycle of substantially 2.1% and an average power of substantially 1.197 watts.

16. The apparatus defined in claim 14, wherein:

said given limited amount of pulsed energy has a value which is sufficiently low as to result in only negligible heating of said irradiated soft tissue.