Provisional Application No. 60/099,339, filed September 8,1998.

BACKGROUND: Palpation is one of the most commonly performed methods of detecting breast cancer due to its inexpensiveness. Women are advised to perform breast self-examination (BSE) at least monthly. Patients detect a large fraction of breast cancers by following an appropriate BSE. Palpation is also an important tool for physicians in the diagnosis of breast cancer. Clinical breast examination (CBE) permits the physician to conveniently and non-invasively evaluate a suspected tumor. Skilled physicians use palpation to quickly determine whether further investigation is required, or that a lump is benign.

Unfortunately, training in breast palpation techniques is difficult and often ineffective. Health care providers are trained in CBE using breast models and by palpating lesions found by experienced physicians.

Since cancer is uncommon in the general patient population, many trainees palpate few cancerous tumors and may be inadequately trained. Patients are also trained to perform BSE using models, but they are at a further disadvantage because they do not palpate actual lesions, relying instead on the fidelity of the models to demonstrate the feel of a tumor. Furthermore, it is

difficult to teach patients the optimum level of force to apply in examining their breasts. Correct force levels are important because too little pressure may result in missed tumors, while too much pressure will produce discomfort that will reduce patient incentive to practice BSE regularly. An additional problem is the difficulty in teaching patients to follow a well-defined search pattern over the complex breast shape to avoid missing portions of the breast and surrounding tissues.

Further problems are encountered when a patient detects a lump and visits a physician for diagnosis.

Often the physician determines that the abnormality is not obviously cancerous but that continued monitoring is needed. This requires maintaining a record of the examination results, which at present is limited to verbal notes about the size, position, orientation, etc. of the lump. These notes may prove difficult to interpret at a later date, so that it is very difficult to detect changes in a palpable abnormality from examination to examination.

Accordingly, it is an object of the present invention to increase the effectiveness and sensitivity of breast palpation substantially beyond the capacity of the human hand. It is a further object of the present invention to reduce the mortality rate from breast cancer by improving detection of significantly smaller tumors, and training medical personnel in detecting tumors, and thus to increase early detection of cancerous lesions in both BSE and DBE.

It is yet a further object of the invention to reduce health care costs by providing palpation procedure results that are easy to document and compare with other

results so that questionable breast masses can be monitored across extended periods of time. This object can also accomplished with the present invention by decreasing the need for biopsies and other expensive and invasive evaluation procedures.

SUMMARY OF THE INVENTION The above objects and others are accomplished by a method and apparatus for sensing a cancerous type of growth in a human. The method includes placing a tactile array sensor in contact with a portion of the human's body, to generate data signals corresponding to pressure gradients encountered by portions of the tactile array sensor. The data signals are then processed to develop a computerized display corresponding to the portion of the human's body subjected to contact by the tactile array sensor, as well as any structural abnormalities in the portion caused by said cancerous type of growth. The computerized display is then exhibited to show the portion of the human's body and a size and location of any structural abnormalities that may be present. The computerized display is preferably a pseudo-3D display.

The method may also include recording the data signals in a patient file history of a memory. The above steps may be repeated, and the patient file history may then be utilized to compare the structural abnormalities from the time of the first detection of the structural abnormalities with a subsequent detection.

The tactile array sensor is attachable to a probe, and includes two flexible surfaces, where each is made of copper or other conductive strips. The surfaces are separated by compressible material. The probe need not

necessarily be a mechanical probe, and in fact may be the examiner's finger.

The data signals carry information dealing with at least the following: a) a coordinate grid of the portion of the body subjected to contact by the tactile array sensor, b) a measurement of a size of the structural abnormalities in the portion caused by the cancerous type of growth, c) a measurement of a texture of the portion of the human's body subjected to contact by the tactile array sensor, and d) an amount of force and pressure distribution used to best determine the size of the structural abnormalities.

The cancerous growth that can be detected using the method and apparatus of the invention can be located in breast tissue of the human. In another embodiment of the invention, the cancerous growth is located in the prostate gland. In the latter case, the tactile array sensor is inserted directly into the rectal area of the human being examined.

According to the principles of the invention, the examination can be performed by the human being examined, and the exhibition of the display is performed at a remote location. The data signals are transferred to the remote location via a modem. In this embodiment, a camera preferably records a visual image of the tactile array sensor as it contacts the human's body. The visual image is then transferred with the other data signals to the remote location via the modem.

A method and apparatus for instructing a trainee in breast cancer examination procedures further meet the above objects and others. The method includes the step of placing a breast model having an outer surface of

simulated tissue texture on a six-axis force-torque sensor, where the breast model has one or more embedded tumor-like members. At least the trainee's finger or a sensor array is then placed in contact with at least a portion of an exterior surface of the breast model. Data signals are then generated by having the trainee palpate the breast model with at least his or her finger, so that the data signals represent a contact location of at least the finger when in contact with the breast model. The data signals also represent the force level applied by the trainee's finger. The data signals are then processed to develop a computerized display corresponding to the location and size of the embedded tumor members and to the force level applied. The method may further include the step of exhibiting the computerized display, to show the breast model and the size and location of the embedded tumor members. The computerized display is again preferably a pseudo-3D display.

A video camera may be used to record the location of the trainee's finger. Using the computer, an optimal force level and an optimal contact pattern can be determined for detecting the embedded tumor-like members.

The determined optimal conditions may then be stored in a memory of the computer.

BRIEF DESCRIPTION OF THE DRAWINGS: FIG. 1 shows an exploded view of the capacitive tactile array sensor of the present invention.

FIG. 2 shows the tactile array sensor in a cross sectional view.

FIG. 3 shows the sensor in a curved configuration to approximate its shape if worn on a fingertip. The outer

surface of the sensor is shown palpating a finite element model of simulated tissue with an embedded tumor.

FIG. 4 shows a palpation-mapping probe that fits on a user's finger.

FIG. 5 shows a planar diagram of a model of a breast phantom, and the contact localization technique associated with the model.

FIG. 6 shows a diagram representing the coordination of instrumentation used for training ideal palpation techniques.

FIG. 7 shows a diagram representing the coordination of instrumentation used for tactile imaging of a breast cancer examination.

FIG. 8 shows a diagram representing the coordination of instrumentation used for tactile imaging of a breast cancer examination at a remote location relative to the place of examination.

FIG. 9 shows a block diagram including the steps for a BSE and the subsequent utilization of the system of the present invention and the tactile imaging data acquired thereby.

FIG. 10 shows a tactile and force sensor for probing the prostate to detect prostate tumors.

DESCRIPTION OF THE PREFERRED EMBODIMENT: The above objects and others are provided by the tactile sensory apparatus of the present invention, and by a method of using the same. The capacitive tactile sensory apparatus will first be described, although it is to be understood that the sensor may be a peizo or resistive sensor, for example, in accordance with the principles of the invention. FIG. 1 shows an exploded

view of the capacitive tactile array sensor 100 of the present invention. FIG. 2 shows the tactile array sensor 100 in a cross sectional view. A first set of copper strips 20 is disposed so that the strips are in a parallel, coplanar arrangement. When so arranged, the copper strips 20 are set approximately one half of a millimeter apart, and together form an upper surface 23 that will contact the tissue being examined. Each of the copper strips 20 is less than two millimeters wide. A second set of copper strips 21 are also disposed in a parallel, coplanar arrangement, with each of the copper strips 21 being approximately one half of a millimeter apart. The second set of copper strips 21 are disposed perpendicular to the first set of copper strips 20, and the planes that the first and second sets of copper strips each form are in parallel with respect to each other. The second set of copper strips 21 together form a lower surface 24 that will contact the probe, finger, or other pressure applicator when in use.

Spacers 22 are disposed between each of the copper strips 21 in the lower surface 24. The spacers 22 are made of a compressible, electrically insulative material such as silicone rubber. Each of the spacers 22 has a bottom portion 25 that is disposed between the copper strips 21, and a top portion 26 that extends above the bottom portion 25 and above the copper strips 21 that form the lower surface 24. The top portions 26 of the spacers 22 space the top surface 23 from the bottom surface 24 of the array sensor 10G. In one embodiment of the invention, the top portions 26 of the spacers 22 are approximately 0.25 millimeters in width, and cause the top surface 23 and the bottom surface 24 of the array

sensor 100 to be uniformly spaced approximately 0.13 millimeters apart. When contact between the array sensor 100 and a tissue occurs, the spacers 22 are compressed and the distance between the top surface 23 and the bottom surface 24 decreases.

The flexibility of the array sensor 100 described above allows for its being shaped around virtually any probe that is suitable for detection of tumors under the skin. As shown in FIG. 3, the sensor 100 can be curved to approximate its shape if worn on a fingertip. The outer surface 23 of the sensor 100 is shown palpating a finite element model of simulated tissue 27 with an embedded tumor 28. Because the sensor 100 is very flexible, it can be formed around the user's finger, as well as with the surface of the tissue 28 that the sensor 100 palpates. Accordingly, the physician, for example, wearing the array sensor 100 need not roll his or her finger to accurately determine the differing material properties due to the presence of the tumor 28 as measured by the sensor.

FIG. 4 shows a palpation-mapping probe 29 that fits on a user's middle finger. The probe 29 is covered with a pressure sensor 100 as described above and shown in FIGs. 1 and 2. The user, such as a physician, will impress the sensor against a region of a tissue to detect any unusual masses. Normally, the physician will use the sensor probe on his or her fingertip and indent and roll it over a suspect region found while performing a routine CBE. The system which incorporates the force sensor and a tactile array sensor mounted on the physician's finger to make a tactile image of the suspect mass extracts four types of tactile topology features of the breast that can

be sought from breast palpation, namely: 1) a geographic map of the location, i. e., a coordinate grid defining the suspect region or a larger region such as the entire breast being examined, 2) a measurement of the size of masses detected, 3) a measurement of the underlying breast texture, and 4) the force used to best demonstrate the palpable abnormality.

Several probe sizes and shapes can be covered with a pressure sensor to provide complete coverage of a range of breast mass sizes. A commercially available Tactile 8 x 8 element array that is available from Pressure Profile Systems of Los Angeles, California may be used, for example. Furthermore, the array sensor could be either a resistive or piezo electric array with a corresponding data acquisition function card in software substantially similar to that available from Pressure Profile Systems.

Also, the array sensor 100 may be attached to a mover arm 30, shown in FIG. 7, that may be manually controlled by the physician conducting a CBE.

Continuing to refer to FIG. 7, the array sensor 100 generates data that are fed from the array sensor 100 to a converter 32 when necessary. For example, the array sensor 100 may generate analog data that is fed to an ADD converter. The converter 32 is associated with a computer 33, which may be associated with any PC, for example, having the requisite hard disk memory and display 31. The converter 32 receives the analog signals, for example, 74 bit data, which in effect has eight levels of gray scale for each information data point and in converted by the converter 32 for transmission to its input to the computer 33. The computer may be an IBM PC or other suitable workstation,

programmed with the commercially availabe MetLab software program, for example.

The computer 33 detects the position of the array sensor 100 from the data stream, and converts the data into a pseudo 3D presentation on the monitor display 31.

Depending on the particular computer program selected, as well as the type of the display 31 selected, the data may be used to produce a gray scale 3D presentation. The presentation is stored in the memory 34 of the computer 33, in a patient file. The filed data can then be used in subsequent examinations to compare the location and properties of a suspect breast mass with its previous properties.

The above system is essentially complementary to mammograms that are often used currently by physicians to further examine a patient for any abnormality uncovered during routine clinical examination of a patient. The tactile display complements mammograms by generating a video presentation of the portion of the breast under examination, and further characterizes and documents the location, size, and other physical properties of any detected abnormality.

As mentioned above, the computer 33 will record the pressure distribution and impression force and save it for comparison at subsequent exams. Using this system, documentation can be provided that shows the adequacy of a breast examination and the force applied during the examination. Furthermore, the documentation can be used to determine the biomechanical properties of a specific patient's breast tissue, and to detect the size and nature of the suspect breast mass, as well as relatively small changes in the breast mass.

Referring now to FIG. 8, a home examination procedure is shown in block diagram format. The sensor array 100 and system as described above are used in this procedure to the extent that such are practicable. The output of the converter 32 in the home examination system is sent to a modem 35 that may be any well-known and commercially available type. The modem 35 is connected to a telephone line 36, thereby connecting the patient's home sensor array 100 with the physician's office 37. At the physician's office, the data transmitted from the patient's home is recorded in computer memory 34 that functions in the same manner as described above. FIG. 8 also illustrates a video camera, preferably a 3D video camera, that may be connected via the Internet to the doctor's office to give the location of the array sensor when the patient detects the abnormality, the cause of which data is sent to the physician's office. Having received the data, the physician can review the data utilizing a PC type processor and video display, and determine whether a patient visit is advisable.

Referring now to FIG. 9, a block diagram shows the steps for a BSE 40 and the subsequent utilization of the system of the present invention and the tactile imaging data acquired thereby. As illustrated in block 38, if the SBE procedure 40 detects no abnormalities, the process stops there and no further action is deemed necessary. In the unhappy event that the BSE procedure 40 detects an abnormality 38 there are two options. The first option 44 is to visit the physician for a CBE. The second option 46 is to perform a SBE utilizing tactile imaging. The data generated by the tactile imaging SBE is electronically sent 50 to the physician's office. The

sensor location data can also be generated and recorded 48 as described above and shown in FIGs. 8 and 9. The sensor location data can also be sent 50 to the physician for review. The transmitted tactile image and sensor location information is processed 52 and then retained in the patient's files (in computer memory 34). The physician can then call up from memory 34 the patient's earlier data to compare the recent examination data with that previously stored in tactile image form.

Next, a realistic breast biomechanical model for palpation training and examination documentation will be described. FIG. 5 shows a planar diagram of the model 200, and the contact localization technique associated with the model 200. A breast phantom 30 is situated above a force-torque sensor 31. Contact is made with the breast phantom 30 using a person's bare finger. Since the shape of the breast phantom 30 is known, Salisbury's algorithm provides a method for determining the contact position. The contact position is determined using the force-torque sensor 31 as it provides a measurement of the contact force f = [fx fy] T and torque t. These quantities are related by the equation defining the torque t = r x f, where r = [x y] T is the location of the contact on the finger tip. Also, because the shape of the breast phantom 30 is known (given, for example, by g (r) = 0), the above equations can be solved for the x and y components of the contact location. The extension to three dimensions (using x, y, and z, instead of x and y) is a straightforward computation. Furthermore, this technique of contact location is understood in the related art as it has been used in robotic applications to determine contact locations on a robot finger tip.

As mentioned above, the breast biomechanical model 200 is used for palpation training and examination documentation. For a breast palpation to be informative during a SBE or CBE, it is essential that the correct areas of the breast are covered, and the appropriate amount of force on the breast is exerted. Accordingly, the breast biomechanical model 200 and its force/torque sensing system are together used by examiners to learn proper palpation techniques. FIG. 6 shows the instrumentation used for training ideal palpation techniques. The breast biomechanical model 200 is palpated by a trainee, while a computer 32 that is connected to the model 200 and to the force-torque sensor determines the contact location and force level using the data from the six-axis force/torque sensor 31 located beneath the breast model 30. As in the embodiment described above, a cameral may be provided to record a visual image that is combined with the tactile image to further track the location of the array sensor. A video monitor 51 displays an image 34 of the breast model 30 to provide visual feedback of both coverage and the force level to the trainee. For example, a region of the breast image 34 on the monitor 51 can change color to indicate the coverage and applied force level on a corresponding portion of the breast model 30. The computer 32 is preferably programmed as described above to receive and store, in a memory, accurate force levels and contact patterns used by experienced breast cancer specialists during the palpation process. These force levels and contact patterns are used to develop a reference technique for differentiating good and poor palpation. Trainees can use the real time feedback

provided by the system to optimize their palpation techniques. Further, the training procedure preferably includes use of the array sensor 100 and the overall system described above in combination with FIGs. 7,8, and 9, to improve palpation proficiency in detecting very small abnormalities embedded in the breast model 200.

While the invention as described above is directed to detection of tumors in breast tissue, its principles may be applied to detect tumors in other areas of the body. Referring to FIG. 10, in accordance with another aspect of the current invention a tactile and force sensor is provided for probing the prostate to detect prostate tumors. The apparatus as shown in FIG. 10 includes a sensor array 200 that is similar to the array sensor 100 described above except that it is adapted for rectal insertion. The force/torque sensor 56 is used to measure the force or torque involved in any prostate examination due to the manipulation of the mover arm/handle 57 as shown. A position sensor 58 is provided to generate data representing the location of the sensor array 200. Furthermore, the data acquisition in this system and the calibration of the same is similar as described above, although performed to generate data to estimate and document the volume and extent of detected prostate tumors. As was the case with the breast cancer examination, the data is preferably stored for further utilization by the physician to compare the change if any, in the size and location of prostate tumors and thus facilitate documentation of the patient's history.

Having described the invention, it is to be understood that the invention is not limited to any of the precise embodiments described herein. Various changes and modifications could be effected by one skilled in the art without departing from the spirit or scope of the invention as defined in the appended claims.