Tissue assessment
The tissue assessment device consists of a fluid pressure system ( 1, 2, 11 ); an optical system ( 3, 5, 6 ); and a micro-controller ( 13 ). Compression of bladder ( 11 ) by actuator ( 12 ) displaces the fluid within the bladder 11 into chamber ( 2 ) causing diaphragm ( 1 ) to inflate and apply pressure onto the tissue surface in order to initiate a blanch. The diaphragm ( 1 ) is deflated after a predetermined time, either by releasing the actuator ( 12 ) or opening exhaust valve ( 8 ). Throughout the blanching, the optical system ( 3, 5, 6 ) illuminates the blanch area and the returned light data is collected at regular intervals for several wavelengths from the point when the blanch is initiated, throughout the blanching and a predetermined time thereafter during the recovery phase. The micro-controller controls the process and analyses the returned signals to provide assessment of the tissue surface area. The invention provides a simple low skill tissue assessment device that is highly reliable.
1 - 12 . (canceled)
13 . A tissue assessment method comprising the steps of:
a. applying fluid pressure to a tissue surface area to push blood out of the area;
b. removing the fluid pressure to allow blood to re-enter the area;
c. illuminating the area during the foregoing steps,
d. collecting the returned light, and
e. analyzing the results to provide assessment of the microvasculature damage at the area.
14 . The tissue assessment method of claim 13 wherein the pressure applied onto the area is constant for a predetermined time.
15 . The tissue assessment method of claim 13 wherein the pressure applied onto the area is pulsed.
16 . The tissue assessment method of claim 13 wherein varying pressure is applied onto the area.
17 . The tissue assessment method of claim 13 wherein the pressure applied is rapidly released to allow blood reflow into the area.
18 . The tissue assessment method of claim 13 wherein an inflatable diaphragm applies the fluid pressure to the tissue surface area.
19 . The tissue assessment method of claim 18 wherein:
a. the diaphragm is transparent, and
b. the optical system collects the returned light through the diaphragm.
20 . The tissue assessment method of claim 18 wherein the diaphragm molds itself to the contour of the tissue area when fluid pressure is removed.
21 . The tissue assessment method of claim 13 used to assess limb ischaemia.
22 . The tissue assessment method of claim 13 used to assess diabetic peripheral neuropathy.
23 . A tissue assessment device comprising:
a. means for applying fluid pressure onto a tissue surface area to initiate a blanch,
b. an optical system to deliver and collect light to and from the area, wherein the values of collected light may be analyzed to provide a measure of microvasculature damage at the tissue area.
24 . The tissue assessment device of claim 23 wherein the means for applying fluid pressure comprises an inflatable diaphragm.
25 . The tissue assessment device of claim 24 wherein:
a. the diaphragm is transparent, and
b. the optical system delivers and collects light through the diaphragm.
26 . The tissue assessment device of claim 23 further comprising a rigid housing:
a. wherein at least a portion of the optical system is located, and
b. having an end whereupon the means for applying fluid pressure is situated.
27 . The tissue assessment device of claim 26 wherein the means for applying fluid pressure is defined by a flexible diaphragm removably fittable about the end of the housing.
28 . The tissue assessment device of claim 27 wherein two or more light sources:
a. are within the housing and are oriented to emit light through the diaphragm, and
b. emit light having different mean wavelengths.
29 . The tissue assessment device of claim 26 wherein:
a. the housing is defined by a probe sized and configured to be held and manipulated by a single hand, and
b. the housing bears an actuator thereon which actuates the fluid supply, the actuator being configured to be actuated by any hand holding the housing.
30 . A tissue assessment device comprising:
a. a housing terminating in a flexible diaphragm, with a chamber being provided in the housing behind the diaphragm;
b. an actuatable fluid supply in communication with the chamber, wherein the fluid supply supplies fluid to and from the chamber to flex the diaphragm;
b. a light source within the housing, wherein the light source emits light through the diaphragm;
c. a photodetector within the housing, wherein the photodetector detects any light returned by a tissue surface area from the light source.
31 . The tissue assessment device of claim 30 wherein:
a. the housing is defined by a probe sized and configured to be held and manipulated by a single hand, and
b. the housing bears an actuator thereon which actuates the fluid supply, the actuator being configured to be actuated by any hand holding the housing.
32 . The tissue assessment device of claim 30 wherein the diaphragm is removably fittable about an end of the housing
33 . The tissue assessment device of claim 30 wherein two or more light sources:
a. are within the housing and are oriented to emit light through the diaphragm, and
b. emit light having different mean wavelengths.