Physical assessment device

An instrument head is provided for attachment to a plurality of instrument handles having different power profiles. The instrument head contains an illumination assembly including at least one LED as well as a drive circuit for detecting a power profile of an attached instrument handle and converting variable voltages received from the attached instrument handle to a constant current for powering the at least one LED based on the power profile. Accordingly, the instrument head enables use with a plurality of instrument handles, including those originally configured for use only with incandescent light sources.

TECHNICAL FIELD

This application is generally directed to the field of diagnostic medicine and more specifically to an improved physical assessment device, (e.g., an otoscope or ophthalmoscope), which is configured for performing diagnostic patient examinations.

BACKGROUND

Physical assessment devices are well known in the field of diagnostic medicine for examining patients as part of wellness visits and/or routine examinations. These devices include, among others, otoscopes for diagnosing conditions of the ear, ophthalmoscopes for diagnosing conditions associated with the eye of a patient, and dermatoscopes for examining the skin of a patient. Each of these physical assessment devices typically includes an instrument head that is releasably attached to the upper end of an instrument handle, the latter containing a set of batteries, enabling the devices to be compact and capable of being handled with one hand. The instrument head can retain optics that enable an image of a medical target (e.g., ear, eye) to be viewed by a caregiver through an eyepiece, or alternatively the image of the medical target can be transmitted to an electronic imager associated with the physical assessment device. Suitable illumination of the medical target of interest is provided by a resident light source, such as an incandescent lamp.

There is a general need in the field of diagnostic medicine to improve physical assessment devices, such those described above.

BRIEF DESCRIPTION

According to one aspect, there is provided an instrument head for attachment to a plurality of instrument handles having different power profiles. The instrument head includes an illumination assembly including at least one LED, and a drive circuit for detecting a power profile of an attached instrument handle and converting variable voltages received from the attached instrument handle to a constant current for powering the at least one LED based on the power profile.

The drive circuit outputs a pulse width modulation (PWM) of the constant current to illuminate the at least one LED, wherein dimming of the at least one LED is achieved by varying a duty cycle of the PWM of the constant current responsive to changes in the variable voltages received from the attached instrument handle.

In one version, the drive circuit outputs the pulse width modulation (PWM) of the constant current to power the at least one LED at a given illumination level when connected to either a first of the plurality of instrument handles with a first power profile and first variable voltages or a second of the plurality of instrument handles with a second power profile and second variable voltages, wherein the first and second power profiles are different power profiles.

According to another version, the drive circuit comprises a buck/boost circuit that outputs a constant voltage notwithstanding an input voltage from the instrument handle being above or below the constant voltage.

The drive circuit can comprise a rectifier including field effect transistors (FETs) for converting an alternating current input from the instrument handle to a direct current for powering the at least one LED.

In at least one version, the drive circuit includes a controller, wherein the controller detects a polarity of the instrument handle attached to the instrument head. The controller can detect a vibration or idle state of the instrument head and responsive thereto can powers up or power down the instrument head. In at least one version, the controller uses a lookup table to determine the power profile of the attached instrument handle based on power up signals received when attached.

According to a preferred embodiment, the instrument head is part of a physical assessment device. More specifically, the physical assessment device is an otoscope or an ophthalmoscope in which at least one of the instrument handles used with the instrument head are typically configured only for use with an incandescent light source.

According to another aspect, there is provided a physical assessment device including an instrument head that is attached to an instrument handle, in which the instrument head has a distal end and an opposing proximal end. An illumination assembly disposed within the instrument head includes at least one LED as a light source. An optical assembly is also disposed within the instrument head and includes a plurality of optical components aligned along an imaging axis. An accessory attached to the distal end of the instrument head acts as an interface to a patient for purposes of examination in which the optical assembly creates an entrance pupil that is sufficiently distal from a distalmost optical element of the imaging assembly such that the attached accessory is not in the field of view of the optical assembly.

In at least one version, the attached accessory is a speculum tip and the physical assessment device is an otoscope in which the speculum tip is cropped from a resulting image of the ear canal of a patient due to the location of the distal entrance pupil. The optical assembly permits the entire tympanic membrane to be viewed all at once in the field of view.

The instrument head can include a pair of mating housing sections defining an interior of the instrument head, an innerformer disposed within the interior, and a sealing member attached to the innerformer to permit insufflation of a patient. According to at least one version, the sealing member is elastomeric and attached to a proximal end of the innerformer. Advantageously, the sealing member further provides an antifogging measure relative to at least one optical component of the optical assembly.

According to yet another aspect, an illumination assembly includes an LED attached to a circuit board, and a component that centers and aligns the LED in relation to a defined illumination axis. The centering and aligning component can include a domed surface configured to receive and collimate the light from the LED.

According to one version, the centering and aligning component comprises an annular ring that centers the domed surface relative to the LED and in which the domed surface is a condensing lens. Advantageously, the annular ring can include according to at least one version, an outer threaded portion that provides a dirt and debris barrier to the LED.

The illumination assembly can be used in a physical assessment device which is at least one of an otoscope or an ophthalmoscope. Preferably, the instrument head is attachable to an instrument handle having at least contained power source for energizing the LED. According to one version, the instrument head is attachable to one of a disparate number of instrument handles, including instrument handles configured to power illumination assemblies having an incandescent bulb as a light source. The circuit board can include circuitry configured to permit any of the disparate instrument handles to be attached to the instrument head and energize the LED without flickering thereof.

According to yet another aspect, there is provided a physical assessment device that includes an instrument head having a distal end, an opposing proximal end and an interior. An optical assembly is disposed within the instrument head, including a plurality of optical components disposed along an optical axis. In addition, an adapter interface member is disposed at the proximal end of the instrument head. The adapter interface member enables the attachment of a smart device to be attached and aligned with the optical axis.

In at least one version, a smart device adapter is releasably engageable with the adapter interface member, the smart device adapter having a surface sized and configured for receiving a smart device.

According to at least one embodiment, the adapter interface member includes a distal portion, a proximal portion and a recess between the distal and proximal portions. At least one optical component of the optical assembly can be retained in the adapter interface member.

In at least one version, the smart device adapter includes a device engagement portion made up of a plurality of engagement surfaces that are engageable with the recess of the adapter interface member. The recess of the adapter interface member can include a plurality of machined flats that are engageable with the engagement surfaces of the smart device adapter. According to at least one version, the smart device adapter includes a slot which includes the device engagement portion. The device engagement portion can include three engagement surfaces including two parallel engagement surfaces with a defined spacing therebetween and a third engagement surface orthogonal to the two parallel engagement surfaces, the engagement surfaces forming an open-ended clevis. According to at least one embodiment, one of the two parallel engagement surfaces is part of a slider member that biases the engagement surface into the adapter slot.

The distal portion of the adapter interface member can include a plurality of axial openings in which each of the axial openings retains a ball or similar feature that is biased into the recess and configured to axially engage the smart device adapter when attached. The machined flats of the recess of the adapter interface member further enables the smart device adapter and an attached smart device to be selectively placed in multiple orientations about the optical axis of the physical assessment device.

According to at least one version, the smart device adapter includes a slot sized and configured to receive a device engagement member. According to certain embodiments, the device engagement member includes an adhesive strip on one side that enables attachment to a smart device and an opposing side of the device engagement member includes a transverse groove.

The smart device adapter can include a detent member that is engageable with the transverse groove of the device engagement member when attached through the slot. In at least one embodiment, the detent member is disposed within a detent cover supported within the slot of the smart device adapter wherein the detent member is biased by a spring which is supported by the detent cover.

A strip of insulating material supported on an interior surface of the supported detent cover is configured to provide resistance to the device engagement member, when the latter is attached to the smart device adapter via the slot. The smart device adapter includes an opening at the device engagement portion that is aligned with the optical axis of the optical assembly when attached to the physical assessment device.

According to another aspect, there is provided a smart device adapter for a physical assessment device. The adapter includes an adapter housing, including a proximal surface that is sized and shaped to support a smart device, as well as a device engagement portion, the latter being sized and configured to releasably engage a physical assessment device. A smart device engagement member having at least one feature enables releasable attachment to a smart device.

According to one version, the device engagement portion includes an arm extending from the adapter housing that is suitably shaped and configured to engage the lower end of an instrument head of the physical assessment device. The arm may include a ring-shaped engagement portion that is sized to engage over the lower end of the instrument head, the arm being made from an elastomeric material. In at least one version, the device engagement portion includes a C-shaped engagement feature at a lower end of the adapter housing that is sized and shaped to snap fittingly engage a cylindrical handle of the physical assessment device.

According to another version, the device engagement portion is configured to engage an adapter interface member at the proximal end of the physical assessment device. The adapter can include a detent member that is engageable with the smart device engagement member when the smart device engagement member is attached to the adapter housing via a slot. The detent member is supported by a detent cover and biased outward into the slot by a spring supported by the detent cover.

According to yet another aspect, there is provided a smart device adapter for a physical assessment device that includes a pair of housing sections defining an interior, a device engagement portion sized and configured to releasably engage the proximal end of a physical assessment device, and a smart device engagement member configured to releasably engage a slot of one of the housing sections and having at least one feature that enables releasable attachment to a smart device.

In at least one embodiment, one of the housing portions includes a slot that is sized and configured to receive the smart device engagement member.

The adapter can include a detent member extending through the slot and engageable with the smart device engagement member. According to at least one version, one side of the smart device engagement member includes an adhesive strip on one side that is engageable with a smart device. A transverse groove on an opposing side is engageable with the detent member when the smart device engagement member is attached to the slot of the adapter.

The detent member is supported within a detent cover within the interior of the adapter housing, the detent member being biased outward into the slot by a spring. According to at least one version, the device engagement portion includes a plurality of engagement surfaces formed in a slotted configuration that enables releasable attachment to the adapter interface member of a physical assessment device. One of the engagement surfaces can be biased inwardly relative to the slotted configuration of the device engagement portion and in which the biased engagement surface is an edge surface of a slider member whose position relative to the slotted configuration is biased by a spring.

The smart device adapter also includes an opening formed in the adapter housing that is aligned with the optics of an attached smart device.

According to yet another aspect, there is provided an ophthalmic device that includes an instrument head including a distal end and an opposing proximal end. An illumination assembly is disposed within the instrument head including at least one light source for illuminating a medical target of interest and a pair of fixation lights disposed in spaced relation at the distal end of the instrument head.

In at least one embodiment, a plurality of optical fibers extend from the at least one light source to the fixation lights. An optical assembly includes an objective lens disposed at the distal end of the instrument head, in which the fixation lights are distally disposed in relation to the objective lens.

According to a preferred embodiment, the at least one light source is an LED in which the fixation lights include polarizer windows that are disposed in spaced relation. The ophthalmic device can further receive an elastomeric eye cup at its distal end adjacent the fixation lights.

According to yet another aspect, there is provided a physical assessment device comprising an instrument head having a distal end, an opposing proximal end and an interior. An illumination assembly is disposed within the instrument head and includes at least one light source and a plurality of components aligned along a defined illumination axis The illumination assembly further includes a mirror to direct light from the at least one light source and at least one feature for enabling adjustment of the mirror.

According to at least one embodiment, the physical assessment device comprises a mirror support mount that retains the mirror. An adjustment member is accessible through the housing of the instrument head preferably during manufacture that engages the mirror mount to adjust the position of the mirror relative to the illumination axis.

According to at least one version, the light source is an LED, wherein the illumination assembly further includes a condensing lens disposed above the LED. The condensing lens is disposed in a component having a feature that aligns and centers the condensing lens with the LED along the illumination axis. According to at least one version, the condensing lens is formed as a molded domed section or surface on the aligning and centering component.

One advantage realized by the herein described physical assessment device is that a smart device, such as a smart phone, can be mechanically and optically coupled to a device, such as an otoscope or ophthalmoscope, which is typically only configured for optical viewing by a caregiver.

Another advantage is that a plurality of accessories, such as speculum tip elements having different engagement features, can be releasably and interchangeably attached to an otoscope made in accordance with at least one embodiment.

Still another advantage is that according to at least one embodiment, a smart device can be attached to an existing physical assessment device without modification such that the optical axis of the attached smart device is aligned with the optical axis of the physical assessment device.

Yet another advantage is that an instrument head made in accordance with the invention can be interchangeably attached to a plurality of instrument handles in which the instrument head is configured to detect the attached handle and suitably adjust a retained light source.

Still another advantage realized is that the optical system of the physical assessment device enables the attachment of an accessory, such as a speculum tip without the accessory being part of the field of view of an intended medical target.

These and other features and advantages will be apparent from the following Detailed Description, which should be read in conjunction with the accompanying drawings.

DETAILED DESCRIPTION

The following relates to various embodiments of physical assessment devices that are typically used for examining a patient, and more specifically otoscopes typically used for examining the ears of a patient and ophthalmoscopes typically used for examining the eyes of a patient. It will be readily apparent to the reader from the description that follows that a number of the herein described features can be incorporated into physical assessment devices other than those being described. In addition, a number of the inventive features described are not confined to any specific embodiment and are equally applicable to other described embodiments/devices. In addition, a number of terms are used throughout the following description for purposes of providing a suitable frame of reference in regard to the accompanying drawings. These terms, which include “first”, “second”, “upper”, “lower”, “left”, “right”, “above”, “below”, “distal”, “proximal”, “interior”, “exterior”, “internal” and “external”, among others, are not intended to limit any of the described inventive aspects, except where so specifically and conspicuously indicated. In addition and for purposes of clarity, like reference numerals are used throughout the discussion of each of the various embodiments.

In addition, the drawings provided are intended to show salient features of the herein described physical assessment devices. The drawings, however, are not intended to provide scalar relationships between any of the various depicted components unless specified to the contrary.

A first physical assessment device (otoscope) is described.FIGS. 1(a) and 1(b)depict a side view and a front perspective view of the physical assessment device, respectively, which according to this embodiment is an otoscope100. The otoscope100is designed primarily for performing diagnostic examinations of the ear of a patient, although the herein described physical assessment device100can also be used for examining other anatomical cavities (i.e., the nose, throat) of a patient. The otoscope100is defined by an instrument head104that is releasably attached to the upper end of an instrument handle or handle portion108. The instrument handle108is sized and shaped to permit the otoscope100to be handheld and is further configured to retain at least one battery (not shown in these views) for powering a light source (not shown) contained in the instrument head104. The contained light source is energized by an on-off button118disposed on the exterior of the handle portion108, wherein the illumination output of the contained light source can be controlled using a rheostat117, the latter including a twistable portion formed on the handle portion108. The contained battery can preferably be recharged via a charging port119, which is provided in the bottom end of the handle portion108.

As shown inFIG. 2(a), the instrument head104according to this embodiment is defined by a body or housing having a distal or patient end112and an opposing proximal or caregiver end116. A hollow speculum tip element120is releasably attached to the distal end112of the instrument head104, the speculum tip element120being designed and shaped to fit a predetermined distance into the ear canal while the proximal end116of the instrument head104includes an adapter interface member180.

The interior of the instrument head104is essentially hollow and sized and configured to retain a plurality of components. With reference toFIGS. 2(a)-2(k)and3and according to this exemplary embodiment, the instrument head104includes a pair of mated housing sections; specifically a front housing section130and a rear housing section134. Each housing section130,134is a shell-like member made from a structural material, such as a moldable plastic. Each of the housing sections130,134are mated to one another according to this embodiment using fasteners136,FIG. 3, to define an interior cavity. Alternatively, the housing sections130,134can also be secured by welding, such as ultrasonic welding or other suitable means. As discussed in greater detail in a later portion of this description, the lower ends131,135of each of the housing sections130,134are retained at the bottom of the instrument head104using a securing ring280. According to this embodiment, a peripheral bumper137is disposed between the front and rear housing sections130,134. An innerformer138disposed within the interior of the front housing section130includes a conical distal portion139, as well as a lower portion141. The innerformer138is essentially hollow and defines an interior cavity of the instrument head104to enable insufflation via a port connector (not shown) extending outwardly to a corresponding access opening114,FIG. 1(b), formed in the front housing section130.

With reference toFIGS. 2(b)-4, the herein described otoscope100retains an optical assembly that includes a hollow lens tube152containing a plurality of optical components is supported within the interior of the instrument head104and more specifically within the innerformer138. The lens tube152is defined by opposing distal and proximal ends154,156, respectively. An objective lens160is fitted within the distal end154of the lens tube152adjacent an optical window161that covers the distal end154of the lens tube152. A cylindrical hollow spacer163is provided proximally of the objective lens160along with a relay lens166, each of the spacer163and relay lens166being disposed within an intermediate axial portion155of the lens tube152. The diameter of the lens tube152further widens at its proximal end156, which retains an imaging lens169disposed in relation to a field stop170with a coiled spring172being disposed therebetween. A threaded retaining cap175at the proximal end156of the lens tube152maintains pressure against the imaging lens169. In addition, a field stop164is disposed within the lens tube152between the window161and objective lens160to reduce light scatter and an aperture plate167is disposed within the lens tube152proximal to the relay lens166.

As shown inFIGS. 2(b),3and4, the proximal threaded portion157of the hollow lens tube152engages a set of corresponding internal threads formed on a distal portion of the adapter interface member180. The adapter interface member180is a substantially cylindrical section according to this embodiment having its distal portion182extending into the proximal end116of the instrument head104and further including an outwardly extending proximal portion188. A recess184defined between the distal and proximal portions182,188of the adapter interface member180is sized and configured to receive a smart device adapter300, partially shown inFIG. 5. The recess184, is substantially annular with the inclusion of a series of machined flats186,FIG. 2(a)andFIGS. 2(d)-2(k). According to this embodiment, four (4) flats186are provided, although the specific number can be suitably varied. Further details relating to the smart device adapter300are described in greater detail in a subsequent section of this application.

When assembled, the distal end154of the hollow lens tube152is positioned at the distal end112of the instrument head104with the opposing proximal end156of the lens tube152extending from an opening formed in the innerformer138. The adapter interface member180is threadingly engaged with the proximal end156of the hollow lens tube152and extends outwardly from an opening formed in the rear housing section134of the instrument head104.

A series of circumferentially spaced axial openings183are provided within the distal portion182of the adapter interface member180. Each axial opening183, which extends into the defined recess184, receives a coiled compression spring185as well as a ball187, the latter extending partially into the recess184to provide positive engagement with a smart device adapter300, when the latter is attached. An intermediate plate190is positioned onto the exterior of the proximal end156of the lens tube152distally relative to the threaded portion of the lens tube152and in contact with a sealing member142. According to this embodiment, the adapter interface member180is further defined by an interior that includes an optical window189secured within the outwardly extending proximal portion188. A brow rest or cap194covers the extending proximal portion188of the adapter interface member180.

The sealing member142is made from an elastomeric material and disposed at the proximal end of the innerformer138on a formed annular shoulder. When assembled, the sealing member142is further engaged against the intermediate plate190and the adapter interface member180to provide adequate sealing within the innerformer138to enable insufflation of a patient.

With further reference toFIGS. 2(b)and3, the distal end154of the hollow lens tube152extends through the distal insertion portion140such that the optical window161and adjacent objective lens160are disposed at the distal end154of the distal insertion portion140. As previously discussed, a speculum tip element120is releasably attached to the distal end112of the instrument head104. According to this embodiment, the speculum tip element120is a hollow member made from a lightweight molded plastic material defined by a truncated frusto-conical shape having a distal tip opening124and an opposing proximal tip opening128. The exterior surface of the speculum tip element120at its proximal end includes at least one engagement feature that enables the speculum tip element120to be releasably attached to the distal end112of the instrument head104. According to this specific version, a total of three (3) engagement features are provided, each engagement feature including a ramped surface having a series of closely spaced engagement teeth.

The speculum tip element120is disposed in overlaying relation onto a distal insertion portion140, the latter being defined by a substantially conical surface that is disposed in overlaying relation onto the conical distal portion139of the innerformer138. According to this exemplary amendment, the innerformer138can include at least one exterior feature shaped and configured for engaging and retaining the distal insertion portion140. The speculum tip element120is releasably secured to a distal ring member146, the latter being disposed within the distal end of the front housing section130with the distal insertion portion140extending distally outward of the distal ring member146.

The distal ring member146, which is disposed relative to the front housing section130includes a number of engagement features that are configured to permit releasable attachment of the speculum tip element120. More specifically, the distal ring member146includes a plurality of ramped surfaces formed at circumferentially spaced locations, each ramped surface being shaped and configured to engage the exterior engagement features of the speculum tip member120. According to this embodiment, the distal ring member146is configured to receive one of a plurality of speculum tip elements120, including those having instrumentation, each tip element120having exterior engagement features that engage with the ramped surfaces of the distal ring member146.

The speculum tip element120is mounted onto the distal insertion portion140with the exterior engagement features of the speculum tip element120being engaged by the ramped surfaces provided on the distal ring member146. The speculum tip element120is secured and released by means of an appropriate twisting motion. As noted and when attached, the speculum tip element120is designed to be fitted up to a predetermined distance into the ear canal of the patient.

The foregoing components combine to define the optical assembly for the herein described otoscope100. As described in later portions of this application, a smart device adapter can be attached to the adapter interface member180to enable a smart device (e.g., a smart phone) to be attached to the instrument head104and enable images of the ear canal and more specifically the tympanic membrane to be captured.

An alternative version of an otoscopic instrument head104A is shown inFIGS. 5(a) and 5(b). Similar parts are labeled with the same reference numerals for the sake of clarity. This instrument head104A according to this embodiment includes the front housing portion130, a rear housing portion134A and an innerformer138, as well as a distal insertion member140, distal ring member146and sealing member142. However, this specific instrument version does not include a lens tube or an adapter interface member. In lieu of these components, the instrument head104A includes an eyepiece window196that is provided at the proximal end116within a cover portion198disposed within the rear housing portion134A. The eyepiece window196may or may not be configured to provide optical power (magnification) for enhanced viewing of the medical target.

With reference toFIGS. 2(b),3and5(b), the lower portion of each of the herein described instrument heads104,104A retains an illumination assembly. According to this version, the light source of the illumination assembly is an LED244, which is disposed upon the upper surface of a printed circuit board240. The circuit board240is electrically coupled to a downwardly depending electrical contact220, the latter being retained within an insulator member224biased by a spring254, which is disposed within a lens retainer248provided above the circuit board240, along with a condensing lens250. The opposite end of the electrical contact220extends from an opening formed in the insulator member224and a handle stud base member270. The securing ring280is secured over the lower end of the handle stud base member270. The handle stud base member270includes an intermediate recessed portion273that is sized to retain the lower ends131,135of the front and rear housing sections130,134,134A of the instrument head104, which is engaged by the securing ring280. According to at least one version, the securing ring280can include a locking element, such as, for example, a pin (not shown) that is insertable through a transverse opening281formed in the securing ring280.

The circuit board240is retained upon an upper shoulder of the handle stud base member270according to this embodiment. The condensing lens250is integrally molded as a domed section into the lens retainer248that is disposed above the LED244and circuit board240. According to this version, the lens retainer248is made from a moldable plastic. One end of the biasing spring254acts upon a surface of the lens retainer248, allowing the LED244and condensing lens250to be aligned and suitably positioned relative to the lower portion141of the innerformer138and more specifically a sleeve144that retains the polished end of a set of optical fibers (not shown). The optical fibers are advanced upwardly within the innerformer138and extend as a ringlet (not shown) that is provided in an annular spacing between the distal insertion portion140and the conical distal section139of the innerformer138in order to emit light toward the target of interest.

In operation, the contained LED244is engaged electrically via the contact220, as biased by the retained spring254. Upon energization of the LED244by the on/off switch118,FIG. 1(a)provided on the handle portion108,FIG. 1(a), illumination from the LED244is directed through the condensing lens250with the collimated light being directed to the polished proximal end of the optical fibers (not shown) at a lower end of the innerformer138. As noted, the optical fibers (not shown) are directed through the innerformer138with the distal ends of the optical fibers being arranged in a ring-like configuration at the distal end opening of the distal insertion portion140and about the periphery of the hollow lens tube152.

Smart Device Adapter

As shown inFIGS. 6-13(b), a smart device adapter300in accordance with an exemplary embodiment is described. The smart device adapter300is releasably attachable to the proximal end116,FIG. 1(a), of a suitably configured physical assessment device, such as the previously described otoscope100,FIG. 1(a). The smart device adapter300according to this exemplary embodiment is defined by an housing or body304having a pair of housing sections, namely a front housing section308and a rear housing section312, which when assembled combine to create an interior that is suitably sized and shaped to retain a plurality of components. Each of the components of the smart device adapter300according to this embodiment are manufactured from a moldable plastic, although other suitable materials can be used.

The front housing section308of the smart device adapter300is defined by a lower portion320, which includes a semicircular slot322provided at one end. The semicircular slot322extends entirely through the thickness of the front housing section308with the exception of a device engagement section328, which is most clearly depicted inFIG. 8(a), as well asFIGS. 11(e), 11(i) and 11(j).

The device engagement portion328is defined by a pair of device engagement surfaces330,332, each of which extend inwardly relative to the formed slot322and adjacent a front facing surface309of the front housing section308. These engagement surfaces330,332are orthogonal to one another and have a defined thickness.

The front facing surface309of the front housing section308further includes a recess335,FIG. 6, adjacent the defined semicircular slot322on one side of the slot322opposite one of the engagement surfaces330. The recess335is sized and configured to receive a slider member350, which is secured by a slider retainer356. According to this embodiment, the slider member350is defined by an upper plate352having an edge surface354, as well as a lower portion353. The slider retainer356is attached to the lower portion353of the slider member350using at least one fastener358, as well as engagement between a downwardly extending tab of the lower portion353of the slider member350and a corresponding slot formed in an upper surface of the slider retainer356. When positioned within the recess335, the edge surface354of the slider member350is positioned at the same plane as the two device engagement surfaces330,332, thereby forming a third device engagement surface. As shown inFIG. 8(b), a compression spring346is provided within a lateral cavity formed in the lower portion353of the slider member350that engages a spring pin provided on the front housing portion308, laterally biasing the slider member350and more specifically the edge surface354inwardly relative to the formed slot322. To facilitate movement, the underside of the upper plate352of the slider member350includes a set of rails359that are configured to slide within corresponding tracks355formed in the front housing portion308.

With reference toFIGS. 6, 7, 11(b) and11(f), the rear housing section312of the smart device adapter300includes respective interior and exterior surfaces313,314. A slot316is formed at a lower end of the rear housing section312. The slot316is further defined by an interior ridge324. A peripheral border326formed on the interior surface313extends around the formed slot316, as well as the entire perimeter of the rear housing section312. As discussed herein, the portion of the peripheral border326about the slot316and the interior ridge324are sized and configured to support a detent cover370, as well as a device engagement member360. The peripheral border326includes a semicircular section at the lower end of the rear housing section312that corresponds to the semicircular slot322formed in the front housing section308of the herein described adapter300. A through opening327is also formed at the lower end of the rear housing section308as part of a protruding portion340.

According to this embodiment, the detent cover370is an elongate member having a front facing surface371and opposing rear facing surface372that is sized and configured to be fitted within the formed slot316of the rear housing portion312. A molded projecting portion373is provided on the front facing surface371of the detent cover370that is sized to accommodate a detent member384, as well as a detent spring394. The molded projecting portion373is circular in configuration according to this exemplary embodiment and includes a pair of diametrically spaced slots375that are sized to engage ears389formed on the detent member384to insure a predetermined placement within the projecting portion373. It will be readily apparent that the molded projecting portion373can assume other suitable configurations. The projecting portion373is further defined by a through opening extending entirely through the thickness of the detent cover370, the opening enabling access to a projecting detent391.

Adjacent the molded projecting portion373on the front facing surface371of the detent cover370is a formed recess376that is sized and configured to receive a strip of insulating material395. According to this embodiment, the strip of insulating material395is made from an open-celled foam material such as poron, although other similar materials can be utilized.

The device engagement member360is attachable to the rear housing section312of the smart device adapter300and more specifically is attachable to the formed slot316. According to this embodiment, the device engagement member360is elongate and defined by opposing planar front and rear facing sides361,362, respectively. The rear facing side or surface362of the device engagement member360receives an adhesive strip363, which can be fitted thereto. According to one version and with reference toFIGS. 6, 7 and 12(a)-12(h), the rear facing surface362of the device engagement member360is defined by a recess366sized to accommodate the adhesive strip363and position it in a predetermined location and orientation. According to another version, the adhesive strip can be removed and relocated anywhere on the rear facing side362. The front facing side361of the device engagement member360includes a groove367which is formed transversely relative to the major dimension of the member360and adjacent one end.

An exemplary assembly flow is provided inFIGS. 10(a)-10(e). First and with reference toFIG. 10(a), the slider member350is attached to the front housing section308and fitted within the formed recess335with the lower portion353of the slider member350extending through an access slot provided in the front facing surface309. The compression spring346is engaged within the lateral slot formed in the lower portion353of the slider member350wherein one end of the compression spring346is engaged with a spring pin (shown inFIG. 10(a)). As shown inFIG. 10(b), the slider retainer384is then attached to the slider member350through the access slot by engaging the tab of the lower portion353with the corresponding slot formed in the upper surface of the slider retainer356and inserting the fastener358to secure the slider retainer356and the slider member350within the recess335of the front housing portion308.

As shown inFIG. 10(c), the strip of insulating material395is added to the recess376formed in the rear housing section312and the detent member384and detent spring394is placed within the projecting enclosure373of the detent cover370, aligning the ears389of the detent member384with the corresponding spaced slots375formed on the projecting enclosure373. Once the foregoing components are in place, the detent cover370is placed onto the interior side of the rear housing section312and more specifically, the slot316with a bordering edge of the detent cover370being placed on the peripheral border326.

As shown inFIG. 10(d), the front housing section308having the assembled slider member350and slider retainer356is then aligned with and attached to the rear housing section312having the assembled detent cover370, detent member384and detent spring394, as well as the strip of insulating material395.

Finally and as shown inFIG. 10(e), the rear housing section312and the front housing section308are secured using a series of threaded fasteners317through a series of mounting holes315provided in each of the rear housing portion312and front housing portion308of the smart device adapter300. When assembled, the detent cover370is sandwiched within the interior of the smart device adapter300along with the detent member384, the detent spring394and the strip of insulating material395, and with the slider member350also attached as shown.

The device engagement member360can then be slidingly attached to the slot316. With reference toFIGS. 9(a), 9(b), 11(a), 11(b) and 11(k), the detent member384is retained in the interior of the adapter300within the detent cover370. The detent member384according to this embodiment includes a projecting detent391that is sized and shaped to engage the transverse groove367formed on the front surface361of the device engagement member360when the device engagement member360is attached by sliding the device engagement member360within the open end of the formed slot316.

As shown inFIGS. 9(a), 9(b) and 11(a)and as the device engagement member360is engaged within the slot316of the rear housing section312, the bias of the detent spring394enables the detent member384to be moved slightly forward relative to the transverse groove367formed in the device engagement member360to provide greater retention when the device engagement member360is attached to the adapter300. The strip or pad of insulating material395eliminates rattle and provides a defined drag when a user slides the device engagement member360in the defined slot316. The device engagement member360is slid an appropriate distance within the slot316until the front surface of the device engagement member360engages the spring loaded detent member384. Preferably, there is a slight mismatch created between the projecting detent391and the transverse groove367formed in the device engagement member360that biases the device engagement member360forward. Additional views of the front and rear interfacing portions of the smart device adapter300illustrating each of the foregoing features are depicted inFIGS. 11(a)-11(l).

In operation, the device engagement member360can first be attached to a smart device using a fixture (not shown) to a facing surface of a smart device. The device engagement member360is preferably located on the smart device (e.g., smart phone) in a position that enables the optical axis of the smart device to be aligned with the optical axis of the physical assessment device when the smart device is attached. The through opening327of the rear housing section312is aligned with the optical axis of the smart device when the device engagement member360is attached to the smart device. When attached, the protruding portion340formed on the rear housing portion312of the adapter300minimizes the intrusion of ambient (room) light into the system.

With reference toFIG. 13(a), the smart device adapter300is attachable to the proximal end116of the physical assessment device100by aligning the device engagement portion328of the adapter300with the recess184of the adapter interface member180. The three engagement surfaces330,332and354have a thickness that enables a fit within the recess184of the adapter interface member180. Moreover, the configuration of the three (3) device engagement surfaces330,332and354of the smart device adapter300, including their length and relative spacing enables releasable attachment of the smart device adapter300relative to the recess184of the adapter interface member180, and more specifically the machined flats186. The slot322of the front housing section308of the adapter300is sufficiently wide so as to accommodate the proximal section188of the adapter interface member180, including the brow rest194.

As noted, the engagement surface354is biased due to the spring loaded slider member providing consistent peripheral contact of the engagement surfaces330,332and354with the machined flats186. In addition, the axial openings of the adapter interface member and more specifically the spring loaded balls187of the adapter interface member180against the intermediate plate190, further bias the attached smart device adapter300in the direction of the optical axis of the physical assessment device100and provide a stable mounted platform for purposes of conducting an examination.

For purposes of positioning, the smart device adapter300(and attached smart device (not shown) can be placed in one of four (4) different positions, each position clocked about 90 degrees about the optical axis of the physical assessment device100. According to this embodiment, the smart device adapter300is removed from the physical assessment device100and rotated before reengaging the slots of the adapter300with the machined flats186of the adapter interface member180. This adjustment can be made either with or without a smart phone being attached to the smart device adapter300. It will be understood, for example, that the number of machined flats can be suitably varied in order to provide a suitable number of mounting positions.

According to another embodiment, the herein described adapter can be fitted to a physical assessment device, such as an otoscope or ophthalmoscope, without prior optical alignment using a calibration device. Instead of attaching the device engagement member360adhesively or otherwise to the smart device following calibration, the device engagement member360is initially attached to the smart device adapter300by sliding the device engagement member360into the slot316provided on the rear housing portion of the adapter300until there is an audible or other indication that the device engagement member360has been placed at a predetermined position. In at least one version, an audible click or other indication, detent is provided to the user. The adhesive layer363of the device engagement member360is then removed to enable the device engagement member360to be attached to a facing surface of the smart device, wherein visual alignment by the user aligns the through opening327in the adapter300with the optical axis of the attached smart device. The two components can then be assembled by pressing the adhesive surface363of the device engagement member360against the front facing side of the smart device. To remove the smart device from the adapter300, the smart device can be pulled from the device engagement member360. This technique permits a varied number of differently sized smart devices to be releasable fitted to a common smart device adapter300.

As shown by the ray trace depicted inFIG. 13(b)for the physical assessment device100including instrument head104and attached smart device adapter300, the optical assembly of the herein described otoscope100creates a virtual distal entrance pupil125within the attached speculum tip element120,FIG. 2(a). The position of the formed entrance pupil according to this embodiment is well distal of the optical window and objective lens. The entrance pupil is positioned such that the attached speculum tip element120is not “seen”; that is, the rays of light reflected from the medical target pass sufficiently within the tip opening of the speculum tip element120,FIG. 2(a), while still enabling a large field of view, permitting the entire tympanic membrane to be viewed all at once. As shown, the light reflected from the medical target is directed along a defined optical axis to the optics of an attached smart device, not shown. The advantageous effect of the entrance pupil is further illustrated inFIGS. 54(a)and55.

With reference toFIGS. 14-16, a variation of the smart device adapter400is described for use on another physical assessment device450. Similar parts are labeled with the same reference numerals for the sake of clarity. According to this embodiment, the physical assessment device450is a Pan Optic™ Ophthalmoscope sold commercially by Welch Allyn, Inc. of Skaneateles Falls, N.Y. The ophthalmoscope450is defined by an instrument head454that can be releasably attached to a handle portion (not shown). The instrument head454includes a distal (patient) end456and an opposing proximal (caregiver) end459. An optical system (not shown) within the instrument head454is configured to enable examinations of the eye of a patient, along with a contained illumination system (not shown) that includes at least one light source to illuminate the eye being examined.

According to this embodiment, aspects of the smart device adapter400are structurally and functionally similar to the version previously described inFIGS. 6-13(a), including a pair of housing portions308,312that retain a detent cover370as well as a detent member384, the latter being biased by a contained detent spring394. The rear housing portion312includes a slot316that is configured to receive the detent cover370, as well as a device engagement member360that is slidably engaged with the slot316formed on the adapter400and including a transverse groove367that engages the detent member384. The housing portions308,312are secured to one another using a set of fasteners317, The adapter400further includes a through opening327that is aligned with the optical axis of the physical assessment device450when the adapter400(and smart device480) are attached, as shown inFIG. 16.

The smart device adapter400according to this embodiment further includes a flexible arm420having a distal end424that includes a ring-shaped portion428. The ring-shaped portion428is sized to enable it to be disposed over the downwardly extending portion458of the instrument head454. The proximal end429of the flexible arm420can be releasably attached to the front housing section308of the smart device adapter400. According to this version, the front housing section308includes an opening433that is sized to receive the proximal end429of the flexible arm420.

With reference toFIGS. 17-20, a smart device adapter made in accordance with another exemplary embodiment is herein described. First and referring toFIG. 17, a known physical assessment device500and the otoscope100,FIG. 1(a), are shown in side by side relation. As previously discussed, the otoscope100includes an adapter interface member180at its proximal end116that enables a smart device adapter300,FIG. 6, to be releasably attached. The known assessment device500, which is a Macroview™ otoscope, commercially sold by Welch Allyn, Inc. of Skaneateles Falls, N.Y., can also be configured with an adapter to enable a smart device to be attached. The known device is defined by an instrument head554that includes a distal (patient) end556and an opposing (caregiver) end559, wherein the instrument head554is attached to the upper end of a handle portion558. A speculum tip element560is attached to the distal end556of the instrument head554. An optical and an illumination assembly (not shown) are contained within the instrument550, including an eyepiece563provided at the proximal end558and a focusing wheel562intermediately provided on the exterior of the instrument head554that enables relative movement of at least one contained optical element (not shown).

With reference toFIGS. 18-20, a smart device adapter500according to this embodiment includes a support or base plate504having an upper portion508and an opposing lower portion512. The support plate508can be made from a durable molded plastic, although other structural materials can be suitably utilized. The upper portion508includes a through opening516, as well as a hollow cylindrically shaped projection520that is aligned with the through opening516. The hollow projection520extends distally from the upper portion508and is defined by a cavity that is sized and configured to be fitted over the proximal end558and more specifically the eyepiece563of the known physical assessment device550. A flexible engagement portion522formed at the lower portion512of the base plate504is defined by a C-shaped engagement end524. This engagement end524is sized and configured to releasably engage the cylindrical handle portion558of the known physical assessment device500. Though the known physical assessment device550is an otoscope, it will be readily apparent to those in the field that other handheld medical diagnostic devices can be similarly configured for attachment.

With further reference toFIGS. 18-20and in terms of attachment, the projecting cylindrical portion520is first fitted onto the proximal end558of the physical assessment device550. This fit still enables the caregiver to access the focusing mechanism562of the physical assessment device550. The smart device adapter500is then rotated until the open end of the C-shaped engagement feature524is aligned with the handle portion558, permitting the C-shaped engagement feature524to be clamped onto the handle558. The C-shaped engagement portion556is angled relative to the base plate504to account for the angled configuration of the instrument head554of the otoscope550.

A smart device such as a smart phone (not shown) can be attached to the proximal side of the support plate504in a manner similar to those previously described. Advantageously, the herein described adapter500can be attached to a physical assessment device in a matter of seconds, thereby converting the physical assessment device from an optical to a digital physical assessment device without requiring any modification to the device. Once attached, the smart device permits users to use the physical assessment device550to take pictures and video and then seamlessly transfer the images or video to a digital medical record or other digital storage medium used in an office or hospital.

An otoscope1100made in accordance with another exemplary embodiment is depicted inFIGS. 21 and 23. According to this embodiment, the instrument head1104of the otoscope1100is defined by a distal end1112, an opposing proximal end1116and a downwardly extending portion1120attached to the handle1108, the latter being shown only inFIG. 21. A disposable hollow speculum tip element1124is releasably attached to the distal end1112of the instrument head1104and more specifically to a tip retaining member1170, while an optical window1128is provided at the proximal end1116. In use, the speculum tip1124is shaped and configured to be inserted a predetermined distance into the ear of the patient and the optical window1128enables viewing of a medical target of interest (e.g., the tympanic membrane) through the open distal opening1125of the speculum tip1124.

With reference toFIGS. 22 and 24(a), an alternative instrument head1204of an otoscope1200is similarly defined by a distal end1212, an opposing proximal end1216and a downwardly extending portion1220. A disposable speculum tip element1124is releasably attached to the distal end1212of the instrument head1204and more specifically a tip retaining member1170. As shown inFIG. 24(b), a rear mounting member1224(also referred to throughout as an adapter interface member) extending from the proximal end1216is configured to receive a smart device1230, such as a smart phone, using an interface member1240that aligns the electronic imager of the smart device1230with an optical axis of the instrument1200to enable digital imaging of the target of interest (e.g. the tympanic membrane) via the display1234of the attached smart device1230.

Assembly of the instrument head1104is shown inFIGS. 25(a)-25(d). The instrument head1104according to this embodiment includes a pair of housing sections1134,1138(one housing section1134being shown as exploded inFIG. 25(a)) that are mated to one another about an innerformer1140, the latter component creating an interior chamber for the instrument head1104. An interface stud1150extends downwardly from the innerformer1140into the downwardly extending portion1120of the instrument head1104to enable connection to the instrument handle1108,FIG. 21. A conically-shaped distal insertion portion1160is provided at the distal end1112of the instrument head1104onto which the speculum tip1124is placed in overlaying relation and releasably secured to the tip retaining member1170. A proximal housing member1180is secured to the rear end of the innerformer1140. The proximal housing member1180includes a mounting flange1184having a pair of spaced slots1186that permits the transverse attachment of the optical window1128. Between the mounted proximal housing member1180and the rear of the innerformer1140is a groove1187that permits the inclusion of a sealing member (not shown). A retaining ring1190threadingly attached to the interface stud1150secures the housing sections1134,1138together and a cover1142attached to the top of the instrument head1104covers the mating edges of the housing sections1134,1138.

With reference toFIGS. 26(a)-26(b), the assembly of the instrument head1204similarly incorporates the housing portions1134,1138that are mated about the innerformer1150, the latter component forming an interior compartment of the instrument head1204. Similarly, this assembly incorporates a cover1142, the distal insertion portion160and the tip retaining member1170as well as an interface stud1150and threadingly retained retaining ring1190extending downwardly into the narrowed neck portion1220. In lieu of the proximal housing member that retains an optical window, the rear mounting (adapter interface) member1224is disposed at the proximal end1218of the instrument head1204. According to this embodiment, and similar to the design previously discussed (see180atFIG. 1(a)), the rear mounting member1224has a defined mounting flange1226and an annular slot1228that is configured to receive the interface member (smart device adapter)1240and attached smart device1230, as shown in the assembled form previously shown inFIG. 24(b).

Sectioned views of the assembled instrument heads1104,1204are shown inFIGS. 27 and 28. respectively. Referring toFIG. 27, the instrument head1104of the otoscope1100,FIG. 21, enables an image of the medical target (e.g., the tympanic membrane) to be seen through the proximal end1116of the instrument head1104by viewing through the optical window1128as supported by the proximal housing member1180. This enables viewing of the medical target (e.g. tympanic membrane) through the interior compartment created by the innerformer1140and the distal openings1127,1161that are formed in the distal insertion portion1160and speculum tip1124, respectively.

With reference toFIG. 28, an optical assembly is disposed in the interior of the instrument head1204of the otoscope1200according to this exemplary embodiment. Portions of the optical assembly are retained within a tubular member (also referred to throughout as a lens tube) disposed within the interior compartment created by the innerformer1140including a plurality of optical elements, each aligned and disposed along a defined optical or viewing axis of the device1200extending between the distal and proximal ends1212,1216of the instrument head1204. The specifics of the optical assembly are more specifically described in a later portion of this description. As referred to herein, an “optical element” refers to lenses and prisms as well as field stops, aperture stops, polarizers, and any component used to directing or transmitting light along the defined optical or viewing axis. As in the prior described versions of the physical assessment device100,FIGS. 1(a), 13(b), the optical assembly according to this exemplary embodiment produces an entrance pupil distal relative to the distal most optical element of the optical assembly, creating a field of view that permits the entire tympanic membrane (about 7 mm for an average adult) to be seen all at one time.

A sealing member1250is further provided at the rear of the innerformer1140as engaged within a formed annular groove1187. The sealing member1250provides an adequate seal to the formed interior compartment of the instrument head1204in order to permit insufflation capability (insufflation port not shown in this view) and also preventing fogging of the retained optical elements.

Each of the otoscopic instrument heads1104,1204depicted inFIGS. 27 and 28commonly include an illumination assembly that is disposed within the downwardly extending portion1120,1220and more specifically the interface stud1150. The illumination assembly according to this embodiment is more clearly shown inFIG. 33and includes an LED1270as a light source. More specifically, the LED1270is disposed upon the upper surface1272of a printed circuit board1274that is electrically coupled to a downwardly depending electrical contact1278biased by a spring279disposed within an internal sleeve1280, the distal end of the electrical contact1278extending from an opening of a narrowed portion of the internal sleeve1280and proximate an opening1285formed in the bottom of the instrument head1104,1204. The LED1270is disposed in relation to a condensing lens1290and the polished proximal end of a fiber optic bundle1287, the latter of which is advanced upwardly about the innerformer1140and extends as a ringlet of optical fibers (not shown) between the distal end of the distal insertion portion1160and the innerformer1140in order to emit light toward the target of interest.

In each of the above noted devices1100,1200and as described, the pair of housing sections1134,1138can be secured to one another at corresponding mating edges by means of ultrasonic welding with a cover1142being introduced at the top of the instrument head1104,1204.

With reference toFIGS. 29 and 30and according to yet another exemplary embodiment, instrument heads1304,FIG. 29, and 1310,FIG. 30are shown. Each of these instrument heads1304,1310are similar to instrument heads1104,1204. Instrument heads1304and1310include a pair of mating housing shell sections1324,1328that are attached to one another using an intermediate member, herein referred to as a strap1340. For purposes of clarity, like structural components are herein labeled with the same reference numerals. The strap1340according to this specific embodiment is a singular member made from a flexible, but structural material and having an upper portion1344and a lower portion1348.

As shown more specifically inFIG. 31, the upper portion1344of the strap1340is defined by a rounded interior surface1346configured and sized to wrap around the exterior of the respective first and second housing shell sections1324,1328after the mating edges of the housing sections1324,1328have been placed in intimate contact with one another. According to this embodiment, the housing shell sections1324,1328define respective halves of the instrument head1304,1310. Each of the housing sections1324,1328includes a recess1330formed in the exterior surface into which the strap1340is received such that the exterior surface of the strap1340is substantially coplanar with the exterior surface of the mated housing sections1324,1328when attached.

During assembly/manufacture, the inner edges of the pair of housing sections1324,1328are placed in intimate contact and the strap1340is snap-fitted into place onto the instrument head1304via the recess1330. As shown inFIGS. 31 and 32, the lower extending portions1348of the intermediate strap1340each include an annular flange1352formed on an inner surface, as well as an annular shoulder1356formed at the end of each lower extending section1348. Referring toFIG. 32, the annular flange1352of each lower extending section1348is retained within an annular groove1153formed in the interface stud1150and secured by means of the retaining ring1190by threading engagement with the bottom of the interface stud1150of the instrument head1304, the upper end of the retaining ring1190engaging the shoulder1356.

With reference toFIG. 33-36, an illumination assembly is retained within the downwardly extending portion1120of the instrument head1104. According to the depicted embodiment, the illumination assembly includes the LED1270attached in a known manner to a top or upper surface1272of a printed circuit board1274. Disposed above the LED1270and printed circuit board1274is an integrated component1420that serves to center and align the LED1270and also collimates the light that is emitted from the LED1270. The outer edges1275of the printed circuit board1274are retained upon an interior shoulder1156of the interface stud1150. As shown in the sectioned view ofFIG. 34, the integrated component1420is defined by a cylindrically shaped body1422having an upper end1426, a lower end1430, and a set of external threads1434extending along the length of the integrated component1420. An interior flange1438is disposed at an intermediate distance between the upper and lower ends1426,1430of the integrated component1420, the flange1438having respective and opposing top and bottom surfaces1442,1446.

A domed portion1450, which is provided at the center of the top surface1442of the internal flange1438, is axially aligned with the LED1270and acts as a condensing lens. An annular ring1458extending downwardly from the bottom surface1446of the interior flange1438is configured and sized to surround the lens envelope of the LED1270and functions to center the domed portion1450with the LED1270, thus minimizing decentration between the LED1270and the domed portion1450and any associated losses in light transmission. The set of external threads1434are configured to mate with corresponding internal threads1460that are provided in the interface stud1150of the instrument head1104. Thus mating allows the integrated component1420itself to fasten the printed circuit board1274into the interface stud1150and further ensure a secure electrical contact between the printed circuit board1274and the interface stud1150. This securement further prevents ingress of dirt and debris.

According to this particular embodiment, a series of notches1468are provided in spaced relation along the upper end1426of the integrated component1420, as shown inFIG. 35. The notches1468are shaped and configured to accept protrusions provided in a complementary driving or torqueing tool (not shown) for purposes of assembly. The printed circuit board1274according to this embodiment further includes an outer ground ring that makes intimate electrical contact with a metal stud. The threaded connection between the integrated component1420and the interface stud1150of the instrument head insures a secure high pressure mating at this junction. As noted, the domed portion1450collimates illumination from the LED1270. Advantageously, the design of the integrated component1420serves to save manufacturing costs and labor and also reduces tolerance build ups, as well as preventing or minimizing ingress of dirt and contaminants.

An embodiment depicting the interconnection between an instrument head1104and instrument handle1108for the physical assessment device1100ofFIG. 21is illustrated in the sectioned view ofFIG. 37. As shown, the instrument handle1108is a substantially cylindrical member having an upper or top end and an opposing lower end, as well as at least one interior compartment that is sized and configured to retain at least one battery for powering the contained light source in the instrument head1104. It should be noted that similar connections are provided for the instrument heads previously described in this application.

Each of the instrument heads1104,1204such as those shown inFIGS. 27 and 28and having an LED1270as a contained light source can be interchangeably attached to the instrument handle1108by means of a bayonet connection between the top end of the instrument handle1108and the narrowed neck portion of the instrument head1104. Known physical assessment devices, such as those commercially sold by Welch Allyn, Inc provide a bayonet connection between the instrument head and the instrument handle. More specifically, a set of spaced lugs are provided on the top of the instrument handle that engage a corresponding slot formed in the lower end of the instrument head when the instrument head is twisted in a predetermined direction.

As noted, each of the previously described instrument heads, including instrument heads1104,1204or104,FIG. 13(b),104A,FIG. 5(a), include an LED as a light source for the contained illumination assembly.

There is a need with the evolution of LEDs as light sources in physical assessment devices to prevent instrument handles, especially those wired to wall mounted systems that will not power instrument heads equipped with halogen lamps. Halogen lamps draw large currents and the associated voltage drop through wall unit power cords. This voltage drop makes compliance with safety standards difficult and forces the further inclusion of expensive electronics. LED systems, on the other hand, draw relatively small currents and do not have this drawback. As instrument heads evolve and utilize LED as illumination sources, it is anticipated these instrument heads can be used with existing instrument handles. However and as wall mounted systems also evolve, it is a desire to prevent the use of existing instrument heads having halogen lamp light sources.

With reference toFIGS. 37-43, an embodiment is herein described to enable an instrument handle to be incompatible with certain instrument heads (i.e. those having halogen lamps). With reference toFIG. 38, an instrument handle1602includes a top portion1604. A pair of equally spaced male lugs1612are provided on the exterior of the top portion1604of the instrument handle1602. Each lug1612according to this embodiment is defined by a width dimension denoted by arrows1616that enables the lug1612to be fitted within a defined bayonet slot of a mated instrument head.

An instrument head1620is shown inFIGS. 39 and 40. In this instance, the physical assessment device is an ophthalmoscope, but the principle is common to other physical assessment devices, such as the previously described otoscopes. The mating connection is provided at the bottom of the instrument head1620and includes an interface stud1624whose bottom end1628is defined with a contoured slot1632to provide a secure locking engagement when the instrument head1620is rotated relative to the instrument handle1602by means of a bayonet connection.

The assembled interface is shown more clearly inFIGS. 41 and 42with each of the spaced lugs1612of the instrument handle1602engaged within the contoured mating slot1632of the instrument head1620. In this mounted position, the electrical contacts1640,1646of the instrument head1620and the instrument handle1602are positioned into contact with one another. For purposes of this embodiment and referring toFIG. 42, the width dimension of the contoured mating slot1632is increased enabling interchangeability between various instrument heads and handles. With reference toFIG. 43, the width dimension of the mating lugs1612of the instrument handle1602can be increased such that the lugs1612will not fit within the mating slot (not shown) of an already existing ophthalmic instrument head having a halogen light source.

Referring toFIG. 44, an exemplary instrument handle1706is shown having a upper end1707including a top portion1709and an opposing bottom end1711. A partially sectioned view of the upper end1707of the instrument handle1706is further depicted inFIG. 45. More specifically, the upper end1707includes a rheostat assembly1712that selectively adjusts the level of illumination of the retained light source, such as the at least one LED1270,FIG. 33, when the instrument head (not shown) is attached to the instrument handle1706. This connection is made using bayonet engagement features provided on each of the mated components such as those previously discussed. When connected, the LED1270,FIG. 33, is powered through coupling between the retained battery1714(partially shown inFIG. 45), the rheostat assembly1712, the electrical contact1717biased by spring1721and the electrical contact1640,FIG. 40, in order to electrically couple the LED1270,FIG. 33, with the battery1714.

Referring toFIGS. 45-48and according to one embodiment, the rheostat assembly1704includes a twistable grip section1718that is provided on the exterior of the instrument handle1706. The twistable grip section1718is disposed over a cylindrically shaped detent ring member1722having a series of holes1726arranged along its periphery proximate a lower end729of the detent ring member1722, as shown more clearly inFIG. 47. A pin member1732extends within an annular recess1734formed in the detent ring member1722and is biasedly retained within a recess1736formed in an internal sleeve1750. A ball1740is also biasedly retained in an opening formed in the internal sleeve1750which is diametrically opposite that of the pin member1732. The ball1740is configured to rotate with the twistable grip section1718and is caused to extend into one of the holes1726in the detent ring member1732, the latter being stationary to create an audible and tactile sensation for the user. Each of the ball1740and the pin member1732are biased by springs1744,1748which are disposed within the diametrically opposed openings in the internal sleeve1750extending in a direction that is transverse to a primary axis of the instrument handle1706. The detent ring member1732includes the set of interior threads1725that engage a corresponding set of external threads1757provided on a rheostat housing1758.

In operation, the twistable grip section1718rotates around the stationary detent ring member1722. The pin member1732keys into the twistable grip section1718and rotates with the grip section1718when twisted by a user. The spring-loaded ball1740also rotates with the twistable grip section1718and depending on the rotational position of the grip section1718detents into one of the series of holes1726provided in the stationary detent ring member1722. Attributes of the spring1748biasing the ball1740can be suitably varied as needed in order to provide a desired detent release force. The foregoing provides audible and tactile feedback about the location of the rheostat. This feature allows a user of the instrument to create a preferred setting which can repeated to obtain a consistent amount of light with each use. The detent positions and size and configuration of the detent stops can be altered in order to provide a different sound or release strength at different or selected positions, such as the zero position or other rheostat position.

With reference toFIGS. 48 and 49, the instrument handle1706can be equipped with a USB charging or power boosting port1760. According to this embodiment, the USB port1760is provided on the exterior of the instrument handle1706and proximate the bottom or lower end1711. It will be understood, however, that the location of this port1760can be suitably varied relative to the instrument handle1706. With reference to the sectioned view ofFIG. 49and according to this embodiment, the charging port1760extends to a USB connector1768mounted to the top surface of a printed circuit board1772that is disposed within the interior of the instrument handle1706in which contacts extend to the contained battery1714(partially shown in this view). According to this embodiment, a set of electrical charging contacts axially extend from the lower end1709of the instrument handle1706enabling the instrument to be used in conjunction with a charging base or cradle1800,FIG. 52, that enables the at least one contained battery1714to be recharged.

According to this embodiment and with reference toFIGS. 49 and 50, a positive contact1777extending from the lower end1709of the instrument handle1706is soldered to the printed circuit board1772via a connection1779and a conductive spring clip1782is provided to serve as a negative contact connecting an outer ring1713at the bottom end1711of the instrument handle1706with the printed circuit board1772, the latter being electrically coupled to the lower contact end of the battery1714. As such, the herein described instrument handle1706can be configured with dual charging modes.

The norm in the medical industry is to charge the instrument handle (power source) through either a desk charger or more recently using USB. With reference toFIG. 50, a circuit is depicted that allows one or more instrument handles to be charged through a desk charger, such as base1800, or the USB charging port1760. This charging circuit uses a charging IC and accepts power from either a USB input or via positive and negative contact pins.

FIG. 51illustrates a sectioned view of the alternative charging mode with the electrical contacts1777and1782being coupled to respective charging pins1809that are provided within a charging well1814of the charging base1800, which is only partially shown in this view.

FIG. 52provides a perspective view of a charging base1800made in accordance with an embodiment and including a pair of charging wells1814extending from a top surface1811. Each of the charging wells1814are sized to receive an instrument handle1822,1832of a physical assessment device1820,1830and provide a stable base, the charging wells1814having a defined height that creates a stable base for the retained physical assessment devices1820,1830. With continued reference toFIG. 52, a pair of physical assessment devices1820,1830and more specifically, an ophthalmoscope and an otoscope are commonly retained in separate charging wells1814of the charging base1800in which each of the retained devices1820,1830includes an attached smart device1828,1838, such as a smart phone. The two physical assessment devices1820,1830are mounted at the same time, as shown, with the respective instrument handles1824,1834being inserted into the charging wells1814such that the retained smart devices1828,1838are opposed to one another. In this mounted position, there is with no interference between the mounted devices or between either retained physical assessment device1820,1830and the charging base1800.

According to one version and as shown inFIG. 53, a thermistor, thermocouple1790or other temperature determining apparatus can extend from the printed circuit board1772within the instrument handle1706by connection1792and be disposed in relation with the contained battery1714. The output of the thermistor1790provides direct battery temperature measurement during charging and discharging of the battery1714which can further be coupled to an indicator (not shown) on the charging base1800,FIG. 52, or the instrument handle1706. As such, potential overheating of a contained battery, such as an alkaline battery, can be monitored.

Due to the fact that both halogen lamp based and LED-based instrument heads may be used interchangeably, instrument handles should be designed so as to prevent overheating of a contained alkaline battery, especially if a halogen-based instrument head is attached.

An example of an electrical circuit intended to solve this problem is depicted inFIG. 53, preventing overheating of a contained battery. The electrical circuit employs a voltage boost design with input current limit (such as Texas Instruments TPS 61251). With this circuit's design, a current limit can be set on the voltage boost IC so that if a halogen based lamp is connected to the instrument handle having an alkaline battery, the current will be limited and not exceed the battery's limit that would cause overheating.

In addition, this voltage boost IC will enable improved performance of an instrument head that is equipped with an LED as a light source and subsequent use of LED replacement lamps.

As discussed, the interior of at least one of the herein described instrument heads104,FIG. 2(b),FIGS. 13(b)and1204,FIG. 28, can retain an optical system or assembly that includes a plurality of components aligned along an optical or viewing axis extending through the distal end opening124,1125of the hollow speculum tip element120,1124, which is releasably attached to the instrument head104,1204and continuing through the interior of the instrument head104,1204, passing through the proximal end1014,1216thereof.

Reference is herein made toFIG. 54(a), which depicts a ray trace of the optical system or assembly1900of the physical assessment device100,FIGS. 2(b) and 13(b)andFIG. 54(b), providing a comparison between three (3) additional optical assemblies1910,1940and1950for an exemplary instrument head, including that of instrument head1204. The bottommost optical assembly1910depicted is representative of a known optical assembly which is fully described in U.S. Pat. No. 7,399,275, and incorporated herein by reference in its entirety.

First and with reference toFIG. 54(b), the known optical assembly1910includes a distal objective lens doublet1914that would be disposed proximate the distal opening of the distal insertion portion1160,FIG. 28, of the instrument head1204having an attached speculum tip element1124. A pair of aligned relay lenses1919,1922are disposed proximally to the objective lens doublet1914, as well as an aperture plate1920disposed between the pair of relay lenses1919,1922. A set of eyepiece lenses1930is disposed proximally from the second relay lens1922, each aligned along a defined optical axis. This optical assembly1910produces an entrance pupil (shown as1934) that is proximate to, but distal relative to the objective lens doublet1914, and creating a field of view that enables the entire tympanic membrane to be viewed all at one time at the image plane of the clinician's eye, if viewed optically, or the image plane of an attached digital imager (not shown). More specifically, this optical assembly1910produces a field of view of about 9 mm at a working distance (distance between the distalmost optic and the patient) of about 33 mm, which allows the entire tympanic membrane (about 7 mm) to be viewed all at one time. Though this optical assembly1910is highly effective due to the increased field of view, the resulting image is influenced by the attached speculum tip1124, as shown in the top illustration ofFIG. 55.

Referring toFIG. 54(b), two other optical assemblies1940and1950are shown and compared to optical assembly1910as well asFIG. 54(a), which illustrates the optical assembly1900of instrument head100,FIG. 2(b),FIG. 13(b). More specifically, the optical assembly1940includes in order and arranged from distalmost to proximalmost: an objective lens1941, relay lens1942, field stop1945, imaging lens1943and a plano window1944. The optical assembly1950is similarly defined starting from the distal end and moving toward the proximal end by an objective lens1967, relay lens1968, a field stop1971, an imaging lens doublet1969and a plano window1970. The optical assembly1900,FIG. 54(a)is similar to the optical assembly1950and is defined by the following elements from distalmost to proximalmost: an optical window161disposed distally relative to an objective lens160separated by a field stop164,FIG. 4, that reduces light scatter, a relay lens166, an aperture plate167,FIG. 4, a field stop170,FIG. 4, an imaging lens169and a window189provided at the proximal end of the assembly1900.

The optical components of each of these optical assemblies1900,1940,1950are also configured to create an entrance pupil that is distal from the distalmost optical element160/161,1941,1967, respectively.

The overall effect is shown in the schematic comparative view depicted inFIG. 55, contrasting the known optical system1910with optical assemblies1900and1950in which each optical assembly is disposed within the instrument head1204for purposes of comparison. A similar field of view is created by each of the optical assemblies1900,1950, but the distal entrance pupil1966created by each of the latter optical assemblies1900,1950is moved distally toward the patient, as compared with that of the distal entrance pupil1934. Consequently, the cone of light rays does not chop the attached speculum tip element1124and enabling the tympanic membrane to still be viewed all at one time by the caregiver, but without any portion of the speculum tip element1124being in the resulting image.

Surprisingly and resulting from the above optical system, Applicants have further discovered that the attached speculum tip element can be made optically clear, as opposed to the typical black opaque versions of these elements. The resulting light spot produced is clear, crisp and well defined without edge effects.

Another alternative optical assembly1980is depicted schematically inFIG. 56based on a change in materials that produces a similar overall effect (distal entrance pupil1966,FIG. 55) upon a resulting image of the medical target. In the optical assemblies1900and1950, each of the optical elements are made from a moldable plastic, while the optical elements according to this latter optical assembly1980are made from glass. More specifically, two (2) glass lenses are used in place of a plastic aspheric lens for each of the objective lens1982, relay lens1984and eyepiece lens1986wherein the two glass lenses achieve image quality by two facing plano-convex lenses of high index of refraction (greater than 1.80) and abbe value greater than 35. The optical assembly1980further includes a plano window1988. It will be understood that similar configurations are possible.

The following portion of the description relates to the design of another physical assessment device that is made in accordance with various exemplary embodiments. More specifically, the physical assessment device is an ophthalmic device that is configured for examining the eyes of a patient. It will be understood, however, to those in the field that certain of the inventive aspects described herein can be applied to various other medical examination or diagnostic devices.

With reference toFIGS. 57(a) and 57(b), the ophthalmoscope2000includes an instrument head2004that is releasably supported to the upper end of a handle or handle portion2008using a bayonet or similar connection, the handle portion2008enabling the instrument2000to be portable and configured for hand-held use. The handle portion2008includes at least one contained battery (not shown) for powering a light source (i.e., an LED—not shown) provided in the instrument head2004. In addition, a rheostat2020, which includes a rotatable portion of the handle portion2008is configured to control the amount of illumination of the light source, as well as a depressible on-off button2022. The contained battery is preferably rechargeable, wherein the lower portion of the handle portion2008includes a charging port2024.

The instrument head2004is defined by a distal (patient) end2010and an opposing proximal (caregiver) end2014, and further defined by an interior that is sized and configured to retain a plurality of components. As described in greater detail below, the distal end2010of the instrument head2004receives a deformable eye cup2030, while the proximal end2014of the instrument head2004includes an adapter interface member2040, similar to the adapter interface member180,FIG. 2(a), and1224,FIG. 30, to enable releasable attachment of a smart device adapter300,FIGS. 6-13(b). The instrument2000further includes a rotatable diopter wheel2050supported between mating front and rear housing sections2210and2214, as well as an rotatable aperture wheel2060, the latter being disposed in a lower portion of the instrument head2004and having a portion of the aperture wheel2050extending outwardly from a formed slot that is provided in the front housing section2210.

An optical assembly and an illumination assembly are commonly retained within the interior of the instrument head2004. According to this exemplary embodiment and with reference toFIGS. 58, 59(a) and59(b), the distal most component of the optical assembly is an objective lens2240, which is mounted adjacent the distal end2010of the instrument head2004. The rear peripheral edge2242of the objective lens2240is secured against an annular shoulder2245formed in the instrument head2004and held in position by means of an end cap2248that is threadingly positioned onto the distal end of the front housing section2016, the latter having a corresponding set of threads2249. When secured, the end cap2248also is configured to retain a fixation target retainer2254, the latter of which is peripherally disposed about the objective lens2240. An O-ring2260creates a seal between the objective lens2240and the fixation target retainer2254.

Angled slots are provided on a front facing surface of the fixation target retainer2254that receive polarizer windows2256, (shown only in the explodedFIG. 58) which according to this embodiment can be formed of different colors (i.e., blue, red) for directing a pair of fixation targets to the patient. The polarizer windows2256are positioned at the distal (objective) end2010of the instrument head2004with slots being disposed on diametrically opposite (left/right) sides of the objective lens2240where the fixation illumination targets are located. When the patient looks at the fixation target in the opposite direction relative to the eye being examined (that is, the right eye looking at the left target or the left eye looking at the right target), the patient's eye will align at approximately 17 degrees positioning their optic disc near the center of the view. According to this embodiment, a set of optical fibers (not shown), preferably having polished ends, extend from a contained LED2356of the illumination assembly of the ophthalmoscope2000to each of the fixation targets. More specifically, the polished distal end of the optical fibers are placed in contact with the polarizer windows2256, with the fibers being routed through the interior of the instrument head2004upwardly from the LED2356, the latter of which is retained in the lower portion of the instrument head2004. According to this embodiment, the proximal end of the fixation target fibers are disposed on lateral sides of the LED2356, although other suitable configurations can be utilized to direct the required illumination efficiently to the distally disposed fixation targets.

The proximal end of the eye cup2030is disposed over the distal end2010of the instrument head2204and about the contained objective lens2240to create the proper working distance between the physical assessment device2000and the eye of the patient, which according to this embodiment is approximately 25 mm. The eye cup2030is made from an elastomeric material and is shaped and configured to allow the distal end of the eye cup to be placed over the eye of the patient. The proximal end of the eye cup2030includes at least one internal engagement feature and is shaped to be releasably and securely attached to the end cap2248, the latter also being suitably shaped and configured for this engagement.

At the proximal end2014of the instrument head2004, the contained optical assembly includes an eyepiece holder2270projecting outwardly (proximally) from the instrument head2004and contained within the adapter interface member2040. According to this embodiment, the eyepiece holder2270is defined by an open-ended structure that retains a pair of eyepiece lenses2280,2284each separated an appropriate distance by an intermediate eyepiece spacer2288. The eyepiece lenses2280,2284are retained proximally relative to a field stop holder2290in which the eyepiece holder2270is threadingly engaged within an opening formed in the adapter interface member2040. A field stop2297is retained within a narrowed portion2299of the field stop holder2290, which is aligned with the eyepiece lenses2280,2284and the objective lens2240along a defined optical axis of the device2000.

Disposed between the proximal and distal ends2010,2014of the herein described physical assessment device2200is a relay lens2286that is aligned along the defined viewing axis, as well as an aperture stop2291, each of the foregoing optical components being intermediately disposed within the interior of the instrument head2004as part of the optical assembly. The relay lens2286is retained within a relay lens holder2287and more specifically within an aperture that is sized to retain the relay lens2286and aligned with the remaining optical components along the defined optical axis. A polarizer window is disposed immediately distal to the supported relay lens2286. The relay lens holder2287is attached to a proximal end of a top optical base member2426.

Regarding the illumination assembly and with reference toFIGS. 58, 59(a) and59(b), the instrument head2004further retains a plurality of components configured for illuminating the patient's eye. An electrical contact pin2320is disposed within a hollow plastic insulator2328, the latter having an upper portion which is sized and configured to retain a coil spring2332for biasing the contact pin2320. The coil spring2332is preferably disposed between a top or upper end of the contact pin2320and a shoulder formed in an upper portion of the insulator2328.

When a lowermost end of the contact pin2320is engaged with electrical contacts (not shown) in the handle (not shown) of the physical assessment device2000, the top end of the contact pin2320is pressed into contact with a lower surface of a printed circuit board2350for an LED2356that is disposed on the upper surface of the circuit board2350. The circuit board2350is positioned in place onto a circuit board retainer2330that further retains the insulator2328and contact pin2320, the circuit board retainer2330having a set of external threads2331that engage a set of corresponding threads that are provided within an optical base member2390. As discussed herein, the circuit board2350can be configured with an LED drive circuit that is compatable with different instrument handles, including those typically configured for driving incandescent light sources. This circuitry is described in a later portion of this application.

For purposes of this embodiment, the LED2356is aligned with a condenser lens2364along a defined illumination axis, the condenser lens2364being retained within a lens holder2380that is snapfitted in a manner that creates alignment with the LED2356. Each of these latter components are further retained within the optical base member2390, in which the optical base member2390is fitted within a lower necked portion of the instrument head2004.

According to this embodiment, the aperture wheel2060is disposed above the condenser lens2364and supported for rotation by the optical base member2390. A slot is provided in the front housing section2016to permit access to the aperture wheel2060, which is configured for rotational movement in order to selectively position each of a series of circumferentially spaced apertures formed on an aperture plate2404into alignment with the LED2356and condenser lens2364along the defined illumination axis. A pair of cover sections2062,2064retain the rotatable aperture wheel2060within a recessed portion of the optical base member2390. The cover portions2062,2064retain ends of an axle2065that extends through the center of the aperture wheel2060and the aperture plate2404, enabling rotation. More specifically, a plurality of windows are circumferentially disposed on the aperture wheel2060that may include a red free filter, a blue filter, as well as varying sized apertures. Various other configurations can easily be realized.

Above the aperture wheel2060and the optical base member2390, the illumination assembly further includes a relay lens2420, which according to this exemplary embodiment is retained within the upper end of the optical base member2390and aligned with the condenser lens2364, the rotatable aperture wheel2060, and the LED2356along the defined illumination axis.

A polarizer window2440is retained at the top surface of the optical base member2390above and distally relative to the relay lens2420and in relation to a mirror2450, the latter being supported by a mirror mount assembly2453. A compression spring2395,FIG. 60(a), provided between the top optical base member2426and the upper portion of the optical base member2390maintains pressure against the polarizer window2440and relay lens2420of the illumination assembly in which the lower end of the optical base member2426is accommodated, but not secured, within an upper portion of the optical base member2390. The foregoing arrangement further maintains the alignment of the relay lens2286and relay lens holder2287of the optical assembly of the herein described device2000, each of which are retained within the top optical base member2426as previously discussed.

With reference toFIGS. 58, 59(b), and60(a)-60(d), the mirror mount assembly2453includes a elongate mirror mount2454having an upper end2455and a lower end2456. The lower end2456of the mirror mount2454retains the mirror2450along an inclined support surface2451. The mirror mount2454is pivotally supported within an enclosure2458that is provided within the top optical base member2426. An adjustment member2462, such as a threaded fastener, extends into a formed slot in the rear housing section2018of the instrument head2004and further extends into an upper section of2459of the enclosure2458. The distal end of the adjustment member2462is configured to engage a rear facing surface2457at the top of the mirror mount2454in order to cause the mirror mount2454to pivot and enable the angle of the supported mirror2450to be adjusted to direct light from the LED2356,FIG. 59(b), toward the distal end of the instrument head2004.

A block2466of a elastomeric material, such as poron, is also fitted within the top of the enclosure2458immediately adjacent a front facing surface of the mirror mount2454against which the adjustment member2462engages. With reference toFIG. 60(c), the enclosure2458according to this embodiment is defined by a substantially cylindrical upper portion2459and a pair of lower extending legs2460, the latter which retain the lower end2456of the mirror mount2454through a pinned connection. The upper end2459of the enclosure2458includes a threaded sleeve2461aligned with the rear facing surface2457of the top of the mirror mount2454that receives the adjustment member2462. The enclosure2458according to this embodiment is supported within the top optical base member2426along with a sealing member, such as an O-ring2470. According to this embodiment, the adjustment member2462further permits lateral adjustments of the retained mirror2450in addition to angular (pivotal) adjustments of the mirror mount2454, wherein the O-ring2470contacting the inner surface of the optical base member2426provides sufficient resistance to maintain the lateral adjustment of the supported mirror2450.

Referring toFIG. 59(b), the illumination assembly allows light from the contained LED2356to be directed through the aligned condenser lens2364, the aperture wheel2060, the relay lens2420and the polarizer window2440to the supported mirror2450along the defined illumination axis. A reticle (not shown) can further be provided as part of the aperture wheel or otherwise within the optical base member. The light is then further directed toward the distal end2012of the instrument head2004and more specifically through the objective lens2240and in which the light is focused at the edge of the pupil of the patient's eye. The position of the objective lens2240can be suitably adjusted at the time of manufacture to further offset any tolerancing mismatches in addition to the adjustment of the supported mirror via the mirror mount assembly.

Referring toFIG. 59(a), light reflected from the back of the patient's eye is directed into the distal end of the ophthalmoscope2000through the objective lens2240in which the light is then focused onto the relay lens2286, which directs the light through the field stop2297and the imaging lenses2280,2284to the clinician's eye (not shown) or to an attached smart device attached to the adapter interface member2040. The adapter interface member2040according to this embodiment is structurally similar to the adapter interface member180,FIGS. 6-13(b), and does not require additional discussion.

As shown inFIG. 61, an ophthalmoscope3100made in accordance with another exemplary embodiment is herein described. As discussed herein and shown inFIG. 65, the ophthalmoscope3100includes an instrument head3104that is releasably attached to the upper end of a handle portion3108. The instrument head3104is defined by a distal (patient) end3112and an opposing proximal (caregiver) end3116. The interior3105of the instrument head3104is sized and configured for retaining an illumination assembly3101and an optical assembly3102.

According to this version and as shown inFIGS. 62 and 63, an eye cup3120is attached to the distal end3112of the instrument head3104. According to this embodiment, the eye cup3120is a flexible component, preferably made from an elastomeric material that is designed for direct engagement with the patient. When attached, the eye cup3120establishes a working distance between the patient's eye and a first distalmost lens component of a contained optical assembly.

The eye cup3120according to this embodiment is defined by a solid contiguous member. In an alternative embodiment, the eye cup can include one or a plurality of slits or openings (not shown) that do not sacrifice structural integrity for purposes of patient alignment.

In accordance with an embodiment and as shown inFIGS. 64(a) and 64(b), a disposable ring member3124can be provided which is configured and sized to fit within the distal end opening3122of the eye cup3120. More specifically, the disposable ring member3124is defined by a flexible material, such as, for example, a foam material or polypropylene and defined by opposing distal and proximal end openings3125,3127in which the distal end opening3125includes an annular outer flange3129. When attached, the disposable ring member3124can be inserted into the distal end opening3125of the eye cup3120with the annular outer flange3129of the disposable ring member3124creating a stop.

According to one embodiment, a user can load the disposable ring member3124from a stacked set of rings (not shown) in a container (not shown) having an open top and engaging the distal end of the eye cup3120with the disposable ring member3124until the distal end of the eye cup3120engages the annular outer flange3129of the disposable ring member3124. Compression of the eye cup3120creates positive engagement between the inner portions of the eye cup3120and the outer surface of the disposable ring member3124, allowing the disposable ring member3124to remain attached to the eye cup3120when the eye cup3120is removed from the container. Advantageously, the disposable ring member3124can be attached without having to touch the ring member3124and wherein the disposable ring member3124permits reuse of the eye cup3120as shown. The disposable ring member3124also serves as a stop, preventing eye cup3120from fully compressing against a patient's eye.

With reference to the sectioned view ofFIG. 65, the instrument head3104according to this embodiment is manufactured using a two-part housing made up of a front housing section3109and a rear housing section3110that are mated together. The instrument head3104is defined by an interior3105that is sized and configured for retaining a plurality of components, including an optical assembly3101and an illumination assembly3102. As shown schematically according toFIGS. 66-68, the optical assembly3101includes a plurality of optical components or elements disposed and aligned along a defined viewing or optical axis3132that extends through the eye3130of the patient, as well as the distal and proximal ends3112,3116of the device3100. As previously referred to herein, an “optical component” or “optical element” refers to lenses and prisms as well as field stops, aperture stops, polarizers, and any component used to directing or transmitting light along a defined optical or viewing axis.

According to this embodiment, the distal most component of the optical assembly is an objective lens3140, which is mounted adjacent the distal end3112of the instrument head3104. As shown inFIG. 65, the rear peripheral edge3142of the objective lens3140is secured against an annular shoulder3145formed in the instrument head3104and held in position by means of an end cap3148that is threadingly positioned to the distal end3112of the instrument head3104. When secured, the end cap3148also is configured to retain a fixation target retainer3154, the latter of which is peripherally disposed about the objective lens3140and as further shown inFIG. 69. Angled slots are provided on a front facing surface of the fixation target retainer3154that receive polarizer windows which according to this embodiment can be formed of different colors (i.e., blue, red) for directing a pair of fixation targets to the patient.

As shown inFIG. 69, the objective end of the instrument head3104is shown with two slots on each side (left/right) of the lens3140where the fixation illumination targets are located. When the patient looks at the target in the opposite direction relative to the eye being examined (that is, the right eye looking at the left target or the left eye looking at the right target), the patient's eye will align at approximately 17 degrees positioning their optic disc near the center of the view. According to this embodiment, a set of optical fibers, preferably having polished ends, extend from the contained LED to each of the fixation targets. More specifically, the polished distal end of the optical fibers are placed in contact with the polarizer windows, with the fibers being routed through the interior of the instrument head and downwardly to the contained LED. According to this embodiment, the proximal end of the fixation target fibers are disposed on lateral sides of the LED, although other configurations can be utilized.

The proximal end of the eye cup3120is disposed over the distal end3112of the instrument head3104and about the contained objective lens3140to create the proper working distance between the device3100and the patient, schematically shown inFIG. 66, which according to this embodiment is approximately 25 mm.

The proximal end3116of the instrument head3104includes an eyepiece holder3170projecting outwardly (proximally) from the instrument head3104. According to this embodiment, the eyepiece holder3170is defined by an open-ended structure including an annular shoulder3172formed on an outward (proximal) facing side, which is sized and configured to retain a brow rest3176for use by the clinician. The eyepiece holder3170retains a pair of eyepiece lenses3180,3184that are separated an appropriate distance by an eyepiece spacer3188. The eyepiece lenses3180,3184are retained in a field stop holder3190that is threadingly engaged within an opening formed in the eyepiece holder3170and the instrument head3104. A field stop3197is retained within a narrowed portion3199of the field stop holder3190and aligned with the eyepiece lenses3180,3184and the objective lens3140along the defined optical axis.

Disposed between the proximal and distal ends3112,3116of the device3100and referring toFIGS. 65-68, the herein described optical assembly3101further includes a relay lens3186that is aligned along the defined viewing axis3132, as well as an aperture stop3191, each intermediately disposed within the interior3105of the instrument head3104.

The components of the optical assembly3101are shown in respective layouts presented according toFIG. 66-68, which includes the objective lens3140, the aperture stop3191, relay lens3186, field stop3197and eyepiece lenses3180and3184, each aligned along the viewing axis3132relative to the clinician's eye (not shown) as brought to the brow rest3176or as shown inFIG. 62, relative to the interface and imaging aperture of an attached smart device3106.

Regarding the illumination assembly3102and with reference toFIG. 70, the lower necked portion3107of the instrument head3104includes a plurality of components configured for illuminating the target (eye) of interest. An electrical contact pin3220is disposed within an opening3224formed in a plastic insulator3228, the latter having an upper portion3229that retains a coil spring3232for biasing the contact pin3220. The spring3232is disposed between a top or upper end3224of the contact pin3220and a shoulder3238formed in the upper portion3229of the insulator3228.

When a lowermost end of the contact pin3220is engaged with electrical contacts (not shown) in the handle (not shown) of the physical assessment device3100, the top end3224of the contact pin3220is pressed into contact with a lower surface of a printed circuit board3250for an LED3256that is disposed on the upper surface of the circuit board3250, shown most clearly inFIG. 70. The circuit board3250is positioned in place onto a circuit board retainer3230that further retains the insulator3224and contact pin3220, the retainer3230having a set of external threads that engage corresponding threads provided within an assembly support member3290.

The LED3256is aligned with a condenser lens3264along an illumination axis3310,FIG. 66, the condenser lens3264being retained within a lens holder3280that further retains a centering ring3281aligned with the LED3256. Each of these latter components are further retained within the assembly support member3290, the assembly support member3290being fitted within the lower necked portion3107,FIGS. 65, 70, of the instrument head3104.

Referring toFIGS. 65 and 70, an aperture wheel3300is disposed above the condenser lens3264. The aperture wheel3300is supported by the assembly support member3290and configured for rotational movement so as to selectively locate and position each of a series of circumferentially spaced apertures formed on an aperture plate3304into alignment with the LED3256and condenser lens3264along the defined illumination axis3310,FIG. 67. More specifically, a plurality of windows3304are circumferentially disposed on the aperture wheel3300that include a red free filter, a blue filter, as well as varying sized apertures. It will be readily apparent that various other configurations can easily be realized. Additional details relating to the assembly support member3290and retention of the illumination assembly components are provided in U.S. Pat. No. 9,629,544, the entire contents of which are herein incorporated by reference.

With reference toFIGS. 65 and 67and above the aperture wheel3300and the assembly support member3290, the illumination assembly further includes a relay lens3320which according to this embodiment is retained in a holder3326. According to this embodiment, the relay lens holder3326is threadingly secured to an upper portion of the assembly support member3290and aligned with the condenser lens3264, aperture wheel3300, and the LED3256along the defined illumination axis3310.

With reference toFIGS. 66-68, the optical and illumination assembly components of this physical assessment instrument are illustrated in schematic form for the sake of clarity. As noted, the optical assembly3101includes the objective lens3140aligned with eyepiece lenses3180,3184and the field stop3197, as well as the relay lens3186and the aperture stop3191, each of which are aligned along the defined optical axis3132. In addition, a diopter wheel3200supports a plurality of optical elements3204of varying power (concave/convex). The diopter wheel3200is rotatably movable into and out of the defined viewing axis3132for purposes of establishing the focus of the patient's eye3130.

Still referring toFIG. 67, the illumination assembly3102comprises the LED3256aligned along the defined illumination axis with the condenser lens3264and the rotatable aperture wheel3300, as well as the illumination relay lens3320, each disposed in alignment with an angled mirror3350, the latter being offset relative to the imaging axis3132.

In accordance with this embodiment and referring toFIGS. 71(a) and 71(b), the mirror support member3354can be threadingly fitted into a formed port at the top of the instrument head3104. A mirror3350is attached to a pivotable portion3360which can be accessed and enables adjustment during the time of manufacture. According to one version, the mirror3350can be adjusted using and adjustment member3352that is accessible through a port formed in the rear of the instrument head3104. The mirror3350is further attached to a movable member that enables additional adjustment of the supported mirror3350, as needed. The mirror mount assembly described is exemplary. For example, the mirror mount assembly2453described in the prior embodiment (seeFIGS. 60(a)-60(f)) can be substituted for this version.

For purposes of this embodiment, the illumination assembly3101utilizes a single LED3256, though the number and color temperature of the LED can be suitably varied. According to this embodiment, a magnification lens3210is provided adjacent a window of the necked portion3107in order to permit a caregiver to more easily read the diopter wheel setting of the herein described ophthalmic device3100.

FIG. 67illustrates an illumination ray trace of the herein described instrument3100. According to this embodiment and upon engagement between the lower end of the contact pin with the contained battery (not shown) in the instrument handle (not shown), the contained LED3256is energized. The output of the LED3256is directed through the centering ring3251, the condenser lens3260and the aperture wheel3300along the defined illumination axis3310in which the beam passes through the relay lens3320and a polarizer3340and is directed against the folded mirror3350, whose position is adjusted at the time of manufacture within the mirror mount by accessing a threaded adjustment member.

Though the imaging elements of the assembly are also shown in this view, the light does not cross the imaging axis3132. In addition and also not shown, a portion of the emitted light is directed through a set of optical fibers (not shown) through the instrument head3104and to the fixation targets positioned at the distal end3112.

Still referring toFIG. 67, the emitted light from the LED3256is reflected from the angled mirror3350, the latter having an angled surface that directs the light toward the distal end3112of the instrument head3104and more specifically through the objective lens3140. The reflected light passes through the objective lens3140and is then focused onto the eye3130of the patient. According to this embodiment, the focal point of the reflected light is off center relative to the front of the eye3130of the patient and more specifically the pupil serving as the image plane wherein the light is then spread outward onto the back of the eye and more specifically the retina3137. As shown and described herein, the focused spot is off-line relative to the optical axis3132of the device3100.

With reference toFIGS. 66 and 68, the imaging of the target (i.e., the retina3137) is reflected from the back of the eye3130to the objective lens3140in which the light is further directed along the defined optical axis3132through the image aperture plate3188in which an inverted image is passed. The light is then directed to the relay lens3186, field stop3197and through the eyepiece lenses3180,3184, respectively, wherein the light is focused onto the eye (not shown) of the caregiver as an erect image.

Alternatively and in lieu of the eyepiece, the light can be directed through the aperture of a smart device3106,FIG. 62, such as a smart phone, which is attached to the proximal end3116of the device3100and aligned in relation to the optical axis3132. This attachment can be done in the manner previously described according toFIGS. 6-13(b) or the alternative techniques described inFIGS. 14-20.

FIG. 73illustrates an optical layout illustrating scaling for instrument heads3404,3414, such as shown inFIG. 74. More specifically, the instrument heads3404,3414can include scaled optical assemblies maintaining back ends that commonly include relay lenses3440,3444and eyepiece lenses3448, while axially adjusting the position and dimensionally scaling the objective lens3424,3434and aperture plate3427,3437, the latter enabling common interfaces for various physical assessment devices.

A benefit of the optics of the illumination assembly is depicted inFIG. 75. At the top of the figure is a known ophthalmic illumination assembly in which the positioning of the condensing lens in which the focus distance creates a potential issue in which dirt or debris on the condensing lens can interfere with the resulting examination. The lower portion of the figure indicates a point focus relative to the front and back surface of the condensing lens that effectively removes this issue, while maintaining a reticle plan focus at infinity.

A general need in the field of diagnostic medicine is that of enhancing versatility and interchangeability between physical assessment devices, such as, for example, otoscopes and ophthalmoscopes. According to one example, depicted inFIGS. 76(a) and 76(b), ophthalmoscopes can be reconfigured in order to permit examinations of eye of a patient. The depicted ophthalmoscopes3450,3470in these figures are those of Model 117 Ophthalmoscope and Model 12800 Pocket Ophthalmoscopes, respectively, each commercially sold by Welch Allyn, Inc of Skaneateles Falls, N.Y. In accordance with this exemplary embodiment, each of the instrument heads3454,3474are configured to permit otoscopic examinations. More specifically, a tip attaching and releasing mechanism is fitted into the distal end3456,3476of each ophthalmoscope3450,3470to enable the releasable retention of a disposable speculum tip element120at the distal end as a patient interface, in lieu of an eye cup. For purposes of this conversion, each existing instrument head3450,3470can be configured with a distal insertion portion and distal ring member similar to that included in the previously described otoscope100,FIG. 2(b).

In use and for purposes of close-up viewing, the existing diopter wheel3462,3482of each ophthalmoscope3450,3470can be used to provide accommodation at a setting of approximately 10-15 diopters, based on the caregiver's personal vision and the application/use. Each are accomplished using the rotatable diopter wheel common to the known ophthalmoscopes.

According to a further version, the speculum tip attachment mechanism can be installed onto the distal end3456,3476of the instrument head3452,3472in order to preset the angle of the attached tip element120relative to the contained light source. Advantageously, this preset positioning of the attached speculum tip can optimize uniformity and concentricity of the illuminated light from the contained light source in the handle portion of each of the depicted instruments3450,3470.

LED Drive Circuitry

Current instrument heads, such as those commercially sold by Welch Allyn, Inc. are wholly halogen lamp based. Electrically, the lamp filament is a piece of wire whose resistance increases with temperature. So, for any given input voltage, the filament heats up which increases its resistance until the drive circuit reaches a natural equilibrium (heat/light/resistance/current for the given input voltage). When the input voltage is raised, the lamp filament becomes brighter and when the input voltage is lowered the lamp filament dims.

Contrasting, all known LED controller ICs in the electronics industry are designed to ignore its input voltage. This is done for a number of valid reasons, but the crucial point is that by definition, a system that varies voltage as a way of controlling light output is categorically incompatible with LED technology. Therefore, it is not recommended to vary/dim LED brightness by changing its input voltage. With the incorporation of both light sources into instrument heads, a solution is needed for driving and dimming both halogen lamps and LEDs.

Accordingly,FIGS. 77-81describe an exemplary embodiment of circuitry for controlling LED lighting in an instrument head. The embodiments disclosed herein provide numerous enhancements over conventional lighting control circuits. For instance, typical instrument heads are only compatible with specific instrument handles, because the instrument handles provide electrical power to the instrument head, and must provide that electrical power in a very specific profile of voltage and current. Thus, instrument heads are not typically usable with different instrument handles, requiring a proliferation of instrument heads and designs.

For instance, different types of lighting have different electrical properties. For example, LED light dimming may be achieved by constant voltage, and thus a constant current, that is pulse-width modulated to reduce the duty time that the LED is on, whereas incandescent light dimming may be achieved by changing voltages. In addition, traditional instrument heads may include alternating current (AC) power sources, and may only be compatible with lighting that can use AC power, such as incandescent or halogen lighting. Further, different instrument handles may be wired with different polarities, requiring the instrument heads to be hardwired to accept the specific polarity. And LEDs and LED drive circuits have strict requirements for polarity. Current instrument handles have multiple polarities (+/−, −/+ and a variation of AC), and therefore the input power must be rectified to a single polarity before an LED in the instrument head can be driven.

Advantageously, the circuits disclosed herein are designed to solve these problems by allowing compatibility between different instrument heads and instrument handles.

FIG. 77depicts a block diagram of a circuit3510for controlling or driving LED lighting. The circuit3510may be disposed within an instrument head, such as the instrument head104of the otoscope ofFIGS. 1(a)-5or the instrument head2004of the ophthalmoscope ofFIG. 59(b), which provides power and has buttons for controlling the lighting, including turning on or off, dimming, brightening, etc. The circuit3510includes a controller3514, a buck/boost or power circuit3516, and a rectifier circuit3518. The circuit3510may be connected to an instrument handle3512, and such connection may be through a 2-wire connection, 3-wire connection, or any other suitable connection having multiple wires for voltages and/or signals. Working examples of specific implementations of the controller3514, the power circuit3516, and the rectifier circuit3518are discussed below with respect toFIGS. 79-81.

FIG. 78is a flowchart depicting a method3500for controlling LED lighting in an instrument head, by using the circuit3510ofFIG. 77. With reference toFIGS. 77-78, in one example, at block3520an instrument handle3512may be connected to an instrument head, such as the instrument head104of the otoscope ofFIGS. 1(a)-5or the instrument head2004of the ophthalmoscope ofFIG. 59(b), where the instrument head includes the circuit3510. This connection may be through a 2-wire, 3-wire, or other suitable connection. In one example, simple 2-wire connection would only allow the instrument handle3512to provide electrical power (e.g., at specific voltages and currents) to the circuit3510. In another example, the instrument head may include one or more wires with a control signal, such as a serial port, for sending control signals from the instrument handle3512to the circuit3510. The signals received by the circuit3510from the instrument handle3512may be an AC voltage or a DC voltage signal having varying levels of voltage and/or current.

Based on the signals received by the circuit3510from the instrument handle3512, at block3530the power profile of the instrument handle3512may be determined. For instance, the controller3514of the circuit3510may be programmed to sense the voltage, current, polarity, and other signals from the instrument handle3512, and use this information to determine what type of instrument handle is in fact connected.

For example, conventional instrument handles may be designed to use voltage change to control dimming of halogen or other incandescent lamps. In such a case, electrically, the lamp filament is a piece of wire whose resistance increases with temperature. So, for any given input voltage, the filament heats up which increases its resistance until the drive circuit reaches a natural equilibrium (heat/light/resistance/current for the given input voltage). When the input voltage is raised, the lamp filament becomes brighter and when the input voltage is lowered the lamp filament dims. Contrasting, all LED controller ICs in the electronics industry are designed to ignore its input voltage. This is done for a number of valid reasons, but the crucial point is that by definition, a system that varies voltage as a way of controlling light output is incompatible with LED technology. Therefore, it is not recommended to vary/dim LED brightness by changing its input voltage. With the incorporation of both light sources into instrument heads, the present circuit3510allows for driving both LED and incandescent light sources from a single instrument handle3512. Thus, the controller3514could sense the properties described above and make a determination that the instrument handle connected is of a type typically used to drive halogen or other incandescent lamps, but that this instrument handle now needs to drive LED lighting.

Continuing with method3500ofFIG. 78, at block3540, the circuit3510may be configured for operation at the power profile determined at block3530. This configuration may include configuring the controller3514and/or the power circuit3516, as explained in further detail below with respect toFIGS. 79-81.

Advantageously, configuring the circuit3510for operation with the instrument handle3512, based upon auto-detection of the handle profile, allows any number of different instrument handles that have been deployed in the field to be used with the new instrument heads described herein. Thus, the benefits of the features, such as LED lighting, may be realized even without replacing these previously deployed instrument handles. This auto-detection and configuration of instrument heads for use with instrument handles represent improves the field of medical scopes, because the technique allows mixing and matching of different handles and heads by the medical user, increasing efficiency with which patients may be treated.

Next, at block3550, the LED lighting of the instrument handle, which is driven by the power circuit3516, may be operated and controlled using the instrument handle3512. In order to facilitate operating and controlling the LED lighting with different instrument handles3512that may have very different electrical profiles, the power circuit3516includes buck-boost voltage conversion that allow variable input voltages to be converted into a specified output voltage, where the input voltages may be above or below the specified output voltages. The buck portion of power circuit3516decreases a higher input voltage to meet the requirements of a lower specified output voltage, and the boost portion of power circuit3516increases a lower input voltage to meet the requirements of a higher specified output voltage. Specific details of this power circuit3516is set forth with respect toFIG. 80. In addition, operating and controlling (at block3550) the LED lighting with the instrument handle3512is also achieved by converting changes in voltage to changes in current, as will be described in more detail with respect toFIGS. 79-81.

Further, at block3560of the method3500, the controller3514can detect an idle state of the instrument handle. Upon detection of an idle state, the instrument head can be powered off. And, at block3570, the controller3514can detect a vibration state of the instrument handle, and can perform a specific action based on that state, such as powering off the instrument head.

Another problem identified with portable physical assessment devices is that of theft of the instrument handles from the charging base. Using the controller3514to detect state changes, a theft deterrent mechanism that could be included. For example, an audible alarm could be set off from the charging base if the instrument handle is not returned in a predetermined time interval. In addition, an LED indicator can also be provided on the charging base when the alarm feature is enabled.

An electrical circuit design can provide a controller that generates an audible alarm if the instrument handle is not returned to the charging base, such as base1800,FIG. 52, in a defined amount of time.

In another embodiment, an auto-off feature will turn off the instrument after a predetermined time period of inactivity. In such an example, the controller is programmed with a timer. If a motion sensor subsystem that is connected to the controller fails to report any motion during the time period, as counted by the timer, the system will turn off the instrument.

FIG. 79is a circuit diagram of the controller3514and affiliated circuitry. In the embodiment ofFIG. 79the controller3514may be a model CY8C4025LQI-S401 microcontroller available from Cypress Semiconductor Corporation, of San Jose, Calif., USA. In other embodiments, discrete logic elements may be employed instead of a microcontroller.

As shown inFIG. 79, the controller3514is connected to the input voltage that has passed through the rectifier ofFIG. 81. The rectifier is needed because the LEDs may be powered by direct current rather than alternating current. The rectified voltage then is input into the controller3514, which then outputs a pulse width modulation signal LED_PWM. The LED_PWM signal is input into the buck/boost or power circuit3516, as depicted inFIG. 81. Any of a number of PWM algorithms may be used with the circuit. For instance, in traditional voltage based dimming, a voltage vs. brightness curve may be described that relates a given voltage to a given brightness. A linear relation would mean that if the voltage is reduced by 50% from a nominal high voltage, the brightness would reduce by 50%. In order to translate this into dimming an LED, a PWM signal that is on for 50% of the time would power an LED half the time and thus achieve 50% brightness.

In other embodiments, a non-linear relationship between the voltage an brightness may be observed. In one example, a calibration of a legacy handle and legacy incandescent head can be carried out, so that the legacy handle can later be used with a new head of the present disclosure. For example, the calibration process could use the legacy handle connected to the legacy incandescent head, and the legacy handle's voltage may be varied from maximum to minimum while measuring the brightness percentage as a function of voltage. The resulting calibration data set relates voltage to expected brightness percentage for the legacy handle. This calibration curve can be loaded into the controller on an instrument head of the present disclosure so that the brightness control of the legacy handle will have the same effective result when using the new instrument head.

The controller would achieve this by detecting the input voltage from the handle, and using a lookup table containing the calibration data set to find the appropriate desired brightness percentage. Then, instead of applying the input voltage to the LED, the input voltage would be buck/boost converted to yield a constant LED current. The brightness would be controlled by a PWM signal that turned on and off the LED such that the LED was on for the desired brightness percentage of the time, and off the rest of the time. In such a manner, numerous different legacy handles with different voltages can be profiled to find calibration data for use in the instrument head described herein.

In an embodiment, the controller3514receives the input voltage VIN from the instrument handle and determines its polarity. Depending on the polarity of the voltage VIN received from the instrument handle, and potentially other indicia such as power on signals, initial voltage, etc., the controller can determine the power profile for that specific instrument handle, e.g., by using a lookup table that lists all the known instrument handles and their known polarities, initial voltages, power on signals, etc. In such a case, the controller can determine what type of instrument handle has been attached, and then can access the voltage calibration curve of the instrument handle, which relates the voltage to the output illumination level of the LED as explained above. The LED_PWM signal from the controller may the appropriately drive a PWM signal of the correct duty cycle (e.g., percentage on to off) to achieve the brightness of the LED that corresponds to the brightness that an incandescent instrument head would output if the same instrument head were connected to it and directly driven using the voltages. In such a manner, the input voltages changes have been converted to PWM signals of specific duty cycles of a constant current that can be used to power and dim an LED. In another example, specific pins on the instrument handle may carry identification or handshake data that tells the instrument head which handle has been connected, allowing the controller to lookup a pre-loaded power profile for that handle.

In an embodiment, the controller3514may also determine vibration/motion or idle states of the instrument head and/or handle, and perform appropriate actions as described with respect to method3500above. In one example, idle states can be determined by a lack of motion sensor indicated activity during a predetermined time period, and the action can be to shut off the instrument. In another example, motion of the instrument can be detected by the motion sensor, and an idle timer can be reset, or other subsystems may be turned on.

FIG. 80is a circuit diagram of the buck/boost or power circuit3516. In the example ofFIG. 80, the power circuit3516is based on a TPS63036 Buck/Boost converter U5with support for receiving the LED_PWM signals from the controller as described above. The TPS63036 is available from Texas Instruments Inc., Dallas, Tex., USA. In the circuit diagram ofFIG. 80, we see that the input voltage is fed into the converter U5, which is also controlled using the EN and PWM_LED signal from the controller3514, in order to apply the PWM profile to dim the LED lighting as noted above with respect toFIG. 79.

In operation, the buck/boost or power circuit3516may receive the input voltage VIN and provide an output voltage VOUT that generates a fixed or constant current for powering the LED lights. The output voltage VOUT may be tuned by appropriately setting resistors R1and R2, in the specific example using a TPS63036 converter. Once set up, the buck/boost or power circuit3516would output the fixed or constant current for powering the LEDS, and the PWM_LED wire from the controller3514would be used to provide the PWM signal with the appropriate duty cycle for achieving a specific brightness. In other examples, the buck and boost portions of the circuit may be implemented separately using discrete components instead of a single buck/boost converter. In such a case, the circuit would boost a VIN that was less than VOUT through a boosting sub-circuit, and decrease or buck a VIN that was greater than VOUT through a buck sub-circuit.

FIG. 81is a circuit diagram of the FET full-wave bridge circuit3518. Rectification to a single polarity is typically done with a diode Full Wave Bridge (FWB). Diode FWB's typically lose between 1V and 1.4V in the rectification process. This is a considerable proportion of the LED voltage, which is typically 2.7V. That ratio approximates the loss of energy from the battery never to produce light. In order to minimize losses associated with a diode full-wave-bridge, a FET full-wave-bridge is introduced, as shown inFIG. 81. The FET FWB design only loses about 50 mV, depending upon the current and FETs selected. The energy not lost means energy available to produce light and increasing overall battery life of the device.

The FET FWB circuit design is made up of two NFETs, two PFETs, and the necessary capacitors. The FET full-wave-bridge has considerable ESD protection, mostly realized in capacitors across the gate-source for each FET.

In accordance with another embodiment and with reference toFIG. 82, an instrument head for a physical assessment device is configured with a buck convertor head design, which is an LED controller circuit design that will drive an LED effectively and without risk of instability (LED Flicker) with a PWM(Bang-Bang) power source.

For the power source, a traditional RC hysteretic oscillator (nicknamed bang-bang in the electronics world) will be used. This power source will drive both a halogen lamp head and the LED instrument head having the buck converter. For the buck converter LED driver head, and while the input voltage is sufficient, there is controlled brightness. For output voltage varying power sources (as the drive voltage lowers (dimming)), the buck converter eventually runs out of headroom and the LED is driven directly by the driving voltage (in series with the parasitic resistances of the controller and the mechanical system). This occurs when Vinapproaches the LED's VF plus the controller's sense voltage plus the parasitic IR losses. For a PWM power source, as long as the output voltage is greater than the LED's VF, the bang-bang dimming will dim the LED effectively and without instability (flicker). For purposes of this specific embodiment, the circuit is the PAM2804 IC LED driver applied as the manufacturer recommends. The PAM2804 is a suitable example of an LED Driver IC since it will run down to the appropriate voltage of 2.5V. This is an anomaly because no high brightness LED has a forward voltage of 2.5V. The 2.5V capable DC-DC converter IC, PAM2312-ADJ, can be repurposed for LED drive by lowering its reference voltage from 0.6V to 0.1V.

An alternative drive circuit is shown inFIG. 83in which R25, R26and R27are additionally provided to enable fine tuning in order to adjust the LED effective forward voltage. This capability enables a number of LEDs to operate in a representative manner across instrument heads and handles.

LED's and LED drive circuits have strict requirements for polarity. Current instrument handles have multiple polarities(+/−, −/+ and a variation of AC), and therefore the input power must be rectified to a single polarity before an LED in the instrument head can be driven.

Rectification to a single polarity is typically done with a diode Full Wave Bridge (FWB). Diode FWB's typically lose between 1V and 1.4V in the rectification process. This is a considerable proportion of the LED voltage, which is typically 2.7V. That ratio approximates the loss of energy from the battery never to produce light. In order to minimize losses associated with a diode full-wave-bridge, a FET full-wave-bridge is introduced, as shown inFIG. 82. The FET FWB design only loses about 50 mV, depending upon the current and FETs selected. The energy not lost means energy available to produce light and increasing overall battery life of the device.

The FET FWB circuit design is made up of two NFETs, two PFETs, and the necessary capacitors. The FET full-wave-bridge has considerable ESD protection, mostly realized in capacitors across the gate-source for each FET.

While a 2-wire voltage varying input is the standard method for adjusting brightness for a halogen or incandescent lamp, it's problematic for LED circuits as has happened in the commercial and residential lighting industry. The most significant issue is loop stability going unstable, causing LED's to blink. This can be a serious problem in physical assessment devices such as ophthalmoscopes, otoscopes, etc. Industry LED circuits rely upon pulse width modulation for dimming LEDs. In order to drive both an LED and halogen based lamp from a single voltage varying power source an electrical solution must be designed.

The herein described electrical circuit design shown inFIGS. 83(a), 83(b)will drive both an LED and halogen based lamp from a single varying power source and maintain loop stability so that there is no risk of blinking LEDs.

This electrical circuit design works when first energized, the output of the comparator is low, turning on the PFET. Assuming the LED voltage to approximate a constant, the voltage across the Power Inductor will approximate a constant. As such, current will rise at a linear rate. This causes a positive slope voltage ramp across the sense resistor. For purposes of this circuit, this sense voltage is “faked” low at the positive input of the comparator by the voltage divider (ratio Hyst Res/(hyst Res×FeedBack Res). When this comparator positive input voltage reaches VREF, the comparator output goes high, turning off the PFET. This is called the “Upper Threshold” of the hysteresis circuit. This output swing instantaneously reverses the voltage divider, faking the sense current high instead of low at the positive input to the comparator. As such, the current must go to the Lower Threshold of a hysteresis circuit before it crosses +VREF before the output will again go low. While the PFET is turned off (comparator output high), current continues to flow through the inductor, through the catch diode, causing a negative slope across the sense resistor.

When the current reaches the lower threshold, the output goes low, turning on the FET and the cycle continues. Since the sense voltage ramp is nearly linear both up and down, the average current will be the +VREF/SENSE RESISTOR. In other words, given a triangle wave, there will be half the area above and below its average. The circuit is regulated and controlled. The only drawback is high ripple current, but this doesn't matter for a LED, especially since practical frequencies are far above what the human eye can detect. More so, increasing the output capacitor (C17) of the hysteretic current source will reduce the ripple current and make the slopes more linear. Of more importance though, is that there is no high gain closed loop most often used in power supply control circuits, including LED drivers. Since the oscillation is no more than an inductor being charged and discharged while banging into two predictable thresholds, the instability of the oscillator cycle eliminates the chance of subharmonic oscillations that traditional controllers are prone to. In other words, the connected LEDs will not be prone to blinking.

This described circuit is stable. This circuit also does not dim with input voltage so no advantage is otherwise over traditional LED driver circuits. However, and if the reference voltage is varied as a function of input voltage (something that cannot be done with traditional power supply—including LED controllers—control loops without risking instability), the LED current will vary as a function of input voltage. Unlike high-gain control loops which vary many of their stability parameters with input voltage and reference voltage changes, the hysteretic controller continues to bang between the upper and lower thresholds and the average is the reference voltage. The addition of a voltage divider to create +VREF and the LED voltage will vary proportionally to +VIN.

As previously discussed, another problem identified with portable physical assessment devices that require base charging is that of theft of the instrument handles from the charging base. Another object of the herein described invention is to provide a theft deterrent mechanism that would be included in the charging base.

Such theft detection could include an audible alarm from the charging base if the instrument handle is not returned in a predetermined time interval. In addition, an LED indicator can also be provided on the charging base when the alarm feature is enabled.

An electrical circuit design can provide a controller that generates an audible alarm if the instrument handle is not returned to the charging base, such as base1800,FIG. 52, in a defined amount of time. According to one version, there are four (4) pogo pins provided in the charging base; a positive contact, two negative contacts, and one contact for instrument handle detection. This handle detection contact would be what triggers the time period once the instrument handle is removed and stop the timer once the handle is placed back into the charging base. In addition, an LED indicator on the charging base can be illuminated to alert individuals that the theft alarm is enabled. This LED indicator would flash/blink when the audible alarm is sounded. A switch can be provided on the bottom or otherwise upon the charging base to enable/disable the alarm feature. This switch could be recessed in the housing of the charging base and be made only accessible by a specialized tool or other access feature, such as small piece of metal (e.g., a paper clip). There may also be some other type of switch to set the defined time for the alarm to enable once the handle is removed.

PARTS LIST FOR FIGS.1(a)-86

Additional variations and modifications of the inventive concepts which are described herein will be readily apparent based on the above description and further in accordance with the following claims.